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 <string.h> 32 33#ifdef HAVE_ERRNO_H 34#include <errno.h> 35#endif 36 37#include <config.h> 38 39/* Whether we have a "monotonic" clock; i.e. a clock not affected by 40 * changes in system time. 41 * This is initialized once in check_monotonic_clock below. 42 * https://bugs.freedesktop.org/show_bug.cgi?id=18121 43 */ 44static dbus_bool_t have_monotonic_clock = 0; 45 46struct DBusRMutex { 47 pthread_mutex_t lock; /**< the lock */ 48}; 49 50struct DBusCMutex { 51 pthread_mutex_t lock; /**< the lock */ 52}; 53 54struct DBusCondVar { 55 pthread_cond_t cond; /**< the condition */ 56}; 57 58#define DBUS_MUTEX(m) ((DBusMutex*) m) 59#define DBUS_MUTEX_PTHREAD(m) ((DBusMutexPThread*) m) 60 61#define DBUS_COND_VAR(c) ((DBusCondVar*) c) 62#define DBUS_COND_VAR_PTHREAD(c) ((DBusCondVarPThread*) c) 63 64 65#ifdef DBUS_DISABLE_ASSERT 66/* (tmp != 0) is a no-op usage to silence compiler */ 67#define PTHREAD_CHECK(func_name, result_or_call) \ 68 do { int tmp = (result_or_call); if (tmp != 0) {;} } while (0) 69#else 70#define PTHREAD_CHECK(func_name, result_or_call) do { \ 71 int tmp = (result_or_call); \ 72 if (tmp != 0) { \ 73 _dbus_warn_check_failed ("pthread function %s failed with %d %s in %s\n", \ 74 func_name, tmp, strerror(tmp), _DBUS_FUNCTION_NAME); \ 75 } \ 76} while (0) 77#endif /* !DBUS_DISABLE_ASSERT */ 78 79DBusCMutex * 80_dbus_platform_cmutex_new (void) 81{ 82 DBusCMutex *pmutex; 83 int result; 84 85 pmutex = dbus_new (DBusCMutex, 1); 86 if (pmutex == NULL) 87 return NULL; 88 89 result = pthread_mutex_init (&pmutex->lock, NULL); 90 91 if (result == ENOMEM || result == EAGAIN) 92 { 93 dbus_free (pmutex); 94 return NULL; 95 } 96 else 97 { 98 PTHREAD_CHECK ("pthread_mutex_init", result); 99 } 100 101 return pmutex; 102} 103 104DBusRMutex * 105_dbus_platform_rmutex_new (void) 106{ 107 DBusRMutex *pmutex; 108 pthread_mutexattr_t mutexattr; 109 int result; 110 111 pmutex = dbus_new (DBusRMutex, 1); 112 if (pmutex == NULL) 113 return NULL; 114 115 pthread_mutexattr_init (&mutexattr); 116 pthread_mutexattr_settype (&mutexattr, PTHREAD_MUTEX_RECURSIVE); 117 result = pthread_mutex_init (&pmutex->lock, &mutexattr); 118 pthread_mutexattr_destroy (&mutexattr); 119 120 if (result == ENOMEM || result == EAGAIN) 121 { 122 dbus_free (pmutex); 123 return NULL; 124 } 125 else 126 { 127 PTHREAD_CHECK ("pthread_mutex_init", result); 128 } 129 130 return pmutex; 131} 132 133void 134_dbus_platform_cmutex_free (DBusCMutex *mutex) 135{ 136 PTHREAD_CHECK ("pthread_mutex_destroy", pthread_mutex_destroy (&mutex->lock)); 137 dbus_free (mutex); 138} 139 140void 141_dbus_platform_rmutex_free (DBusRMutex *mutex) 142{ 143 PTHREAD_CHECK ("pthread_mutex_destroy", pthread_mutex_destroy (&mutex->lock)); 144 dbus_free (mutex); 145} 146 147void 148_dbus_platform_cmutex_lock (DBusCMutex *mutex) 149{ 150 PTHREAD_CHECK ("pthread_mutex_lock", pthread_mutex_lock (&mutex->lock)); 151} 152 153void 154_dbus_platform_rmutex_lock (DBusRMutex *mutex) 155{ 156 PTHREAD_CHECK ("pthread_mutex_lock", pthread_mutex_lock (&mutex->lock)); 157} 158 159void 160_dbus_platform_cmutex_unlock (DBusCMutex *mutex) 161{ 162 