dplayx: Fix semaphore deadlock.

- Make sure to release the dplayx semaphore in for error cases as well. - Prevent race condition between creation of the semaphore and grabbing of the lock by creating the semaphore in the locked state instead of unlocked.

dplayx: Fix semaphore deadlock.
75fc82c9 · Aric Cyr · Alexandre Julliard · c04cbbfe · 75fc82c9
Commit 75fc82c9 authored Mar 04, 2006 by Aric Cyr Committed by Alexandre Julliard Mar 15, 2006
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Showing with 4 additions and 3 deletions

dplayx_global.c dlls/dplayx/dplayx_global.c +4 -3

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--- a/dlls/dplayx/dplayx_global.c
+++ b/dlls/dplayx/dplayx_global.c
@@ -229,7 +229,7 @@ BOOL DPLAYX_ConstructData(void)
  s_attrib.lpSecurityDescriptor = NULL;
  s_attrib.nLength              = sizeof(s_attrib);

-  hDplayxSema = CreateSemaphoreA( &s_attrib, 1, 1, lpszDplayxSemaName );
+  hDplayxSema = CreateSemaphoreA( &s_attrib, 0, 1, lpszDplayxSemaName );

  /* First instance creates the semaphore. Others just use it */
  if( GetLastError() == ERROR_SUCCESS )
@@ -242,6 +242,7 @@ BOOL DPLAYX_ConstructData(void)
  else if ( GetLastError() == ERROR_ALREADY_EXISTS )
  {
    TRACE( "Found semaphore handle %p\n", hDplayxSema );
+    DPLAYX_AquireSemaphore();
  }
  else
  {
@@ -251,8 +252,6 @@ BOOL DPLAYX_ConstructData(void)

  SetLastError( ERROR_SUCCESS );

-  DPLAYX_AquireSemaphore();
-
  hDplayxSharedMem = CreateFileMappingA( INVALID_HANDLE_VALUE,
                                         &s_attrib,
                                         PAGE_READWRITE | SEC_COMMIT,
@@ -271,6 +270,7 @@ BOOL DPLAYX_ConstructData(void)
  else
  {
    ERR( ": unable to create shared memory (%ld)\n", GetLastError() );
+    DPLAYX_ReleaseSemaphore();
    return FALSE;
  }

@@ -282,6 +282,7 @@ BOOL DPLAYX_ConstructData(void)
  {
    ERR( ": unable to map static data into process memory space (%ld)\n",
         GetLastError() );
+    DPLAYX_ReleaseSemaphore();
    return FALSE;
  }
  else