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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 | ||
4d762f26 | 50 | void frr_pthread_init(void) |
98f14af8 | 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 | ||
4d762f26 | 60 | void frr_pthread_finish(void) |
98f14af8 | 61 | { |
1ac267a2 | 62 | pthread_mutex_lock(&frr_pthread_list_mtx); |
d62a17ae | 63 | { |
6a154c88 | 64 | list_delete(&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) | |
e77cc2a9 | 86 | strlcpy(fpt->os_name, os_name, OS_THREAD_NAMELEN); |
b8dccd94 | 87 | else |
e77cc2a9 | 88 | strlcpy(fpt->os_name, name, OS_THREAD_NAMELEN); |
1ac267a2 DL |
89 | /* initialize startup synchronization primitives */ |
90 | fpt->running_cond_mtx = XCALLOC( | |
91 | MTYPE_PTHREAD_PRIM, sizeof(pthread_mutex_t)); | |
92 | fpt->running_cond = XCALLOC(MTYPE_PTHREAD_PRIM, | |
93 | sizeof(pthread_cond_t)); | |
94 | pthread_mutex_init(fpt->running_cond_mtx, NULL); | |
95 | pthread_cond_init(fpt->running_cond, NULL); | |
96 | ||
97 | pthread_mutex_lock(&frr_pthread_list_mtx); | |
d62a17ae | 98 | { |
1ac267a2 | 99 | listnode_add(frr_pthread_list, fpt); |
d62a17ae | 100 | } |
1ac267a2 | 101 | pthread_mutex_unlock(&frr_pthread_list_mtx); |
d62a17ae | 102 | |
103 | return fpt; | |
98f14af8 QY |
104 | } |
105 | ||
106 | void frr_pthread_destroy(struct frr_pthread *fpt) | |
107 | { | |
d62a17ae | 108 | thread_master_free(fpt->master); |
a45dc974 | 109 | |
d8a8a8de | 110 | pthread_mutex_destroy(&fpt->mtx); |
a45dc974 QY |
111 | pthread_mutex_destroy(fpt->running_cond_mtx); |
112 | pthread_cond_destroy(fpt->running_cond); | |
d8a8a8de QY |
113 | if (fpt->name) |
114 | XFREE(MTYPE_FRR_PTHREAD, fpt->name); | |
a45dc974 QY |
115 | XFREE(MTYPE_PTHREAD_PRIM, fpt->running_cond_mtx); |
116 | XFREE(MTYPE_PTHREAD_PRIM, fpt->running_cond); | |
d62a17ae | 117 | XFREE(MTYPE_FRR_PTHREAD, fpt); |
98f14af8 QY |
118 | } |
119 | ||
c80bedb8 | 120 | int frr_pthread_set_name(struct frr_pthread *fpt) |
d8a8a8de | 121 | { |
57019528 CS |
122 | int ret = 0; |
123 | ||
e9d938b8 DL |
124 | #ifdef HAVE_PTHREAD_SETNAME_NP |
125 | # ifdef GNU_LINUX | |
c80bedb8 | 126 | ret = pthread_setname_np(fpt->thread, fpt->os_name); |
a64c953a | 127 | # elif defined(__NetBSD__) |
c80bedb8 | 128 | ret = pthread_setname_np(fpt->thread, fpt->os_name, NULL); |
e9d938b8 DL |
129 | # endif |
130 | #elif defined(HAVE_PTHREAD_SET_NAME_NP) | |
c80bedb8 | 131 | pthread_set_name_np(fpt->thread, fpt->os_name); |
57019528 | 132 | #endif |
57019528 CS |
133 | |
134 | return ret; | |
d8a8a8de QY |
135 | } |
136 | ||
a45dc974 | 137 | int frr_pthread_run(struct frr_pthread *fpt, const pthread_attr_t *attr) |
98f14af8 | 138 | { |
d62a17ae | 139 | int ret; |
98f14af8 | 140 | |
a45dc974 | 141 | ret = pthread_create(&fpt->thread, attr, fpt->attr.start, fpt); |
98f14af8 | 142 | |
a45dc974 QY |
143 | /* |
144 | * Per pthread_create(3), the contents of fpt->thread are undefined if | |
145 | * pthread_create() did not succeed. Reset this value to zero. | |
146 | */ | |
d62a17ae | 147 | if (ret < 0) |
148 | memset(&fpt->thread, 0x00, sizeof(fpt->thread)); | |
98f14af8 | 149 | |
d62a17ae | 150 | return ret; |
98f14af8 QY |
151 | } |
152 | ||
a45dc974 | 153 | void frr_pthread_wait_running(struct frr_pthread *fpt) |
98f14af8 | 154 | { |
a45dc974 QY |
155 | pthread_mutex_lock(fpt->running_cond_mtx); |
156 | { | |
157 | while (!fpt->running) | |
158 | pthread_cond_wait(fpt->running_cond, | |
159 | fpt->running_cond_mtx); | |
160 | } | |
161 | pthread_mutex_unlock(fpt->running_cond_mtx); | |
98f14af8 QY |
162 | } |
163 | ||
a45dc974 | 164 | void frr_pthread_notify_running(struct frr_pthread *fpt) |
98f14af8 | 165 | { |
a45dc974 QY |
166 | pthread_mutex_lock(fpt->running_cond_mtx); |
167 | { | |
168 | fpt->running = true; | |
169 | pthread_cond_signal(fpt->running_cond); | |
170 | } | |
171 | pthread_mutex_unlock(fpt->running_cond_mtx); | |
98f14af8 QY |
172 | } |
173 | ||
a45dc974 QY |
