/* * Wrappers around mutex/cond/thread functions * * Copyright Red Hat, Inc. 2009 * * Author: * Marcelo Tosatti <mtosatti@redhat.com> * * This work is licensed under the terms of the GNU GPL, version 2 or later. * See the COPYING file in the top-level directory. * */ #include <stdlib.h> #include <stdio.h> #include <errno.h> #include <time.h> #include <signal.h> #include <stdint.h> #include <string.h> #include <limits.h> #include <unistd.h> #include <sys/time.h> #include "qemu-thread.h" static void error_exit(int err, const char *msg) { fprintf(stderr, "qemu: %s: %s\n", msg, strerror(err)); abort(); } void qemu_mutex_init(QemuMutex *mutex) { int err; pthread_mutexattr_t mutexattr; pthread_mutexattr_init(&mutexattr); pthread_mutexattr_settype(&mutexattr, PTHREAD_MUTEX_ERRORCHECK); err = pthread_mutex_init(&mutex->lock, &mutexattr); pthread_mutexattr_destroy(&mutexattr); if (err) error_exit(err, __func__); } void qemu_mutex_destroy(QemuMutex *mutex) { int err; err = pthread_mutex_destroy(&mutex->lock); if (err) error_exit(err, __func__); } void qemu_mutex_lock(QemuMutex *mutex) { int err; err = pthread_mutex_lock(&mutex->lock); if (err) error_exit(err, __func__); } int qemu_mutex_trylock(QemuMutex *mutex) { return pthread_mutex_trylock(&mutex->lock); } void qemu_mutex_unlock(QemuMutex *mutex) { int err; err = pthread_mutex_unlock(&mutex->lock); if (err) error_exit(err, __func__); } void qemu_cond_init(QemuCond *cond) { int err; err = pthread_cond_init(&cond->cond, NULL); if (err) error_exit(err, __func__); } void qemu_cond_destroy(QemuCond *cond) { int err; err = pthread_cond_destroy(&cond->cond); if (err) error_exit(err, __func__); } void qemu_cond_signal(QemuCond *cond) { int err; err = pthread_cond_signal(&cond->cond); if (err) error_exit(err, __func__); } void qemu_cond_broadcast(QemuCond *cond) { int err; err = pthread_cond_broadcast(&cond->cond); if (err) error_exit(err, __func__); } void qemu_cond_wait(QemuCond *cond, QemuMutex *mutex) { int err; err = pthread_cond_wait(&cond->cond, &mutex->lock); if (err) error_exit(err, __func__); } void qemu_sem_init(QemuSemaphore *sem, int init) { int rc; #if defined(__OpenBSD__) || defined(__APPLE__) || defined(__NetBSD__) rc = pthread_mutex_init(&sem->lock, NULL); if (rc != 0) { error_exit(rc, __func__); } rc = pthread_cond_init(&sem->cond, NULL); if (rc != 0) { error_exit(rc, __func__); } if (init < 0) { error_exit(EINVAL, __func__); } sem->count = init; #else rc = sem_init(&sem->sem, 0, init); if (rc < 0) { error_exit(errno, __func__); } #endif } void qemu_sem_destroy(QemuSemaphore *sem) { int rc; #if defined(__OpenBSD__) || defined(__APPLE__) || defined(__NetBSD__) rc = pthread_cond_destroy(&sem->cond); if (rc < 0) { error_exit(rc, __func__); } rc = pthread_mutex_destroy(&sem->lock); if (rc < 0) { error_exit(rc, __func__); } #else rc = sem_destroy(&sem->sem); if (rc < 0) { error_exit(errno, __func__); } #endif } void qemu_sem_post(QemuSemaphore *sem) { int rc; #if defined(__OpenBSD__) || defined(__APPLE__) || defined(__NetBSD__) pthread_mutex_lock(&sem->lock); if (sem->count == INT_MAX) { rc = EINVAL; } else if (sem->count++ < 0) { rc = pthread_cond_signal(&sem->cond); } else { rc = 0; } pthread_mutex_unlock(&sem->lock); if (rc != 0) { error_exit(rc, __func__); } #else rc = sem_post(&sem->sem); if (rc < 0) { error_exit(errno, __func__); } #endif } static void compute_abs_deadline(struct timespec *ts, int ms) { struct timeval tv; gettimeofday(&tv, NULL); ts->tv_nsec = tv.tv_usec * 1000 + (ms % 1000) * 1000000; ts->tv_sec = tv.tv_sec + ms / 1000; if (ts->tv_nsec >= 1000000000) { ts->tv_sec++; ts->tv_nsec -= 1000000000; } } int qemu_sem_timedwait(QemuSemaphore *sem, int ms) { int rc; struct timespec ts; #if defined(__OpenBSD__) || defined(__APPLE__) || defined(__NetBSD__) compute_abs_deadline(&ts, ms); pthread_mutex_lock(&sem->lock); --sem->count; while (sem->count < 0) { rc = pthread_cond_timedwait(&sem->cond, &sem->lock, &ts); if (rc == ETIMEDOUT) { break; } if (rc != 0) { error_exit(rc, __func__); } } pthread_mutex_unlock(&sem->lock); return (rc == ETIMEDOUT ? -1 : 0); #else if (ms <= 0) { /* This is cheaper than sem_timedwait. */ do { rc = sem_trywait(&sem->sem); } while (rc == -1 && errno == EINTR); if (rc == -1 && errno == EAGAIN) { return -1; } } else { compute_abs_deadline(&ts, ms); do { rc = sem_timedwait(&sem->sem, &ts); } while (rc == -1 && errno == EINTR); if (rc == -1 && errno == ETIMEDOUT) { return -1; } } if (rc < 0) { error_exit(errno, __func__); } return 0; #endif } void qemu_sem_wait(QemuSemaphore *sem) { #if defined(__OpenBSD__) || defined(__APPLE__) || defined(__NetBSD__) pthread_mutex_lock(&sem->lock); --sem->count; while (sem->count < 0) { pthread_cond_wait(&sem->cond, &sem->lock); } pthread_mutex_unlock(&sem->lock); #else int rc; do { rc = sem_wait(&sem->sem); } while (rc == -1 && errno == EINTR); if (rc < 0) { error_exit(errno, __func__); } #endif } void qemu_thread_create(QemuThread *thread, void *(*start_routine)(void*), void *arg, int mode) { sigset_t set, oldset; int err; pthread_attr_t attr; err = pthread_attr_init(&attr); if (err) { error_exit(err, __func__); } if (mode == QEMU_THREAD_DETACHED) { err = pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED); if (err) { error_exit(err, __func__); } } /* Leave signal handling to the iothread. */ sigfillset(&set); pthread_sigmask(SIG_SETMASK, &set, &oldset); err = pthread_create(&thread->thread, &attr, start_routine, arg); if (err) error_exit(err, __func__); pthread_sigmask(SIG_SETMASK, &oldset, NULL); pthread_attr_destroy(&attr); } void qemu_thread_get_self(QemuThread *thread) { thread->thread = pthread_self(); } bool qemu_thread_is_self(QemuThread *thread) { return pthread_equal(pthread_self(), thread->thread); } void qemu_thread_exit(void *retval) { pthread_exit(retval); } void *qemu_thread_join(QemuThread *thread) { int err; void *ret; err = pthread_join(thread->thread, &ret); if (err) { error_exit(err, __func__); } return ret; }