2 * Copyright (c) 2013, 2014, 2015, 2016 Nicira, Inc.
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at:
8 * http://www.apache.org/licenses/LICENSE-2.0
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
18 #include "ovs-thread.h"
27 #include "fatal-signal.h"
29 #include "openvswitch/list.h"
31 #include "openvswitch/poll-loop.h"
33 #include "socket-util.h"
37 /* Omit the definitions in this file because they are somewhat difficult to
38 * write without prompting "sparse" complaints, without ugliness or
39 * cut-and-paste. Since "sparse" is just a checker, not a compiler, it
40 * doesn't matter that we don't define them. */
42 #include "openvswitch/vlog.h"
44 VLOG_DEFINE_THIS_MODULE(ovs_thread
);
46 /* If there is a reason that we cannot fork anymore (unless the fork will be
47 * immediately followed by an exec), then this points to a string that
49 static const char *must_not_fork
;
51 /* True if we created any threads beyond the main initial thread. */
52 static bool multithreaded
;
54 #define LOCK_FUNCTION(TYPE, FUN) \
56 ovs_##TYPE##_##FUN##_at(const struct ovs_##TYPE *l_, \
58 OVS_NO_THREAD_SAFETY_ANALYSIS \
60 struct ovs_##TYPE *l = CONST_CAST(struct ovs_##TYPE *, l_); \
63 /* Verify that 'l' was initialized. */ \
64 if (OVS_UNLIKELY(!l->where)) { \
65 ovs_abort(0, "%s: %s() passed uninitialized ovs_"#TYPE, \
69 error = pthread_##TYPE##_##FUN(&l->lock); \
70 if (OVS_UNLIKELY(error)) { \
71 ovs_abort(error, "%s: pthread_%s_%s failed", where, #TYPE, #FUN); \
75 LOCK_FUNCTION(mutex
, lock
);
76 LOCK_FUNCTION(rwlock
, rdlock
);
77 LOCK_FUNCTION(rwlock
, wrlock
);
78 #ifdef HAVE_PTHREAD_SPIN_LOCK
79 LOCK_FUNCTION(spin
, lock
);
82 #define TRY_LOCK_FUNCTION(TYPE, FUN) \
84 ovs_##TYPE##_##FUN##_at(const struct ovs_##TYPE *l_, \
86 OVS_NO_THREAD_SAFETY_ANALYSIS \
88 struct ovs_##TYPE *l = CONST_CAST(struct ovs_##TYPE *, l_); \
91 /* Verify that 'l' was initialized. */ \
92 if (OVS_UNLIKELY(!l->where)) { \
93 ovs_abort(0, "%s: %s() passed uninitialized ovs_"#TYPE, \
97 error = pthread_##TYPE##_##FUN(&l->lock); \
98 if (OVS_UNLIKELY(error) && error != EBUSY) { \
99 ovs_abort(error, "%s: pthread_%s_%s failed", where, #TYPE, #FUN); \
106 TRY_LOCK_FUNCTION(mutex
, trylock
);
107 TRY_LOCK_FUNCTION(rwlock
, tryrdlock
);
108 TRY_LOCK_FUNCTION(rwlock
, trywrlock
);
109 #ifdef HAVE_PTHREAD_SPIN_LOCK
110 TRY_LOCK_FUNCTION(spin
, trylock
);
113 #define UNLOCK_FUNCTION(TYPE, FUN, WHERE) \
115 ovs_##TYPE##_##FUN(const struct ovs_##TYPE *l_) \
116 OVS_NO_THREAD_SAFETY_ANALYSIS \
118 struct ovs_##TYPE *l = CONST_CAST(struct ovs_##TYPE *, l_); \
121 /* Verify that 'l' was initialized. */ \
122 ovs_assert(l->where); \
125 error = pthread_##TYPE##_##FUN(&l->lock); \
126 if (OVS_UNLIKELY(error)) { \
127 ovs_abort(error, "pthread_%s_%s failed", #TYPE, #FUN); \
