ceph/src/boost/libs/fiber/doc/html/fiber/scheduling.html

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  24 </div>
  25 <div class="section">
  26 <div class="titlepage"><div><div><h2 class="title" style="clear: both">
  27 <a name="fiber.scheduling"></a><a name="scheduling"></a><a class="link" href="scheduling.html" title="Scheduling">Scheduling</a>
  28 </h2></div></div></div>
  29 <p>
  30       The fibers in a thread are coordinated by a fiber manager. Fibers trade control
  31       cooperatively, rather than preemptively: the currently-running fiber retains
  32       control until it invokes some operation that passes control to the manager.
  33       Each time a fiber suspends (or yields), the fiber manager consults a scheduler
  34       to determine which fiber will run next.
  35     </p>
  36 <p>
  37       <span class="bold"><strong>Boost.Fiber</strong></span> provides the fiber manager, but
  38       the scheduler is a customization point. (See <a class="link" href="custom.html#custom">Customization</a>.)
  39     </p>
  40 <p>
  41       Each thread has its own scheduler. Different threads in a process may use different
  42       schedulers. By default, <span class="bold"><strong>Boost.Fiber</strong></span> implicitly
  43       instantiates <a class="link" href="scheduling.html#class_round_robin"><code class="computeroutput">round_robin</code></a> as the scheduler for each thread.
  44     </p>
  45 <p>
  46       You are explicitly permitted to code your own <a class="link" href="scheduling.html#class_algorithm"><code class="computeroutput">algorithm</code></a> subclass.
  47       For the most part, your <code class="computeroutput"><span class="identifier">algorithm</span></code>
  48       subclass need not defend against cross-thread calls: the fiber manager intercepts
  49       and defers such calls. Most <code class="computeroutput"><span class="identifier">algorithm</span></code>
  50       methods are only ever directly called from the thread whose fibers it is managing
  51       &#8212; with exceptions as documented below.
  52     </p>
  53 <p>
  54       Your <code class="computeroutput"><span class="identifier">algorithm</span></code> subclass is
  55       engaged on a particular thread by calling <a class="link" href="fiber_mgmt/fiber.html#use_scheduling_algorithm"><code class="computeroutput">use_scheduling_algorithm()</code></a>:
  56     </p>
  57 <pre class="programlisting"><span class="keyword">void</span> <span class="identifier">thread_fn</span><span class="special">()</span> <span class="special">{</span>
  58     <span class="identifier">boost</span><span class="special">::</span><span class="identifier">fibers</span><span class="special">::</span><span class="identifier">use_scheduling_algorithm</span><span class="special">&lt;</span> <span class="identifier">my_fiber_scheduler</span> <span class="special">&gt;();</span>
  59     <span class="special">...</span>
  60 <span class="special">}</span>
  61 </pre>
  62 <p>
  63       A scheduler class must implement interface <a class="link" href="scheduling.html#class_algorithm"><code class="computeroutput">algorithm</code></a>. <span class="bold"><strong>Boost.Fiber</strong></span> provides one scheduler: <a class="link" href="scheduling.html#class_round_robin"><code class="computeroutput">round_robin</code></a>.
  64     </p>
  65 <p>
  66       </p>
  67 <h5>
  68 <a name="class_algorithm_bridgehead"></a>
  69   <span><a name="class_algorithm"></a></span>
  70   <a class="link" href="scheduling.html#class_algorithm">Class <code class="computeroutput">algorithm</code></a>
  71 </h5>
  72 <p>
  73     </p>
  74 <p>
  75       <code class="computeroutput"><span class="identifier">algorithm</span></code> is the abstract base
  76       class defining the interface that a fiber scheduler must implement.
  77     </p>
  78 <pre class="programlisting"><span class="preprocessor">#include</span> <span class="special">&lt;</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">fiber</span><span class="special">/</span><span class="identifier">algo</span><span class="special">/</span><span class="identifier">algorithm</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">&gt;</span>
  79
  80 <span class="keyword">namespace</span> <span class="identifier">boost</span> <span class="special">{</span>
  81 <span class="keyword">namespace</span> <span class="identifier">fibers</span> <span class="special">{</span>
  82 <span class="keyword">namespace</span> <span class="identifier">algo</span> <span class="special">{</span>
  83
  84 <span class="keyword">struct</span> <span class="identifier">algorithm</span> <span class="special">{</span>
  85     <span class="keyword">virtual</span> <span class="special">~</span><span class="identifier">algorithm</span><span class="special">();</span>
  86
  87     <span class="keyword">virtual</span> <span class="keyword">void</span> <span class="identifier">awakened</span><span class="special">(</span> <span class="identifier">context</span> <span class="special">*)</span> <span class="keyword">noexcept</span> <span class="special">=</span> <span class="number">0</span><span class="special">;</span>
  88
  89     <span class="keyword">virtual</span> <span class="identifier">context</span> <span class="special">*</span> <span class="identifier">pick_next</span><span class="special">()</span> <span class="keyword">noexcept</span> <span class="special">=</span> <span class="number">0</span><span class="special">;</span>
  90
  91     <span class="keyword">virtual</span> <span class="keyword">bool</span> <span class="identifier">has_ready_fibers</span><span class="special">()</span> <span class="keyword">const</span> <span class="keyword">noexcept</span> <span class="special">=</span> <span class="number">0</span><span class="special">;</span>
  92
  93     <span class="keyword">virtual</span> <span class="keyword">void</span> <span class="identifier">suspend_until</span><span class="special">(</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">chrono</span><span class="special">::</span><span class="identifier">steady_clock</span><span class="special">::</span><span class="identifier">time_point</span> <span class="keyword">const</span><span class="special">&amp;)</span> <span class="keyword">noexcept</span> <span class="special">=</span> <span class="number">0</span><span class="special">;</span>
  94
  95     <span class="keyword">virtual</span> <span class="keyword">void</span> <span class="identifier">notify</span><span class="special">()</span> <span class="keyword">noexcept</span> <span class="special">=</span> <span class="number">0</span><span class="special">;</span>
  96 <span class="special">};</span>
  97
  98 <span class="special">}}}</span>
  99 </pre>
 100 <p>
 101       </p>
 102 <h5>
 103 <a name="algorithm_awakened_bridgehead"></a>
 104   <span><a name="algorithm_awakened"></a></span>
 105   <a class="link" href="scheduling.html#algorithm_awakened">Member function
 106       <code class="computeroutput">awakened</code>()</a>
 107 </h5>
 108 <p>
 109     </p>
 110 <pre class="programlisting"><span class="keyword">virtual</span> <span class="keyword">void</span> <span class="identifier">awakened</span><span class="special">(</span> <span class="identifier">context</span> <span class="special">*</span> <span class="identifier">f</span><span class="special">)</span> <span class="keyword">noexcept</span> <span class="special">=</span> <span class="number">0</span><span class="special">;</span>
 111 </pre>
 112 <div class="variablelist">
 113 <p class="title"><b></b></p>
 114 <dl>
 115 <dt><span class="term">Effects:</span></dt>
 116 <dd><p>
 117             Informs the scheduler that fiber <code class="computeroutput"><span class="identifier">f</span></code>
 118             is ready to run. Fiber <code class="computeroutput"><span class="identifier">f</span></code>
 119             might be newly launched, or it might have been blocked but has just been
 120             awakened, or it might have called <a class="link" href="fiber_mgmt/this_fiber.html#this_fiber_yield"><code class="computeroutput">this_fiber::yield()</code></a>.
 121           </p></dd>
 122 <dt><span class="term">Note:</span></dt>
 123 <dd><p>
 124             This method advises the scheduler to add fiber <code class="computeroutput"><span class="identifier">f</span></code>
 125             to its collection of fibers ready to run. A typical scheduler implementation
 126             places <code class="computeroutput"><span class="identifier">f</span></code> into a queue.
 127           </p></dd>
 128 <dt><span class="term">See also:</span></dt>
 129 <dd><p>
 130             <a class="link" href="scheduling.html#class_round_robin"><code class="computeroutput">round_robin</code></a>
 131           </p></dd>
 132 </dl>
 133 </div>
 134 <p>
 135       </p>
 136 <h5>
 137 <a name="algorithm_pick_next_bridgehead"></a>
 138   <span><a name="algorithm_pick_next"></a></span>
 139   <a class="link" href="scheduling.html#algorithm_pick_next">Member
 140       function <code class="computeroutput">pick_next</code>()</a>
 141 </h5>
 142 <p>
 143     </p>
 144 <pre class="programlisting"><span class="keyword">virtual</span> <span class="identifier">context</span> <span class="special">*</span> <span class="identifier">pick_next</span><span class="special">()</span> <span class="keyword">noexcept</span> <span class="special">=</span> <span class="number">0</span><span class="special">;</span>
 145 </pre>
 146 <div class="variablelist">
 147 <p class="title"><b></b></p>
 148 <dl>
 149 <dt><span class="term">Returns:</span></dt>
 150 <dd><p>
 151             the fiber which is to be resumed next, or <code class="computeroutput"><span class="keyword">nullptr</span></code>
 152             if there is no ready fiber.
 153           </p></dd>
 154 <dt><span class="term">Note:</span></dt>
 155 <dd><p>
 156             This is where the scheduler actually specifies the fiber which is to
 157             run next. A typical scheduler implementation chooses the head of the
 158             ready queue.
 159           </p></dd>
 160 <dt><span class="term">See also:</span></dt>
 161 <dd><p>
 162             <a class="link" href="scheduling.html#class_round_robin"><code class="computeroutput">round_robin</code></a>
 163           </p></dd>
 164 </dl>
 165 </div>
 166 <p>
 167       </p>
 168 <h5>
 169 <a name="algorithm_has_ready_fibers_bridgehead"></a>
 170   <span><a name="algorithm_has_ready_fibers"></a></span>
 171   <a class="link" href="scheduling.html#algorithm_has_ready_fibers">Member
 172       function <code class="computeroutput">has_ready_fibers</code>()</a>
 173 </h5>
 174 <p>
 175     </p>
 176 <pre class="programlisting"><span class="keyword">virtual</span> <span class="keyword">bool</span> <span class="identifier">has_ready_fibers</span><span class="special">()</span> <span class="keyword">const</span> <span class="keyword">noexcept</span> <span class="special">=</span> <span class="number">0</span><span class="special">;</span>
 177 </pre>
 178 <div class="variablelist">
 179 <p class="title"><b></b></p>
 180 <dl>
 181 <dt><span class="term">Returns:</span></dt>
 182 <dd><p>
 183             <code class="computeroutput"><span class="keyword">true</span></code> if scheduler has fibers
 184             ready to run.
 185           </p></dd>
 186 </dl>
 187 </div>
 188 <p>
 189       </p>
 190 <h5>
 191 <a name="algorithm_suspend_until_bridgehead"></a>
 192   <span><a name="algorithm_suspend_until"></a></span>
 193   <a class="link" href="scheduling.html#algorithm_suspend_until">Member
 194       function <code class="computeroutput">suspend_until</code>()</a>
 195 </h5>
 196 <p>
 197     </p>
 198 <pre class="programlisting"><span class="keyword">virtual</span> <span class="keyword">void</span> <span class="identifier">suspend_until</span><span class="special">(</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">chrono</span><span class="special">::</span><span class="identifier">steady_clock</span><span class="special">::</span><span class="identifier">time_point</span> <span class="keyword">const</span><span class="special">&amp;</span> <span class="identifier">abs_time</span><span class="special">)</span> <span class="keyword">noexcept</span> <span class="special">=</span> <span class="number">0</span><span class="special">;</span>
 199 </pre>
 200 <div class="variablelist">
 201 <p class="title"><b></b></p>
 202 <dl>
 203 <dt><span class="term">Effects:</span></dt>
 204 <dd><p>
 205             Informs the scheduler that no fiber will be ready until time-point <code class="computeroutput"><span class="identifier">abs_time</span></code>.
 206           </p></dd>
 207 <dt><span class="term">Note:</span></dt>
 208 <dd><p>
 209             This method allows a custom scheduler to yield control to the containing
 210             environment in whatever way makes sense. The fiber manager is stating
 211             that <code class="computeroutput"><span class="identifier">suspend_until</span><span class="special">()</span></code>
 212             need not return until <code class="computeroutput"><span class="identifier">abs_time</span></code>
 213             &#8212; or <a class="link" href="scheduling.html#algorithm_notify"><code class="computeroutput">algorithm::notify()</code></a> is called &#8212; whichever comes first.
 214             The interaction with <code class="computeroutput"><span class="identifier">notify</span><span class="special">()</span></code> means that, for instance, calling
 215             <a href="http://en.cppreference.com/w/cpp/thread/sleep_until" target="_top"><code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">this_thread</span><span class="special">::</span><span class="identifier">sleep_until</span><span class="special">(</span><span class="identifier">abs_time</span><span class="special">)</span></code></a>
 216             would be too simplistic. <a class="link" href="scheduling.html#round_robin_suspend_until"><code class="computeroutput">round_robin::suspend_until()</code></a> uses
 217             a <a href="http://en.cppreference.com/w/cpp/thread/condition_variable" target="_top"><code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">condition_variable</span></code></a> to coordinate
 218             with <a class="link" href="scheduling.html#round_robin_notify"><code class="computeroutput">round_robin::notify()</code></a>.
