Changeset 3254 for trunk/libtransmission/platform.c

Timestamp:

Oct 1, 2007, 3:17:15 PM (13 years ago)

Author:

charles

Message:

simplify libT locks now that it's (more-or-less) single-threaded. fix deadlocks. make tr_locks nestable.

File:

• trunk/libtransmission/platform.c (modified) (6 diffs)

trunk/libtransmission/platform.c

@@ -57 +57 @@
 ***/
 
+#ifdef __BEOS__
+typedef thread_id tr_thread_id;
+#elif defined(WIN32)
+typedef DWORD tr_thread_id;
+#else
+typedef pthread_t tr_thread_id;
+#endif
+
+static tr_thread_id
+tr_getCurrentThread( void )
+{
+#ifdef __BEOS__
+    return find_thread( NULL );
+#elif defined(WIN32)
+    return GetCurrentThreadId();
+#else
+    return pthread_self( );
+#endif
+}
+
+static int
+tr_areThreadsEqual( tr_thread_id a, tr_thread_id b )
+{
+#ifdef __BEOS__
+    return a == b;
+#elif defined(WIN32)
+    return a == b;
+#else
+    return pthread_equal( a, b );
+#endif
+}
+
 struct tr_thread
 {
@@ -73 +105 @@
 
 };
+
+int
+tr_amInThread ( const tr_thread * t )
+{
+    return tr_areThreadsEqual( tr_getCurrentThread(), t->thread );
+}
 
 #ifdef WIN32
@@ -123 +161 @@
     return t;
 }
-
-int
-tr_amInThread ( const tr_thread * t )
-{
-#ifdef __BEOS__
-    return find_thread(NULL) == t->thread;
-#elif defined(WIN32)
-    return GetCurrentThreadId() == t->thread_id;
-#else
-    return pthread_equal( t->thread, pthread_self( ) );
-#endif
-}
     
 void
@@ -164 +190 @@
 struct tr_lock
 {
+    uint32_t depth;
 #ifdef __BEOS__
     sem_id lock;
+    thread_id lockThread;
 #elif defined(WIN32)
     CRITICAL_SECTION lock;
+    DWORD lockThread;
 #else
     pthread_mutex_t lock;
+    pthread_t lockThread;
 #endif
 };
@@ -217 +247 @@
 tr_lockLock( tr_lock * l )
 {
-#ifdef __BEOS__
-    acquire_sem( l->lock );
-#elif defined(WIN32)
-    EnterCriticalSection( &l->lock );
-#else
-    pthread_mutex_lock( &l->lock );
-#endif
+    tr_thread_id currentThread = tr_getCurrentThread( );
+    if( l->lockThread == currentThread )
+    {
+        ++l->depth;
+    }
+    else
+    {
+#ifdef __BEOS__
+        acquire_sem( l->lock );
+#elif defined(WIN32)
+        EnterCriticalSection( &l->lock );
+#else
+        pthread_mutex_lock( &l->lock );
+#endif
+        l->lockThread = tr_getCurrentThread( );
+        l->depth = 1;
+    }
+}
+
+int
+tr_lockHave( const tr_lock * l )
+{
+    return ( l->depth > 0 )
+        && ( l->lockThread == tr_getCurrentThread() );
 }
 
@@ -229 +276 @@
 tr_lockUnlock( tr_lock * l )
 {
-#ifdef __BEOS__
-    release_sem( l->lock );
-#elif defined(WIN32)
-    LeaveCriticalSection( &l->lock );
-#else
-    pthread_mutex_unlock( &l->lock );
-#endif
+    assert( tr_lockHave( l ) );
+
+    if( !--l->depth )
+    {
+        l->lockThread = 0;
+#ifdef __BEOS__
+        release_sem( l->lock );
+#elif defined(WIN32)
+        LeaveCriticalSection( &l->lock );
+#else
+        pthread_mutex_unlock( &l->lock );
+#endif
+    }
 }