130 UNLOCK_FUNCTION(mutex
, unlock
, "<unlocked>");
131 UNLOCK_FUNCTION(mutex
, destroy
, NULL
);
132 UNLOCK_FUNCTION(rwlock
, unlock
, "<unlocked>");
133 UNLOCK_FUNCTION(rwlock
, destroy
, NULL
);
134 #ifdef HAVE_PTHREAD_SPIN_LOCK
135 UNLOCK_FUNCTION(spin
, unlock
, "<unlocked>");
136 UNLOCK_FUNCTION(spin
, destroy
, NULL
);
139 #define XPTHREAD_FUNC1(FUNCTION, PARAM1) \
141 x##FUNCTION(PARAM1 arg1) \
143 int error = FUNCTION(arg1); \
144 if (OVS_UNLIKELY(error)) { \
145 ovs_abort(error, "%s failed", #FUNCTION); \
148 #define XPTHREAD_FUNC2(FUNCTION, PARAM1, PARAM2) \
150 x##FUNCTION(PARAM1 arg1, PARAM2 arg2) \
152 int error = FUNCTION(arg1, arg2); \
153 if (OVS_UNLIKELY(error)) { \
154 ovs_abort(error, "%s failed", #FUNCTION); \
157 #define XPTHREAD_FUNC3(FUNCTION, PARAM1, PARAM2, PARAM3)\
159 x##FUNCTION(PARAM1 arg1, PARAM2 arg2, PARAM3 arg3) \
161 int error = FUNCTION(arg1, arg2, arg3); \
162 if (OVS_UNLIKELY(error)) { \
163 ovs_abort(error, "%s failed", #FUNCTION); \
167 XPTHREAD_FUNC1(pthread_mutexattr_init
, pthread_mutexattr_t
*);
168 XPTHREAD_FUNC1(pthread_mutexattr_destroy
, pthread_mutexattr_t
*);
169 XPTHREAD_FUNC2(pthread_mutexattr_settype
, pthread_mutexattr_t
*, int);
170 XPTHREAD_FUNC2(pthread_mutexattr_gettype
, pthread_mutexattr_t
*, int *);
172 XPTHREAD_FUNC1(pthread_rwlockattr_init
, pthread_rwlockattr_t
*);
173 XPTHREAD_FUNC1(pthread_rwlockattr_destroy
, pthread_rwlockattr_t
*);
174 #ifdef PTHREAD_RWLOCK_WRITER_NONRECURSIVE_INITIALIZER_NP
175 XPTHREAD_FUNC2(pthread_rwlockattr_setkind_np
, pthread_rwlockattr_t
*, int);
178 XPTHREAD_FUNC2(pthread_cond_init
, pthread_cond_t
*, pthread_condattr_t
*);
179 XPTHREAD_FUNC1(pthread_cond_destroy
, pthread_cond_t
*);
180 XPTHREAD_FUNC1(pthread_cond_signal
, pthread_cond_t
*);
181 XPTHREAD_FUNC1(pthread_cond_broadcast
, pthread_cond_t
*);
183 XPTHREAD_FUNC2(pthread_join
, pthread_t
, void **);
185 typedef void destructor_func(void *);
186 XPTHREAD_FUNC2(pthread_key_create
, pthread_key_t
*, destructor_func
*);
187 XPTHREAD_FUNC1(pthread_key_delete
, pthread_key_t
);
188 XPTHREAD_FUNC2(pthread_setspecific
, pthread_key_t
, const void *);
191 XPTHREAD_FUNC3(pthread_sigmask
, int, const sigset_t
*, sigset_t
*);
195 ovs_mutex_init__(const struct ovs_mutex
*l_
, int type
)
197 struct ovs_mutex
*l
= CONST_CAST(struct ovs_mutex
*, l_
);
198 pthread_mutexattr_t attr
;
201 l
->where
= "<unlocked>";
202 xpthread_mutexattr_init(&attr
);
203 xpthread_mutexattr_settype(&attr
, type
);
204 error
= pthread_mutex_init(&l
->lock
, &attr
);
205 if (OVS_UNLIKELY(error
)) {
206 ovs_abort(error
, "pthread_mutex_init failed");
208 xpthread_mutexattr_destroy(&attr
);
211 /* Initializes 'mutex' as a normal (non-recursive) mutex. */
213 ovs_mutex_init(const struct ovs_mutex
