Changeset 689dd889dee2ea43e8a7cb64ccec0b923a8a60bd

Timestamp:

28/01/08 18:01:48 (9 months ago)

Author:

Rémi Denis-Courmont <rem@videolan.org>

git-committer:

Rémi Denis-Courmont <rem@videolan.org> 1201539708 +0000

git-parent:

[e15891a3316a7b2c3fc0480fd5ff8f18858d8802]

git-author:

Rémi Denis-Courmont <rem@videolan.org> 1201539708 +0000

Message:

Only use waitpipe for _kill, rather than _signal, which is what people expect
(You really don't usually want your net_Read/net_Write to interrupted).
In the process, fix a deadlock in vlc_cond_wait() when waitpipe is used - fixes #1448

Files:

• src/libvlc.h (modified) (1 diff)
• src/misc/objects.c (modified) (7 diffs)

src/libvlc.h

@@ -110 +110 @@
-
-    /* Objects thread synchronization */
-    vlc_bool_t      b_signaled;
-    int             pipes[2];
-    vlc_spinlock_t  spin;

src/misc/objects.c

@@ -451 +451 @@
-    vlc_cond_destroy( &p_this->object_wait );
-    vlc_spin_destroy( &p_priv->spin );
+    if( p_priv->pipes[1] != -1 )
+        close( p_priv->pipes[1] );
-    if( p_priv->pipes[0] != -1 )
-        close( p_priv->pipes[0] );
-    if( p_priv->pipes[1] != -1 )
-        close( p_priv->pipes[1] );
-
-    /* global is not dynamically allocated by vlc_object_create */
@@ -529 +529 @@
-
-/**
-
-
-
+
+
+
+
- *
- * Note that the pipe will remain the same for the lifetime of the object.
-
+read the pipe nor 
- *
-
-
-
-
-
+
- * @return a readable pipe descriptor, or -1 on error.
- */
@@ -547 +544 @@
-    int pfd[2] = { -1, -1 };
-    struct vlc_object_internals_t *internals = obj->p_internals;
-race = VLC_FALSE, signa
+kil
-
-    vlc_spin_lock (&internals->spin);
@@ -560 +557 @@
-
-        vlc_spin_lock (&internals->spin);
-        signaled = internals->b_signaled;
-        if (internals->pipes[0] == -1)
-        {
-            internals->pipes[0] = pfd[0];
-            internals->pipes[1] = pfd[1];
-}
-else
-    race = VLC_TRUE
+    pfd[0] = pfd[1] = -1;
+}
+killed = obj->b_die
-    }
-    vlc_spin_unlock (&internals->spin);
-
-
-
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
-        close (pfd[0]);
+    if (pfd[1] != -1)
-        close (pfd[1]);
-    }
-
-    if (signaled)
-        /* Race condition: lc_object_signal() already invoked! */
-        while (write (internals->pipes[1], &(char){ 0 }, 1) < 0);
-
-    return internals->pipes[0];
@@ -594 +599 @@
-vlc_bool_t __vlc_object_wait( vlc_object_t *obj )
-{
-    int fd;
-
-    vlc_assert_locked( &obj->object_lock );
-
-    fd = obj->p_internals->pipes[0];
-    if (fd != -1)
-    {
-        while (read (fd, &(char){ 0 }, 1)  < 0);
-        return obj->b_die;
-    }
-
-    vlc_cond_wait( &obj->object_wait, &obj->object_lock );
-    obj->p_internals->b_signaled = VLC_FALSE;
-    return obj->b_die;
-}
@@ -668 +662 @@
-void __vlc_object_signal_unlocked( vlc_object_t *obj )
-{
-    struct vlc_object_internals_t *internals = obj->p_internals;
-    int fd;
-
-    vlc_assert_locked (&obj->object_lock);
-
-    vlc_spin_lock (&internals->spin);
-    fd = internals->pipes[1];
-    internals->b_signaled = VLC_TRUE;
-    vlc_spin_unlock (&internals->spin);
-
-    if( fd != -1 )
-        while( write( fd, &(char){ 0 }, 1 ) < 0 );
-
-    vlc_cond_signal( &obj->object_wait );
-}
@@ -691 +673 @@
-void __vlc_object_kill( vlc_object_t *p_this )
-{
+    struct vlc_object_internals_t *internals = p_this->p_internals;
+    int fd;
+
-    vlc_mutex_lock( &p_this->object_lock );
-    p_this->b_die = VLC_TRUE;
+
+    vlc_spin_lock (&internals->spin);
+    fd = internals->pipes[1];
+    internals->pipes[1] = -1;
+    vlc_spin_unlock (&internals->spin);
+
+    if( fd != -1 )
+        close (fd);
-
-    if( p_this->i_object_type == VLC_OBJECT_LIBVLC )