qemu-thread-posix.c

   1 /*
   2  * Wrappers around mutex/cond/thread functions
   3  *
   4  * Copyright Red Hat, Inc. 2009
   5  *
   6  * Author:
   7  *  Marcelo Tosatti <mtosatti@redhat.com>
   8  *
   9  * This work is licensed under the terms of the GNU GPL, version 2 or later.
  10  * See the COPYING file in the top-level directory.
  11  *
  12  */
  13 #include <stdlib.h>
  14 #include <stdio.h>
  15 #include <errno.h>
  16 #include <time.h>
  17 #include <signal.h>
  18 #include <stdint.h>
  19 #include <string.h>
  20 #include <limits.h>
  21 #include <unistd.h>
  22 #include <sys/time.h>
  23 #include "qemu-thread.h"
  24
  25 static void error_exit(int err, const char *msg)
  26 {
  27     fprintf(stderr, "qemu: %s: %s\n", msg, strerror(err));
  28     abort();
  29 }
  30
  31 void qemu_mutex_init(QemuMutex *mutex)
  32 {
  33     int err;
  34     pthread_mutexattr_t mutexattr;
  35
  36     pthread_mutexattr_init(&mutexattr);
  37     pthread_mutexattr_settype(&mutexattr, PTHREAD_MUTEX_ERRORCHECK);
  38     err = pthread_mutex_init(&mutex->lock, &mutexattr);
  39     pthread_mutexattr_destroy(&mutexattr);
  40     if (err)
  41         error_exit(err, __func__);
  42 }
  43
  44 void qemu_mutex_destroy(QemuMutex *mutex)
  45 {
  46     int err;
  47
  48     err = pthread_mutex_destroy(&mutex->lock);
  49     if (err)
  50         error_exit(err, __func__);
  51 }
  52
  53 void qemu_mutex_lock(QemuMutex *mutex)
  54 {
  55     int err;
  56
  57     err = pthread_mutex_lock(&mutex->lock);
  58     if (err)
  59         error_exit(err, __func__);
  60 }
  61
  62 int qemu_mutex_trylock(QemuMutex *mutex)
  63 {
  64     return pthread_mutex_trylock(&mutex->lock);
  65 }
  66
  67 void qemu_mutex_unlock(QemuMutex *mutex)
  68 {
  69     int err;
  70
  71     err = pthread_mutex_unlock(&mutex->lock);
  72     if (err)
  73         error_exit(err, __func__);
  74 }
  75
  76 void qemu_cond_init(QemuCond *cond)
  77 {
  78     int err;
  79
  80     err = pthread_cond_init(&cond->cond, NULL);
  81     if (err)
  82         error_exit(err, __func__);
  83 }
  84
  85 void qemu_cond_destroy(QemuCond *cond)
  86 {
  87     int err;
  88
  89     err = pthread_cond_destroy(&cond->cond);
  90     if (err)
  91         error_exit(err, __func__);
  92 }
  93
  94 void qemu_cond_signal(QemuCond *cond)
  95 {
  96     int err;
  97
  98     err = pthread_cond_signal(&cond->cond);
  99     if (err)
 100         error_exit(err, __func__);
 101 }
 102
 103 void qemu_cond_broadcast(QemuCond *cond)
 104 {
 105     int err;
 106
 107     err = pthread_cond_broadcast(&cond->cond);
 108     if (err)
 109         error_exit(err, __func__);
 110 }
 111
 112 void qemu_cond_wait(QemuCond *cond, QemuMutex *mutex)
 113 {
 114     int err;
 115
 116     err = pthread_cond_wait(&cond->cond, &mutex->lock);
 117     if (err)
 118         error_exit(err, __func__);
 119 }
 120
 121 void qemu_sem_init(QemuSemaphore *sem, int init)
 122 {
 123     int rc;
 124
 125     rc = sem_init(&sem->sem, 0, init);
 126     if (rc < 0) {
 127         error_exit(errno, __func__);
 128     }
 129 }
 130
 131 void qemu_sem_destroy(QemuSemaphore *sem)
 132 {
 133     int rc;
 134
