Changeset aa6b5c552d671fc1fce4ca38e5aff41ae259c28e

Timestamp:

27/08/08 21:43:09 (3 months ago)

Author:

Rémi Denis-Courmont <rdenis@simphalempin.com>

git-committer:

Rémi Denis-Courmont <rdenis@simphalempin.com> 1219866189 +0300

git-parent:

[8458705f21592934c5d2a1ebff7d8a8d7c8e63c1]

git-author:

Rémi Denis-Courmont <rdenis@simphalempin.com> 1218391571 +0300

Message:

Support for cancellation cleanup functions

Files:

• include/vlc_threads.h (modified) (2 diffs)
• src/misc/threads.c (modified) (3 diffs)

include/vlc_threads.h

@@ -188 +188 @@
-    VLC_TEST_CANCEL,
-    VLC_DO_CANCEL,
+    VLC_CLEANUP_PUSH,
+    VLC_CLEANUP_POP,
-};
-#endif
@@ -317 +319 @@
-#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 */
-
-/*****************************************************************************

src/misc/threads.c

@@ -865 +865 @@
-}
-
-
-
-
-
-
-
-
+
-typedef struct vlc_cancel_t
-{
@@ -878 +872 @@
-    bool           killed;
-} vlc_cancel_t;
+#endif
-
-void vlc_control_cancel (int cmd, ...)
-{
+    /* NOTE: This function only modifies thread-specific data, so there is no
+     * need to lock anything. */
-#ifdef LIBVLC_USE_PTHREAD
-    (void) cmd;
@@ -936 +933 @@
-            nfo->killed = true;
-            break;
+
+        case VLC_CLEANUP_PUSH:
+        {
+            /* cleaner is a pointer to the caller stack, no need to allocate
+             * and copy anything. As a nice side effect, this cannot fail. */
+            vlc_cleanup_t *cleaner = va_arg (ap, vlc_cleanup_t *);
+            cleaner->next = nfo->cleaners;
+            nfo->cleaners = cleaner;
+            break;
+        }
+
+        case VLC_CLEANUP_POP:
+        {
+            nfo->cleaners = nfo->cleaners->next;
+            break;
+        }
-    }
-    va_end (ap);