Ken Thomases : winecoreaudio: Fix race to open.

[Alexandre Julliard]

Module: wine
Branch: refs/heads/master
Commit: 00e99963398ae0f46f25fc6cc541e37958ab1224
URL:    http://source.winehq.org/git/?p=wine.git;a=commit;h=00e99963398ae0f46f25fc6c...

Author: Ken Thomases 
Date:   Wed May 24 05:27:24 2006 -0500

winecoreaudio: Fix race to open.

Fixes a race condition (noted in a comment for wodOpen) when multiple
threads try to open the same wave-out device simultaneously.
Addressed by creating the device mutexes when the driver is
initialized, instead of as each device is opened.  Then use the mutex
to protect the open operation against races.  At the same time, made
the mutexes recursive to avoid self-deadlocks the driver was
encountering when reentered from the callback.

---

dlls/winmm/winecoreaudio/audio.c |   43 +++++++++++++++++++++++++++-----------
 1 files changed, 30 insertions(+), 13 deletions(-)

diff --git a/dlls/winmm/winecoreaudio/audio.c b/dlls/winmm/winecoreaudio/audio.c
index 7c43d95..ea15635 100644
--- a/dlls/winmm/winecoreaudio/audio.c
+++ b/dlls/winmm/winecoreaudio/audio.c
@@ -445,6 +445,7 @@ LONG CoreAudio_WaveInit(void)
     OSStatus status;
     UInt32 propertySize;
     CHAR szPname[MAXPNAMELEN];
+    pthread_mutexattr_t mutexattr;
     int i;
     HANDLE hThread;

@@ -476,6 +477,9 @@ LONG CoreAudio_WaveInit(void)
     CoreAudio_DefaultDevice.interface_name=HeapAlloc(GetProcessHeap(),0,strlen(CoreAudio_DefaultDevice.dev_name)+1);
     sprintf(CoreAudio_DefaultDevice.interface_name, "%s", CoreAudio_DefaultDevice.dev_name);

+    pthread_mutexattr_init(&mutexattr);
+    pthread_mutexattr_settype(&mutexattr, PTHREAD_MUTEX_RECURSIVE);
+
     for (i = 0; i < MAX_WAVEOUTDRV; ++i)
     {
         WOutDev[i].state = WINE_WS_CLOSED;
@@ -509,7 +513,11 @@ LONG CoreAudio_WaveInit(void)
         WOutDev[i].caps.dwFormats |= WAVE_FORMAT_1S08;
         WOutDev[i].caps.dwFormats |= WAVE_FORMAT_1M16;
         WOutDev[i].caps.dwFormats |= WAVE_FORMAT_1S16;
+
+        pthread_mutex_init(&WOutDev[i].lock, &mutexattr); /* initialize the mutex */
     }
+
+    pthread_mutexattr_destroy(&mutexattr);

/* create mach messages handler */
     hThread = CreateThread(NULL, 0, messageThread, NULL, 0, NULL);
@@ -526,12 +534,18 @@ void CoreAudio_WaveRelease(void)
 {
     /* Stop CFRunLoop in messageThread */
     CFMessagePortRef messagePort;
+    int i;

TRACE("()\n");

messagePort = CFMessagePortCreateRemote(kCFAllocatorDefault, CFSTR("WaveMessagePort"));
     CFMessagePortSendRequest(messagePort, kStopLoopMessage, NULL, 0.0, 0.0, NULL, NULL);
     CFRelease(messagePort);
+
+    for (i = 0; i < MAX_WAVEOUTDRV; ++i)
+    {
+        pthread_mutex_destroy(&WOutDev[i].lock);
+    }
 }

/*======================================================================*
@@ -591,9 +605,6 @@ static DWORD wodGetDevCaps(WORD wDevID,

/**************************************************************************
 * 				wodOpen				[internal]
-*
-* NOTE: doesn't it seem like there is a race condition if you try to open 
-* the same device twice?
 */
 static DWORD wodOpen(WORD wDevID, LPWAVEOPENDESC lpDesc, DWORD dwFlags)
 {
@@ -637,9 +648,18 @@ static DWORD wodOpen(WORD wDevID, LPWAVE
     }

wwo = &WOutDev[wDevID];
+    pthread_mutex_lock(&wwo->lock);
+
+    if (wwo->state != WINE_WS_CLOSED)
+    {
+        pthread_mutex_unlock(&wwo->lock);
+        return MMSYSERR_ALLOCATED;
+    }
+
     if (!AudioUnit_CreateDefaultAudioUnit((void *) wwo, &wwo->audioUnit))
     {
         ERR("CoreAudio_CreateDefaultAudioUnit(%p) failed\n", wwo);
+        pthread_mutex_unlock(&wwo->lock);
         return MMSYSERR_ERROR;
     }

@@ -648,11 +668,6 @@ static DWORD wodOpen(WORD wDevID, LPWAVE
    /* not supported, ignore it */
    dwFlags &= ~WAVE_DIRECTSOUND;

-    if (wwo->state != WINE_WS_CLOSED) return MMSYSERR_ALLOCATED;
-    
-    pthread_mutex_init(&wwo->lock, NULL); /* initialize the mutex */
-    pthread_mutex_lock(&wwo->lock);
-
     streamFormat.mFormatID = kAudioFormatLinearPCM;

/* FIXME check for 32bits float -> kLinearPCMFormatFlagIsFloat */
@@ -677,8 +692,6 @@ # endif
     }
     wwo->streamDescription = streamFormat;
     wwo->state = WINE_WS_STOPPED;
-        
-    pthread_mutex_unlock(&wwo->lock);

wwo->wFlags = HIWORD(dwFlags & CALLBACK_TYPEMASK);

@@ -695,6 +708,8 @@ # endif

wwo->dwPlayedTotal = 0;
     wwo->dwWrittenTotal = 0;
+        
+    pthread_mutex_unlock(&wwo->lock);

retval = wodNotifyClient(wwo, WOM_OPEN, 0L, 0L);

@@ -718,9 +733,11 @@ static DWORD wodClose(WORD wDevID)
     }

wwo = &WOutDev[wDevID];
+    pthread_mutex_lock(&wwo->lock);
     if (wwo->lpQueuePtr)
     {
         WARN("buffers still playing !\n");
+        pthread_mutex_unlock(&wwo->lock);
         ret = WAVERR_STILLPLAYING;
     } else
     {
@@ -736,17 +753,17 @@ static DWORD wodClose(WORD wDevID)
                                                             (char) (err >> 16),
                                                             (char) (err >> 8),
                                                             (char) err);
-            pthread_mutex_destroy(&wwo->lock);
+            pthread_mutex_unlock(&wwo->lock);
             return MMSYSERR_ERROR; /* FIXME return an error based on the OSStatus */
         }

if ( !AudioUnit_CloseAudioUnit(wwo->audioUnit) )
         {
             ERR("Can't close AudioUnit\n");
-            pthread_mutex_destroy(&wwo->lock);
+            pthread_mutex_unlock(&wwo->lock);
             return MMSYSERR_ERROR; /* FIXME return an error based on the OSStatus */
         }  
-        pthread_mutex_destroy(&wwo->lock);
+        pthread_mutex_unlock(&wwo->lock);

ret = wodNotifyClient(wwo, WOM_CLOSE, 0L, 0L);
     }