174 | int frr_pthread_stop(struct frr_pthread *fpt, void **result) |
175 | { | |
176 | int ret = (*fpt->attr.stop)(fpt, result); | |
177 | memset(&fpt->thread, 0x00, sizeof(fpt->thread)); | |
178 | return ret; | |
179 | } | |
180 | ||
4d762f26 | 181 | void frr_pthread_stop_all(void) |
98f14af8 | 182 | { |
1ac267a2 | 183 | pthread_mutex_lock(&frr_pthread_list_mtx); |
d62a17ae | 184 | { |
1ac267a2 DL |
185 | struct listnode *n; |
186 | struct frr_pthread *fpt; | |
187 | for (ALL_LIST_ELEMENTS_RO(frr_pthread_list, n, fpt)) | |
188 | frr_pthread_stop(fpt, NULL); | |
d62a17ae | 189 | } |
1ac267a2 | 190 | pthread_mutex_unlock(&frr_pthread_list_mtx); |
98f14af8 | 191 | } |
b2140cb7 | 192 | |
a45dc974 QY |
193 | /* |
194 | * ---------------------------------------------------------------------------- | |
195 | * Default Event Loop | |
196 | * ---------------------------------------------------------------------------- | |
197 | */ | |
198 | ||
199 | /* dummy task for sleeper pipe */ | |
200 | static int fpt_dummy(struct thread *thread) | |
201 | { | |
202 | return 0; | |
203 | } | |
204 | ||
205 | /* poison pill task to end event loop */ | |
206 | static int fpt_finish(struct thread *thread) | |
207 | { | |
208 | struct frr_pthread *fpt = THREAD_ARG(thread); | |
985e36a6 | 209 | |
a45dc974 QY |
210 | atomic_store_explicit(&fpt->running, false, memory_order_relaxed); |
211 | return 0; | |
212 | } | |
213 | ||
214 | /* stop function, called from other threads to halt this one */ | |
215 | static int fpt_halt(struct frr_pthread *fpt, void **res) | |
216 | { | |
217 | thread_add_event(fpt->master, &fpt_finish, fpt, 0, NULL); | |
218 | pthread_join(fpt->thread, res); | |
a45dc974 QY |
219 | |
220 | return 0; | |
221 | } | |
222 | ||
a6275055 QY |
223 | /* |
224 | * Entry pthread function & main event loop. | |
225 | * | |
226 | * Upon thread start the following actions occur: | |
227 | * | |
228 | * - frr_pthread's owner field is set to pthread ID. | |
229 | * - All signals are blocked (except for unblockable signals). | |
230 | * - Pthread's threadmaster is set to never handle pending signals | |
231 | * - Poker pipe for poll() is created and queued as I/O source | |
232 | * - The frr_pthread->running_cond condition variable is signalled to indicate | |
233 | * that the previous actions have completed. It is not safe to assume any of | |
234 | * the above have occurred before receiving this signal. | |
235 | * | |
236 | * After initialization is completed, the event loop begins running. Each tick, | |
237 | * the following actions are performed before running the usual event system | |
238 | * tick function: | |
239 | * | |
240 | * - Verify that the running boolean is set | |
241 | * - Verify that there are no pending cancellation requests | |
242 | * - Verify that there are tasks scheduled | |
243 | * | |
244 | * So long as the conditions are met, the event loop tick is run and the | |
245 | * returned task is executed. | |
246 | * | |
247 | * If any of these conditions are not met, the event loop exits, closes the | |
248 | * pipes and dies without running any cleanup functions. | |
249 | */ | |
a45dc974 QY |
250 | static void *fpt_run(void *arg) |
251 | { | |
252 | struct frr_pthread *fpt = arg; | |
253 | fpt->master->owner = pthread_self(); | |
254 | ||
255 | int sleeper[2]; | |
256 | pipe(sleeper); | |
257 | thread_add_read(fpt->master, &fpt_dummy, NULL, sleeper[0], NULL); | |
258 | ||
259 | fpt->master->handle_signals = false; | |
260 | ||
c80bedb8 | 261 | frr_pthread_set_name(fpt); |
57019528 | 262 | |
a45dc974 QY |
263 | frr_pthread_notify_running(fpt); |
264 | ||
265 | struct thread task; | |
266 | while (atomic_load_explicit(&fpt->running, memory_order_relaxed)) { | |
a6275055 | 267 | pthread_testcancel(); |
a45dc974 QY |
268 | if (thread_fetch(fpt->master, &task)) { |
269 | thread_call(&task); | |
270 | } | |
271 | } | |
272 | ||
273 | close(sleeper[1]); | |
274 | close(sleeper[0]); | |
275 | ||
276 | return NULL; | |
277 | } |