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

D-Bus 1.14.10

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 * Licensed under the Academic Free License version 2.1
7 *
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License as published by
10 * the Free Software Foundation; either version 2 of the License, or
11 * (at your option) any later version.
12 *
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 * GNU General Public License for more details.
17 *
18 * You should have received a copy of the GNU General Public License
19 * along with this program; if not, write to the Free Software
20 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
21 *
22 */
23
24#include <config.h>
25#include "dbus-internals.h"
26#include "dbus-sysdeps.h"
27#include "dbus-threads.h"
28
29#include <sys/time.h>
30#include <pthread.h>
31#include <stdio.h>
32#include <string.h>
33
34#ifdef HAVE_ERRNO_H
35#include <errno.h>
36#endif
37
38#include <config.h>
39
40#ifdef HAVE_MONOTONIC_CLOCK
41/* Whether we have a "monotonic" clock; i.e. a clock not affected by
42 * changes in system time.
43 * This is initialized once in check_monotonic_clock below.
44 * https://bugs.freedesktop.org/show_bug.cgi?id=18121
45 */
46static dbus_bool_t have_monotonic_clock = 0;
47#endif
48
49 struct DBusRMutex {
50 pthread_mutex_t lock;
51};
52
53 struct DBusCMutex {
54 pthread_mutex_t lock;
55};
56
57 struct DBusCondVar {
58 pthread_cond_t cond;
59};
60
61#define DBUS_MUTEX(m) ((DBusMutex*) m)
62#define DBUS_MUTEX_PTHREAD(m) ((DBusMutexPThread*) m)
63
64#define DBUS_COND_VAR(c) ((DBusCondVar*) c)
65#define DBUS_COND_VAR_PTHREAD(c) ((DBusCondVarPThread*) c)
66
67
68#ifdef DBUS_DISABLE_ASSERT
69/* (tmp != 0) is a no-op usage to silence compiler */
70#define PTHREAD_CHECK(func_name, result_or_call) \
71 do { int tmp = (result_or_call); if (tmp != 0) {;} } while (0)
72#else
73#define PTHREAD_CHECK(func_name, result_or_call) do { \
74 int tmp = (result_or_call); \
75 if (tmp != 0) { \
76 _dbus_warn_check_failed ("pthread function %s failed with %d %s in %s", \
77 func_name, tmp, strerror(tmp), _DBUS_FUNCTION_NAME); \
78 } \
79} while (0)
80#endif /* !DBUS_DISABLE_ASSERT */
81
82 DBusCMutex *
83_dbus_platform_cmutex_new (void)
84{
85 DBusCMutex *pmutex;
86 int result;
87
88 pmutex = dbus_new (DBusCMutex, 1);
89 if (pmutex == NULL)
90 return NULL;
91
92 result = pthread_mutex_init (&pmutex->lock, NULL);
93
94 if (result == ENOMEM || result == EAGAIN)
95 {
96 dbus_free (pmutex);
97 return NULL;
98 }
99 else
100 {
101 PTHREAD_CHECK ("pthread_mutex_init", result);
102 }
103
104 return pmutex;
105}
106
107 DBusRMutex *
108_dbus_platform_rmutex_new (void)
109{
110 DBusRMutex *pmutex;
111 pthread_mutexattr_t mutexattr;
112 int result;
113
114 pmutex = dbus_new (DBusRMutex, 1);
115 if (pmutex == NULL)
116 return NULL;
117
118 pthread_mutexattr_init (&mutexattr);
119 pthread_mutexattr_settype (&mutexattr, PTHREAD_MUTEX_RECURSIVE);
120 result = pthread_mutex_init (&pmutex->lock, &mutexattr);
121 pthread_mutexattr_destroy (&mutexattr);
122
123 if (result == ENOMEM || result == EAGAIN)
124 {
125 dbus_free (pmutex);
126 return NULL;
127 }
128 else
129 {
130 PTHREAD_CHECK ("pthread_mutex_init", result);
131 }
132
133 return pmutex;
134}
135
136void
137_dbus_platform_cmutex_free (DBusCMutex *mutex)
138{
139 PTHREAD_CHECK ("pthread_mutex_destroy", pthread_mutex_destroy (&mutex->lock));
140 dbus_free (mutex);
141}
142
143void
144_dbus_platform_rmutex_free (DBusRMutex *mutex)
145{
146 PTHREAD_CHECK ("pthread_mutex_destroy", pthread_mutex_destroy (&mutex->lock));
147 dbus_free (mutex);
148}
149
150void
151_dbus_platform_cmutex_lock (DBusCMutex *mutex)
152{
153 PTHREAD_CHECK ("pthread_mutex_lock", pthread_mutex_lock (&mutex->lock));
154}
155
156void
157_dbus_platform_rmutex_lock (DBusRMutex *mutex)
158{
159 PTHREAD_CHECK ("pthread_mutex_lock", pthread_mutex_lock (&mutex->lock));
160}
161
162void
163_dbus_platform_cmutex_unlock (DBusCMutex *mutex)
164{
165 PTHREAD_CHECK ("pthread_mutex_unlock", pthread_mutex_unlock (&mutex->lock));
166}
167
168void
169_dbus_platform_rmutex_unlock (DBusRMutex *mutex)
170{
171 PTHREAD_CHECK ("pthread_mutex_unlock", pthread_mutex_unlock (&mutex->lock));
172}
173
174 DBusCondVar *
175_dbus_platform_condvar_new (void)
176{
177 DBusCondVar *pcond;
178 pthread_condattr_t attr;
179 int result;
180
181 pcond = dbus_new (DBusCondVar, 1);
182 if (pcond == NULL)
183 return NULL;
184
185 pthread_condattr_init (&attr);
186#ifdef HAVE_MONOTONIC_CLOCK
187 if (have_monotonic_clock)
188 pthread_condattr_setclock (&attr, CLOCK_MONOTONIC);