*mutex
)
215 ovs_mutex_init__(mutex
, PTHREAD_MUTEX_ERRORCHECK
);
218 /* Initializes 'mutex' as a recursive mutex. */
220 ovs_mutex_init_recursive(const struct ovs_mutex
*mutex
)
222 ovs_mutex_init__(mutex
, PTHREAD_MUTEX_RECURSIVE
);
225 /* Initializes 'mutex' as a recursive mutex. */
227 ovs_mutex_init_adaptive(const struct ovs_mutex
*mutex
)
229 #ifdef PTHREAD_ADAPTIVE_MUTEX_INITIALIZER_NP
230 ovs_mutex_init__(mutex
, PTHREAD_MUTEX_ADAPTIVE_NP
);
232 ovs_mutex_init(mutex
);
237 ovs_rwlock_init(const struct ovs_rwlock
*l_
)
239 struct ovs_rwlock
*l
= CONST_CAST(struct ovs_rwlock
*, l_
);
242 l
->where
= "<unlocked>";
244 #ifdef PTHREAD_RWLOCK_WRITER_NONRECURSIVE_INITIALIZER_NP
245 pthread_rwlockattr_t attr
;
246 xpthread_rwlockattr_init(&attr
);
247 xpthread_rwlockattr_setkind_np(
248 &attr
, PTHREAD_RWLOCK_PREFER_WRITER_NONRECURSIVE_NP
);
249 error
= pthread_rwlock_init(&l
->lock
, &attr
);
250 xpthread_rwlockattr_destroy(&attr
);
252 /* It is important to avoid passing a rwlockattr in this case because
253 * Windows pthreads 2.9.1 (and earlier) fail and abort if passed one, even
254 * one without any special attributes. */
255 error
= pthread_rwlock_init(&l
->lock
, NULL
);
258 if (OVS_UNLIKELY(error
)) {
259 ovs_abort(error
, "pthread_rwlock_init failed");
263 /* Provides an error-checking wrapper around pthread_cond_wait().
265 * If the wait can take a significant amount of time, consider bracketing this
266 * call with calls to ovsrcu_quiesce_start() and ovsrcu_quiesce_end(). */
268 ovs_mutex_cond_wait(pthread_cond_t
*cond
, const struct ovs_mutex
*mutex_
)
269 OVS_NO_THREAD_SAFETY_ANALYSIS
271 struct ovs_mutex
*mutex
= CONST_CAST(struct ovs_mutex
*, mutex_
);
274 error
= pthread_cond_wait(cond
, &mutex
->lock
);
276 if (OVS_UNLIKELY(error
)) {
277 ovs_abort(error
, "pthread_cond_wait failed");
281 #ifdef HAVE_PTHREAD_SPIN_LOCK
283 ovs_spin_init__(const struct ovs_spin
*l_
, int pshared
)
285 struct ovs_spin
*l
= CONST_CAST(struct ovs_spin
*, l_
);
288 l
->where
= "<unlocked>";
289 error
= pthread_spin_init(&l
->lock
, pshared
);
290 if (OVS_UNLIKELY(error
)) {
291 ovs_abort(error
, "pthread_spin_init failed");
296 ovs_spin_init(const struct ovs_spin
*spin
)
298 ovs_spin_init__(spin
, PTHREAD_PROCESS_PRIVATE
);
302 /* Initializes the 'barrier'. 'size' is the number of threads
303 * expected to hit the barrier. */
305 ovs_barrier_init(struct ovs_barrier
*barrier
, uint32_t size
)
307 barrier
->size
= size
;
308 atomic_count_init(&barrier
->count
, 0);
309 barrier
->seq
= seq_create();
312 /* Destroys the 'barrier'. */
314 ovs_barrier_destroy(struct ovs_barrier
*barrier
)
316 seq_destroy(barrier
->seq
);
319 /* Makes the calling thread block on the 'barrier' until all
320 * 'barrier->size' threads hit the barrier.
