[vlc-commits] os2: thread: implement vlc_cond_signal() correctly
KO Myung-Hun
git at videolan.org
Tue Dec 8 10:18:09 CET 2015
vlc/vlc-2.2 | branch: master | KO Myung-Hun <komh78 at gmail.com> | Sun Dec 6 18:57:38 2015 +0900| [03c486577b06a1b012a8e32918bdbdfa3afe6c2a] | committer: Jean-Baptiste Kempf
os2: thread: implement vlc_cond_signal() correctly
Signed-off-by: Rémi Denis-Courmont <remi at remlab.net>
(cherry picked from commit 867024da82f9e13d9ff8da1ce41bf47d6aebbd0e)
Signed-off-by: KO Myung-Hun <komh at chollian.net>
Signed-off-by: Jean-Baptiste Kempf <jb at videolan.org>
> http://git.videolan.org/gitweb.cgi/vlc/vlc-2.2.git/?a=commit;h=03c486577b06a1b012a8e32918bdbdfa3afe6c2a
---
include/vlc_threads.h | 5 ++-
src/os2/thread.c | 117 ++++++++++++++++++++++++++++++++-----------------
2 files changed, 81 insertions(+), 41 deletions(-)
diff --git a/include/vlc_threads.h b/include/vlc_threads.h
index d3f021b..ff43d6f 100644
--- a/include/vlc_threads.h
+++ b/include/vlc_threads.h
@@ -94,9 +94,12 @@ typedef struct
typedef struct
{
HEV hev;
+ unsigned waiters;
+ HEV hevAck;
+ unsigned signaled;
unsigned clock;
} vlc_cond_t;
-#define VLC_STATIC_COND { 0, 0 }
+#define VLC_STATIC_COND { NULLHANDLE, 0, NULLHANDLE, 0, 0 }
#define LIBVLC_NEED_SEMAPHORE
#define LIBVLC_NEED_RWLOCK
typedef struct vlc_threadvar *vlc_threadvar_t;
diff --git a/src/os2/thread.c b/src/os2/thread.c
index 1f3885c..7d49c1c 100644
--- a/src/os2/thread.c
+++ b/src/os2/thread.c
@@ -45,6 +45,8 @@
#include <sys/time.h>
#include <sys/select.h>
+#include <386/builtin.h>
+
static vlc_threadvar_t thread_key;
/**
@@ -261,9 +263,12 @@ enum
static void vlc_cond_init_common (vlc_cond_t *p_condvar, unsigned clock)
{
- /* Create a manual-reset event (manual reset is needed for broadcast). */
- if (DosCreateEventSem (NULL, &p_condvar->hev, 0, FALSE))
+ if (DosCreateEventSem (NULL, &p_condvar->hev, 0, FALSE) ||
+ DosCreateEventSem (NULL, &p_condvar->hevAck, 0, FALSE))
abort();
+
+ p_condvar->waiters = 0;
+ p_condvar->signaled = 0;
p_condvar->clock = clock;
}
@@ -280,6 +285,7 @@ void vlc_cond_init_daytime (vlc_cond_t *p_condvar)
void vlc_cond_destroy (vlc_cond_t *p_condvar)
{
DosCloseEventSem( p_condvar->hev );
+ DosCloseEventSem( p_condvar->hevAck );
}
void vlc_cond_signal (vlc_cond_t *p_condvar)
@@ -287,8 +293,28 @@ void vlc_cond_signal (vlc_cond_t *p_condvar)
if (!p_condvar->hev)
return;
- /* This is suboptimal but works. */
- vlc_cond_broadcast (p_condvar);
+ if (!__atomic_cmpxchg32 (&p_condvar->waiters, 0, 0))
+ {
+ ULONG ulPost;
+
+ __atomic_xchg (&p_condvar->signaled, 1);
+ DosPostEventSem (p_condvar->hev);
+
+ DosWaitEventSem (p_condvar->hevAck, SEM_INDEFINITE_WAIT);
+ DosResetEventSem (p_condvar->hevAck, &ulPost);
+
+ while (ulPost-- > 0)
+ __atomic_decrement (&p_condvar->waiters);
+
+ /* Already timed out ? */
+ if (__atomic_cmpxchg32 (&p_condvar->waiters, 0, 0) &&
+ __atomic_cmpxchg32 (&p_condvar->signaled, 1, 1))
+ {
+ /* Clear signaled status */
+ __atomic_xchg (&p_condvar->signaled, 0);