 135     rc = sem_destroy(&sem->sem);
 136     if (rc < 0) {
 137         error_exit(errno, __func__);
 138     }
 139 }
 140
 141 void qemu_sem_post(QemuSemaphore *sem)
 142 {
 143     int rc;
 144
 145     rc = sem_post(&sem->sem);
 146     if (rc < 0) {
 147         error_exit(errno, __func__);
 148     }
 149 }
 150
 151 int qemu_sem_timedwait(QemuSemaphore *sem, int ms)
 152 {
 153     int rc;
 154
 155     if (ms <= 0) {
 156         /* This is cheaper than sem_timedwait.  */
 157         do {
 158             rc = sem_trywait(&sem->sem);
 159         } while (rc == -1 && errno == EINTR);
 160         if (rc == -1 && errno == EAGAIN) {
 161             return -1;
 162         }
 163     } else {
 164         struct timeval tv;
 165         struct timespec ts;
 166         gettimeofday(&tv, NULL);
 167         ts.tv_nsec = tv.tv_usec * 1000 + (ms % 1000) * 1000000;
 168         ts.tv_sec = tv.tv_sec + ms / 1000;
 169         if (ts.tv_nsec >= 1000000000) {
 170             ts.tv_sec++;
 171             ts.tv_nsec -= 1000000000;
 172         }
 173         do {
 174             rc = sem_timedwait(&sem->sem, &ts);
 175         } while (rc == -1 && errno == EINTR);
 176         if (rc == -1 && errno == ETIMEDOUT) {
 177             return -1;
 178         }
 179     }
 180     if (rc < 0) {
 181         error_exit(errno, __func__);
 182     }
 183     return 0;
 184 }
 185
 186 void qemu_sem_wait(QemuSemaphore *sem)
 187 {
 188     int rc;
 189
 190     do {
 191         rc = sem_wait(&sem->sem);
 192     } while (rc == -1 && errno == EINTR);
 193     if (rc < 0) {
 194         error_exit(errno, __func__);
 195     }
 196 }
 197
 198 void qemu_thread_create(QemuThread *thread,
 199                        void *(*start_routine)(void*),
 200                        void *arg, int mode)
 201 {
 202     sigset_t set, oldset;
 203     int err;
 204     pthread_attr_t attr;
 205
 206     err = pthread_attr_init(&attr);
 207     if (err) {
 208         error_exit(err, __func__);
 209     }
 210     if (mode == QEMU_THREAD_DETACHED) {
 211         err = pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED);
 212         if (err) {
 213             error_exit(err, __func__);
 214         }
 215     }
 216
 217     /* Leave signal handling to the iothread.  */
 218     sigfillset(&set);
 219     pthread_sigmask(SIG_SETMASK, &set, &oldset);
 220     err = pthread_create(&thread->thread, &attr, start_routine, arg);
 221     if (err)
 222         error_exit(err, __func__);
 223
 224     pthread_sigmask(SIG_SETMASK, &oldset, NULL);
 225
 226     pthread_attr_destroy(&attr);
 227 }
 228
 229 void qemu_thread_get_self(QemuThread *thread)
 230 {
 231     thread->thread = pthread_self();
 232 }
 233
 234 bool qemu_thread_is_self(QemuThread *thread)
 235 {
 236    return pthread_equal(pthread_self(), thread->thread);
 237 }
 238
 239 void qemu_thread_exit(void *retval)
 240 {
 241     pthread_exit(retval);
 242 }
 243
 244 void *qemu_thread_join(QemuThread *thread)
 245 {
 246     int err;
 247     void *ret;
 248
 249     err = pthread_join(thread->thread, &ret);
 250     if (err) {
 251         error_exit(err, __func__);
 252     }
 253     return ret;
 254 }