 219           </p></dd>
 220 <dt><span class="term">Note:</span></dt>
 221 <dd><p>
 222             Given that <code class="computeroutput"><span class="identifier">notify</span><span class="special">()</span></code>
 223             might be called from another thread, your <code class="computeroutput"><span class="identifier">suspend_until</span><span class="special">()</span></code> implementation &#8212; like the rest of your
 224             <code class="computeroutput"><span class="identifier">algorithm</span></code> implementation
 225             &#8212; must guard any data it shares with your <code class="computeroutput"><span class="identifier">notify</span><span class="special">()</span></code> implementation.
 226           </p></dd>
 227 </dl>
 228 </div>
 229 <p>
 230       </p>
 231 <h5>
 232 <a name="algorithm_notify_bridgehead"></a>
 233   <span><a name="algorithm_notify"></a></span>
 234   <a class="link" href="scheduling.html#algorithm_notify">Member function
 235       <code class="computeroutput">notify</code>()</a>
 236 </h5>
 237 <p>
 238     </p>
 239 <pre class="programlisting"><span class="keyword">virtual</span> <span class="keyword">void</span> <span class="identifier">notify</span><span class="special">()</span> <span class="keyword">noexcept</span> <span class="special">=</span> <span class="number">0</span><span class="special">;</span>
 240 </pre>
 241 <div class="variablelist">
 242 <p class="title"><b></b></p>
 243 <dl>
 244 <dt><span class="term">Effects:</span></dt>
 245 <dd><p>
 246             Requests the scheduler to return from a pending call to <a class="link" href="scheduling.html#algorithm_suspend_until"><code class="computeroutput">algorithm::suspend_until()</code></a>.
 247           </p></dd>
 248 <dt><span class="term">Note:</span></dt>
 249 <dd><p>
 250             Alone among the <code class="computeroutput"><span class="identifier">algorithm</span></code>
 251             methods, <code class="computeroutput"><span class="identifier">notify</span><span class="special">()</span></code>
 252             may be called from another thread. Your <code class="computeroutput"><span class="identifier">notify</span><span class="special">()</span></code> implementation must guard any data
 253             it shares with the rest of your <code class="computeroutput"><span class="identifier">algorithm</span></code>
 254             implementation.
 255           </p></dd>
 256 </dl>
 257 </div>
 258 <p>
 259       </p>
 260 <h5>
 261 <a name="class_round_robin_bridgehead"></a>
 262   <span><a name="class_round_robin"></a></span>
 263   <a class="link" href="scheduling.html#class_round_robin">Class <code class="computeroutput">round_robin</code></a>
 264 </h5>
 265 <p>
 266     </p>
 267 <p>
 268       This class implements <a class="link" href="scheduling.html#class_algorithm"><code class="computeroutput">algorithm</code></a>, scheduling fibers in round-robin
 269       fashion.
 270     </p>
 271 <pre class="programlisting"><span class="preprocessor">#include</span> <span class="special">&lt;</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">fiber</span><span class="special">/</span><span class="identifier">algo</span><span class="special">/</span><span class="identifier">round_robin</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">&gt;</span>
 272
 273 <span class="keyword">namespace</span> <span class="identifier">boost</span> <span class="special">{</span>
 274 <span class="keyword">namespace</span> <span class="identifier">fibers</span> <span class="special">{</span>
 275 <span class="keyword">namespace</span> <span class="identifier">algo</span> <span class="special">{</span>
 276
 277 <span class="keyword">class</span> <span class="identifier">round_robin</span> <span class="special">:</span> <span class="keyword">public</span> <span class="identifier">algorithm</span> <span class="special">{</span>
 278     <span class="keyword">virtual</span> <span class="keyword">void</span> <span class="identifier">awakened</span><span class="special">(</span> <span class="identifier">context</span> <span class="special">*)</span> <span class="keyword">noexcept</span><span class="special">;</span>
 279
 280     <span class="keyword">virtual</span> <span class="identifier">context</span> <span class="special">*</span> <span class="identifier">pick_next</span><span class="special">()</span> <span class="keyword">noexcept</span><span class="special">;</span>
 281
 282     <span class="keyword">virtual</span> <span class="keyword">bool</span> <span class="identifier">has_ready_fibers</span><span class="special">()</span> <span class="keyword">const</span> <span class="keyword">noexcept</span><span class="special">;</span>
 283
 284     <span class="keyword">virtual</span> <span class="keyword">void</span> <span class="identifier">suspend_until</span><span class="special">(</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">chrono</span><span class="special">::</span><span class="identifier">steady_clock</span><span class="special">::</span><span class="identifier">time_point</span> <span class="keyword">const</span><span class="special">&amp;)</span> <span class="keyword">noexcept</span><span class="special">;</span>
 285
 286     <span class="keyword">virtual</span> <span class="keyword">void</span> <span class="identifier">notify</span><span class="special">()</span> <span class="keyword">noexcept</span><span class="special">;</span>
 287 <span class="special">};</span>
 288
 289 <span class="special">}}}</span>
 290 </pre>
 291 <p>
 292       </p>
 293 <h5>
 294 <a name="round_robin_awakened_bridgehead"></a>
 295   <span><a name="round_robin_awakened"></a></span>
 296   <a class="link" href="scheduling.html#round_robin_awakened">Member
 297       function <code class="computeroutput">awakened</code>()</a>
 298 </h5>
 299 <p>
 300     </p>
 301 <pre class="programlisting"><span class="keyword">virtual</span> <span class="keyword">void</span> <span class="identifier">awakened</span><span class="special">(</span> <span class="identifier">context</span> <span class="special">*</span> <span class="identifier">f</span><span class="special">)</span> <span class="keyword">noexcept</span><span class="special">;</span>
 302 </pre>
 303 <div class="variablelist">
 304 <p class="title"><b></b></p>
 305 <dl>
 306 <dt><span class="term">Effects:</span></dt>
 307 <dd><p>
 308             Enqueues fiber <code class="computeroutput"><span class="identifier">f</span></code> onto
 309             a ready queue.
 310           </p></dd>
 311 <dt><span class="term">Throws:</span></dt>
 312 <dd><p>
 313             Nothing.
 314           </p></dd>
 315 </dl>
 316 </div>
 317 <p>
 318       </p>
 319 <h5>
 320 <a name="round_robin_pick_next_bridgehead"></a>
 321   <span><a name="round_robin_pick_next"></a></span>
 322   <a class="link" href="scheduling.html#round_robin_pick_next">Member
 323       function <code class="computeroutput">pick_next</code>()</a>
 324 </h5>
 325 <p>
 326     </p>
 327 <pre class="programlisting"><span class="keyword">virtual</span> <span class="identifier">context</span> <span class="special">*</span> <span class="identifier">pick_next</span><span class="special">()</span> <span class="keyword">noexcept</span><span class="special">;</span>
 328 </pre>
 329 <div class="variablelist">
 330 <p class="title"><b></b></p>
 331 <dl>
 332 <dt><span class="term">Returns:</span></dt>
 333 <dd><p>
 334             the fiber at the head of the ready queue, or <code class="computeroutput"><span class="keyword">nullptr</span></code>
 335             if the queue is empty.
 336           </p></dd>
 337 <dt><span class="term">Throws:</span></dt>
 338 <dd><p>
 339             Nothing.
 340           </p></dd>
 341 <dt><span class="term">Note:</span></dt>
 342 <dd><p>
 343             Placing ready fibers onto the tail of a queue, and returning them from
 344             the head of that queue, shares the thread between ready fibers in round-robin
 345             fashion.
 346           </p></dd>
 347 </dl>
 348 </div>
 349 <p>
 350       </p>
 351 <h5>
 352 <a name="round_robin_has_ready_fibers_bridgehead"></a>
 353   <span><a name="round_robin_has_ready_fibers"></a></span>
 354   <a class="link" href="scheduling.html#round_robin_has_ready_fibers">Member
 355       function <code class="computeroutput">has_ready_fibers</code>()</a>
 356 </h5>
 357 <p>
 358     </p>
 359 <pre class="programlisting"><span class="keyword">virtual</span> <span class="keyword">bool</span> <span class="identifier">has_ready_fibers</span><span class="special">()</span> <span class="keyword">const</span> <span class="keyword">noexcept</span><span class="special">;</span>
 360 </pre>
 361 <div class="variablelist">
 362 <p class="title"><b></b></p>
 363 <dl>
 364 <dt><span class="term">Returns:</span></dt>
 365 <dd><p>
 366             <code class="computeroutput"><span class="keyword">true</span></code> if scheduler has fibers
 367             ready to run.
 368           </p></dd>
 369 <dt><span class="term">Throws:</span></dt>
 370 <dd><p>
 371             Nothing.
 372           </p></dd>
 373 </dl>
 374 </div>
 375 <p>
 376       </p>
 377 <h5>
 378 <a name="round_robin_suspend_until_bridgehead"></a>
 379   <span><a name="round_robin_suspend_until"></a></span>
 380   <a class="link" href="scheduling.html#round_robin_suspend_until">Member
 381       function <code class="computeroutput">suspend_until</code>()</a>
 382 </h5>
 383 <p>
 384     </p>
 385 <pre class="programlisting"><span class="keyword">virtual</span> <span class="keyword">void</span> <span class="identifier">suspend_until</span><span class="special">(</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">chrono</span><span class="special">::</span><span class="identifier">steady_clock</span><span class="special">::</span><span class="identifier">time_point</span> <span class="keyword">const</span><span class="special">&amp;</span> <span class="identifier">abs_time</span><span class="special">)</span> <span class="keyword">noexcept</span><span class="special">;</span>
 386 </pre>
 387 <div class="variablelist">
 388 <p class="title"><b></b></p>
 389 <dl>
 390 <dt><span class="term">Effects:</span></dt>
 391 <dd><p>
 392             Informs <code class="computeroutput"><span class="identifier">round_robin</span></code> that
 393             no ready fiber will be available until time-point <code class="computeroutput"><span class="identifier">abs_time</span></code>.
 394             This implementation blocks in <a href="http://en.cppreference.com/w/cpp/thread/condition_variable/wait_until" target="_top"><code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">condition_variable</span><span class="special">::</span><span class="identifier">wait_until</span><span class="special">()</span></code></a>.
 395           </p></dd>
 396 <dt><span class="term">Throws:</span></dt>
 397 <dd><p>
 398             Nothing.
 399           </p></dd>
 400 </dl>
 401 </div>
 402 <p>
 403       </p>
 404 <h5>
 405 <a name="round_robin_notify_bridgehead"></a>
 406   <span><a name="round_robin_notify"></a></span>
 407   <a class="link" href="scheduling.html#round_robin_notify">Member function
 408       <code class="computeroutput">notify</code>()</a>
 409 </h5>
 410 <p>
 411     </p>
 412 <pre class="programlisting"><span class="keyword">virtual</span> <span class="keyword">void</span> <span class="identifier">notify</span><span class="special">()</span> <span class="keyword">noexcept</span> <span class="special">=</span> <span class="number">0</span><span class="special">;</span>
 413 </pre>
 414 <div class="variablelist">
 415 <p class="title"><b></b></p>
 416 <dl>
 417 <dt><span class="term">Effects:</span></dt>
 418 <dd><p>
 419             Wake up a pending call to <a class="link" href="scheduling.html#round_robin_suspend_until"><code class="computeroutput">round_robin::suspend_until()</code></a>,
 420             some fibers might be ready. This implementation wakes <code class="computeroutput"><span class="identifier">suspend_until</span><span class="special">()</span></code> via <a href="http://en.cppreference.com/w/cpp/thread/condition_variable/notify_all" target="_top"><code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">condition_variable</span><span class="special">::</span><span class="identifier">notify_all</span><span class="special">()</span></code></a>.
 421           </p></dd>
 422 <dt><span class="term">Throws:</span></dt>
 423 <dd><p>
 424             Nothing.
 425           </p></dd>
 426 </dl>
 427 </div>
 428 <p>
 429       </p>
 430 <h5>
 431 <a name="class_shared_work_bridgehead"></a>
 432   <span><a name="class_shared_work"></a></span>
 433   <a class="link" href="scheduling.html#class_shared_work">Class <code class="computeroutput">shared_work</code></a>
 434 </h5>
 435 <p>
 436     </p>
 437 <p>
 438       This class implements <a class="link" href="scheduling.html#class_algorithm"><code class="computeroutput">algorithm</code></a>; ready fibers are shared between
 439       all instances (running on different threads) of shared_work.