PTHREAD_CHECK ("pthread_mutex_unlock", pthread_mutex_unlock (&mutex->lock)); 163} 164 165void 166_dbus_platform_rmutex_unlock (DBusRMutex *mutex) 167{ 168 PTHREAD_CHECK ("pthread_mutex_unlock", pthread_mutex_unlock (&mutex->lock)); 169} 170 171DBusCondVar * 172_dbus_platform_condvar_new (void) 173{ 174 DBusCondVar *pcond; 175 pthread_condattr_t attr; 176 int result; 177 178 pcond = dbus_new (DBusCondVar, 1); 179 if (pcond == NULL) 180 return NULL; 181 182 pthread_condattr_init (&attr); 183#ifdef HAVE_MONOTONIC_CLOCK 184 if (have_monotonic_clock) 185 pthread_condattr_setclock (&attr, CLOCK_MONOTONIC); 186#endif 187 188 result = pthread_cond_init (&pcond->cond, &attr); 189 pthread_condattr_destroy (&attr); 190 191 if (result == EAGAIN || result == ENOMEM) 192 { 193 dbus_free (pcond); 194 return NULL; 195 } 196 else 197 { 198 PTHREAD_CHECK ("pthread_cond_init", result); 199 } 200 201 return pcond; 202} 203 204void 205_dbus_platform_condvar_free (DBusCondVar *cond) 206{ 207 PTHREAD_CHECK ("pthread_cond_destroy", pthread_cond_destroy (&cond->cond)); 208 dbus_free (cond); 209} 210 211void 212_dbus_platform_condvar_wait (DBusCondVar *cond, 213 DBusCMutex *mutex) 214{ 215 PTHREAD_CHECK ("pthread_cond_wait", pthread_cond_wait (&cond->cond, &mutex->lock)); 216} 217 218dbus_bool_t 219_dbus_platform_condvar_wait_timeout (DBusCondVar *cond, 220 DBusCMutex *mutex, 221 int timeout_milliseconds) 222{ 223 struct timeval time_now; 224 struct timespec end_time; 225 int result; 226 227#ifdef HAVE_MONOTONIC_CLOCK 228 if (have_monotonic_clock) 229 { 230 struct timespec monotonic_timer; 231 clock_gettime (CLOCK_MONOTONIC,&monotonic_timer); 232 time_now.tv_sec = monotonic_timer.tv_sec; 233 time_now.tv_usec = monotonic_timer.tv_nsec / 1000; 234 } 235 else 236 /* This else falls through to gettimeofday */ 237#endif 238 gettimeofday (&time_now, NULL); 239 240 end_time.tv_sec = time_now.tv_sec + timeout_milliseconds / 1000; 241 end_time.tv_nsec = (time_now.tv_usec + (timeout_milliseconds % 1000) * 1000) * 1000; 242 if (end_time.tv_nsec > 1000*1000*1000) 243 { 244 end_time.tv_sec += 1; 245 end_time.tv_nsec -= 1000*1000*1000; 246 } 247 248 result = pthread_cond_timedwait (&cond->cond, &mutex->lock, &end_time); 249 250 if (result != ETIMEDOUT) 251 { 252 PTHREAD_CHECK ("pthread_cond_timedwait", result); 253 } 254 255 /* return true if we did not time out */ 256 return result != ETIMEDOUT; 257} 258 259void 260_dbus_platform_condvar_wake_one (DBusCondVar *cond) 261{ 262 PTHREAD_CHECK ("pthread_cond_signal", pthread_cond_signal (&cond->cond)); 263} 264 265static void 266check_monotonic_clock (void) 267{ 268#ifdef HAVE_MONOTONIC_CLOCK 269 struct timespec dummy; 270 if (clock_getres (CLOCK_MONOTONIC, &dummy) == 0) 271 have_monotonic_clock = TRUE; 272#endif 273} 274 275dbus_bool_t 276_dbus_threads_init_platform_specific (void) 277{ 278 /* These have static variables, and we need to handle both the case 279 * where dbus_threads_init() has been called and when it hasn't; 280 * so initialize them before any threads are allowed to enter. 281 */ 282 check_monotonic_clock (); 283 (void) _dbus_check_setuid (); 284 return dbus_threads_init (NULL); 285} 286