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98f14af8 | 1 | /* |
a45dc974 | 2 | * Utilities and interfaces for managing POSIX threads within FRR. |
d8a8a8de | 3 | * Copyright (C) 2017 Cumulus Networks, Inc. |
896014f4 DL |
4 | * |
5 | * This program is free software; you can redistribute it and/or modify | |
6 | * it under the terms of the GNU General Public License as published by | |
7 | * the Free Software Foundation; either version 2 of the License, or | |
8 | * (at your option) any later version. | |
9 | * | |
10 | * This program is distributed in the hope that it will be useful, but | |
11 | * WITHOUT ANY WARRANTY; without even the implied warranty of | |
12 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
13 | * General Public License for more details. | |
14 | * | |
15 | * You should have received a copy of the GNU General Public License along | |
16 | * with this program; see the file COPYING; if not, write to the Free Software | |
17 | * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA | |
98f14af8 QY |
18 | */ |
19 | ||
20 | #include <zebra.h> | |
21 | #include <pthread.h> | |
324be174 DL |
22 | #ifdef HAVE_PTHREAD_NP_H |
23 | #include <pthread_np.h> | |
24 | #endif | |
b2140cb7 | 25 | #include <sched.h> |
98f14af8 QY |
26 | |
27 | #include "frr_pthread.h" | |
28 | #include "memory.h" | |
1ac267a2 | 29 | #include "linklist.h" |
98f14af8 | 30 | |
a45dc974 | 31 | DEFINE_MTYPE(LIB, FRR_PTHREAD, "FRR POSIX Thread"); |
0bbb9e72 | 32 | DEFINE_MTYPE(LIB, PTHREAD_PRIM, "POSIX synchronization primitives"); |
98f14af8 | 33 | |
a45dc974 QY |
34 | /* default frr_pthread start/stop routine prototypes */ |
35 | static void *fpt_run(void *arg); | |
36 | static int fpt_halt(struct frr_pthread *fpt, void **res); | |
98f14af8 | 37 | |
a45dc974 QY |
38 | /* default frr_pthread attributes */ |
39 | struct frr_pthread_attr frr_pthread_attr_default = { | |
a45dc974 QY |
40 | .start = fpt_run, |
41 | .stop = fpt_halt, | |
a45dc974 QY |
42 | }; |
43 | ||
1ac267a2 DL |
44 | /* list to keep track of all frr_pthreads */ |
45 | static pthread_mutex_t frr_pthread_list_mtx = PTHREAD_MUTEX_INITIALIZER; | |
46 | static struct list *frr_pthread_list; | |
a45dc974 | 47 | |
98f14af8 QY |
48 | /* ------------------------------------------------------------------------ */ |
49 | ||
50 | void frr_pthread_init() | |
51 | { | |
1ac267a2 | 52 | pthread_mutex_lock(&frr_pthread_list_mtx); |
d62a17ae | 53 | { |
1ac267a2 DL |
54 | frr_pthread_list = list_new(); |
55 | frr_pthread_list->del = (void (*)(void *))&frr_pthread_destroy; | |
d62a17ae | 56 | } |
1ac267a2 | 57 | pthread_mutex_unlock(&frr_pthread_list_mtx); |
98f14af8 QY |
58 | } |
59 | ||
60 | void frr_pthread_finish() | |
61 | { | |
1ac267a2 | 62 | pthread_mutex_lock(&frr_pthread_list_mtx); |
d62a17ae | 63 | { |
1ac267a2 | 64 | list_delete_and_null(&frr_pthread_list); |
d62a17ae | 65 | } |
1ac267a2 | 66 | pthread_mutex_unlock(&frr_pthread_list_mtx); |