 440     </p>
 441 <pre class="programlisting"><span class="preprocessor">#include</span> <span class="special">&lt;</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">fiber</span><span class="special">/</span><span class="identifier">algo</span><span class="special">/</span><span class="identifier">shared_work</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">&gt;</span>
 442
 443 <span class="keyword">namespace</span> <span class="identifier">boost</span> <span class="special">{</span>
 444 <span class="keyword">namespace</span> <span class="identifier">fibers</span> <span class="special">{</span>
 445 <span class="keyword">namespace</span> <span class="identifier">algo</span> <span class="special">{</span>
 446
 447 <span class="keyword">class</span> <span class="identifier">shared_work</span> <span class="special">:</span> <span class="keyword">public</span> <span class="identifier">algorithm</span> <span class="special">{</span>
 448     <span class="keyword">virtual</span> <span class="keyword">void</span> <span class="identifier">awakened</span><span class="special">(</span> <span class="identifier">context</span> <span class="special">*)</span> <span class="keyword">noexcept</span><span class="special">;</span>
 449
 450     <span class="keyword">virtual</span> <span class="identifier">context</span> <span class="special">*</span> <span class="identifier">pick_next</span><span class="special">()</span> <span class="keyword">noexcept</span><span class="special">;</span>
 451
 452     <span class="keyword">virtual</span> <span class="keyword">bool</span> <span class="identifier">has_ready_fibers</span><span class="special">()</span> <span class="keyword">const</span> <span class="keyword">noexcept</span><span class="special">;</span>
 453
 454     <span class="keyword">virtual</span> <span class="keyword">void</span> <span class="identifier">suspend_until</span><span class="special">(</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">chrono</span><span class="special">::</span><span class="identifier">steady_clock</span><span class="special">::</span><span class="identifier">time_point</span> <span class="keyword">const</span><span class="special">&amp;)</span> <span class="keyword">noexcept</span><span class="special">;</span>
 455
 456     <span class="keyword">virtual</span> <span class="keyword">void</span> <span class="identifier">notify</span><span class="special">()</span> <span class="keyword">noexcept</span><span class="special">;</span>
 457 <span class="special">};</span>
 458
 459 <span class="special">}}}</span>
 460 </pre>
 461 <p>
 462       </p>
 463 <h5>
 464 <a name="shared_work_awakened_bridgehead"></a>
 465   <span><a name="shared_work_awakened"></a></span>
 466   <a class="link" href="scheduling.html#shared_work_awakened">Member
 467       function <code class="computeroutput">awakened</code>()</a>
 468 </h5>
 469 <p>
 470     </p>
 471 <pre class="programlisting"><span class="keyword">virtual</span> <span class="keyword">void</span> <span class="identifier">awakened</span><span class="special">(</span> <span class="identifier">context</span> <span class="special">*</span> <span class="identifier">f</span><span class="special">)</span> <span class="keyword">noexcept</span><span class="special">;</span>
 472 </pre>
 473 <div class="variablelist">
 474 <p class="title"><b></b></p>
 475 <dl>
 476 <dt><span class="term">Effects:</span></dt>
 477 <dd><p>
 478             Enqueues fiber <code class="computeroutput"><span class="identifier">f</span></code> onto
 479             the shared ready queue.
 480           </p></dd>
 481 <dt><span class="term">Throws:</span></dt>
 482 <dd><p>
 483             Nothing.
 484           </p></dd>
 485 </dl>
 486 </div>
 487 <p>
 488       </p>
 489 <h5>
 490 <a name="shared_work_pick_next_bridgehead"></a>
 491   <span><a name="shared_work_pick_next"></a></span>
 492   <a class="link" href="scheduling.html#shared_work_pick_next">Member
 493       function <code class="computeroutput">pick_next</code>()</a>
 494 </h5>
 495 <p>
 496     </p>
 497 <pre class="programlisting"><span class="keyword">virtual</span> <span class="identifier">context</span> <span class="special">*</span> <span class="identifier">pick_next</span><span class="special">()</span> <span class="keyword">noexcept</span><span class="special">;</span>
 498 </pre>
 499 <div class="variablelist">
 500 <p class="title"><b></b></p>
 501 <dl>
 502 <dt><span class="term">Returns:</span></dt>
 503 <dd><p>
 504             the fiber at the head of the ready queue, or <code class="computeroutput"><span class="keyword">nullptr</span></code>
 505             if the queue is empty.
 506           </p></dd>
 507 <dt><span class="term">Throws:</span></dt>
 508 <dd><p>
 509             Nothing.
 510           </p></dd>
 511 <dt><span class="term">Note:</span></dt>
 512 <dd><p>
 513             Placing ready fibers onto the tail of the shared queue, and returning
 514             them from the head of that queue, shares the thread between ready fibers
 515             in round-robin fashion.
 516           </p></dd>
 517 </dl>
 518 </div>
 519 <p>
 520       </p>
 521 <h5>
 522 <a name="shared_work_has_ready_fibers_bridgehead"></a>
 523   <span><a name="shared_work_has_ready_fibers"></a></span>
 524   <a class="link" href="scheduling.html#shared_work_has_ready_fibers">Member
 525       function <code class="computeroutput">has_ready_fibers</code>()</a>
 526 </h5>
 527 <p>
 528     </p>
 529 <pre class="programlisting"><span class="keyword">virtual</span> <span class="keyword">bool</span> <span class="identifier">has_ready_fibers</span><span class="special">()</span> <span class="keyword">const</span> <span class="keyword">noexcept</span><span class="special">;</span>
 530 </pre>
 531 <div class="variablelist">
 532 <p class="title"><b></b></p>
 533 <dl>
 534 <dt><span class="term">Returns:</span></dt>
 535 <dd><p>
 536             <code class="computeroutput"><span class="keyword">true</span></code> if scheduler has fibers
 537             ready to run.
 538           </p></dd>
 539 <dt><span class="term">Throws:</span></dt>
 540 <dd><p>
 541             Nothing.
 542           </p></dd>
 543 </dl>
 544 </div>
 545 <p>
 546       </p>
 547 <h5>
 548 <a name="shared_work_suspend_until_bridgehead"></a>
 549   <span><a name="shared_work_suspend_until"></a></span>
 550   <a class="link" href="scheduling.html#shared_work_suspend_until">Member
 551       function <code class="computeroutput">suspend_until</code>()</a>
 552 </h5>
 553 <p>
 554     </p>
 555 <pre class="programlisting"><span class="keyword">virtual</span> <span class="keyword">void</span> <span class="identifier">suspend_until</span><span class="special">(</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">chrono</span><span class="special">::</span><span class="identifier">steady_clock</span><span class="special">::</span><span class="identifier">time_point</span> <span class="keyword">const</span><span class="special">&amp;</span> <span class="identifier">abs_time</span><span class="special">)</span> <span class="keyword">noexcept</span><span class="special">;</span>
 556 </pre>
 557 <div class="variablelist">
 558 <p class="title"><b></b></p>
 559 <dl>
 560 <dt><span class="term">Effects:</span></dt>
 561 <dd><p>
 562             Informs <code class="computeroutput"><span class="identifier">shared_work</span></code> that
 563             no ready fiber will be available until time-point <code class="computeroutput"><span class="identifier">abs_time</span></code>.
 564             This implementation blocks in <a href="http://en.cppreference.com/w/cpp/thread/condition_variable/wait_until" target="_top"><code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">condition_variable</span><span class="special">::</span><span class="identifier">wait_until</span><span class="special">()</span></code></a>.
 565           </p></dd>
 566 <dt><span class="term">Throws:</span></dt>
 567 <dd><p>
 568             Nothing.
 569           </p></dd>
 570 </dl>
 571 </div>
 572 <p>
 573       </p>
 574 <h5>
 575 <a name="shared_work_notify_bridgehead"></a>
 576   <span><a name="shared_work_notify"></a></span>
 577   <a class="link" href="scheduling.html#shared_work_notify">Member function
 578       <code class="computeroutput">notify</code>()</a>
 579 </h5>
 580 <p>
 581     </p>
 582 <pre class="programlisting"><span class="keyword">virtual</span> <span class="keyword">void</span> <span class="identifier">notify</span><span class="special">()</span> <span class="keyword">noexcept</span> <span class="special">=</span> <span class="number">0</span><span class="special">;</span>
 583 </pre>
 584 <div class="variablelist">
 585 <p class="title"><b></b></p>
 586 <dl>
 587 <dt><span class="term">Effects:</span></dt>
 588 <dd><p>
 589             Wake up a pending call to <a class="link" href="scheduling.html#shared_work_suspend_until"><code class="computeroutput">shared_work::suspend_until()</code></a>,
 590             some fibers might be ready. This implementation wakes <code class="computeroutput"><span class="identifier">suspend_until</span><span class="special">()</span></code> via <a href="http://en.cppreference.com/w/cpp/thread/condition_variable/notify_all" target="_top"><code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">condition_variable</span><span class="special">::</span><span class="identifier">notify_all</span><span class="special">()</span></code></a>.
 591           </p></dd>
 592 <dt><span class="term">Throws:</span></dt>
 593 <dd><p>
 594             Nothing.
 595           </p></dd>
 596 </dl>
 597 </div>
 598 <h4>
 599 <a name="fiber.scheduling.h0"></a>
 600       <span><a name="fiber.scheduling.custom_scheduler_fiber_properties"></a></span><a class="link" href="scheduling.html#fiber.scheduling.custom_scheduler_fiber_properties">Custom
 601       Scheduler Fiber Properties</a>
 602     </h4>
 603 <p>
 604       A scheduler class directly derived from <a class="link" href="scheduling.html#class_algorithm"><code class="computeroutput">algorithm</code></a> can use any
 605       information available from <a class="link" href="scheduling.html#class_context"><code class="computeroutput">context</code></a> to implement the <code class="computeroutput"><span class="identifier">algorithm</span></code> interface. But a custom scheduler
 606       might need to track additional properties for a fiber. For instance, a priority-based
 607       scheduler would need to track a fiber&#8217;s priority.
 608     </p>
 609 <p>
 610       <span class="bold"><strong>Boost.Fiber</strong></span> provides a mechanism by which
 611       your custom scheduler can associate custom properties with each fiber.
 612     </p>
 613 <p>
 614       </p>
 615 <h5>
 616 <a name="class_fiber_properties_bridgehead"></a>
 617   <span><a name="class_fiber_properties"></a></span>
 618   <a class="link" href="scheduling.html#class_fiber_properties">Class
 619       <code class="computeroutput">fiber_properties</code></a>
 620 </h5>
 621 <p>
 622     </p>
 623 <p>
 624       A custom fiber properties class must be derived from <code class="computeroutput"><span class="identifier">fiber_properties</span></code>.
 625     </p>
 626 <pre class="programlisting"><span class="preprocessor">#include</span> <span class="special">&lt;</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">fiber</span><span class="special">/</span><span class="identifier">properties</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">&gt;</span>
 627
 628 <span class="keyword">namespace</span> <span class="identifier">boost</span> <span class="special">{</span>
 629 <span class="keyword">namespace</span> <span class="identifier">fibers</span> <span class="special">{</span>
 630
 631 <span class="keyword">class</span> <span class="identifier">fiber_properties</span> <span class="special">{</span>
 632 <span class="keyword">public</span><span class="special">:</span>
 633     <span class="identifier">fiber_properties</span><span class="special">(</span> <span class="identifier">context</span> <span class="special">*)</span> <span class="keyword">noexcept</span><span class="special">;</span>
 634
 635     <span class="keyword">virtual</span> <span class="special">~</span><span class="identifier">fiber_properties</span><span class="special">();</span>
 636
 637 <span class="keyword">protected</span><span class="special">:</span>
 638     <span class="keyword">void</span> <span class="identifier">notify</span><span class="special">()</span> <span class="keyword">noexcept</span><span class="special">;</span>
 639 <span class="special">};</span>
 640
 641 <span class="special">}}</span>
 642 </pre>
 643 <h4>
 644 <a name="fiber.scheduling.h1"></a>
 645       <span><a name="fiber.scheduling.constructor"></a></span><a class="link" href="scheduling.html#fiber.scheduling.constructor">Constructor</a>
 646     </h4>
 647 <pre class="programlisting"><span class="identifier">fiber_properties</span><span class="special">(</span> <span class="identifier">context</span> <span class="special">*</span> <span class="identifier">f</span><span class="special">)</span> <span class="keyword">noexcept</span><span class="special">;</span>
 648 </pre>
 649 <div class="variablelist">
 650 <p class="title"><b></b></p>
 651 <dl>
 652 <dt><span class="term">Effects:</span></dt>
 653 <dd><p>
 654             Constructs base-class component of custom subclass.
 655           </p></dd>
 656 <dt><span class="term">Throws:</span></dt>
 657 <dd><p>
 658             Nothing.
 659           </p></dd>
 660 <dt><span class="term">Note:</span></dt>
 661 <dd><p>
 662             Your subclass constructor must accept a <code class="computeroutput"><span class="identifier">context</span><span class="special">*</span></code> and pass it to the base-class <code class="computeroutput"><span class="identifier">fiber_properties</span></code> constructor.
 663           </p></dd>
 664 </dl>
 665 </div>
 666 <p>
 667       </p>
 668 <h5>
 669 <a name="fiber_properties_notify_bridgehead"></a>
 670   <span><a name="fiber_properties_notify"></a></span>
 671   <a class="link" href="scheduling.html#fiber_properties_notify">Member
 672       function <code class="computeroutput">notify</code>()</a>
 673 </h5>
 674 <p>
 675     </p>
 676 <pre class="programlisting"><span class="keyword">void</span> <span class="identifier">notify</span><span class="special">()</span> <span class="keyword">noexcept</span><span class="special">;</span>
 677 </pre>
 678 <div class="variablelist">
 679 <p class="title"><b></b></p>
 680 <dl>
 681 <dt><span class="term">Effects:</span></dt>
 682 <dd><p>
 683             Pass control to the custom <a class="link" href="scheduling.html#class_algorithm_with_properties"><code class="computeroutput">algorithm_with_properties&lt;&gt;</code></a> subclass&#8217;s
 684             <a class="link" href="scheduling.html#algorithm_with_properties_property_change"><code class="computeroutput">algorithm_with_properties::property_change()</code></a> method.
