mpv/osdep/win32/pthread.c

270 lines
6.7 KiB
C

/* Permission to use, copy, modify, and/or distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
#include <pthread.h>
#include <semaphore.h>
#include <stdlib.h>
#include <stdint.h>
#include <errno.h>
#include <sys/time.h>
// We keep this around to avoid active waiting while handling static
// initializers.
static pthread_once_t init_cs_once = PTHREAD_ONCE_INIT;
static CRITICAL_SECTION init_cs;
static void init_init_cs(void)
{
InitializeCriticalSection(&init_cs);
}
static void init_lock(void)
{
pthread_once(&init_cs_once, init_init_cs);
EnterCriticalSection(&init_cs);
}
static void init_unlock(void)
{
LeaveCriticalSection(&init_cs);
}
int pthread_once(pthread_once_t *once_control, void (*init_routine)(void))
{
BOOL pending;
if (!InitOnceBeginInitialize(once_control, 0, &pending, NULL))
abort();
if (pending) {
init_routine();
InitOnceComplete(once_control, 0, NULL);
}
return 0;
}
int pthread_mutex_destroy(pthread_mutex_t *mutex)
{
DeleteCriticalSection(&mutex->cs);
return 0;
}
int pthread_mutex_init(pthread_mutex_t *restrict mutex,
const pthread_mutexattr_t *restrict attr)
{
InitializeCriticalSection(&mutex->cs);
return 0;
}
int pthread_mutex_lock(pthread_mutex_t *mutex)
{
if (mutex->requires_init) {
init_lock();
if (mutex->requires_init)
InitializeCriticalSection(&mutex->cs);
_InterlockedAnd(&mutex->requires_init, 0);
init_unlock();
}
EnterCriticalSection(&mutex->cs);
return 0;
}
int pthread_mutex_unlock(pthread_mutex_t *mutex)
{
LeaveCriticalSection(&mutex->cs);
return 0;
}
static int cond_wait(pthread_cond_t *restrict cond,
pthread_mutex_t *restrict mutex,
DWORD ms)
{
return SleepConditionVariableCS(cond, &mutex->cs, ms) ? 0 : ETIMEDOUT;
}
int pthread_cond_timedwait(pthread_cond_t *restrict cond,
pthread_mutex_t *restrict mutex,
const struct timespec *restrict abstime)
{
// mpv uses mingw's gettimeofday() as time source too.
struct timeval tv;
gettimeofday(&tv, NULL);
DWORD timeout_ms = 0;
if (abstime->tv_sec >= INT64_MAX / 10000) {
timeout_ms = INFINITE;
} else if (abstime->tv_sec >= tv.tv_sec) {
long long msec = (abstime->tv_sec - tv.tv_sec) * 1000LL +
abstime->tv_nsec / 1000LL / 1000LL - tv.tv_usec / 1000LL;
if (msec > INT_MAX) {
timeout_ms = INFINITE;
} else if (msec > 0) {
timeout_ms = msec;
}
}
return cond_wait(cond, mutex, timeout_ms);
}
int pthread_cond_wait(pthread_cond_t *restrict cond,
pthread_mutex_t *restrict mutex)
{
return cond_wait(cond, mutex, INFINITE);
}
struct m_thread_info {
HANDLE handle;
void *(*user_fn)(void *);
void *user_arg;
void *res;
};
// Assuming __thread maps to __declspec(thread)
static __thread struct m_thread_info *self;
pthread_t pthread_self(void)
{
return (pthread_t){GetCurrentThreadId(), self};
}
void pthread_exit(void *retval)
{
if (!self)
abort(); // not started with pthread_create
self->res = retval;
if (!self->handle) {
// detached case
free(self);
self = NULL;
}
ExitThread(0);
}
int pthread_join(pthread_t thread, void **retval)
{
if (!thread.info)
abort(); // not started with pthread_create
HANDLE h = thread.info->handle;
if (!h)
abort(); // thread was detached
WaitForSingleObject(h, INFINITE);
CloseHandle(h);
if (retval)
*retval = thread.info->res;
free(thread.info);
return 0;
}
int pthread_detach(pthread_t thread)
{
if (!pthread_equal(thread, pthread_self()))
abort(); // restriction of this wrapper
if (!thread.info)
abort(); // not started with pthread_create
if (!thread.info->handle)
abort(); // already deatched
CloseHandle(thread.info->handle);
thread.info->handle = NULL;
return 0;
}
static DWORD WINAPI run_thread(LPVOID lpParameter)
{
struct m_thread_info *info = lpParameter;
self = info;
pthread_exit(info->user_fn(info->user_arg));
abort(); // not reached
}
int pthread_create(pthread_t *thread, const pthread_attr_t *attr,
void *(*start_routine) (void *), void *arg)
{
struct m_thread_info *info = calloc(1, sizeof(*info));
if (!info)
return EAGAIN;
info->user_fn = start_routine;
info->user_arg = arg;
HANDLE h = CreateThread(NULL, 0, run_thread, info, CREATE_SUSPENDED, NULL);
if (!h) {
free(info);
return EAGAIN;
}
info->handle = h;
*thread = (pthread_t){GetThreadId(h), info};
ResumeThread(h);
return 0;
}
int sem_init(sem_t *sem, int pshared, unsigned int value)
{
if (pshared)
abort(); // unsupported
pthread_mutex_init(&sem->lock, NULL);
pthread_cond_init(&sem->wakeup, NULL);
sem->value = value;
return 0;
}
int sem_destroy(sem_t *sem)
{
pthread_mutex_destroy(&sem->lock);
pthread_cond_destroy(&sem->wakeup);
return 0;
}
int sem_wait(sem_t *sem)
{
pthread_mutex_lock(&sem->lock);
while (!sem->value)
pthread_cond_wait(&sem->wakeup, &sem->lock);
sem->value -= 1;
pthread_mutex_unlock(&sem->lock);
return 0;
}
int sem_trywait(sem_t *sem)
{
pthread_mutex_lock(&sem->lock);
int r;
if (sem->value > 0) {
sem->value -= 1;
r = 0;
} else {
errno = EAGAIN;
r = -1;
}
pthread_mutex_unlock(&sem->lock);
return r;
}
int sem_timedwait(sem_t *sem, const struct timespec *abs_timeout)
{
pthread_mutex_lock(&sem->lock);
while (!sem->value) {
int err = pthread_cond_timedwait(&sem->wakeup, &sem->lock, abs_timeout);
if (err) {
pthread_mutex_unlock(&sem->lock);
errno = err;
return -1;
}
}
sem->value -= 1;
pthread_mutex_unlock(&sem->lock);
return 0;
}
int sem_post(sem_t *sem)
{
pthread_mutex_lock(&sem->lock);
sem->value += 1;
pthread_cond_broadcast(&sem->wakeup);
pthread_mutex_unlock(&sem->lock);
return 0;
}