98f14af8 QY |
67 | } |
68 | ||
d8a8a8de | 69 | struct frr_pthread *frr_pthread_new(struct frr_pthread_attr *attr, |
57019528 | 70 | const char *name, const char *os_name) |
98f14af8 | 71 | { |
d62a17ae | 72 | struct frr_pthread *fpt = NULL; |
73 | ||
a45dc974 QY |
74 | attr = attr ? attr : &frr_pthread_attr_default; |
75 | ||
1ac267a2 DL |
76 | fpt = XCALLOC(MTYPE_FRR_PTHREAD, sizeof(struct frr_pthread)); |
77 | /* initialize mutex */ | |
78 | pthread_mutex_init(&fpt->mtx, NULL); | |
79 | /* create new thread master */ | |
80 | fpt->master = thread_master_create(name); | |
81 | /* set attributes */ | |
82 | fpt->attr = *attr; | |
83 | name = (name ? name : "Anonymous thread"); | |
84 | fpt->name = XSTRDUP(MTYPE_FRR_PTHREAD, name); | |
85 | if (os_name) | |
86 | snprintf(fpt->os_name, OS_THREAD_NAMELEN, "%s", os_name); | |
87 | /* initialize startup synchronization primitives */ | |
88 | fpt->running_cond_mtx = XCALLOC( | |
89 | MTYPE_PTHREAD_PRIM, sizeof(pthread_mutex_t)); | |
90 | fpt->running_cond = XCALLOC(MTYPE_PTHREAD_PRIM, | |
91 | sizeof(pthread_cond_t)); | |
92 | pthread_mutex_init(fpt->running_cond_mtx, NULL); | |
93 | pthread_cond_init(fpt->running_cond, NULL); | |
94 | ||
95 | pthread_mutex_lock(&frr_pthread_list_mtx); | |
d62a17ae | 96 | { |
1ac267a2 | 97 | listnode_add(frr_pthread_list, fpt); |
d62a17ae | 98 | } |
1ac267a2 | 99 | pthread_mutex_unlock(&frr_pthread_list_mtx); |
d62a17ae | 100 | |
101 | return fpt; | |
98f14af8 QY |
102 | } |
103 | ||
104 | void frr_pthread_destroy(struct frr_pthread *fpt) | |
105 | { | |
d62a17ae | 106 | thread_master_free(fpt->master); |
a45dc974 | 107 | |
d8a8a8de | 108 | pthread_mutex_destroy(&fpt->mtx); |
a45dc974 QY |
109 | pthread_mutex_destroy(fpt->running_cond_mtx); |
110 | pthread_cond_destroy(fpt->running_cond); | |
d8a8a8de QY |
111 | if (fpt->name) |
112 | XFREE(MTYPE_FRR_PTHREAD, fpt->name); | |
a45dc974 QY |
113 | XFREE(MTYPE_PTHREAD_PRIM, fpt->running_cond_mtx); |
114 | XFREE(MTYPE_PTHREAD_PRIM, fpt->running_cond); | |
d62a17ae | 115 | XFREE(MTYPE_FRR_PTHREAD, fpt); |
98f14af8 QY |
116 | } |
117 | ||
57019528 CS |
118 | int frr_pthread_set_name(struct frr_pthread *fpt, const char *name, |
119 | const char *os_name) | |
d8a8a8de | 120 | { |
57019528 CS |
121 | int ret = 0; |
122 | ||
123 | if (name) { | |
124 | pthread_mutex_lock(&fpt->mtx); | |
125 | { | |
126 | if (fpt->name) | |
127 | XFREE(MTYPE_FRR_PTHREAD, fpt->name); | |
128 | fpt->name = XSTRDUP(MTYPE_FRR_PTHREAD, name); | |
129 | } | |
130 | pthread_mutex_unlock(&fpt->mtx); | |
131 | thread_master_set_name(fpt->master, name); | |
d8a8a8de | 132 | } |
57019528 CS |
133 | |
134 | if (os_name) { | |
135 | pthread_mutex_lock(&fpt->mtx); | |
136 | snprintf(fpt->os_name, OS_THREAD_NAMELEN, "%s", os_name); | |
137 | pthread_mutex_unlock(&fpt->mtx); | |
e9d938b8 DL |
138 | #ifdef HAVE_PTHREAD_SETNAME_NP |
139 | # ifdef GNU_LINUX | |
57019528 | 140 | ret = pthread_setname_np(fpt->thread, fpt->os_name); |