 685           </p></dd>
 686 <dt><span class="term">Throws:</span></dt>
 687 <dd><p>
 688             Nothing.
 689           </p></dd>
 690 <dt><span class="term">Note:</span></dt>
 691 <dd><p>
 692             A custom scheduler&#8217;s <a class="link" href="scheduling.html#algorithm_with_properties_pick_next"><code class="computeroutput">algorithm_with_properties::pick_next()</code></a> method
 693             might dynamically select from the ready fibers, or <a class="link" href="scheduling.html#algorithm_with_properties_awakened"><code class="computeroutput">algorithm_with_properties::awakened()</code></a> might
 694             instead insert each ready fiber into some form of ready queue for <code class="computeroutput"><span class="identifier">pick_next</span><span class="special">()</span></code>.
 695             In the latter case, if application code modifies a fiber property (e.g.
 696             priority) that should affect that fiber&#8217;s relationship to other ready
 697             fibers, the custom scheduler must be given the opportunity to reorder
 698             its ready queue. The custom property subclass should implement an access
 699             method to modify such a property; that access method should call <code class="computeroutput"><span class="identifier">notify</span><span class="special">()</span></code>
 700             once the new property value has been stored. This passes control to the
 701             custom scheduler&#8217;s <code class="computeroutput"><span class="identifier">property_change</span><span class="special">()</span></code> method, allowing the custom scheduler
 702             to reorder its ready queue appropriately. Use at your discretion. Of
 703             course, if you define a property which does not affect the behavior of
 704             the <code class="computeroutput"><span class="identifier">pick_next</span><span class="special">()</span></code>
 705             method, you need not call <code class="computeroutput"><span class="identifier">notify</span><span class="special">()</span></code> when that property is modified.
 706           </p></dd>
 707 </dl>
 708 </div>
 709 <p>
 710       </p>
 711 <h5>
 712 <a name="class_algorithm_with_properties_bridgehead"></a>
 713   <span><a name="class_algorithm_with_properties"></a></span>
 714   <a class="link" href="scheduling.html#class_algorithm_with_properties">Template
 715       <code class="computeroutput">algorithm_with_properties&lt;&gt;</code></a>
 716 </h5>
 717 <p>
 718     </p>
 719 <p>
 720       A custom scheduler that depends on a custom properties class <code class="computeroutput"><span class="identifier">PROPS</span></code> should be derived from <code class="computeroutput"><span class="identifier">algorithm_with_properties</span><span class="special">&lt;</span><span class="identifier">PROPS</span><span class="special">&gt;</span></code>.
 721       <code class="computeroutput"><span class="identifier">PROPS</span></code> should be derived from
 722       <a class="link" href="scheduling.html#class_fiber_properties"><code class="computeroutput">fiber_properties</code></a>.
 723     </p>
 724 <pre class="programlisting"><span class="preprocessor">#include</span> <span class="special">&lt;</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">fiber</span><span class="special">/</span><span class="identifier">algorithm</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">&gt;</span>
 725
 726 <span class="keyword">namespace</span> <span class="identifier">boost</span> <span class="special">{</span>
 727 <span class="keyword">namespace</span> <span class="identifier">fibers</span> <span class="special">{</span>
 728 <span class="keyword">namespace</span> <span class="identifier">algo</span> <span class="special">{</span>
 729
 730 <span class="keyword">template</span><span class="special">&lt;</span> <span class="keyword">typename</span> <span class="identifier">PROPS</span> <span class="special">&gt;</span>
 731 <span class="keyword">struct</span> <span class="identifier">algorithm_with_properties</span> <span class="special">{</span>
 732     <span class="keyword">virtual</span> <span class="keyword">void</span> <span class="identifier">awakened</span><span class="special">(</span> <span class="identifier">context</span> <span class="special">*,</span> <span class="identifier">PROPS</span> <span class="special">&amp;)</span> <span class="keyword">noexcept</span> <span class="special">=</span> <span class="number">0</span><span class="special">;</span>
 733
 734     <span class="keyword">virtual</span> <span class="identifier">context</span> <span class="special">*</span> <span class="identifier">pick_next</span><span class="special">()</span> <span class="keyword">noexcept</span><span class="special">;</span>
 735
 736     <span class="keyword">virtual</span> <span class="keyword">bool</span> <span class="identifier">has_ready_fibers</span><span class="special">()</span> <span class="keyword">const</span> <span class="keyword">noexcept</span><span class="special">;</span>
 737
 738     <span class="keyword">virtual</span> <span class="keyword">void</span> <span class="identifier">suspend_until</span><span class="special">(</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">chrono</span><span class="special">::</span><span class="identifier">steady_clock</span><span class="special">::</span><span class="identifier">time_point</span> <span class="keyword">const</span><span class="special">&amp;)</span> <span class="keyword">noexcept</span> <span class="special">=</span> <span class="number">0</span><span class="special">;</span>
 739
 740     <span class="keyword">virtual</span> <span class="keyword">void</span> <span class="identifier">notify</span><span class="special">()</span> <span class="keyword">noexcept</span> <span class="special">=</span> <span class="number">0</span><span class="special">;</span>
 741
 742     <span class="identifier">PROPS</span> <span class="special">&amp;</span> <span class="identifier">properties</span><span class="special">(</span> <span class="identifier">context</span> <span class="special">*)</span> <span class="keyword">noexcept</span><span class="special">;</span>
 743
 744     <span class="keyword">virtual</span> <span class="keyword">void</span> <span class="identifier">property_change</span><span class="special">(</span> <span class="identifier">context</span> <span class="special">*,</span> <span class="identifier">PROPS</span> <span class="special">&amp;)</span> <span class="keyword">noexcept</span><span class="special">;</span>
 745
 746     <span class="keyword">virtual</span> <span class="identifier">fiber_properties</span> <span class="special">*</span> <span class="identifier">new_properties</span><span class="special">(</span> <span class="identifier">context</span> <span class="special">*);</span>
 747 <span class="special">};</span>
 748
 749 <span class="special">}}}</span>
 750 </pre>
 751 <p>
 752       </p>
 753 <h5>
 754 <a name="algorithm_with_properties_awakened_bridgehead"></a>
 755   <span><a name="algorithm_with_properties_awakened"></a></span>
 756   <a class="link" href="scheduling.html#algorithm_with_properties_awakened">Member
 757       function <code class="computeroutput">awakened</code>()</a>
 758 </h5>
 759 <p>
 760     </p>
 761 <pre class="programlisting"><span class="keyword">virtual</span> <span class="keyword">void</span> <span class="identifier">awakened</span><span class="special">(</span> <span class="identifier">context</span> <span class="special">*</span> <span class="identifier">f</span><span class="special">,</span> <span class="identifier">PROPS</span> <span class="special">&amp;</span> <span class="identifier">properties</span><span class="special">)</span> <span class="keyword">noexcept</span><span class="special">;</span>
 762 </pre>
 763 <div class="variablelist">
 764 <p class="title"><b></b></p>
 765 <dl>
 766 <dt><span class="term">Effects:</span></dt>
 767 <dd><p>
 768             Informs the scheduler that fiber <code class="computeroutput"><span class="identifier">f</span></code>
 769             is ready to run, like <a class="link" href="scheduling.html#algorithm_awakened"><code class="computeroutput">algorithm::awakened()</code></a>. Passes
 770             the fiber&#8217;s associated <code class="computeroutput"><span class="identifier">PROPS</span></code>
 771             instance.
 772           </p></dd>
 773 <dt><span class="term">Throws:</span></dt>
 774 <dd><p>
 775             Nothing.
 776           </p></dd>
 777 <dt><span class="term">Note:</span></dt>
 778 <dd><p>
 779             An <code class="computeroutput"><span class="identifier">algorithm_with_properties</span><span class="special">&lt;&gt;</span></code> subclass must override this method
 780             instead of <code class="computeroutput"><span class="identifier">algorithm</span><span class="special">::</span><span class="identifier">awakened</span><span class="special">()</span></code>.
 781           </p></dd>
 782 </dl>
 783 </div>
 784 <p>
 785       </p>
 786 <h5>
 787 <a name="algorithm_with_properties_pick_next_bridgehead"></a>
 788   <span><a name="algorithm_with_properties_pick_next"></a></span>
 789   <a class="link" href="scheduling.html#algorithm_with_properties_pick_next">Member
 790       function <code class="computeroutput">pick_next</code>()</a>
 791 </h5>
 792 <p>
 793     </p>
 794 <pre class="programlisting"><span class="keyword">virtual</span> <span class="identifier">context</span> <span class="special">*</span> <span class="identifier">pick_next</span><span class="special">()</span> <span class="keyword">noexcept</span><span class="special">;</span>
 795 </pre>
 796 <div class="variablelist">
 797 <p class="title"><b></b></p>
 798 <dl>
 799 <dt><span class="term">Returns:</span></dt>
 800 <dd><p>
 801             the fiber which is to be resumed next, or <code class="computeroutput"><span class="keyword">nullptr</span></code>
 802             if there is no ready fiber.
 803           </p></dd>
 804 <dt><span class="term">Throws:</span></dt>
 805 <dd><p>
 806             Nothing.
 807           </p></dd>
 808 <dt><span class="term">Note:</span></dt>
 809 <dd><p>
 810             same as <a class="link" href="scheduling.html#algorithm_pick_next"><code class="computeroutput">algorithm::pick_next()</code></a>
 811           </p></dd>
 812 </dl>
 813 </div>
 814 <p>
 815       </p>
 816 <h5>
 817 <a name="algorithm_with_properties_has_ready_fibers_bridgehead"></a>
 818   <span><a name="algorithm_with_properties_has_ready_fibers"></a></span>
 819   <a class="link" href="scheduling.html#algorithm_with_properties_has_ready_fibers">Member
 820       function <code class="computeroutput">has_ready_fibers</code>()</a>
 821 </h5>
 822 <p>
 823     </p>
 824 <pre class="programlisting"><span class="keyword">virtual</span> <span class="keyword">bool</span> <span class="identifier">has_ready_fibers</span><span class="special">()</span> <span class="keyword">const</span> <span class="keyword">noexcept</span><span class="special">;</span>
 825 </pre>
 826 <div class="variablelist">
 827 <p class="title"><b></b></p>
 828 <dl>
 829 <dt><span class="term">Returns:</span></dt>
 830 <dd><p>
 831             <code class="computeroutput"><span class="keyword">true</span></code> if scheduler has fibers
 832             ready to run.
 833           </p></dd>
 834 <dt><span class="term">Throws:</span></dt>
 835 <dd><p>
 836             Nothing.
 837           </p></dd>
 838 <dt><span class="term">Note:</span></dt>
 839 <dd><p>
 840             same as <a class="link" href="scheduling.html#algorithm_has_ready_fibers"><code class="computeroutput">algorithm::has_ready_fibers()</code></a>
 841           </p></dd>
 842 </dl>
 843 </div>
 844 <p>
 845       </p>
 846 <h5>
 847 <a name="algorithm_with_properties_suspend_until_bridgehead"></a>
 848   <span><a name="algorithm_with_properties_suspend_until"></a></span>
 849   <a class="link" href="scheduling.html#algorithm_with_properties_suspend_until">Member
 850       function <code class="computeroutput">suspend_until</code>()</a>
 851 </h5>
 852 <p>
 853     </p>
 854 <pre class="programlisting"><span class="keyword">virtual</span> <span class="keyword">void</span> <span class="identifier">suspend_until</span><span class="special">(</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">chrono</span><span class="special">::</span><span class="identifier">steady_clock</span><span class="special">::</span><span class="identifier">time_point</span> <span class="keyword">const</span><span class="special">&amp;</span> <span class="identifier">abs_time</span><span class="special">)</span> <span class="keyword">noexcept</span> <span class="special">=</span> <span class="number">0</span><span class="special">;</span>
 855 </pre>
 856 <div class="variablelist">
 857 <p class="title"><b></b></p>
 858 <dl>
 859 <dt><span class="term">Effects:</span></dt>
 860 <dd><p>
 861             Informs the scheduler that no fiber will be ready until time-point <code class="computeroutput"><span class="identifier">abs_time</span></code>.
 862           </p></dd>
 863 <dt><span class="term">Note:</span></dt>
 864 <dd><p>
 865             same as <a class="link" href="scheduling.html#algorithm_suspend_until"><code class="computeroutput">algorithm::suspend_until()</code></a>
 866           </p></dd>
 867 </dl>
 868 </div>
 869 <p>
 870       </p>
 871 <h5>
 872 <a name="algorithm_with_properties_notify_bridgehead"></a>
 873   <span><a name="algorithm_with_properties_notify"></a></span>
 874   <a class="link" href="scheduling.html#algorithm_with_properties_notify">Member
 875       function <code class="computeroutput">notify</code>()</a>
 876 </h5>
 877 <p>
 878     </p>
 879 <pre class="programlisting"><span class="keyword">virtual</span> <span class="keyword">void</span> <span class="identifier">notify</span><span class="special">()</span> <span class="keyword">noexcept</span> <span class="special">=</span> <span class="number">0</span><span class="special">;</span>
 880 </pre>
 881 <div class="variablelist">
 882 <p class="title"><b></b></p>
 883 <dl>
 884 <dt><span class="term">Effects:</span></dt>
 885 <dd><p>
 886             Requests the scheduler to return from a pending call to <a class="link" href="scheduling.html#algorithm_with_properties_suspend_until"><code class="computeroutput">algorithm_with_properties::suspend_until()</code></a>.