321 * ovs_barrier provides the necessary acquire-release semantics to make
322 * the effects of prior memory accesses of all the participating threads
323 * visible on return and to prevent the following memory accesses to be
324 * reordered before the ovs_barrier_block(). */
326 ovs_barrier_block(struct ovs_barrier
*barrier
)
328 uint64_t seq
= seq_read(barrier
->seq
);
331 orig
= atomic_count_inc(&barrier
->count
);
332 if (orig
+ 1 == barrier
->size
) {
333 atomic_count_set(&barrier
->count
, 0);
334 /* seq_change() serves as a release barrier against the other threads,
335 * so the zeroed count is visible to them as they continue. */
336 seq_change(barrier
->seq
);
338 /* To prevent thread from waking up by other event,
339 * keeps waiting for the change of 'barrier->seq'. */
340 while (seq
== seq_read(barrier
->seq
)) {
341 seq_wait(barrier
->seq
, seq
);
347 DEFINE_EXTERN_PER_THREAD_DATA(ovsthread_id
, OVSTHREAD_ID_UNSET
);
349 struct ovsthread_aux
{
350 void *(*start
)(void *);
356 ovsthread_id_init(void)
358 static atomic_count next_id
= ATOMIC_COUNT_INIT(0);
360 ovs_assert(*ovsthread_id_get() == OVSTHREAD_ID_UNSET
);
361 return *ovsthread_id_get() = atomic_count_inc(&next_id
);
365 ovsthread_wrapper(void *aux_
)
367 struct ovsthread_aux
*auxp
= aux_
;
368 struct ovsthread_aux aux
;
371 id
= ovsthread_id_init();
376 /* The order of the following calls is important, because
377 * ovsrcu_quiesce_end() saves a copy of the thread name. */
378 char *subprogram_name
= xasprintf("%s%u", aux
.name
, id
);
379 set_subprogram_name(subprogram_name
);
380 free(subprogram_name
);
381 ovsrcu_quiesce_end();
383 return aux
.start(aux
.arg
);
387 set_min_stack_size(pthread_attr_t
*attr
, size_t min_stacksize
)
392 error
= pthread_attr_getstacksize(attr
, &stacksize
);
394 ovs_abort(error
, "pthread_attr_getstacksize failed");
397 if (stacksize
< min_stacksize
) {
398 error
= pthread_attr_setstacksize(attr
, min_stacksize
);
400 ovs_abort(error
, "pthread_attr_setstacksize failed");
405 /* Starts a thread that calls 'start(arg)'. Sets the thread's name to 'name'
406 * (suffixed by its ovsthread_id()). Returns the new thread's pthread_t. */
408 ovs_thread_create(const char *name
, void *(*start
)(void *), void *arg
)
410 static struct ovsthread_once once
= OVSTHREAD_ONCE_INITIALIZER
;
411 struct ovsthread_aux
*aux
;
415 forbid_forking("multiple threads exist");
417 if (ovsthread_once_start(&once
)) {
418 /* The first call to this function has to happen in the main thread.
419 * Before the process becomes multithreaded we make sure that the
420 * main thread is considered non quiescent.
422 * For other threads this is done in ovs_thread_wrapper(), but the
423 * main thread has no such wrapper.