189#endif
190
191 result = pthread_cond_init (&pcond->cond, &attr);
192 pthread_condattr_destroy (&attr);
193
194 if (result == EAGAIN || result == ENOMEM)
195 {
196 dbus_free (pcond);
197 return NULL;
198 }
199 else
200 {
201 PTHREAD_CHECK ("pthread_cond_init", result);
202 }
203
204 return pcond;
205}
206
207void
208_dbus_platform_condvar_free (DBusCondVar *cond)
209{
210 PTHREAD_CHECK ("pthread_cond_destroy", pthread_cond_destroy (&cond->cond));
211 dbus_free (cond);
212}
213
214void
215_dbus_platform_condvar_wait (DBusCondVar *cond,
216 DBusCMutex *mutex)
217{
218 PTHREAD_CHECK ("pthread_cond_wait", pthread_cond_wait (&cond->cond, &mutex->lock));
219}
220
221dbus_bool_t
222_dbus_platform_condvar_wait_timeout (DBusCondVar *cond,
223 DBusCMutex *mutex,
224 int timeout_milliseconds)
225{
226 struct timeval time_now;
227 struct timespec end_time;
228 int result;
229
230#ifdef HAVE_MONOTONIC_CLOCK
231 if (have_monotonic_clock)
232 {
233 struct timespec monotonic_timer;
234 clock_gettime (CLOCK_MONOTONIC,&monotonic_timer);
235 time_now.tv_sec = monotonic_timer.tv_sec;
236 time_now.tv_usec = monotonic_timer.tv_nsec / 1000;
237 }
238 else
239 /* This else falls through to gettimeofday */
240#endif
241 gettimeofday (&time_now, NULL);
242
243 end_time.tv_sec = time_now.tv_sec + timeout_milliseconds / 1000;
244 end_time.tv_nsec = (time_now.tv_usec + (timeout_milliseconds % 1000) * 1000) * 1000;
245 if (end_time.tv_nsec > 1000*1000*1000)
246 {
247 end_time.tv_sec += 1;
248 end_time.tv_nsec -= 1000*1000*1000;
249 }
250
251 result = pthread_cond_timedwait (&cond->cond, &mutex->lock, &end_time);
252
253 if (result != ETIMEDOUT)
254 {
255 PTHREAD_CHECK ("pthread_cond_timedwait", result);
256 }
257
258 /* return true if we did not time out */
259 return result != ETIMEDOUT;
260}
261
262void
263_dbus_platform_condvar_wake_one (DBusCondVar *cond)
264{
265 PTHREAD_CHECK ("pthread_cond_signal", pthread_cond_signal (&cond->cond));
266}
267
268static void
269check_monotonic_clock (void)
270{
271#ifdef HAVE_MONOTONIC_CLOCK
272 struct timespec dummy;
273 if (clock_getres (CLOCK_MONOTONIC, &dummy) == 0)
274 have_monotonic_clock = TRUE;
275#endif
276}
277
278dbus_bool_t
279_dbus_threads_init_platform_specific (void)
280{
281 /* These have static variables, and we need to handle both the case
282 * where dbus_threads_init() has been called and when it hasn't;
283 * so initialize them before any threads are allowed to enter.
284 */
285 check_monotonic_clock ();
286 (void) _dbus_check_setuid ();
287
288 return TRUE;
289}
290
291static pthread_mutex_t init_mutex = PTHREAD_MUTEX_INITIALIZER;
292
293void
294_dbus_threads_lock_platform_specific (void)
295{
296 pthread_mutex_lock (&init_mutex);
297}
298
299void
300_dbus_threads_unlock_platform_specific (void)
301{
302 pthread_mutex_unlock (&init_mutex);
303}
304
305#ifdef DBUS_ENABLE_VERBOSE_MODE
306/*
307 * If we can identify the current process and/or thread, print them to stderr followed by a colon.
308 */
309void
310_dbus_print_thread (void)
311{
312#ifdef __linux__
313 /* we know a pthread_t is numeric on Linux */
314 fprintf (stderr, "%lu: 0x%lx: ", _dbus_pid_for_log (), (unsigned long) pthread_self ());
315#else
316 /* in principle pthread_t isn't required to be printable */
317 fprintf (stderr, "%lu: ", _dbus_pid_for_log ());
318#endif
319}
320#endif
NULL
#define NULL
A null pointer, defined appropriately for C or C++.
Definition dbus-macros.h:49
TRUE
#define TRUE
Expands to "1".
Definition dbus-macros.h:39
dbus_free
void dbus_free(void *memory)
Frees a block of memory previously allocated by dbus_malloc() or dbus_malloc0().
Definition dbus-memory.c:692
dbus_new
#define dbus_new(type, count)
Safe macro for using dbus_malloc().
Definition dbus-memory.h:57
_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:3008
_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:294
_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:4817
_dbus_threads_unlock_platform_specific
void _dbus_threads_unlock_platform_specific(void)
Undo _dbus_threads_lock_platform_specific().
Definition dbus-sysdeps-pthread.c:300
_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:279
DBusCMutex
Definition dbus-sysdeps-pthread.c:53
DBusCMutex::lock
pthread_mutex_t lock
the lock
Definition dbus-sysdeps-pthread.c:54
DBusCondVar
Definition dbus-sysdeps-pthread.c:57
DBusCondVar::cond
pthread_cond_t cond
the condition
Definition dbus-sysdeps-pthread.c:58
DBusRMutex
Definition dbus-sysdeps-pthread.c:49
DBusRMutex::lock
pthread_mutex_t lock
the lock
Definition dbus-sysdeps-pthread.c:50