e9d938b8 DL |
141 | # else /* NetBSD */ |
142 | ret = pthread_setname_np(fpt->thread, fpt->os_name, NULL); | |
143 | # endif | |
144 | #elif defined(HAVE_PTHREAD_SET_NAME_NP) | |
145 | pthread_set_name_np(fpt->thread, fpt->os_name); | |
57019528 CS |
146 | #endif |
147 | } | |
148 | ||
149 | return ret; | |
d8a8a8de QY |
150 | } |
151 | ||
a45dc974 | 152 | int frr_pthread_run(struct frr_pthread *fpt, const pthread_attr_t *attr) |
98f14af8 | 153 | { |
d62a17ae | 154 | int ret; |
98f14af8 | 155 | |
a45dc974 | 156 | ret = pthread_create(&fpt->thread, attr, fpt->attr.start, fpt); |
98f14af8 | 157 | |
a45dc974 QY |
158 | /* |
159 | * Per pthread_create(3), the contents of fpt->thread are undefined if | |
160 | * pthread_create() did not succeed. Reset this value to zero. | |
161 | */ | |
d62a17ae | 162 | if (ret < 0) |
163 | memset(&fpt->thread, 0x00, sizeof(fpt->thread)); | |
98f14af8 | 164 | |
d62a17ae | 165 | return ret; |
98f14af8 QY |
166 | } |
167 | ||
a45dc974 | 168 | void frr_pthread_wait_running(struct frr_pthread *fpt) |
98f14af8 | 169 | { |
a45dc974 QY |
170 | pthread_mutex_lock(fpt->running_cond_mtx); |
171 | { | |
172 | while (!fpt->running) | |
173 | pthread_cond_wait(fpt->running_cond, | |
174 | fpt->running_cond_mtx); | |
175 | } | |
176 | pthread_mutex_unlock(fpt->running_cond_mtx); | |
98f14af8 QY |
177 | } |
178 | ||
a45dc974 | 179 | void frr_pthread_notify_running(struct frr_pthread *fpt) |
98f14af8 | 180 | { |
a45dc974 QY |
181 | pthread_mutex_lock(fpt->running_cond_mtx); |
182 | { | |
183 | fpt->running = true; | |
184 | pthread_cond_signal(fpt->running_cond); | |
185 | } | |
186 | pthread_mutex_unlock(fpt->running_cond_mtx); | |
98f14af8 QY |
187 | } |
188 | ||
a45dc974 QY |
189 | int frr_pthread_stop(struct frr_pthread *fpt, void **result) |
190 | { | |
191 | int ret = (*fpt->attr.stop)(fpt, result); | |
192 | memset(&fpt->thread, 0x00, sizeof(fpt->thread)); | |
193 | return ret; | |
194 | } | |
195 | ||
98f14af8 QY |
196 | void frr_pthread_stop_all() |
197 | { | |
1ac267a2 | 198 | pthread_mutex_lock(&frr_pthread_list_mtx); |
d62a17ae | 199 | { |
1ac267a2 DL |
200 | struct listnode *n; |
201 | struct frr_pthread *fpt; | |
202 | for (ALL_LIST_ELEMENTS_RO(frr_pthread_list, n, fpt)) | |
203 | frr_pthread_stop(fpt, NULL); | |
d62a17ae | 204 | } |
1ac267a2 | 205 | pthread_mutex_unlock(&frr_pthread_list_mtx); |
98f14af8 | 206 | } |
b2140cb7 DS |
207 | |
208 | void frr_pthread_yield(void) | |
209 | { | |
210 | (void)sched_yield(); | |
211 | } | |
a45dc974 QY |
212 | |
213 | /* | |
214 | * ---------------------------------------------------------------------------- | |
215 | * Default Event Loop | |
216 | * ---------------------------------------------------------------------------- | |
217 | */ | |
218 | ||
219 | /* dummy task for sleeper pipe */ | |
220 | static int fpt_dummy(struct thread *thread) | |
221 | { | |
222 | return 0; | |
223 | } | |
224 | ||
