diff options
Diffstat (limited to 'qemu/util/qemu-thread-posix.c')
| -rw-r--r-- | qemu/util/qemu-thread-posix.c | 509 |
1 files changed, 0 insertions, 509 deletions
diff --git a/qemu/util/qemu-thread-posix.c b/qemu/util/qemu-thread-posix.c deleted file mode 100644 index 74a3023f3..000000000 --- a/qemu/util/qemu-thread-posix.c +++ /dev/null @@ -1,509 +0,0 @@ -/* - * 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 "qemu/osdep.h" -#ifdef __linux__ -#include <sys/syscall.h> -#include <linux/futex.h> -#endif -#include "qemu/thread.h" -#include "qemu/atomic.h" -#include "qemu/notify.h" - -static bool name_threads; - -void qemu_thread_naming(bool enable) -{ - name_threads = enable; - -#ifndef CONFIG_THREAD_SETNAME_BYTHREAD - /* This is a debugging option, not fatal */ - if (enable) { - fprintf(stderr, "qemu: thread naming not supported on this host\n"); - } -#endif -} - -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; - - err = pthread_mutex_init(&mutex->lock, NULL); - 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(__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(__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(__APPLE__) || defined(__NetBSD__) - pthread_mutex_lock(&sem->lock); - if (sem->count == UINT_MAX) { - rc = EINVAL; - } else { - sem->count++; - rc = pthread_cond_signal(&sem->cond); - } - 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(__APPLE__) || defined(__NetBSD__) - rc = 0; - compute_abs_deadline(&ts, ms); - pthread_mutex_lock(&sem->lock); - while (sem->count == 0) { - rc = pthread_cond_timedwait(&sem->cond, &sem->lock, &ts); - if (rc == ETIMEDOUT) { - break; - } - if (rc != 0) { - error_exit(rc, __func__); - } - } - if (rc != ETIMEDOUT) { - --sem->count; - } - 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) -{ - int rc; - -#if defined(__APPLE__) || defined(__NetBSD__) - pthread_mutex_lock(&sem->lock); - while (sem->count == 0) { - rc = pthread_cond_wait(&sem->cond, &sem->lock); - if (rc != 0) { - error_exit(rc, __func__); - } - } - --sem->count; - pthread_mutex_unlock(&sem->lock); -#else - do { - rc = sem_wait(&sem->sem); - } while (rc == -1 && errno == EINTR); - if (rc < 0) { - error_exit(errno, __func__); - } -#endif -} - -#ifdef __linux__ -#define futex(...) syscall(__NR_futex, __VA_ARGS__) - -static inline void futex_wake(QemuEvent *ev, int n) -{ - futex(ev, FUTEX_WAKE, n, NULL, NULL, 0); -} - -static inline void futex_wait(QemuEvent *ev, unsigned val) -{ - while (futex(ev, FUTEX_WAIT, (int) val, NULL, NULL, 0)) { - switch (errno) { - case EWOULDBLOCK: - return; - case EINTR: - break; /* get out of switch and retry */ - default: - abort(); - } - } -} -#else -static inline void futex_wake(QemuEvent *ev, int n) -{ - pthread_mutex_lock(&ev->lock); - if (n == 1) { - pthread_cond_signal(&ev->cond); - } else { - pthread_cond_broadcast(&ev->cond); - } - pthread_mutex_unlock(&ev->lock); -} - -static inline void futex_wait(QemuEvent *ev, unsigned val) -{ - pthread_mutex_lock(&ev->lock); - if (ev->value == val) { - pthread_cond_wait(&ev->cond, &ev->lock); - } - pthread_mutex_unlock(&ev->lock); -} -#endif - -/* Valid transitions: - * - free->set, when setting the event - * - busy->set, when setting the event, followed by futex_wake - * - set->free, when resetting the event - * - free->busy, when waiting - * - * set->busy does not happen (it can be observed from the outside but - * it really is set->free->busy). - * - * busy->free provably cannot happen; to enforce it, the set->free transition - * is done with an OR, which becomes a no-op if the event has concurrently - * transitioned to free or busy. - */ - -#define EV_SET 0 -#define EV_FREE 1 -#define EV_BUSY -1 - -void qemu_event_init(QemuEvent *ev, bool init) -{ -#ifndef __linux__ - pthread_mutex_init(&ev->lock, NULL); - pthread_cond_init(&ev->cond, NULL); -#endif - - ev->value = (init ? EV_SET : EV_FREE); -} - -void qemu_event_destroy(QemuEvent *ev) -{ -#ifndef __linux__ - pthread_mutex_destroy(&ev->lock); - pthread_cond_destroy(&ev->cond); -#endif -} - -void qemu_event_set(QemuEvent *ev) -{ - if (atomic_mb_read(&ev->value) != EV_SET) { - if (atomic_xchg(&ev->value, EV_SET) == EV_BUSY) { - /* There were waiters, wake them up. */ - futex_wake(ev, INT_MAX); - } - } -} - -void qemu_event_reset(QemuEvent *ev) -{ - if (atomic_mb_read(&ev->value) == EV_SET) { - /* - * If there was a concurrent reset (or even reset+wait), - * do nothing. Otherwise change EV_SET->EV_FREE. - */ - atomic_or(&ev->value, EV_FREE); - } -} - -void qemu_event_wait(QemuEvent *ev) -{ - unsigned value; - - value = atomic_mb_read(&ev->value); - if (value != EV_SET) { - if (value == EV_FREE) { - /* - * Leave the event reset and tell qemu_event_set that there - * are waiters. No need to retry, because there cannot be - * a concurrent busy->free transition. After the CAS, the - * event will be either set or busy. - */ - if (atomic_cmpxchg(&ev->value, EV_FREE, EV_BUSY) == EV_SET) { - return; - } - } - futex_wait(ev, EV_BUSY); - } -} - -static pthread_key_t exit_key; - -union NotifierThreadData { - void *ptr; - NotifierList list; -}; -QEMU_BUILD_BUG_ON(sizeof(union NotifierThreadData) != sizeof(void *)); - -void qemu_thread_atexit_add(Notifier *notifier) -{ - union NotifierThreadData ntd; - ntd.ptr = pthread_getspecific(exit_key); - notifier_list_add(&ntd.list, notifier); - pthread_setspecific(exit_key, ntd.ptr); -} - -void qemu_thread_atexit_remove(Notifier *notifier) -{ - union NotifierThreadData ntd; - ntd.ptr = pthread_getspecific(exit_key); - notifier_remove(notifier); - pthread_setspecific(exit_key, ntd.ptr); -} - -static void qemu_thread_atexit_run(void *arg) -{ - union NotifierThreadData ntd = { .ptr = arg }; - notifier_list_notify(&ntd.list, NULL); -} - -static void __attribute__((constructor)) qemu_thread_atexit_init(void) -{ - pthread_key_create(&exit_key, qemu_thread_atexit_run); -} - - -/* Attempt to set the threads name; note that this is for debug, so - * we're not going to fail if we can't set it. - */ -static void qemu_thread_set_name(QemuThread *thread, const char *name) -{ -#ifdef CONFIG_PTHREAD_SETNAME_NP - pthread_setname_np(thread->thread, name); -#endif -} - -void qemu_thread_create(QemuThread *thread, const char *name, - 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__); - - if (name_threads) { - qemu_thread_set_name(thread, name); - } - - 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; -} |