2005-02-02 Dan Williams <dcbw@redhat.com>

* src/NetworkManagerAPList.c
		- (nm_ap_list_merge_scanned_ap): merge strength too

	* src/NetworkManagerUtils.c
		- (nm_lock_mutex, nm_register_mutex_desc): new calls to facilitate debugging
			of locking issues by printing out prettier information than g_mutex_lock
		- Print out names of mutexes registered with nm_register_mutex_desc()
		- (nm_try_lock_mutex): don't do the waiting thing when trying to lock, causes
			us to seemingly block here for too long

	* src/NetworkManager.c
	  src/NetworkManagerAPList.c
	  src/NetworkManagerDevice.c
		- Convert to using nm_lock_mutex/nm_unlock_mutex rather than the glib variants
			so we get better debug information printed

	* src/NetworkManagerDbus.c
		- (nm_dbus_devices_handle_request): reduce usage of nm_device_need_ap_switch()
			since it sometimes has locking side effects
		- (nm_device_get_association_pause_value): Reduce 802.11a card pause value to 8s
			from 10s
		- (nm_device_need_ap_switch): If we can't acquire the scan lock, return saying
			we don't need a switch.  This gets called often enough that we can't block
			until the scan mutex is acquired, because we'll block on device activation
			and a few other things, which hangs main thread for too long.

	* src/NetworkManagerPolicy.c
		- (nm_policy_auto_get_best_device): reduce the possiblity that
			nm_device_need_ap_switch() will be called


git-svn-id: http://svn-archive.gnome.org/svn/NetworkManager/trunk@407 4912f4e0-d625-0410-9fb7-b9a5a253dbdc

src/NetworkManagerUtils.c

@@ -30,7 +30,50 @@
 #include "NetworkManagerUtils.h"
 
 
-/*#define LOCKING_DEBUG */
+typedef struct MutexDesc
+{
+	GMutex	*mutex;
+	char		*desc;
+} MutexDesc;
+
+GSList	*mutex_descs = NULL;
+
+/*#define LOCKING_DEBUG*/
+
+
+static MutexDesc *nm_find_mutex_desc (GMutex *mutex)
+{
+	GSList	*elt;
+	gboolean	 found = FALSE;
+
+	for (elt = mutex_descs; elt; elt = g_slist_next (elt))
+	{
+		MutexDesc	*desc = (MutexDesc *)(elt->data);
+		if (desc && (desc->mutex == mutex))
+			return desc;
+	}
+
+	return NULL;
+}
+
+
+/*
+ * nm_register_mutex_desc
+ * 
+ * Associate a description with a particular mutex.
+ *
+ */
+void nm_register_mutex_desc (GMutex *mutex, char *string)
+{
+	if (!(nm_find_mutex_desc (mutex)))
+	{
+		MutexDesc	*desc = g_malloc0 (sizeof (MutexDesc));
+		desc->mutex = mutex;
+		desc->desc = g_strdup (string);
+		mutex_descs = g_slist_append (mutex_descs, desc);
+	}
+}
+
 
 /*
  * nm_try_acquire_mutex
@@ -42,30 +85,50 @@
  */
 gboolean nm_try_acquire_mutex (GMutex *mutex, const char *func)
 {
-	gint	i = 5;
-
 	g_return_val_if_fail (mutex != NULL, FALSE);
 
-	while (i > 0)
+	if (g_mutex_trylock (mutex))
 	{
-		if (g_mutex_trylock (mutex))
-		{
 #ifdef LOCKING_DEBUG
-			if (func) syslog (LOG_DEBUG, "MUTEX: %s got mutex 0x%X", func, mutex);
-#endif
-			return (TRUE);
+		if (func)
+		{
+			MutexDesc	*desc = nm_find_mutex_desc (mutex);
+			syslog (LOG_DEBUG, "MUTEX: <%s %p> acquired by %s", desc ? desc->desc : "(none)", mutex, func);
 		}
-		g_usleep (G_USEC_PER_SEC / 2);
-		i++;
+#endif
+		return (TRUE);
 	}
 
 #ifdef LOCKING_DEBUG
-	if (func) syslog (LOG_DEBUG, "MUTEX: %s FAILED to get mutex 0x%X", func, mutex);
+	if (func)
+	{
+		MutexDesc	*desc = nm_find_mutex_desc (mutex);
+		syslog (LOG_DEBUG, "MUTEX: <%s %p> FAILED to be acquired by %s", desc ? desc->desc : "(none)", mutex, func);
+	}
 #endif
 	return (FALSE);
 }
 
 
+/*
+ * nm_lock_mutex
+ *
+ * Blocks until a mutex is grabbed, with debugging.
+ *
+ */
+void nm_lock_mutex (GMutex *mutex, const char *func)
+{
+#ifdef LOCKING_DEBUG
+	if (func)
+	{
+		MutexDesc	*desc = nm_find_mutex_desc (mutex);
+		syslog (LOG_DEBUG, "MUTEX: <%s %p> being acquired by %s", desc ? desc->desc : "(none)", mutex, func);
+	}
+#endif
+	g_mutex_lock (mutex);
+}
+
+
 /*
  * nm_unlock_mutex
  *
@@ -77,7 +140,11 @@ void nm_unlock_mutex (GMutex *mutex, const char *func)
 	g_return_if_fail (mutex != NULL);
 
 #ifdef LOCKING_DEBUG	
-	if (func) syslog (LOG_DEBUG, "MUTEX: %s released mutex 0x%X", func, mutex);
+	if (func)
+	{
+		MutexDesc	*desc = nm_find_mutex_desc (mutex);
+		syslog (LOG_DEBUG, "MUTEX: <%s %p> released by %s", desc ? desc->desc : "(none)", mutex, func);
+	}
 #endif
 
 	g_mutex_unlock (mutex);