D-Bus: dbus-sysdeps-pthread.c Source File

D-Bus 1.16.2

dbus-sysdeps-pthread.c
1/* -*- mode: C; c-file-style: "gnu"; indent-tabs-mode: nil; -*- */
2/* dbus-sysdeps-pthread.c Implements threads using pthreads (internal to libdbus)
3 *
4 * Copyright (C) 2002, 2003, 2006 Red Hat, Inc.
5 *
6 * SPDX-License-Identifier: AFL-2.1 OR GPL-2.0-or-later
7 *
8 * Licensed under the Academic Free License version 2.1
9 *
10 * This program is free software; you can redistribute it and/or modify
11 * it under the terms of the GNU General Public License as published by
12 * the Free Software Foundation; either version 2 of the License, or
13 * (at your option) any later version.
14 *
15 * This program is distributed in the hope that it will be useful,
16 * but WITHOUT ANY WARRANTY; without even the implied warranty of
17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
18 * GNU General Public License for more details.
19 *
20 * You should have received a copy of the GNU General Public License
21 * along with this program; if not, write to the Free Software
22 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
23 *
24 */
25
26#include <config.h>
27#include "dbus-internals.h"
28#include "dbus-sysdeps.h"
29#include "dbus-threads.h"
30
31#include <sys/time.h>
32#include <pthread.h>
33#include <stdio.h>
34#include <string.h>
35
36#ifdef HAVE_ERRNO_H
37#include <errno.h>
38#endif
39
40#include <config.h>
41
42#ifdef HAVE_MONOTONIC_CLOCK
43/* Whether we have a "monotonic" clock; i.e. a clock not affected by
44 * changes in system time.
45 * This is initialized once in check_monotonic_clock below.
46 * https://bugs.freedesktop.org/show_bug.cgi?id=18121
47 */
48static dbus_bool_t have_monotonic_clock = 0;
49#endif
50
51 struct DBusRMutex {
52 pthread_mutex_t lock;
53};
54
55 struct DBusCMutex {
56 pthread_mutex_t lock;
57};
58
59 struct DBusCondVar {
60 pthread_cond_t cond;
61};
62
63#define DBUS_MUTEX(m) ((DBusMutex*) m)
64#define DBUS_MUTEX_PTHREAD(m) ((DBusMutexPThread*) m)
65
66#define DBUS_COND_VAR(c) ((DBusCondVar*) c)
67#define DBUS_COND_VAR_PTHREAD(c) ((DBusCondVarPThread*) c)
68
69
70#ifdef DBUS_DISABLE_ASSERT
71/* (tmp != 0) is a no-op usage to silence compiler */
72#define PTHREAD_CHECK(func_name, result_or_call) \
73 do { int tmp = (result_or_call); if (tmp != 0) {;} } while (0)
74#else
75#define PTHREAD_CHECK(func_name, result_or_call) do { \
76 int tmp = (result_or_call); \
77 if (tmp != 0) { \
78 _dbus_warn_check_failed ("pthread function %s failed with %d %s in %s", \
79 func_name, tmp, strerror(tmp), _DBUS_FUNCTION_NAME); \
80 } \
81} while (0)
82#endif /* !DBUS_DISABLE_ASSERT */
83
84 DBusCMutex *
85_dbus_platform_cmutex_new (void)
86{
87 DBusCMutex *pmutex;
88 int result;
89
90 pmutex = dbus_new (DBusCMutex, 1);
91 if (pmutex == NULL)
92 return NULL;
93
94 result = pthread_mutex_init (&pmutex->lock, NULL);
95
96 if (result == ENOMEM || result == EAGAIN)
97 {
98 dbus_free (pmutex);
99 return NULL;
100 }
101 else
102 {
103 PTHREAD_CHECK ("pthread_mutex_init", result);
104 }
105
106 return pmutex;
107}
108
109 DBusRMutex *
110_dbus_platform_rmutex_new (void)
111{
112 DBusRMutex *pmutex;
113 pthread_mutexattr_t mutexattr;
114 int result;
115
116 pmutex = dbus_new (DBusRMutex, 1);
117 if (pmutex == NULL)
118 return NULL;
119
120 pthread_mutexattr_init (&mutexattr);
121 pthread_mutexattr_settype (&mutexattr, PTHREAD_MUTEX_RECURSIVE);
122 result = pthread_mutex_init (&pmutex->lock, &mutexattr);
123 pthread_mutexattr_destroy (&mutexattr);
124
125 if (result == ENOMEM || result == EAGAIN)
126 {
127 dbus_free (pmutex);
128 return NULL;
129 }
130 else
131 {
132 PTHREAD_CHECK ("pthread_mutex_init", result);
133 }
134
135 return pmutex;
136}
137
138void
139_dbus_platform_cmutex_free (DBusCMutex *mutex)
