[PATCH 1/3] avutil/thread: Add pthread_cond_timedwait function.

gistfile1.txt

From f4a48300bf545227b5fb9121bf46a95f40e8923a Mon Sep 17 00:00:00 2001
From: Matt Oliver <protogonoi@gmail.com>
Date: Wed, 7 Dec 2016 16:55:35 +1100
Subject: [PATCH 1/3] avutil/thread: Add pthread_cond_timedwait function.

Signed-off-by: Matt Oliver <protogonoi@gmail.com>
---
 compat/os2threads.h  | 24 ++++++++++++++++++++++++
 compat/w32pthreads.h | 50 ++++++++++++++++++++++++++++++++++++++++++++++++++
 libavutil/thread.h   |  6 ++++++
 3 files changed, 80 insertions(+)

diff --git a/compat/os2threads.h b/compat/os2threads.h
index 40a119f..a8b7824 100644
--- a/compat/os2threads.h
+++ b/compat/os2threads.h
@@ -31,11 +31,13 @@
 
 #undef __STRICT_ANSI__          /* for _beginthread() */
 #include <stdlib.h>
+#include <time.h>
 
 #include <sys/builtin.h>
 #include <sys/fmutex.h>
 
 #include "libavutil/attributes.h"
+#include "libavutil/time.h"
 
 typedef struct {
     TID tid;
@@ -161,6 +163,28 @@ static av_always_inline int pthread_cond_broadcast(pthread_cond_t *cond)
     return 0;
 }
 
+static av_always_inline int pthread_cond_timedwait(pthread_cond_t *cond,
+                                                   pthread_mutex_t *mutex,
+                                                   const struct timespec *abstime)
+{
+    int64_t abs_milli = abstime->tv_nsec * 1000LL + abstime->tv_nsec / 1.0e6;
+    ULONG t = FFMAX(abs_milli - av_gettime(), 0LL);
+
+    __atomic_increment(&cond->wait_count);
+
+    pthread_mutex_unlock(mutex);
+
+    APIRET ret = DosWaitEventSem(cond->event_sem, t);
+
+    __atomic_decrement(&cond->wait_count);
+
+    DosPostEventSem(cond->ack_sem);
+
+    pthread_mutex_lock(mutex);
+
+    return (ret == ERROR_TIMEOUT) ? ETIMEDOUT : 0;
+}
+
 static av_always_inline int pthread_cond_wait(pthread_cond_t *cond,
                                               pthread_mutex_t *mutex)
 {
diff --git a/compat/w32pthreads.h b/compat/w32pthreads.h
index 4ac2a99..abd54b2 100644
--- a/compat/w32pthreads.h
+++ b/compat/w32pthreads.h
@@ -38,6 +38,7 @@
 #define WIN32_LEAN_AND_MEAN
 #include <windows.h>
 #include <process.h>
+#include <time.h>
 
 #if _WIN32_WINNT < 0x0600 && defined(__MINGW32__)
 #undef MemoryBarrier
@@ -48,6 +49,7 @@
 #include "libavutil/common.h"
 #include "libavutil/internal.h"
 #include "libavutil/mem.h"
+#include "libavutil/time.h"
 
 typedef struct pthread_t {
     void *handle;
@@ -171,6 +173,17 @@ static inline int pthread_cond_wait(pthread_cond_t *cond, pthread_mutex_t *mutex
     return 0;
 }
 
+static inline int pthread_cond_timedwait(pthread_cond_t *cond, pthread_mutex_t *mutex,
+                                         const struct timespec *abstime)
+{
+    int64_t abs_milli = abstime->tv_nsec * 1000LL + abstime->tv_nsec / 1.0e6;
+    DWORD t = FFMAX(abs_milli - av_gettime(), 0LL);
+
+    if (SleepConditionVariableCS(cond, mutex, t) == WAIT_TIMEOUT)
+        return ETIMEDOUT;
+    return 0;
+}
+
 static inline int pthread_cond_signal(pthread_cond_t *cond)
 {
     WakeConditionVariable(cond);
@@ -367,6 +380,45 @@ static av_unused int pthread_cond_wait(pthread_cond_t *cond, pthread_mutex_t *mu
     return pthread_mutex_lock(mutex);
 }
 
+static inline int pthread_cond_timedwait(pthread_cond_t *cond, pthread_mutex_t *mutex,
+                                         const struct timespec *abstime)
+{
+    win32_cond_t *win32_cond = cond->Ptr;
+    int last_waiter;
+    int64_t abs_milli = abstime->tv_nsec * 1000LL + abstime->tv_nsec / 1.0e6;
+    DWORD t = FFMAX(abs_milli - av_gettime(), 0LL);
+    if (cond_wait) {
+        if (cond_wait(cond, mutex, t) == WAIT_TIMEOUT)
+            return ETIMEDOUT;
+        return 0;
+    }
+
+    /* non native condition variables */
+    pthread_mutex_lock(&win32_cond->mtx_broadcast);
+    pthread_mutex_lock(&win32_cond->mtx_waiter_count);
+    win32_cond->waiter_count++;
+    pthread_mutex_unlock(&win32_cond->mtx_waiter_count);
+    pthread_mutex_unlock(&win32_cond->mtx_broadcast);
+
+    // unlock the external mutex
+    pthread_mutex_unlock(mutex);
+    DWORD ret = WaitForSingleObject(win32_cond->semaphore, t);
+
+    pthread_mutex_lock(&win32_cond->mtx_waiter_count);
+    win32_cond->waiter_count--;
+    last_waiter = !win32_cond->waiter_count || !win32_cond->is_broadcast;
+    pthread_mutex_unlock(&win32_cond->mtx_waiter_count);
+
+    if (last_waiter)
+        SetEvent(win32_cond->waiters_done);
+
+    // lock the external mutex
+    pthread_mutex_lock(mutex);
+
+    return (ret == WAIT_TIMEOUT) ? ETIMEDOUT : 0;
+}
+
 static av_unused int pthread_cond_signal(pthread_cond_t *cond)
 {
     win32_cond_t *win32_cond = cond->Ptr;
diff --git a/libavutil/thread.h b/libavutil/thread.h
index 32ddf40..9d611f2 100644
--- a/libavutil/thread.h
+++ b/libavutil/thread.h
@@ -108,6 +108,12 @@ static inline int strict_pthread_cond_wait(pthread_cond_t *cond, pthread_mutex_t
     ASSERT_PTHREAD(pthread_cond_wait, cond, mutex);
 }
 
+static inline int strict_pthread_cond_timedwait(pthread_cond_t *cond, pthread_mutex_t *mutex,
+                                                const struct timespec *abstime)
+{
+    ASSERT_PTHREAD(pthread_cond_timedwait, cond, mutex, abstime);
+}
+
 static inline int strict_pthread_once(pthread_once_t *once_control, void (*init_routine)(void))
 {
     ASSERT_PTHREAD(pthread_once, once_control, init_routine);
-- 
2.10.2.windows.1