 887           </p></dd>
 888 <dt><span class="term">Note:</span></dt>
 889 <dd><p>
 890             same as <a class="link" href="scheduling.html#algorithm_notify"><code class="computeroutput">algorithm::notify()</code></a>
 891           </p></dd>
 892 </dl>
 893 </div>
 894 <p>
 895       </p>
 896 <h5>
 897 <a name="algorithm_with_properties_properties_bridgehead"></a>
 898   <span><a name="algorithm_with_properties_properties"></a></span>
 899   <a class="link" href="scheduling.html#algorithm_with_properties_properties">Member
 900       function <code class="computeroutput">properties</code>()</a>
 901 </h5>
 902 <p>
 903     </p>
 904 <pre class="programlisting"><span class="identifier">PROPS</span><span class="special">&amp;</span> <span class="identifier">properties</span><span class="special">(</span> <span class="identifier">context</span> <span class="special">*</span> <span class="identifier">f</span><span class="special">)</span> <span class="keyword">noexcept</span><span class="special">;</span>
 905 </pre>
 906 <div class="variablelist">
 907 <p class="title"><b></b></p>
 908 <dl>
 909 <dt><span class="term">Returns:</span></dt>
 910 <dd><p>
 911             the <code class="computeroutput"><span class="identifier">PROPS</span></code> instance associated
 912             with fiber <code class="computeroutput"><span class="identifier">f</span></code>.
 913           </p></dd>
 914 <dt><span class="term">Throws:</span></dt>
 915 <dd><p>
 916             Nothing.
 917           </p></dd>
 918 <dt><span class="term">Note:</span></dt>
 919 <dd><p>
 920             The fiber&#8217;s associated <code class="computeroutput"><span class="identifier">PROPS</span></code>
 921             instance is already passed to <a class="link" href="scheduling.html#algorithm_with_properties_awakened"><code class="computeroutput">algorithm_with_properties::awakened()</code></a> and
 922             <a class="link" href="scheduling.html#algorithm_with_properties_property_change"><code class="computeroutput">algorithm_with_properties::property_change()</code></a>.
 923             However, every <a class="link" href="scheduling.html#class_algorithm"><code class="computeroutput">algorithm</code></a> subclass is expected to track
 924             a collection of ready <a class="link" href="scheduling.html#class_context"><code class="computeroutput">context</code></a> instances. This method allows
 925             your custom scheduler to retrieve the <a class="link" href="scheduling.html#class_fiber_properties"><code class="computeroutput">fiber_properties</code></a> subclass
 926             instance for any <code class="computeroutput"><span class="identifier">context</span></code>
 927             in its collection.
 928           </p></dd>
 929 </dl>
 930 </div>
 931 <p>
 932       </p>
 933 <h5>
 934 <a name="algorithm_with_properties_property_change_bridgehead"></a>
 935   <span><a name="algorithm_with_properties_property_change"></a></span>
 936   <a class="link" href="scheduling.html#algorithm_with_properties_property_change">Member
 937       function <code class="computeroutput">property_change</code>()</a>
 938 </h5>
 939 <p>
 940     </p>
 941 <pre class="programlisting"><span class="keyword">virtual</span> <span class="keyword">void</span> <span class="identifier">property_change</span><span class="special">(</span> <span class="identifier">context</span> <span class="special">*</span> <span class="identifier">f</span><span class="special">,</span> <span class="identifier">PROPS</span> <span class="special">&amp;</span> <span class="identifier">properties</span><span class="special">)</span> <span class="keyword">noexcept</span><span class="special">;</span>
 942 </pre>
 943 <div class="variablelist">
 944 <p class="title"><b></b></p>
 945 <dl>
 946 <dt><span class="term">Effects:</span></dt>
 947 <dd><p>
 948             Notify the custom scheduler of a possibly-relevant change to a property
 949             belonging to fiber <code class="computeroutput"><span class="identifier">f</span></code>.
 950             <code class="computeroutput"><span class="identifier">properties</span></code> contains the
 951             new values of all relevant properties.
 952           </p></dd>
 953 <dt><span class="term">Throws:</span></dt>
 954 <dd><p>
 955             Nothing.
 956           </p></dd>
 957 <dt><span class="term">Note:</span></dt>
 958 <dd><p>
 959             This method is only called when a custom <a class="link" href="scheduling.html#class_fiber_properties"><code class="computeroutput">fiber_properties</code></a> subclass
 960             explicitly calls <a class="link" href="scheduling.html#fiber_properties_notify"><code class="computeroutput">fiber_properties::notify()</code></a>.
 961           </p></dd>
 962 </dl>
 963 </div>
 964 <p>
 965       </p>
 966 <h5>
 967 <a name="algorithm_with_properties_new_properties_bridgehead"></a>
 968   <span><a name="algorithm_with_properties_new_properties"></a></span>
 969   <a class="link" href="scheduling.html#algorithm_with_properties_new_properties">Member
 970       function <code class="computeroutput">new_properties</code>()</a>
 971 </h5>
 972 <p>
 973     </p>
 974 <pre class="programlisting"><span class="keyword">virtual</span> <span class="identifier">fiber_properties</span> <span class="special">*</span> <span class="identifier">new_properties</span><span class="special">(</span> <span class="identifier">context</span> <span class="special">*</span> <span class="identifier">f</span><span class="special">);</span>
 975 </pre>
 976 <div class="variablelist">
 977 <p class="title"><b></b></p>
 978 <dl>
 979 <dt><span class="term">Returns:</span></dt>
 980 <dd><p>
 981             A new instance of <a class="link" href="scheduling.html#class_fiber_properties"><code class="computeroutput">fiber_properties</code></a> subclass <code class="computeroutput"><span class="identifier">PROPS</span></code>.
 982           </p></dd>
 983 <dt><span class="term">Note:</span></dt>
 984 <dd><p>
 985             By default, <code class="computeroutput"><span class="identifier">algorithm_with_properties</span><span class="special">&lt;&gt;::</span><span class="identifier">new_properties</span><span class="special">()</span></code> simply returns <code class="computeroutput"><span class="keyword">new</span>
 986             <span class="identifier">PROPS</span><span class="special">(</span><span class="identifier">f</span><span class="special">)</span></code>,
 987             placing the <code class="computeroutput"><span class="identifier">PROPS</span></code> instance
 988             on the heap. Override this method to allocate <code class="computeroutput"><span class="identifier">PROPS</span></code>
 989             some other way. The returned <code class="computeroutput"><span class="identifier">fiber_properties</span></code>
 990             pointer must point to the <code class="computeroutput"><span class="identifier">PROPS</span></code>
 991             instance to be associated with fiber <code class="computeroutput"><span class="identifier">f</span></code>.
 992           </p></dd>
 993 </dl>
 994 </div>
 995 <p>
 996       <a name="context"></a></p>
 997 <h5>
 998 <a name="class_context_bridgehead"></a>
 999   <span><a name="class_context"></a></span>
1000   <a class="link" href="scheduling.html#class_context">Class
1001       <code class="computeroutput">context</code></a>
1002 </h5>
1003 <p>
1004     </p>
1005 <p>
1006       While you are free to treat <code class="computeroutput"><span class="identifier">context</span><span class="special">*</span></code> as an opaque token, certain <code class="computeroutput"><span class="identifier">context</span></code> members may be useful to a custom
1007       scheduler implementation.
1008     </p>
1009 <p>
1010       <a name="ready_queue_t"></a>Of particular note is the fact that <code class="computeroutput"><span class="identifier">context</span></code> contains a hook to participate in
1011       a <a href="http://www.boost.org/doc/libs/release/doc/html/intrusive/list.html" target="_top"><code class="computeroutput"><span class="identifier">boost</span><span class="special">::</span><span class="identifier">intrusive</span><span class="special">::</span><span class="identifier">list</span></code></a>
1012       <code class="literal">typedef</code>&#8217;ed as <code class="computeroutput"><span class="identifier">boost</span><span class="special">::</span><span class="identifier">fibers</span><span class="special">::</span><span class="identifier">scheduler</span><span class="special">::</span><span class="identifier">ready_queue_t</span></code>.
1013       This hook is reserved for use by <a class="link" href="scheduling.html#class_algorithm"><code class="computeroutput">algorithm</code></a> implementations. (For
1014       instance, <a class="link" href="scheduling.html#class_round_robin"><code class="computeroutput">round_robin</code></a> contains a <code class="computeroutput"><span class="identifier">ready_queue_t</span></code>
1015       instance to manage its ready fibers.) See <a class="link" href="scheduling.html#context_ready_is_linked"><code class="computeroutput">context::ready_is_linked()</code></a>,
1016       <a class="link" href="scheduling.html#context_ready_link"><code class="computeroutput">context::ready_link()</code></a>, <a class="link" href="scheduling.html#context_ready_unlink"><code class="computeroutput">context::ready_unlink()</code></a>.
1017     </p>
1018 <p>
1019       Your <code class="computeroutput"><span class="identifier">algorithm</span></code> implementation
1020       may use any container you desire to manage passed <code class="computeroutput"><span class="identifier">context</span></code>
1021       instances. <code class="computeroutput"><span class="identifier">ready_queue_t</span></code> avoids
1022       some of the overhead of typical STL containers.
1023     </p>
1024 <pre class="programlisting"><span class="preprocessor">#include</span> <span class="special">&lt;</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">fiber</span><span class="special">/</span><span class="identifier">context</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">&gt;</span>
1025
1026 <span class="keyword">namespace</span> <span class="identifier">boost</span> <span class="special">{</span>
1027 <span class="keyword">namespace</span> <span class="identifier">fibers</span> <span class="special">{</span>
1028
1029 <span class="keyword">enum</span> <span class="keyword">class</span> <span class="identifier">type</span> <span class="special">{</span>
1030   <span class="identifier">none</span>               <span class="special">=</span> <span class="emphasis"><em>unspecified</em></span><span class="special">,</span>
1031   <span class="identifier">main_context</span>       <span class="special">=</span> <span class="emphasis"><em>unspecified</em></span><span class="special">,</span> <span class="comment">// fiber associated with thread's stack</span>
1032   <span class="identifier">dispatcher_context</span> <span class="special">=</span> <span class="emphasis"><em>unspecified</em></span><span class="special">,</span> <span class="comment">// special fiber for maintenance operations</span>
1033   <span class="identifier">worker_context</span>     <span class="special">=</span> <span class="emphasis"><em>unspecified</em></span><span class="special">,</span> <span class="comment">// fiber not special to the library</span>
1034   <span class="identifier">pinned_context</span>     <span class="special">=</span> <span class="emphasis"><em>unspecified</em></span>  <span class="comment">// fiber must not be migrated to another thread</span>
1035 <span class="special">};</span>
1036
1037 <span class="keyword">class</span> <span class="identifier">context</span> <span class="special">{</span>
1038 <span class="keyword">public</span><span class="special">:</span>
1039     <span class="keyword">class</span> <span class="identifier">id</span><span class="special">;</span>
1040
1041     <span class="keyword">static</span> <span class="identifier">context</span> <span class="special">*</span> <span class="identifier">active</span><span class="special">()</span> <span class="keyword">noexcept</span><span class="special">;</span>
1042
1043     <span class="identifier">context</span><span class="special">(</span> <span class="identifier">context</span> <span class="keyword">const</span><span class="special">&amp;)</span> <span class="special">=</span> <span class="keyword">delete</span><span class="special">;</span>
1044     <span class="identifier">context</span> <span class="special">&amp;</span> <span class="keyword">operator</span><span class="special">=(</span> <span class="identifier">context</span> <span class="keyword">const</span><span class="special">&amp;)</span> <span class="special">=</span> <span class="keyword">delete</span><span class="special">;</span>
1045
1046     <span class="identifier">id</span> <span class="identifier">get_id</span><span class="special">()</span> <span class="keyword">const</span> <span class="keyword">noexcept</span><span class="special">;</span>
1047
1048     <span class="keyword">void</span> <span class="identifier">detach</span><span class="special">()</span> <span class="keyword">noexcept</span><span class="special">;</span>
1049     <span class="keyword">void</span> <span class="identifier">attach</span><span class="special">(</span> <span class="identifier">context</span> <span class="special">*)</span> <span class="keyword">noexcept</span><span class="special">;</span>
1050
1051     <span class="keyword">bool</span> <span class="identifier">is_context</span><span class="special">(</span> <span class="identifier">type</span><span class="special">)</span> <span class="keyword">const</span> <span class="keyword">noexcept</span><span class="special">;</span>
1052
1053     <span class="keyword">bool</span> <span class="identifier">is_terminated</span><span class="special">()</span> <span class="keyword">const</span> <span class="keyword">noexcept</span><span class="special">;</span>
1054
1055     <span class="keyword">bool</span> <span class="identifier">ready_is_linked</span><span class="special">()</span> <span class="keyword">const</span> <span class="keyword">noexcept</span><span class="special">;</span>
1056     <span class="keyword">bool</span> <span class="identifier">remote_ready_is_linked</span><span class="special">()</span> <span class="keyword">const</span> <span class="keyword">noexcept</span><span class="special">;</span>
1057     <span class="keyword">bool</span> <span class="identifier">wait_is_linked</span><span class="special">()</span> <span class="keyword">const</span> <span class="keyword">noexcept</span><span class="special">;</span>
1058
1059     <span class="keyword">template</span><span class="special">&lt;</span> <span class="keyword">typename</span> <span class="identifier">List</span> <span class="special">&gt;</span>
1060     <span class="keyword">void</span> <span class="identifier">ready_link</span><span class="special">(</span> <span class="identifier">List</span> <span class="special">&amp;)</span> <span class="keyword">noexcept</span><span class="special">;</span>
1061     <span class="keyword">template</span><span class="special">&lt;</span> <span class="keyword">typename</span> <span class="identifier">List</span> <span class="special">&gt;</span>
1062     <span class="keyword">void</span> <span class="identifier">remote_ready_link</span><span class="special">(</span> <span class="identifier">List</span> <span class="special">&amp;)</span> <span class="keyword">noexcept</span><span class="special">;</span>
1063     <span class="keyword">template</span><span class="special">&lt;</span> <span class="keyword">typename</span> <span class="identifier">List</span> <span class="special">&gt;</span>
1064     <span class="keyword">void</span> <span class="identifier">wait_link</span><span class="special">(</span> <span class="identifier">List</span> <span class="special">&amp;)</span> <span class="keyword">noexcept</span><span class="special">;</span>
1065
1066     <span class="keyword">void</span> <span class="identifier">ready_unlink</span><span class="special">()</span> <span class="keyword">noexcept</span><span class="special">;</span>
1067     <span class="keyword">void</span> <span class="identifier">remote_ready_unlink</span><span class="special">()</span> <span class="keyword">noexcept</span><span class="special">;</span>
1068     <span class="keyword">void</span> <span class="identifier">wait_unlink</span><span class="special">()</span> <span class="keyword">noexcept</span><span class="special">;</span>
1069
1070     <span class="keyword">void</span> <span class="identifier">suspend</span><span class="special">()</span> <span class="keyword">noexcept</span><span class="special">;</span>
1071     <span class="keyword">void</span> <span class="identifier">set_ready</span><span class="special">(</span> <span class="identifier">context</span> <span class="special">*)</span> <span class="keyword">noexcept</span><span class="special">;</span>
1072 <span class="special">};</span>
1073
1074 <span class="keyword">bool</span> <span class="keyword">operator</span><span class="special">&lt;(</span> <span class="identifier">context</span> <span class="keyword">const</span><span class="special">&amp;</span> <span class="identifier">l</span><span class="special">,</span> <span class="identifier">context</span> <span class="keyword">const</span><span class="special">&amp;</span> <span class="identifier">r</span><span class="special">)</span> <span class="keyword">noexcept</span><span class="special">;</span>
1075
1076 <span class="special">}}</span>
1077 </pre>
1078 <p>
1079       </p>
1080 <h5>
1081 <a name="context_active_bridgehead"></a>
1082   <span><a name="context_active"></a></span>
1083   <a class="link" href="scheduling.html#context_active">Static member function
1084       <code class="computeroutput">active</code>()</a>
1085 </h5>
1086 <p>
1087     </p>
1088 <pre class="programlisting"><span class="keyword">static</span> <span class="identifier">context</span> <span class="special">*</span> <span class="identifier">active</span><span class="special">()</span> <span class="keyword">noexcept</span><span class="special">;</span>
