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/* Copyright (C) 2018 the mpv developers
*
* 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 <assert.h>
#include <string.h>
#include <sys/types.h>
#include <unistd.h>
#include <errno.h>
#ifdef __MINGW32__
#include <windows.h>
#else
#include <poll.h>
#endif
#include "common/common.h"
#include "osdep/atomic.h"
#include "osdep/io.h"
#include "thread_tools.h"
uintptr_t mp_waiter_wait(struct mp_waiter *waiter)
{
pthread_mutex_lock(&waiter->lock);
while (!waiter->done)
pthread_cond_wait(&waiter->wakeup, &waiter->lock);
pthread_mutex_unlock(&waiter->lock);
uintptr_t ret = waiter->value;
// We document that after mp_waiter_wait() the waiter object becomes
// invalid. (It strictly returns only after mp_waiter_wakeup() has returned,
// and the object is "single-shot".) So destroy it here.
// Normally, we expect that the system uses futexes, in which case the
// following functions will do nearly nothing. This is true for Windows
// and Linux. But some lesser OSes still might allocate kernel objects
// when initializing mutexes, so destroy them here.
pthread_mutex_destroy(&waiter->lock);
pthread_cond_destroy(&waiter->wakeup);
memset(waiter, 0xCA, sizeof(*waiter)); // for debugging
return ret;
}
void mp_waiter_wakeup(struct mp_waiter *waiter, uintptr_t value)
{
pthread_mutex_lock(&waiter->lock);
assert(!waiter->done);
waiter->done = true;
waiter->value = value;
pthread_cond_signal(&waiter->wakeup);
pthread_mutex_unlock(&waiter->lock);
}
bool mp_waiter_poll(struct mp_waiter *waiter)
{
pthread_mutex_lock(&waiter->lock);
bool r = waiter->done;
pthread_mutex_unlock(&waiter->lock);
return r;
}
#ifndef __MINGW32__
struct mp_cancel {
atomic_bool triggered;
int wakeup_pipe[2];
};
static void cancel_destroy(void *p)
{
struct mp_cancel *c = p;
if (c->wakeup_pipe[0] >= 0) {
close(c->wakeup_pipe[0]);
close(c->wakeup_pipe[1]);
}
}
struct mp_cancel *mp_cancel_new(void *talloc_ctx)
{
struct mp_cancel *c = talloc_ptrtype(talloc_ctx, c);
talloc_set_destructor(c, cancel_destroy);
*c = (struct mp_cancel){.triggered = ATOMIC_VAR_INIT(false)};
mp_make_wakeup_pipe(c->wakeup_pipe);
return c;
}
void mp_cancel_trigger(struct mp_cancel *c)
{
atomic_store(&c->triggered, true);
(void)write(c->wakeup_pipe[1], &(char){0}, 1);
}
void mp_cancel_reset(struct mp_cancel *c)
{
atomic_store(&c->triggered, false);
// Flush it fully.
while (1) {
int r = read(c->wakeup_pipe[0], &(char[256]){0}, 256);
if (r < 0 && errno == EINTR)
continue;
if (r <= 0)
break;
}
}
bool mp_cancel_test(struct mp_cancel *c)
{
return c ? atomic_load_explicit(&c->triggered, memory_order_relaxed) : false;
}
bool mp_cancel_wait(struct mp_cancel *c, double timeout)
{
struct pollfd fd = { .fd = c->wakeup_pipe[0], .events = POLLIN };
poll(&fd, 1, timeout * 1000);
return fd.revents & POLLIN;
}
int mp_cancel_get_fd(struct mp_cancel *c)
{
return c->wakeup_pipe[0];
}
#else
struct mp_cancel {
atomic_bool triggered;
HANDLE event;
};
static void cancel_destroy(void *p)
{
struct mp_cancel *c = p;
CloseHandle(c->event);
}
struct mp_cancel *mp_cancel_new(void *talloc_ctx)
{
struct mp_cancel *c = talloc_ptrtype(talloc_ctx, c);
talloc_set_destructor(c, cancel_destroy);
*c = (struct mp_cancel){.triggered = ATOMIC_VAR_INIT(false)};
c->event = CreateEventW(NULL, TRUE, FALSE, NULL);
return c;
}
void mp_cancel_trigger(struct mp_cancel *c)
{
atomic_store(&c->triggered, true);
SetEvent(c->event);
}
void mp_cancel_reset(struct mp_cancel *c)
{
atomic_store(&c->triggered, false);
ResetEvent(c->event);
}
bool mp_cancel_test(struct mp_cancel *c)
{
return c ? atomic_load_explicit(&c->triggered, memory_order_relaxed) : false;
}
bool mp_cancel_wait(struct mp_cancel *c, double timeout)
{
return WaitForSingleObject(c->event, timeout < 0 ? INFINITE : timeout * 1000)
== WAIT_OBJECT_0;
}
void *mp_cancel_get_event(struct mp_cancel *c)
{
return c->event;
}
int mp_cancel_get_fd(struct mp_cancel *c)
{
return -1;
}
#endif
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