225 | /* poison pill task to end event loop */ | |
226 | static int fpt_finish(struct thread *thread) | |
227 | { | |
228 | struct frr_pthread *fpt = THREAD_ARG(thread); | |
985e36a6 | 229 | |
a45dc974 QY |
230 | atomic_store_explicit(&fpt->running, false, memory_order_relaxed); |
231 | return 0; | |
232 | } | |
233 | ||
234 | /* stop function, called from other threads to halt this one */ | |
235 | static int fpt_halt(struct frr_pthread *fpt, void **res) | |
236 | { | |
237 | thread_add_event(fpt->master, &fpt_finish, fpt, 0, NULL); | |
238 | pthread_join(fpt->thread, res); | |
a45dc974 QY |
239 | |
240 | return 0; | |
241 | } | |
242 | ||
a6275055 QY |
243 | /* |
244 | * Entry pthread function & main event loop. | |
245 | * | |
246 | * Upon thread start the following actions occur: | |
247 | * | |
248 | * - frr_pthread's owner field is set to pthread ID. | |
249 | * - All signals are blocked (except for unblockable signals). | |
250 | * - Pthread's threadmaster is set to never handle pending signals | |
251 | * - Poker pipe for poll() is created and queued as I/O source | |
252 | * - The frr_pthread->running_cond condition variable is signalled to indicate | |
253 | * that the previous actions have completed. It is not safe to assume any of | |
254 | * the above have occurred before receiving this signal. | |
255 | * | |
256 | * After initialization is completed, the event loop begins running. Each tick, | |
257 | * the following actions are performed before running the usual event system | |
258 | * tick function: | |
259 | * | |
260 | * - Verify that the running boolean is set | |
261 | * - Verify that there are no pending cancellation requests | |
262 | * - Verify that there are tasks scheduled | |
263 | * | |
264 | * So long as the conditions are met, the event loop tick is run and the | |
265 | * returned task is executed. | |
266 | * | |
267 | * If any of these conditions are not met, the event loop exits, closes the | |
268 | * pipes and dies without running any cleanup functions. | |
269 | */ | |
a45dc974 QY |
270 | static void *fpt_run(void *arg) |
271 | { | |
272 | struct frr_pthread *fpt = arg; | |
273 | fpt->master->owner = pthread_self(); | |
274 | ||
275 | int sleeper[2]; | |
276 | pipe(sleeper); | |
277 | thread_add_read(fpt->master, &fpt_dummy, NULL, sleeper[0], NULL); | |
278 | ||
279 | fpt->master->handle_signals = false; | |
280 | ||
c5e7bf3f | 281 | if (fpt->os_name[0]) |
57019528 CS |
282 | frr_pthread_set_name(fpt, NULL, fpt->os_name); |
283 | ||
a45dc974 QY |
284 | frr_pthread_notify_running(fpt); |
285 | ||
286 | struct thread task; | |
287 | while (atomic_load_explicit(&fpt->running, memory_order_relaxed)) { | |
a6275055 | 288 | pthread_testcancel(); |
a45dc974 QY |
289 | if (thread_fetch(fpt->master, &task)) { |
290 | thread_call(&task); | |
291 | } | |
292 | } | |
293 | ||
294 | close(sleeper[1]); | |
295 | close(sleeper[0]); | |
296 | ||
297 | return NULL; | |
298 | } |