1089 </pre>
1090 <div class="variablelist">
1091 <p class="title"><b></b></p>
1092 <dl>
1093 <dt><span class="term">Returns:</span></dt>
1094 <dd><p>
1095             Pointer to instance of current fiber.
1096           </p></dd>
1097 <dt><span class="term">Throws:</span></dt>
1098 <dd><p>
1099             Nothing
1100           </p></dd>
1101 </dl>
1102 </div>
1103 <p>
1104       </p>
1105 <h5>
1106 <a name="context_get_id_bridgehead"></a>
1107   <span><a name="context_get_id"></a></span>
1108   <a class="link" href="scheduling.html#context_get_id">Member function <code class="computeroutput">get_id</code>()</a>
1109 </h5>
1110 <p>
1111     </p>
1112 <pre class="programlisting"><span class="identifier">context</span><span class="special">::</span><span class="identifier">id</span> <span class="identifier">get_id</span><span class="special">()</span> <span class="keyword">const</span> <span class="keyword">noexcept</span><span class="special">;</span>
1113 </pre>
1114 <div class="variablelist">
1115 <p class="title"><b></b></p>
1116 <dl>
1117 <dt><span class="term">Returns:</span></dt>
1118 <dd><p>
1119             If <code class="computeroutput"><span class="special">*</span><span class="keyword">this</span></code>
1120             refers to a fiber of execution, an instance of <a class="link" href="fiber_mgmt.html#class_fiber_id"><code class="computeroutput"><span class="identifier">fiber</span><span class="special">::</span><span class="identifier">id</span></code></a> that represents that fiber. Otherwise
1121             returns a default-constructed <a class="link" href="fiber_mgmt.html#class_fiber_id"><code class="computeroutput"><span class="identifier">fiber</span><span class="special">::</span><span class="identifier">id</span></code></a>.
1122           </p></dd>
1123 <dt><span class="term">Throws:</span></dt>
1124 <dd><p>
1125             Nothing
1126           </p></dd>
1127 <dt><span class="term">See also:</span></dt>
1128 <dd><p>
1129             <a class="link" href="fiber_mgmt/fiber.html#fiber_get_id"><code class="computeroutput">fiber::get_id()</code></a>
1130           </p></dd>
1131 </dl>
1132 </div>
1133 <p>
1134       </p>
1135 <h5>
1136 <a name="context_attach_bridgehead"></a>
1137   <span><a name="context_attach"></a></span>
1138   <a class="link" href="scheduling.html#context_attach">Member function <code class="computeroutput">attach</code>()</a>
1139 </h5>
1140 <p>
1141     </p>
1142 <pre class="programlisting"><span class="keyword">void</span> <span class="identifier">attach</span><span class="special">(</span> <span class="identifier">context</span> <span class="special">*</span> <span class="identifier">f</span><span class="special">)</span> <span class="keyword">noexcept</span><span class="special">;</span>
1143 </pre>
1144 <div class="variablelist">
1145 <p class="title"><b></b></p>
1146 <dl>
1147 <dt><span class="term">Precondition:</span></dt>
1148 <dd><p>
1149             <code class="computeroutput"><span class="keyword">this</span><span class="special">-&gt;</span><span class="identifier">get_scheduler</span><span class="special">()</span>
1150             <span class="special">==</span> <span class="keyword">nullptr</span></code>
1151           </p></dd>
1152 <dt><span class="term">Effects:</span></dt>
1153 <dd><p>
1154             Attach fiber <code class="computeroutput"><span class="identifier">f</span></code> to scheduler
1155             running <code class="computeroutput"><span class="special">*</span><span class="keyword">this</span></code>.
1156           </p></dd>
1157 <dt><span class="term">Postcondition:</span></dt>
1158 <dd><p>
1159             <code class="computeroutput"><span class="keyword">this</span><span class="special">-&gt;</span><span class="identifier">get_scheduler</span><span class="special">()</span>
1160             <span class="special">!=</span> <span class="keyword">nullptr</span></code>
1161           </p></dd>
1162 <dt><span class="term">Throws:</span></dt>
1163 <dd><p>
1164             Nothing
1165           </p></dd>
1166 <dt><span class="term">Note:</span></dt>
1167 <dd><p>
1168             A typical call: <code class="computeroutput"><span class="identifier">boost</span><span class="special">::</span><span class="identifier">fibers</span><span class="special">::</span><span class="identifier">context</span><span class="special">::</span><span class="identifier">active</span><span class="special">()-&gt;</span><span class="identifier">attach</span><span class="special">(</span><span class="identifier">f</span><span class="special">);</span></code>
1169           </p></dd>
1170 <dt><span class="term">Note:</span></dt>
1171 <dd><p>
1172             <code class="computeroutput"><span class="identifier">f</span></code> must not be the running
1173             fiber&#8217;s context. It must not be <a class="link" href="overview.html#blocking"><span class="emphasis"><em>blocked</em></span></a>
1174             or terminated. It must not be a <code class="computeroutput"><span class="identifier">pinned_context</span></code>.
1175             It must be currently detached. It must not currently be linked into an
1176             <a class="link" href="scheduling.html#class_algorithm"><code class="computeroutput">algorithm</code></a> implementation&#8217;s ready queue. Most of these conditions
1177             are implied by <code class="computeroutput"><span class="identifier">f</span></code> being
1178             owned by an <code class="computeroutput"><span class="identifier">algorithm</span></code>
1179             implementation: that is, it has been passed to <a class="link" href="scheduling.html#algorithm_awakened"><code class="computeroutput">algorithm::awakened()</code></a> but
1180             has not yet been returned by <a class="link" href="scheduling.html#algorithm_pick_next"><code class="computeroutput">algorithm::pick_next()</code></a>.
1181             Typically a <code class="computeroutput"><span class="identifier">pick_next</span><span class="special">()</span></code> implementation would call <code class="computeroutput"><span class="identifier">attach</span><span class="special">()</span></code>
1182             with the <code class="computeroutput"><span class="identifier">context</span><span class="special">*</span></code>
1183             it is about to return. It must first remove <code class="computeroutput"><span class="identifier">f</span></code>
1184             from its ready queue. You should never pass a <code class="computeroutput"><span class="identifier">pinned_context</span></code>
1185             to <code class="computeroutput"><span class="identifier">attach</span><span class="special">()</span></code>
1186             because you should never have called its <code class="computeroutput"><span class="identifier">detach</span><span class="special">()</span></code> method in the first place.
1187           </p></dd>
1188 </dl>
1189 </div>
1190 <p>
1191       </p>
1192 <h5>
1193 <a name="context_detach_bridgehead"></a>
1194   <span><a name="context_detach"></a></span>
1195   <a class="link" href="scheduling.html#context_detach">Member function <code class="computeroutput">detach</code>()</a>
1196 </h5>
1197 <p>
1198     </p>
1199 <pre class="programlisting"><span class="keyword">void</span> <span class="identifier">detach</span><span class="special">()</span> <span class="keyword">noexcept</span><span class="special">;</span>
1200 </pre>
1201 <div class="variablelist">
1202 <p class="title"><b></b></p>
1203 <dl>
1204 <dt><span class="term">Precondition:</span></dt>
1205 <dd><p>
1206             <code class="computeroutput"><span class="special">(</span><span class="keyword">this</span><span class="special">-&gt;</span><span class="identifier">get_scheduler</span><span class="special">()</span> <span class="special">!=</span> <span class="keyword">nullptr</span><span class="special">)</span> <span class="special">&amp;&amp;</span> <span class="special">!</span>
1207             <span class="keyword">this</span><span class="special">-&gt;</span><span class="identifier">is_context</span><span class="special">(</span><span class="identifier">pinned_context</span><span class="special">)</span></code>
1208           </p></dd>
1209 <dt><span class="term">Effects:</span></dt>
1210 <dd><p>
1211             Detach fiber <code class="computeroutput"><span class="special">*</span><span class="keyword">this</span></code>
1212             from its scheduler running <code class="computeroutput"><span class="special">*</span><span class="keyword">this</span></code>.
1213           </p></dd>
1214 <dt><span class="term">Throws:</span></dt>
1215 <dd><p>
1216             Nothing
1217           </p></dd>
1218 <dt><span class="term">Postcondition:</span></dt>
1219 <dd><p>
1220             <code class="computeroutput"><span class="keyword">this</span><span class="special">-&gt;</span><span class="identifier">get_scheduler</span><span class="special">()</span>
1221             <span class="special">==</span> <span class="keyword">nullptr</span></code>
1222           </p></dd>
1223 <dt><span class="term">Note:</span></dt>
1224 <dd><p>
1225             This method must be called on the thread with which the fiber is currently
1226             associated. <code class="computeroutput"><span class="special">*</span><span class="keyword">this</span></code>
1227             must not be the running fiber&#8217;s context. It must not be <a class="link" href="overview.html#blocking"><span class="emphasis"><em>blocked</em></span></a>
1228             or terminated. It must not be a <code class="computeroutput"><span class="identifier">pinned_context</span></code>.
1229             It must not be detached already. It must not already be linked into an
1230             <a class="link" href="scheduling.html#class_algorithm"><code class="computeroutput">algorithm</code></a> implementation&#8217;s ready queue. Most of these conditions
1231             are implied by <code class="computeroutput"><span class="special">*</span><span class="keyword">this</span></code>
1232             being passed to <a class="link" href="scheduling.html#algorithm_awakened"><code class="computeroutput">algorithm::awakened()</code></a>; an <code class="computeroutput"><span class="identifier">awakened</span><span class="special">()</span></code>
1233             implementation must, however, test for <code class="computeroutput"><span class="identifier">pinned_context</span></code>.
1234             It must call <code class="computeroutput"><span class="identifier">detach</span><span class="special">()</span></code>
1235             <span class="emphasis"><em>before</em></span> linking <code class="computeroutput"><span class="special">*</span><span class="keyword">this</span></code> into its ready queue.
1236           </p></dd>
1237 <dt><span class="term">Note:</span></dt>
1238 <dd><p>
1239             In particular, it is erroneous to attempt to migrate a fiber from one
1240             thread to another by calling both <code class="computeroutput"><span class="identifier">detach</span><span class="special">()</span></code> and <code class="computeroutput"><span class="identifier">attach</span><span class="special">()</span></code> in the <a class="link" href="scheduling.html#algorithm_pick_next"><code class="computeroutput">algorithm::pick_next()</code></a> method.