140{
141 PTHREAD_CHECK ("pthread_mutex_destroy", pthread_mutex_destroy (&mutex->lock));
142 dbus_free (mutex);
143}
144
145void
146_dbus_platform_rmutex_free (DBusRMutex *mutex)
147{
148 PTHREAD_CHECK ("pthread_mutex_destroy", pthread_mutex_destroy (&mutex->lock));
149 dbus_free (mutex);
150}
151
152void
153_dbus_platform_cmutex_lock (DBusCMutex *mutex)
154{
155 PTHREAD_CHECK ("pthread_mutex_lock", pthread_mutex_lock (&mutex->lock));
156}
157
158void
159_dbus_platform_rmutex_lock (DBusRMutex *mutex)
160{
161 PTHREAD_CHECK ("pthread_mutex_lock", pthread_mutex_lock (&mutex->lock));
162}
163
164void
165_dbus_platform_cmutex_unlock (DBusCMutex *mutex)
166{
167 PTHREAD_CHECK ("pthread_mutex_unlock", pthread_mutex_unlock (&mutex->lock));
168}
169
170void
171_dbus_platform_rmutex_unlock (DBusRMutex *mutex)
172{
173 PTHREAD_CHECK ("pthread_mutex_unlock", pthread_mutex_unlock (&mutex->lock));
174}
175
176 DBusCondVar *
177_dbus_platform_condvar_new (void)
178{
179 DBusCondVar *pcond;
180 pthread_condattr_t attr;
181 int result;
182
183 pcond = dbus_new (DBusCondVar, 1);
184 if (pcond == NULL)
185 return NULL;
186
187 pthread_condattr_init (&attr);
188#ifdef HAVE_MONOTONIC_CLOCK
189 if (have_monotonic_clock)
190 pthread_condattr_setclock (&attr, CLOCK_MONOTONIC);
191#endif
192
193 result = pthread_cond_init (&pcond->cond, &attr);
194 pthread_condattr_destroy (&attr);
195
196 if (result == EAGAIN || result == ENOMEM)
197 {
198 dbus_free (pcond);
199 return NULL;
200 }
201 else
202 {
203 PTHREAD_CHECK ("pthread_cond_init", result);
204 }
205
206 return pcond;
207}
208
209void
210_dbus_platform_condvar_free (DBusCondVar *cond)
211{
212 PTHREAD_CHECK ("pthread_cond_destroy", pthread_cond_destroy (&cond->cond));
213 dbus_free (cond);
214}
215
216void
217_dbus_platform_condvar_wait (DBusCondVar *cond,
218 DBusCMutex *mutex)
219{
220 PTHREAD_CHECK ("pthread_cond_wait", pthread_cond_wait (&cond->cond, &mutex->lock));
221}
222
223 dbus_bool_t
224_dbus_platform_condvar_wait_timeout (DBusCondVar *cond,
225 DBusCMutex *mutex,
226 int timeout_milliseconds)
227{
228 struct timeval time_now;
229 struct timespec end_time;
230 int result;
231
232#ifdef HAVE_MONOTONIC_CLOCK
233 if (have_monotonic_clock)
234 {
235 struct timespec monotonic_timer;
236 clock_gettime (CLOCK_MONOTONIC,&monotonic_timer);
237 time_now.tv_sec = monotonic_timer.tv_sec;
238 time_now.tv_usec = monotonic_timer.tv_nsec / 1000;
239 }
240 else
241 /* This else falls through to gettimeofday */
242#endif
243 gettimeofday (&time_now, NULL);
244
245 end_time.tv_sec = time_now.tv_sec + timeout_milliseconds / 1000;
246 end_time.tv_nsec = (time_now.tv_usec + (timeout_milliseconds % 1000) * 1000) * 1000;
247 if (end_time.tv_nsec > 1000*1000*1000)
248 {
249 end_time.tv_sec += 1;
250 end_time.tv_nsec -= 1000*1000*1000;
251 }
252
253 result = pthread_cond_timedwait (&cond->cond, &mutex->lock, &end_time);
254
255 if (result != ETIMEDOUT)
256 {
257 PTHREAD_CHECK ("pthread_cond_timedwait", result);
258 }
259
260 /* return true if we did not time out */
261 return result != ETIMEDOUT;
262}
263
264void
265_dbus_platform_condvar_wake_one (DBusCondVar *cond)
266{
267 PTHREAD_CHECK ("pthread_cond_signal", pthread_cond_signal (&cond->cond));
268}
269
270static void
271check_monotonic_clock (void)
272{
273#ifdef HAVE_MONOTONIC_CLOCK
274 struct timespec dummy;
275 if (clock_getres (CLOCK_MONOTONIC, &dummy) == 0)
276 have_monotonic_clock = TRUE;
277#endif
278}
279
280 dbus_bool_t
281_dbus_threads_init_platform_specific (void)
282{
283 /* These have static variables, and we need to handle both the case
284 * where dbus_threads_init() has been called and when it hasn't;
285 * so initialize them before any threads are allowed to enter.