425 * There's no reason to call ovsrcu_quiesce_end() in subsequent
426 * invocations of this function and it might introduce problems
427 * for other threads. */
428 ovsrcu_quiesce_end();
429 ovsthread_once_done(&once
);
432 multithreaded
= true;
433 aux
= xmalloc(sizeof *aux
);
436 ovs_strlcpy(aux
->name
, name
, sizeof aux
->name
);
438 /* Some small systems use a default stack size as small as 80 kB, but OVS
439 * requires approximately 384 kB according to the following analysis:
440 * https://mail.openvswitch.org/pipermail/ovs-dev/2016-January/308592.html
442 * We use 512 kB to give us some margin of error. */
444 pthread_attr_init(&attr
);
445 set_min_stack_size(&attr
, 512 * 1024);
447 error
= pthread_create(&thread
, &attr
, ovsthread_wrapper
, aux
);
449 ovs_abort(error
, "pthread_create failed");
451 pthread_attr_destroy(&attr
);
456 ovsthread_once_start__(struct ovsthread_once
*once
)
458 ovs_mutex_lock(&once
->mutex
);
459 /* Mutex synchronizes memory, so we get the current value of 'done'. */
463 ovs_mutex_unlock(&once
->mutex
);
468 ovsthread_once_done(struct ovsthread_once
*once
)
470 /* We need release semantics here, so that the following store may not
471 * be moved ahead of any of the preceding initialization operations.
472 * A release atomic_thread_fence provides that prior memory accesses
473 * will not be reordered to take place after the following store. */
474 atomic_thread_fence(memory_order_release
);
476 ovs_mutex_unlock(&once
->mutex
);
480 single_threaded(void)
482 return !multithreaded
;
485 /* Asserts that the process has not yet created any threads (beyond the initial
488 * ('where' is used in logging. Commonly one would use
489 * assert_single_threaded() to automatically provide the caller's source file
490 * and line number for 'where'.) */
492 assert_single_threaded_at(const char *where
)
495 VLOG_FATAL("%s: attempted operation not allowed when multithreaded",
501 /* Forks the current process (checking that this is allowed). Aborts with
502 * VLOG_FATAL if fork() returns an error, and otherwise returns the value
503 * returned by fork().
505 * ('where' is used in logging. Commonly one would use xfork() to
506 * automatically provide the caller's source file and line number for
509 xfork_at(const char *where
)
514 VLOG_FATAL("%s: attempted to fork but forking not allowed (%s)",
515 where
, must_not_fork
);
520 VLOG_FATAL("%s: fork failed (%s)", where
, ovs_strerror(errno
));
526 /* Notes that the process must not call fork() from now on, for the specified
527 * 'reason'. (The process may still fork() if it execs itself immediately
530 forbid_forking(const char *reason
)
532 ovs_assert(reason
!= NULL
);
533 must_not_fork
= reason
;
536 /* Returns true if the process is allowed to fork, false otherwise. */
540 return !must_not_fork
;
543 /* ovsthread_stats. */
546 ovsthread_stats_init(struct ovsthread_stats
*stats
)
550 ovs_mutex_init(&stats
->mutex
);
551 for (i
= 0; i
< ARRAY_SIZE(stats
->buckets
); i
++) {
552 stats
->buckets
[i
] = NULL
;
557 ovsthread_stats_destroy(struct ovsthread_stats
*stats
)
559 ovs_mutex_destroy(&stats
->mutex
);
563 ovsthread_stats_bucket_get(struct ovsthread_stats
*stats
,
564 void *(*new_bucket
)(void))
566 unsigned int idx
= ovsthread_id_self() & (ARRAY_SIZE(stats
->buckets
) - 1);
567 void *bucket
= stats
->buckets