1241             <code class="computeroutput"><span class="identifier">pick_next</span><span class="special">()</span></code>
1242             is called on the intended destination thread. <code class="computeroutput"><span class="identifier">detach</span><span class="special">()</span></code> must be called on the fiber&#8217;s original
1243             thread. You must call <code class="computeroutput"><span class="identifier">detach</span><span class="special">()</span></code> in the corresponding <code class="computeroutput"><span class="identifier">awakened</span><span class="special">()</span></code>
1244             method.
1245           </p></dd>
1246 <dt><span class="term">Note:</span></dt>
1247 <dd><p>
1248             Unless you intend make a fiber available for potential migration to a
1249             different thread, you should call neither <code class="computeroutput"><span class="identifier">detach</span><span class="special">()</span></code> nor <code class="computeroutput"><span class="identifier">attach</span><span class="special">()</span></code> with its <code class="computeroutput"><span class="identifier">context</span></code>.
1250           </p></dd>
1251 </dl>
1252 </div>
1253 <p>
1254       </p>
1255 <h5>
1256 <a name="context_is_context_bridgehead"></a>
1257   <span><a name="context_is_context"></a></span>
1258   <a class="link" href="scheduling.html#context_is_context">Member function
1259       <code class="computeroutput">is_context</code>()</a>
1260 </h5>
1261 <p>
1262     </p>
1263 <pre class="programlisting"><span class="keyword">bool</span> <span class="identifier">is_context</span><span class="special">(</span> <span class="identifier">type</span> <span class="identifier">t</span><span class="special">)</span> <span class="keyword">const</span> <span class="keyword">noexcept</span><span class="special">;</span>
1264 </pre>
1265 <div class="variablelist">
1266 <p class="title"><b></b></p>
1267 <dl>
1268 <dt><span class="term">Returns:</span></dt>
1269 <dd><p>
1270             <code class="computeroutput"><span class="keyword">true</span></code> if <code class="computeroutput"><span class="special">*</span><span class="keyword">this</span></code> is of the specified type.
1271           </p></dd>
1272 <dt><span class="term">Throws:</span></dt>
1273 <dd><p>
1274             Nothing
1275           </p></dd>
1276 <dt><span class="term">Note:</span></dt>
1277 <dd><p>
1278             <code class="computeroutput"><span class="identifier">type</span><span class="special">::</span><span class="identifier">worker_context</span></code> here means any fiber
1279             not special to the library. For <code class="computeroutput"><span class="identifier">type</span><span class="special">::</span><span class="identifier">main_context</span></code>
1280             the <code class="computeroutput"><span class="identifier">context</span></code> is associated
1281             with the <span class="quote">&#8220;<span class="quote">main</span>&#8221;</span> fiber of the thread: the one implicitly
1282             created by the thread itself, rather than one explicitly created by
1283             <span class="bold"><strong>Boost.Fiber</strong></span>. For <code class="computeroutput"><span class="identifier">type</span><span class="special">::</span><span class="identifier">dispatcher_context</span></code>
1284             the <code class="computeroutput"><span class="identifier">context</span></code> is associated
1285             with a <span class="quote">&#8220;<span class="quote">dispatching</span>&#8221;</span> fiber, responsible for dispatching
1286             awakened fibers to a scheduler&#8217;s ready-queue. The <span class="quote">&#8220;<span class="quote">dispatching</span>&#8221;</span>
1287             fiber is an implementation detail of the fiber manager. The context of
1288             the <span class="quote">&#8220;<span class="quote">main</span>&#8221;</span> or <span class="quote">&#8220;<span class="quote">dispatching</span>&#8221;</span> fiber &#8212; any fiber
1289             for which <code class="computeroutput"><span class="identifier">is_context</span><span class="special">(</span><span class="identifier">pinned_context</span><span class="special">)</span></code> is <code class="computeroutput"><span class="keyword">true</span></code>
1290             &#8212; must never be passed to <a class="link" href="scheduling.html#context_detach"><code class="computeroutput">context::detach()</code></a>.
1291           </p></dd>
1292 </dl>
1293 </div>
1294 <p>
1295       </p>
1296 <h5>
1297 <a name="context_is_terminated_bridgehead"></a>
1298   <span><a name="context_is_terminated"></a></span>
1299   <a class="link" href="scheduling.html#context_is_terminated">Member
1300       function <code class="computeroutput">is_terminated</code>()</a>
1301 </h5>
1302 <p>
1303     </p>
1304 <pre class="programlisting"><span class="keyword">bool</span> <span class="identifier">is_terminated</span><span class="special">()</span> <span class="keyword">const</span> <span class="keyword">noexcept</span><span class="special">;</span>
1305 </pre>
1306 <div class="variablelist">
1307 <p class="title"><b></b></p>
1308 <dl>
1309 <dt><span class="term">Returns:</span></dt>
1310 <dd><p>
1311             <code class="computeroutput"><span class="keyword">true</span></code> if <code class="computeroutput"><span class="special">*</span><span class="keyword">this</span></code> is no longer a valid context.
1312           </p></dd>
1313 <dt><span class="term">Throws:</span></dt>
1314 <dd><p>
1315             Nothing
1316           </p></dd>
1317 <dt><span class="term">Note:</span></dt>
1318 <dd><p>
1319             The <code class="computeroutput"><span class="identifier">context</span></code> has returned
1320             from its fiber-function and is no longer considered a valid context.
1321           </p></dd>
1322 </dl>
1323 </div>
1324 <p>
1325       </p>
1326 <h5>
1327 <a name="context_ready_is_linked_bridgehead"></a>
1328   <span><a name="context_ready_is_linked"></a></span>
1329   <a class="link" href="scheduling.html#context_ready_is_linked">Member
1330       function <code class="computeroutput">ready_is_linked</code>()</a>
1331 </h5>
1332 <p>
1333     </p>
1334 <pre class="programlisting"><span class="keyword">bool</span> <span class="identifier">ready_is_linked</span><span class="special">()</span> <span class="keyword">const</span> <span class="keyword">noexcept</span><span class="special">;</span>
1335 </pre>
1336 <div class="variablelist">
1337 <p class="title"><b></b></p>
1338 <dl>
1339 <dt><span class="term">Returns:</span></dt>
1340 <dd><p>
1341             <code class="computeroutput"><span class="keyword">true</span></code> if <code class="computeroutput"><span class="special">*</span><span class="keyword">this</span></code> is stored in an <a class="link" href="scheduling.html#class_algorithm"><code class="computeroutput">algorithm</code></a>
1342 implementation&#8217;s
1343             ready-queue.
1344           </p></dd>
1345 <dt><span class="term">Throws:</span></dt>
1346 <dd><p>
1347             Nothing
1348           </p></dd>
1349 <dt><span class="term">Note:</span></dt>
1350 <dd><p>
1351             Specifically, this method indicates whether <a class="link" href="scheduling.html#context_ready_link"><code class="computeroutput">context::ready_link()</code></a> has
1352             been called on <code class="computeroutput"><span class="special">*</span><span class="keyword">this</span></code>.
1353             <code class="computeroutput"><span class="identifier">ready_is_linked</span><span class="special">()</span></code>
1354             has no information about participation in any other containers.
1355           </p></dd>
1356 </dl>
1357 </div>
1358 <p>
1359       </p>
1360 <h5>
1361 <a name="context_remote_ready_is_linked_bridgehead"></a>
1362   <span><a name="context_remote_ready_is_linked"></a></span>
1363   <a class="link" href="scheduling.html#context_remote_ready_is_linked">Member
1364       function <code class="computeroutput">remote_ready_is_linked</code>()</a>
1365 </h5>
1366 <p>
1367     </p>
1368 <pre class="programlisting"><span class="keyword">bool</span> <span class="identifier">remote_ready_is_linked</span><span class="special">()</span> <span class="keyword">const</span> <span class="keyword">noexcept</span><span class="special">;</span>
1369 </pre>
1370 <div class="variablelist">
1371 <p class="title"><b></b></p>
1372 <dl>
1373 <dt><span class="term">Returns:</span></dt>
1374 <dd><p>
1375             <code class="computeroutput"><span class="keyword">true</span></code> if <code class="computeroutput"><span class="special">*</span><span class="keyword">this</span></code> is stored in the fiber manager&#8217;s remote-ready-queue.
1376           </p></dd>
1377 <dt><span class="term">Throws:</span></dt>
1378 <dd><p>
1379             Nothing
1380           </p></dd>
1381 <dt><span class="term">Note:</span></dt>
1382 <dd><p>
1383             A <code class="computeroutput"><span class="identifier">context</span></code> signaled as
1384             ready by another thread is first stored in the fiber manager&#8217;s remote-ready-queue.
1385             This is the mechanism by which the fiber manager protects an <a class="link" href="scheduling.html#class_algorithm"><code class="computeroutput">algorithm</code></a> implementation
1386             from cross-thread <a class="link" href="scheduling.html#algorithm_awakened"><code class="computeroutput">algorithm::awakened()</code></a> calls.
1387           </p></dd>
1388 </dl>
1389 </div>
1390 <p>
1391       </p>
1392 <h5>
1393 <a name="context_wait_is_linked_bridgehead"></a>
1394   <span><a name="context_wait_is_linked"></a></span>
1395   <a class="link" href="scheduling.html#context_wait_is_linked">Member
1396       function <code class="computeroutput">wait_is_linked</code>()</a>
1397 </h5>
1398 <p>
1399     </p>
1400 <pre class="programlisting"><span class="keyword">bool</span> <span class="identifier">wait_is_linked</span><span class="special">()</span> <span class="keyword">const</span> <span class="keyword">noexcept</span><span class="special">;</span>
1401 </pre>
1402 <div class="variablelist">
1403 <p class="title"><b></b></p>
1404 <dl>
1405 <dt><span class="term">Returns:</span></dt>
1406 <dd><p>
1407             <code class="computeroutput"><span class="keyword">true</span></code> if <code class="computeroutput"><span class="special">*</span><span class="keyword">this</span></code> is stored in the wait-queue of some
1408             synchronization object.
1409           </p></dd>
1410 <dt><span class="term">Throws:</span></dt>
1411 <dd><p>
1412             Nothing
1413           </p></dd>
1414 <dt><span class="term">Note:</span></dt>
1415 <dd><p>
1416             The <code class="computeroutput"><span class="identifier">context</span></code> of a fiber
1417             waiting on a synchronization object (e.g. <code class="computeroutput"><span class="identifier">mutex</span></code>,
1418             <code class="computeroutput"><span class="identifier">condition_variable</span></code> etc.)
1419             is stored in the wait-queue of that synchronization object.
1420           </p></dd>
1421 </dl>
1422 </div>
1423 <p>
1424       </p>
1425 <h5>
1426 <a name="context_ready_link_bridgehead"></a>
1427   <span><a name="context_ready_link"></a></span>
1428   <a class="link" href="scheduling.html#context_ready_link">Member function
1429       <code class="computeroutput">ready_link</code>()</a>
1430 </h5>
1431 <p>
1432     </p>
1433 <pre class="programlisting"><span class="keyword">template</span><span class="special">&lt;</span> <span class="keyword">typename</span> <span class="identifier">List</span> <span class="special">&gt;</span>
1434 <span class="keyword">void</span> <span class="identifier">ready_link</span><span class="special">(</span> <span class="identifier">List</span> <span class="special">&amp;</span> <span class="identifier">lst</span><span class="special">)</span> <span class="keyword">noexcept</span><span class="special">;</span>
1435 </pre>
1436 <div class="variablelist">
1437 <p class="title"><b></b></p>
1438 <dl>
1439 <dt><span class="term">Effects:</span></dt>
1440 <dd><p>
1441             Stores <code class="computeroutput"><span class="special">*</span><span class="keyword">this</span></code>
1442             in ready-queue <code class="computeroutput"><span class="identifier">lst</span></code>.
1443           </p></dd>
1444 <dt><span class="term">Throws:</span></dt>
1445 <dd><p>
1446             Nothing
1447           </p></dd>
1448 <dt><span class="term">Note:</span></dt>
1449 <dd><p>
1450             Argument <code class="computeroutput"><span class="identifier">lst</span></code> must be
1451             a doubly-linked list from <a href="http://www.boost.org/doc/libs/release/libs/intrusive/index.html" target="_top">Boost.Intrusive</a>,
1452             e.g. an instance of <code class="computeroutput"><span class="identifier">boost</span><span class="special">::</span><span class="identifier">fibers</span><span class="special">::</span><span class="identifier">scheduler</span><span class="special">::</span><span class="identifier">ready_queue_t</span></code>.
1453             Specifically, it must be a <a href="http://www.boost.org/doc/libs/release/doc/html/intrusive/list.html" target="_top"><code class="computeroutput"><span class="identifier">boost</span><span class="special">::</span><span class="identifier">intrusive</span><span class="special">::</span><span class="identifier">list</span></code></a> compatible with the <code class="computeroutput"><span class="identifier">list_member_hook</span></code> stored in the <code class="computeroutput"><span class="identifier">context</span></code> object.