+ DosResetEventSem (p_condvar->hev, &ulPost);
+ }
+ }
}
void vlc_cond_broadcast (vlc_cond_t *p_condvar)
@@ -296,39 +322,55 @@ void vlc_cond_broadcast (vlc_cond_t *p_condvar)
if (!p_condvar->hev)
return;
- /* Wake all threads up (as the event HANDLE has manual reset) */
- DosPostEventSem( p_condvar->hev );
+ while (!__atomic_cmpxchg32 (&p_condvar->waiters, 0, 0))
+ vlc_cond_signal (p_condvar);
}
-void vlc_cond_wait (vlc_cond_t *p_condvar, vlc_mutex_t *p_mutex)
+static int vlc_cond_wait_common (vlc_cond_t *p_condvar, vlc_mutex_t *p_mutex,
+ ULONG ulTimeout)
{
ULONG ulPost;
ULONG rc;
- if (!p_condvar->hev)
- { /* FIXME FIXME FIXME */
- msleep (50000);
- return;
- }
+ __atomic_increment (&p_condvar->waiters);
do
{
vlc_testcancel();
vlc_mutex_unlock (p_mutex);
- rc = vlc_WaitForSingleObject( p_condvar->hev, SEM_INDEFINITE_WAIT );
+
+ do
+ {
+ rc = vlc_WaitForSingleObject( p_condvar->hev, ulTimeout );
+ if (rc == NO_ERROR)
+ DosResetEventSem (p_condvar->hev, &ulPost);
+ } while (rc == NO_ERROR &&
+ __atomic_cmpxchg32 (&p_condvar->signaled, 0, 1) == 0);
+
+ DosPostEventSem (p_condvar->hevAck);
+
vlc_mutex_lock (p_mutex);
} while( rc == ERROR_INTERRUPT );
- DosResetEventSem( p_condvar->hev, &ulPost );
+ return rc ? ETIMEDOUT : 0;
+}
+
+void vlc_cond_wait (vlc_cond_t *p_condvar, vlc_mutex_t *p_mutex)
+{
+ if (!p_condvar->hev)
+ { /* FIXME FIXME FIXME */
+ msleep (50000);
+ return;
+ }
+
+ vlc_cond_wait_common (p_condvar, p_mutex, SEM_INDEFINITE_WAIT);
}
int vlc_cond_timedwait (vlc_cond_t *p_condvar, vlc_mutex_t *p_mutex,
mtime_t deadline)
{
ULONG ulTimeout;
- ULONG ulPost;
- ULONG rc;
if (!p_condvar->hev)
{ /* FIXME FIXME FIXME */
@@ -336,35 +378,30 @@ int vlc_cond_timedwait (vlc_cond_t *p_condvar, vlc_mutex_t *p_mutex,
return 0;
}
- do
+ mtime_t total;
+ switch (p_condvar->clock)
{
- vlc_testcancel();
-
- mtime_t total;
- switch (p_condvar->clock)
+ case CLOCK_REALTIME:
{
- case CLOCK_REALTIME: /* FIXME? sub-second precision */
- total = CLOCK_FREQ * time (NULL);
- break;
- default:
- assert (p_condvar->clock == CLOCK_MONOTONIC);
- total = mdate();
- break;
- }
- total = (deadline - total) / 1000;
- if( total < 0 )
- total = 0;
-
- ulTimeout = ( total > 0x7fffffff ) ? 0x7fffffff : total;
+ struct timeval tv;
+ gettimeofday (&tv, NULL);
- vlc_mutex_unlock (p_mutex);
- rc = vlc_WaitForSingleObject( p_condvar->hev, ulTimeout );
- vlc_mutex_lock (p_mutex);
- } while( rc == ERROR_INTERRUPT );
+ total = CLOCK_FREQ * tv.tv_sec +
+ CLOCK_FREQ * tv.tv_usec / 1000000L;
+ break;
+ }
+ default:
+ assert (p_condvar->clock == CLOCK_MONOTONIC);
+ total = mdate();
+ break;
+ }
+ total = (deadline - total) / 1000;
+ if( total < 0 )
+ total = 0;
- DosResetEventSem( p_condvar->hev, &ulPost );
+ ulTimeout = ( total > 0x7fffffff ) ? 0x7fffffff : total;
- return rc ? ETIMEDOUT : 0;
+ return vlc_cond_wait_common (p_condvar, p_mutex, ulTimeout);
}
/*** Thread-specific variables (TLS) ***/
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