[idx
];
569 ovs_mutex_lock(&stats
->mutex
);
570 bucket
= stats
->buckets
[idx
];
572 bucket
= stats
->buckets
[idx
] = new_bucket();
574 ovs_mutex_unlock(&stats
->mutex
);
580 ovs_thread_stats_next_bucket(const struct ovsthread_stats
*stats
, size_t i
)
582 for (; i
< ARRAY_SIZE(stats
->buckets
); i
++) {
583 if (stats
->buckets
[i
]) {
591 /* Returns the total number of cores available to this process, or 0 if the
592 * number cannot be determined. */
594 count_cpu_cores(void)
596 static struct ovsthread_once once
= OVSTHREAD_ONCE_INITIALIZER
;
597 static long int n_cores
;
599 if (ovsthread_once_start(&once
)) {
601 n_cores
= sysconf(_SC_NPROCESSORS_ONLN
);
604 cpu_set_t
*set
= CPU_ALLOC(n_cores
);
607 size_t size
= CPU_ALLOC_SIZE(n_cores
);
609 if (!sched_getaffinity(0, size
, set
)) {
610 n_cores
= CPU_COUNT_S(size
, set
);
618 GetSystemInfo(&sysinfo
);
619 n_cores
= sysinfo
.dwNumberOfProcessors
;
621 ovsthread_once_done(&once
);
624 return n_cores
> 0 ? n_cores
: 0;
627 /* Returns 'true' if current thread is PMD thread. */
631 const char *name
= get_subprogram_name();
632 return !strncmp(name
, "pmd", 3);
640 #define MAX_KEYS (L1_SIZE * L2_SIZE)
642 /* A piece of thread-specific data. */
643 struct ovsthread_key
{
644 struct ovs_list list_node
; /* In 'inuse_keys' or 'free_keys'. */
645 void (*destructor
)(void *); /* Called at thread exit. */
647 /* Indexes into the per-thread array in struct ovsthread_key_slots.
648 * This key's data is stored in p1[index / L2_SIZE][index % L2_SIZE]. */
652 /* Per-thread data structure. */
653 struct ovsthread_key_slots
{
654 struct ovs_list list_node
; /* In 'slots_list'. */
658 /* Contains "struct ovsthread_key_slots *". */
659 static pthread_key_t tsd_key
;
661 /* Guards data structures below. */
662 static struct ovs_mutex key_mutex
= OVS_MUTEX_INITIALIZER
;
664 /* 'inuse_keys' holds "struct ovsthread_key"s that have been created and not
667 * 'free_keys' holds "struct ovsthread_key"s that have been deleted and are
668 * ready for reuse. (We keep them around only to be able to easily locate
671 * Together, 'inuse_keys' and 'free_keys' hold an ovsthread_key for every index
672 * from 0 to n_keys - 1, inclusive. */
673 static struct ovs_list inuse_keys
OVS_GUARDED_BY(key_mutex
)
674 = OVS_LIST_INITIALIZER(&inuse_keys
);
675 static struct ovs_list free_keys
OVS_GUARDED_BY(key_mutex
)
676 = OVS_LIST_INITIALIZER(&free_keys
);
677 static unsigned int n_keys
OVS_GUARDED_BY(key_mutex
);
679 /* All existing struct ovsthread_key_slots. */
680 static struct ovs_list slots_list
OVS_GUARDED_BY(key_mutex
)
681 = OVS_LIST_INITIALIZER(&slots_list
);
684 clear_slot(struct ovsthread_key_slots
*slots
, unsigned int index
)
686 void **p2
= slots
->p1
[index
/ L2_SIZE
];
688 void **valuep
= &p2
[index
% L2_SIZE
];
689 void *value
= *valuep
;
698 ovsthread_key_destruct__(void *slots_
)
700 struct ovsthread_key_slots
*slots
= slots_
;
701 struct ovsthread_key
*key
;
705 ovs_mutex_lock(&key_mutex
);
706 ovs_list_remove(&slots
->list_node
);
707 LIST_FOR_EACH (key
, list_node
, &inuse_keys
) {
708 void *value
= clear_slot(slots
, key
->index
);
709 if (value
&& key
->destructor
) {
710 key
->destructor(value
);
714 ovs_mutex_unlock(&key_mutex
);
716 for (i
= 0; i
< DIV_ROUND_UP(n
, L2_SIZE
); i
++) {
722 /* Cancels the callback to ovsthread_key_destruct__().
