Cleanup helper for unlocking

[vlc] / include / vlc_threads.h

diff --git a/include/vlc_threads.h b/include/vlc_threads.h
index 63e61d126ee759100cba717cc761d4c8ea845db6..c6be0eacddb1e3f8db17d66149b309e01c37e5b1 100644 (file)
--- a/include/vlc_threads.h
+++ b/include/vlc_threads.h
@@ -186,6 +186,9 @@ enum {
     VLC_SAVE_CANCEL,
     VLC_RESTORE_CANCEL,
     VLC_TEST_CANCEL,
+    VLC_DO_CANCEL,
+    VLC_CLEANUP_PUSH,
+    VLC_CLEANUP_POP,
 };
 #endif
 
@@ -316,6 +319,66 @@ static inline void vlc_testcancel (void)
 #endif
 }
 
+#if defined (LIBVLC_USE_PTHREAD)
+/**
+ * Registers a new procedure to run if the thread is cancelled (or otherwise
+ * exits prematurely). Any call to vlc_cleanup_push() <b>must</b> paired with a
+ * call to either vlc_cleanup_pop() or vlc_cleanup_run(). Branching into or out
+ * of the block between these two function calls is not allowed (read: it will
+ * likely crash the whole process). If multiple procedures are registered,
+ * they are handled in last-in first-out order.
+ *
+ * @param routine procedure to call if the thread ends
+ * @param arg argument for the procedure
+ */
+# define vlc_cleanup_push( routine, arg ) pthread_cleanup_push (routine, arg)
+
+/**
+ * Removes a cleanup procedure that was previously registered with
+ * vlc_cleanup_push().
+ */
+# define vlc_cleanup_pop( ) pthread_cleanup_pop (0)
+
+/**
+ * Removes a cleanup procedure that was previously registered with
+ * vlc_cleanup_push(), and executes it.
+ */
+# define vlc_cleanup_run( ) pthread_cleanup_pop (1)
+#else
+typedef struct vlc_cleanup_t vlc_cleanup_t;
+
+struct vlc_cleanup_t
+{
+    vlc_cleanup_t *next;
+    void         (*proc) (void *);
+    void          *data;
+};
+
+/* This macros opens a code block on purpose. This is needed for multiple
+ * calls within a single function. This also prevent Win32 developpers from
+ * writing code that would break on POSIX (POSIX opens a block as well). */
+# define vlc_cleanup_push( routine, arg ) \
+    do { \
+        vlc_cleanup_t vlc_cleanup_data = { NULL, routine, arg, }; \
+        vlc_control_cancel (VLC_CLEANUP_PUSH, &vlc_cleanup_data)
+
+# define vlc_cleanup_pop( ) \
+        vlc_control_cancel (VLC_CLEANUP_POP); \
+    } while (0)
+
+# define vlc_cleanup_run( ) \
+        vlc_control_cancel (VLC_CLEANUP_POP); \
+        vlc_cleanup_data.proc (vlc_cleanup_data.data); \
+    } while (0)
+
+#endif /* LIBVLC_USE_PTHREAD */
+
+static inline void vlc_cleanup_lock (void *lock)
+{
+    vlc_mutex_unlock ((vlc_mutex_t *)lock);
+}
+#define mutex_cleanup_push( lock ) vlc_cleanup_push (vlc_cleanup_lock, lock)
+
 /*****************************************************************************
  * vlc_cond_init: initialize a condition
  *****************************************************************************/
@@ -392,13 +455,21 @@ static inline void __vlc_cond_wait( const char * psz_file, int i_line,
     vlc_mutex_lock( p_mutex );
 
 #elif defined( WIN32 )
-    (void)psz_file; (void)i_line;
+    DWORD result;
 
-    /* Increase our wait count */
-    SignalObjectAndWait( *p_mutex, *p_condvar, INFINITE, FALSE );
+    do
+    {
+        vlc_testcancel ();
+        result = SignalObjectAndWait (*p_mutex, *p_condvar, INFINITE, TRUE);
 
-    /* Reacquire the mutex before returning. */
-    vlc_mutex_lock( p_mutex );
+        /* Reacquire the mutex before returning. */
+        vlc_mutex_lock( p_mutex );
+    }
+    while (result == WAIT_IO_COMPLETION);
+
+    vlc_testcancel ();
+
+    (void)psz_file; (void)i_line;
 
 #elif defined( SYS_BEOS )
     /* The p_condvar->thread var is initialized before the unlock because
@@ -433,9 +504,9 @@ static inline int __vlc_cond_timedwait( const char * psz_file, int i_line,
     struct timespec ts = { d.quot, d.rem * 1000 };
 
     int val = pthread_cond_timedwait (p_condvar, p_mutex, &ts);
-    if (val == ETIMEDOUT)
-        return ETIMEDOUT; /* this error is perfectly normal */
-    VLC_THREAD_ASSERT ("timed-waiting on condition");
+    if (val != ETIMEDOUT)
+        VLC_THREAD_ASSERT ("timed-waiting on condition");
+    return val;
 
 #elif defined( UNDER_CE )
     mtime_t delay_ms = (deadline - mdate())/1000;
@@ -449,39 +520,35 @@ static inline int __vlc_cond_timedwait( const char * psz_file, int i_line,
     /* Reacquire the mutex before returning. */
     vlc_mutex_lock( p_mutex );
 
-    if(result == WAIT_TIMEOUT)
-       return ETIMEDOUT; /* this error is perfectly normal */
-
     (void)psz_file; (void)i_line;
 
+    return (result == WAIT_TIMEOUT) ? ETIMEDOUT : 0;
+
 #elif defined( WIN32 )
-    mtime_t total = (deadline - mdate())/1000;
-    DWORD result;
-    if( total < 0 )
-        total = 0;
+    mtime_t total;
+    DWORD result = WAIT_TIMEOUT;
 
-    do
+    (void)psz_file; (void)i_line;
+
+    vlc_testcancel ();
+    while ((total = (deadline - mdate ()) > 0))
     {
         DWORD delay = (total > 0x7fffffff) ? 0x7fffffff : total;
         result = SignalObjectAndWait( *p_mutex, *p_condvar,
-                                      delay, FALSE );
-        total -= delay;
+                                      delay, TRUE );
+
+        /* Reacquire the mutex before return/cancel. */
         vlc_mutex_lock (p_mutex);
+        if (result == WAIT_OBJECT_0)
+            return 0; /* Condition signaled! */
+        vlc_testcancel ();
     }
-    while (total);
-
-    /* Reacquire the mutex before returning. */
-    if(result == WAIT_TIMEOUT)
-       return ETIMEDOUT; /* this error is perfectly normal */
-
-    (void)psz_file; (void)i_line;
+    return ETIMEDOUT;
 
 #elif defined( SYS_BEOS )
 #   error Unimplemented
 
 #endif
-
-    return 0;
 }
 
 /*****************************************************************************