1454           </p></dd>
1455 </dl>
1456 </div>
1457 <p>
1458       </p>
1459 <h5>
1460 <a name="context_remote_ready_link_bridgehead"></a>
1461   <span><a name="context_remote_ready_link"></a></span>
1462   <a class="link" href="scheduling.html#context_remote_ready_link">Member
1463       function <code class="computeroutput">remote_ready_link</code>()</a>
1464 </h5>
1465 <p>
1466     </p>
1467 <pre class="programlisting"><span class="keyword">template</span><span class="special">&lt;</span> <span class="keyword">typename</span> <span class="identifier">List</span> <span class="special">&gt;</span>
1468 <span class="keyword">void</span> <span class="identifier">remote_ready_link</span><span class="special">(</span> <span class="identifier">List</span> <span class="special">&amp;</span> <span class="identifier">lst</span><span class="special">)</span> <span class="keyword">noexcept</span><span class="special">;</span>
1469 </pre>
1470 <div class="variablelist">
1471 <p class="title"><b></b></p>
1472 <dl>
1473 <dt><span class="term">Effects:</span></dt>
1474 <dd><p>
1475             Stores <code class="computeroutput"><span class="special">*</span><span class="keyword">this</span></code>
1476             in remote-ready-queue <code class="computeroutput"><span class="identifier">lst</span></code>.
1477           </p></dd>
1478 <dt><span class="term">Throws:</span></dt>
1479 <dd><p>
1480             Nothing
1481           </p></dd>
1482 <dt><span class="term">Note:</span></dt>
1483 <dd><p>
1484             Argument <code class="computeroutput"><span class="identifier">lst</span></code> must be
1485             a doubly-linked list from <a href="http://www.boost.org/doc/libs/release/libs/intrusive/index.html" target="_top">Boost.Intrusive</a>.
1486           </p></dd>
1487 </dl>
1488 </div>
1489 <p>
1490       </p>
1491 <h5>
1492 <a name="context_wait_link_bridgehead"></a>
1493   <span><a name="context_wait_link"></a></span>
1494   <a class="link" href="scheduling.html#context_wait_link">Member function
1495       <code class="computeroutput">wait_link</code>()</a>
1496 </h5>
1497 <p>
1498     </p>
1499 <pre class="programlisting"><span class="keyword">template</span><span class="special">&lt;</span> <span class="keyword">typename</span> <span class="identifier">List</span> <span class="special">&gt;</span>
1500 <span class="keyword">void</span> <span class="identifier">wait_link</span><span class="special">(</span> <span class="identifier">List</span> <span class="special">&amp;</span> <span class="identifier">lst</span><span class="special">)</span> <span class="keyword">noexcept</span><span class="special">;</span>
1501 </pre>
1502 <div class="variablelist">
1503 <p class="title"><b></b></p>
1504 <dl>
1505 <dt><span class="term">Effects:</span></dt>
1506 <dd><p>
1507             Stores <code class="computeroutput"><span class="special">*</span><span class="keyword">this</span></code>
1508             in wait-queue <code class="computeroutput"><span class="identifier">lst</span></code>.
1509           </p></dd>
1510 <dt><span class="term">Throws:</span></dt>
1511 <dd><p>
1512             Nothing
1513           </p></dd>
1514 <dt><span class="term">Note:</span></dt>
1515 <dd><p>
1516             Argument <code class="computeroutput"><span class="identifier">lst</span></code> must be
1517             a doubly-linked list from <a href="http://www.boost.org/doc/libs/release/libs/intrusive/index.html" target="_top">Boost.Intrusive</a>.
1518           </p></dd>
1519 </dl>
1520 </div>
1521 <p>
1522       </p>
1523 <h5>
1524 <a name="context_ready_unlink_bridgehead"></a>
1525   <span><a name="context_ready_unlink"></a></span>
1526   <a class="link" href="scheduling.html#context_ready_unlink">Member
1527       function <code class="computeroutput">ready_unlink</code>()</a>
1528 </h5>
1529 <p>
1530     </p>
1531 <pre class="programlisting"><span class="keyword">void</span> <span class="identifier">ready_unlink</span><span class="special">()</span> <span class="keyword">noexcept</span><span class="special">;</span>
1532 </pre>
1533 <div class="variablelist">
1534 <p class="title"><b></b></p>
1535 <dl>
1536 <dt><span class="term">Effects:</span></dt>
1537 <dd><p>
1538             Removes <code class="computeroutput"><span class="special">*</span><span class="keyword">this</span></code>
1539             from ready-queue: undoes the effect of <a class="link" href="scheduling.html#context_ready_link"><code class="computeroutput">context::ready_link()</code></a>.
1540           </p></dd>
1541 <dt><span class="term">Throws:</span></dt>
1542 <dd><p>
1543             Nothing
1544           </p></dd>
1545 </dl>
1546 </div>
1547 <p>
1548       </p>
1549 <h5>
1550 <a name="context_remote_ready_unlink_bridgehead"></a>
1551   <span><a name="context_remote_ready_unlink"></a></span>
1552   <a class="link" href="scheduling.html#context_remote_ready_unlink">Member
1553       function <code class="computeroutput">remote_ready_unlink</code>()</a>
1554 </h5>
1555 <p>
1556     </p>
1557 <pre class="programlisting"><span class="keyword">void</span> <span class="identifier">remote_ready_unlink</span><span class="special">()</span> <span class="keyword">noexcept</span><span class="special">;</span>
1558 </pre>
1559 <div class="variablelist">
1560 <p class="title"><b></b></p>
1561 <dl>
1562 <dt><span class="term">Effects:</span></dt>
1563 <dd><p>
1564             Removes <code class="computeroutput"><span class="special">*</span><span class="keyword">this</span></code>
1565             from remote-ready-queue.
1566           </p></dd>
1567 <dt><span class="term">Throws:</span></dt>
1568 <dd><p>
1569             Nothing
1570           </p></dd>
1571 </dl>
1572 </div>
1573 <p>
1574       </p>
1575 <h5>
1576 <a name="context_wait_unlink_bridgehead"></a>
1577   <span><a name="context_wait_unlink"></a></span>
1578   <a class="link" href="scheduling.html#context_wait_unlink">Member
1579       function <code class="computeroutput">wait_unlink</code>()</a>
1580 </h5>
1581 <p>
1582     </p>
1583 <pre class="programlisting"><span class="keyword">void</span> <span class="identifier">wait_unlink</span><span class="special">()</span> <span class="keyword">noexcept</span><span class="special">;</span>
1584 </pre>
1585 <div class="variablelist">
1586 <p class="title"><b></b></p>
1587 <dl>
1588 <dt><span class="term">Effects:</span></dt>
1589 <dd><p>
1590             Removes <code class="computeroutput"><span class="special">*</span><span class="keyword">this</span></code>
1591             from wait-queue.
1592           </p></dd>
1593 <dt><span class="term">Throws:</span></dt>
1594 <dd><p>
1595             Nothing
1596           </p></dd>
1597 </dl>
1598 </div>
1599 <p>
1600       </p>
1601 <h5>
1602 <a name="context_suspend_bridgehead"></a>
1603   <span><a name="context_suspend"></a></span>
1604   <a class="link" href="scheduling.html#context_suspend">Member function <code class="computeroutput">suspend</code>()</a>
1605 </h5>
1606 <p>
1607     </p>
1608 <pre class="programlisting"><span class="keyword">void</span> <span class="identifier">suspend</span><span class="special">()</span> <span class="keyword">noexcept</span><span class="special">;</span>
1609 </pre>
1610 <div class="variablelist">
1611 <p class="title"><b></b></p>
1612 <dl>
1613 <dt><span class="term">Effects:</span></dt>
1614 <dd><p>
1615             Suspends the running fiber (the fiber associated with <code class="computeroutput"><span class="special">*</span><span class="keyword">this</span></code>) until some other fiber passes <code class="computeroutput"><span class="keyword">this</span></code> to <a class="link" href="scheduling.html#context_set_ready"><code class="computeroutput">context::set_ready()</code></a>.
1616             <code class="computeroutput"><span class="special">*</span><span class="keyword">this</span></code>
1617             is marked as not-ready, and control passes to the scheduler to select
1618             another fiber to run.
1619           </p></dd>
1620 <dt><span class="term">Throws:</span></dt>
1621 <dd><p>
1622             Nothing
1623           </p></dd>
1624 <dt><span class="term">Note:</span></dt>
1625 <dd><p>
1626             This is a low-level API potentially useful for integration with other
1627             frameworks. It is not intended to be directly invoked by a typical application
1628             program.
1629           </p></dd>
1630 <dt><span class="term">Note:</span></dt>
1631 <dd><p>
1632             The burden is on the caller to arrange for a call to <code class="computeroutput"><span class="identifier">set_ready</span><span class="special">()</span></code> with a pointer to <code class="computeroutput"><span class="keyword">this</span></code>
1633             at some future time.
1634           </p></dd>
1635 </dl>
1636 </div>
1637 <p>
1638       </p>
1639 <h5>
1640 <a name="context_set_ready_bridgehead"></a>
1641   <span><a name="context_set_ready"></a></span>
1642   <a class="link" href="scheduling.html#context_set_ready">Member function
1643       <code class="computeroutput">set_ready</code>()</a>
1644 </h5>
1645 <p>
1646     </p>
1647 <pre class="programlisting"><span class="keyword">void</span> <span class="identifier">set_ready</span><span class="special">(</span> <span class="identifier">context</span> <span class="special">*</span> <span class="identifier">ctx</span> <span class="special">)</span> <span class="keyword">noexcept</span><span class="special">;</span>
1648 </pre>
1649 <div class="variablelist">
1650 <p class="title"><b></b></p>
1651 <dl>
1652 <dt><span class="term">Effects:</span></dt>
1653 <dd><p>
1654             Mark the fiber associated with context <code class="computeroutput"><span class="special">*</span><span class="identifier">ctx</span></code> as being ready to run. This does
1655             not immediately resume that fiber; rather it passes the fiber to the
1656             scheduler for subsequent resumption. If the scheduler is idle (has not
1657             returned from a call to <a class="link" href="scheduling.html#algorithm_suspend_until"><code class="computeroutput">algorithm::suspend_until()</code></a>),
1658             <a class="link" href="scheduling.html#algorithm_notify"><code class="computeroutput">algorithm::notify()</code></a> is called to wake it up.
1659           </p></dd>
1660 <dt><span class="term">Throws:</span></dt>
1661 <dd><p>
1662             Nothing
1663           </p></dd>
1664 <dt><span class="term">Note:</span></dt>
1665 <dd><p>
1666             This is a low-level API potentially useful for integration with other
1667             frameworks. It is not intended to be directly invoked by a typical application
1668             program.
1669           </p></dd>
1670 <dt><span class="term">Note:</span></dt>
1671 <dd><p>
1672             It is explicitly supported to call <code class="computeroutput"><span class="identifier">set_ready</span><span class="special">(</span><span class="identifier">ctx</span><span class="special">)</span></code> from a thread other than the one on
1673             which <code class="computeroutput"><span class="special">*</span><span class="identifier">ctx</span></code>
1674             is currently suspended. The corresponding fiber will be resumed on its
1675             original thread in due course.
1676           </p></dd>
1677 </dl>
1678 </div>
1679 <p>
1680       </p>
1681 <h5>
1682 <a name="context_less_bridgehead"></a>
1683   <span><a name="context_less"></a></span>
1684   <a class="link" href="scheduling.html#context_less">Non-member function <code class="computeroutput">operator&lt;()</code></a>
1685 </h5>
1686 <p>
1687     </p>
1688 <pre class="programlisting"><span class="keyword">bool</span> <span class="keyword">operator</span><span class="special">&lt;(</span> <span class="identifier">context</span> <span class="keyword">const</span><span class="special">&amp;</span> <span class="identifier">l</span><span class="special">,</span> <span class="identifier">context</span> <span class="keyword">const</span><span class="special">&amp;</span> <span class="identifier">r</span><span class="special">)</span> <span class="keyword">noexcept</span><span class="special">;</span>
1689 </pre>
1690 <div class="variablelist">
1691 <p class="title"><b></b></p>
1692 <dl>
1693 <dt><span class="term">Returns:</span></dt>
1694 <dd><p>
1695             <code class="computeroutput"><span class="keyword">true</span></code> if <code class="computeroutput"><span class="identifier">l</span><span class="special">.</span><span class="identifier">get_id</span><span class="special">()</span> <span class="special">&lt;</span> <span class="identifier">r</span><span class="special">.</span><span class="identifier">get_id</span><span class="special">()</span></code>
1696             is <code class="computeroutput"><span class="keyword">true</span></code>, <code class="computeroutput"><span class="keyword">false</span></code>
1697             otherwise.
1698           </p></dd>
1699 <dt><span class="term">Throws:</span></dt>
1700 <dd><p>
1701             Nothing.
1702           </p></dd>
1703 </dl>
1704 </div>
1705 </div>
1706 <table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr>
1707 <td align="left"></td>
1708 <td align="right"><div class="copyright-footer">Copyright &#169; 2013 Oliver Kowalke<p>
1709         Distributed under the Boost Software License, Version 1.0. (See accompanying
1710         file LICENSE_1_0.txt or copy at <a href="http://www.boost.org/LICENSE_1_0.txt" target="_top">http://www.boost.org/LICENSE_1_0.txt</a>)
1711       </p>
1712 </div></td>
1713 </tr></table>
1714 <hr>
1715 <div class="spirit-nav">
1716 <a accesskey="p" href="fiber_mgmt/this_fiber.html"><img src="../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../index.html"><img src="../../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../index.html"><img src="../../../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="stack.html"><img src="../../../../../doc/src/images/next.png" alt="Next"></a>
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