724 * Cancelling the call to the destructor during the main thread exit
725 * is needed while using pthreads-win32 library in Windows. It has been
726 * observed that in pthreads-win32, a call to the destructor during
727 * main thread exit causes undefined behavior. */
729 ovsthread_cancel_ovsthread_key_destruct__(void *aux OVS_UNUSED
)
731 pthread_setspecific(tsd_key
, NULL
);
734 /* Initializes '*keyp' as a thread-specific data key. The data items are
735 * initially null in all threads.
737 * If a thread exits with non-null data, then 'destructor', if nonnull, will be
738 * called passing the final data value as its argument. 'destructor' must not
739 * call any thread-specific data functions in this API.
741 * This function is similar to xpthread_key_create(). */
743 ovsthread_key_create(ovsthread_key_t
*keyp
, void (*destructor
)(void *))
745 static struct ovsthread_once once
= OVSTHREAD_ONCE_INITIALIZER
;
746 struct ovsthread_key
*key
;
748 if (ovsthread_once_start(&once
)) {
749 xpthread_key_create(&tsd_key
, ovsthread_key_destruct__
);
750 fatal_signal_add_hook(ovsthread_cancel_ovsthread_key_destruct__
,
752 ovsthread_once_done(&once
);
755 ovs_mutex_lock(&key_mutex
);
756 if (ovs_list_is_empty(&free_keys
)) {
757 key
= xmalloc(sizeof *key
);
758 key
->index
= n_keys
++;
759 if (key
->index
>= MAX_KEYS
) {
763 key
= CONTAINER_OF(ovs_list_pop_back(&free_keys
),
764 struct ovsthread_key
, list_node
);
766 ovs_list_push_back(&inuse_keys
, &key
->list_node
);
767 key
->destructor
= destructor
;
768 ovs_mutex_unlock(&key_mutex
);
773 /* Frees 'key'. The destructor supplied to ovsthread_key_create(), if any, is
776 * This function is similar to xpthread_key_delete(). */
778 ovsthread_key_delete(ovsthread_key_t key
)
780 struct ovsthread_key_slots
*slots
;
782 ovs_mutex_lock(&key_mutex
);
784 /* Move 'key' from 'inuse_keys' to 'free_keys'. */
785 ovs_list_remove(&key
->list_node
);
786 ovs_list_push_back(&free_keys
, &key
->list_node
);
788 /* Clear this slot in all threads. */
789 LIST_FOR_EACH (slots
, list_node
, &slots_list
) {
790 clear_slot(slots
, key
->index
);
793 ovs_mutex_unlock(&key_mutex
);
797 ovsthread_key_lookup__(const struct ovsthread_key
*key
)
799 struct ovsthread_key_slots
*slots
;
802 slots
= pthread_getspecific(tsd_key
);
804 slots
= xzalloc(sizeof *slots
);
806 ovs_mutex_lock(&key_mutex
);
807 pthread_setspecific(tsd_key
, slots
);
808 ovs_list_push_back(&slots_list
, &slots
->list_node
);
809 ovs_mutex_unlock(&key_mutex
);
812 p2
= slots
->p1
[key
->index
/ L2_SIZE
];
814 p2
= xzalloc(L2_SIZE
* sizeof *p2
);
815 slots
->p1
[key
->index
/ L2_SIZE
] = p2
;
818 return &p2
[key
->index
% L2_SIZE
];
821 /* Sets the value of thread-specific data item 'key', in the current thread, to
824 * This function is similar to pthread_setspecific(). */
826 ovsthread_setspecific(ovsthread_key_t key
, const void *value
)
828 *ovsthread_key_lookup__(key
) = CONST_CAST(void *, value
);
831 /* Returns the value of thread-specific data item 'key' in the current thread.
833 * This function is similar to pthread_getspecific(). */
835 ovsthread_getspecific(ovsthread_key_t key
)
837 return *ovsthread_key_lookup__(key
);