286 */
287 check_monotonic_clock ();
288 (void) _dbus_check_setuid ();
289
290 return TRUE;
291}
292
293static pthread_mutex_t init_mutex = PTHREAD_MUTEX_INITIALIZER;
294
295void
296_dbus_threads_lock_platform_specific (void)
297{
298 pthread_mutex_lock (&init_mutex);
299}
300
301void
302_dbus_threads_unlock_platform_specific (void)
303{
304 pthread_mutex_unlock (&init_mutex);
305}
306
307#ifdef DBUS_ENABLE_VERBOSE_MODE
308/*
309 * If we can identify the current process and/or thread, print them to stderr followed by a colon.
310 */
311void
312_dbus_print_thread (void)
313{
314#ifdef __linux__
315 /* we know a pthread_t is numeric on Linux */
316 fprintf (stderr, "%lu: 0x%lx: ", _dbus_pid_for_log (), (unsigned long) pthread_self ());
317#else
318 /* in principle pthread_t isn't required to be printable */
319 fprintf (stderr, "%lu: ", _dbus_pid_for_log ());
320#endif
321}
322#endif
NULL
#define NULL
A null pointer, defined appropriately for C or C++.
Definition dbus-macros.h:51
TRUE
#define TRUE
Expands to "1".
Definition dbus-macros.h:41
dbus_free
void dbus_free(void *memory)
Frees a block of memory previously allocated by dbus_malloc() or dbus_malloc0().
Definition dbus-memory.c:710
dbus_new
#define dbus_new(type, count)
Safe macro for using dbus_malloc().
Definition dbus-memory.h:59
_dbus_pid_for_log
unsigned long _dbus_pid_for_log(void)
The only reason this is separate from _dbus_getpid() is to allow it on Windows for logging but not fo...
Definition dbus-sysdeps-unix.c:3157
_dbus_threads_lock_platform_specific
void _dbus_threads_lock_platform_specific(void)
Lock a static mutex used to protect _dbus_threads_init_platform_specific().
Definition dbus-sysdeps-pthread.c:296
_dbus_check_setuid
dbus_bool_t _dbus_check_setuid(void)
NOTE: If you modify this function, please also consider making the corresponding change in GLib.
Definition dbus-sysdeps-unix.c:5002
_dbus_threads_unlock_platform_specific
void _dbus_threads_unlock_platform_specific(void)
Undo _dbus_threads_lock_platform_specific().
Definition dbus-sysdeps-pthread.c:302
_dbus_threads_init_platform_specific
dbus_bool_t _dbus_threads_init_platform_specific(void)
Initialize threads as in dbus_threads_init_default(), appropriately for the platform.
Definition dbus-sysdeps-pthread.c:281
dbus_bool_t
dbus_uint32_t dbus_bool_t
A boolean, valid values are TRUE and FALSE.
Definition dbus-types.h:37
DBusCMutex
Definition dbus-sysdeps-pthread.c:55
DBusCMutex::lock
pthread_mutex_t lock
the lock
Definition dbus-sysdeps-pthread.c:56
DBusCondVar
Definition dbus-sysdeps-pthread.c:59
DBusCondVar::cond
pthread_cond_t cond
the condition
Definition dbus-sysdeps-pthread.c:60
DBusRMutex
Definition dbus-sysdeps-pthread.c:51
DBusRMutex::lock
pthread_mutex_t lock
the lock
Definition dbus-sysdeps-pthread.c:52