Changeset 19458 in webkit

Timestamp:

Feb 6, 2007 7:50:43 PM (17 years ago)

Author:

kdecker

Message:

Fixed: <rdar://problem/4976681> ASSERTION failure on quit @ talkcrunch.com in _NPN_ReleaseObject

Reviewed by Anders.

• Plugins/WebPluginDatabase.m: (+[WebPluginDatabase sharedDatabase]): Removed NSApplicationWillTerminateNotification observer and thus also removed code that would unload the entire plug-in database when receiving that notification.

The bug here was that this notification callback would happen first before anything else thus unloading
plug-ins and releasing plug-in memory. That was crash prone because the JavaScriptCore collector would at
a later time attempt to release its CInstance references (references that point to plug-in memory)
without knowing WebKit already unloaded the plug-in out from underneath it. The WebPluginDatabase simply
does not have enough context to make this decision.

• WebView/WebView.mm: Added two statics: applicationIsTerminating, pluginDatabaseClientCount. (+[WebView initialize]): Added NSApplicationWillTerminateNotification observer. (+[WebView _applicationWillTerminate]): Added. (-[WebView _close]): WebKit has both a global plug-in database and a separate, per WebView plug-in database. We need to release both sets of plug-ins because Netscape plug-ins have "destructor functions" that should be called when the browser unloads the plug-in. These functions can do important things, such as closing/deleting files so it is important to ensure that they are properly called when the application terminates.

The new change is that on app shutdown, we unload WebKit's global plug-in database if and only if the last WebView
was closed. To do so otherwise would unload plug-ins out from underneath other WebViews.

Location:

trunk/WebKit

Files:

• ChangeLog (modified) (1 diff)
• Plugins/WebPluginDatabase.m (modified) (3 diffs)
• WebView/WebView.mm (modified) (9 diffs)

trunk/WebKit/ChangeLog

@@ +1 @@
+2007-02-06  Kevin Decker <kdecker@apple.com>
+
+        Fixed: <rdar://problem/4976681> ASSERTION failure on quit @ talkcrunch.com in _NPN_ReleaseObject
+        
+        Reviewed by Anders.
+
+        * Plugins/WebPluginDatabase.m:
+        (+[WebPluginDatabase sharedDatabase]): Removed NSApplicationWillTerminateNotification observer and thus
+        also removed code that would unload the entire plug-in database when receiving that notification. 
+        
+        The bug here was that this notification callback would happen first before anything else thus unloading
+        plug-ins and releasing plug-in memory. That was crash prone because the JavaScriptCore collector would at
+        a later time attempt to release its CInstance references (references that point to plug-in memory)
+        without knowing WebKit already unloaded the plug-in out from underneath it. The WebPluginDatabase simply
+        does not have enough context to make this decision.
+        
+        * WebView/WebView.mm: Added two statics: applicationIsTerminating, pluginDatabaseClientCount.
+        (+[WebView initialize]): Added NSApplicationWillTerminateNotification observer.
+        (+[WebView _applicationWillTerminate]): Added. 
+        (-[WebView _close]): WebKit has both a global plug-in database and a separate, per WebView plug-in database. 
+         We need to release both sets of plug-ins because Netscape plug-ins have "destructor functions" that should be
+         called when the browser unloads the plug-in.  These functions can do important things, such as closing/deleting
+         files so it is important to ensure that they are properly called when the application terminates.
+         
+         The new change is that on app shutdown, we unload WebKit's global plug-in database if and only if the last WebView
+         was closed. To do so otherwise would unload plug-ins out from underneath other WebViews.
+         
 2007-02-06  Darin Adler  <darin@apple.com>
 

trunk/WebKit/Plugins/WebPluginDatabase.m

@@ -48 +48 @@
 - (void)_removePlugin:(WebBasePluginPackage *)plugin;
 - (NSMutableSet *)_scanForNewPlugins;
-- (void)_applicationWillTerminate;
 @end
 
@@ -61 +60 @@
         [sharedDatabase setPlugInPaths:[self _defaultPlugInPaths]];
         [sharedDatabase refresh];
-        
-        // Clear the global plug-in database on app exit
-        [[NSNotificationCenter defaultCenter] addObserver:sharedDatabase
-                                                 selector:@selector(_applicationWillTerminate)
-                                                     name:NSApplicationWillTerminateNotification
-                                                   object:NSApp];
     }
     
@@ -375 +368 @@
 }
 
-- (void)_applicationWillTerminate
-{
-    ASSERT(self == sharedDatabase);
-    // Remove all plug-ins from database.  Netscape plug-ins have "destructor functions" that should be called
-    // when the browser unloads the plug-in.  These functions can do important things, such as closing/deleting files,
-    // so it is important to ensure that they are properly called when the application terminates.
-    [self close];
-}
-
 @end

trunk/WebKit/WebView/WebView.mm

@@ -232 +232 @@
 macro(yankAndSelect) \
 
+static BOOL applicationIsTerminating;
+static int pluginDatabaseClientCount = 0;
+
 @interface NSSpellChecker (AppKitSecretsIKnow)
 - (void)_preflightChosenSpellServer;
@@ -308 +311 @@
     BOOL selectWordBeforeMenuEvent;
     
+    // WebKit has both a global plug-in database and a separate, per WebView plug-in database. Dashboard uses the per WebView database.
     WebPluginDatabase *pluginDatabase;
     
@@ -392 +396 @@
     if (!self)
         return nil;
-    
     allowsUndo = YES;
     textSizeMultiplier = 1;
@@ -398 +401 @@
     shouldCloseWithWindow = objc_collecting_enabled();
     continuousSpellCheckingEnabled = [[NSUserDefaults standardUserDefaults] boolForKey:WebContinuousSpellCheckingEnabled];
+
 #ifndef BUILDING_ON_TIGER
     grammarCheckingEnabled = [[NSUserDefaults standardUserDefaults] boolForKey:WebGrammarCheckingEnabled];
@@ -404 +408 @@
     
     identifierMap = new HashMap<unsigned long, RetainPtr<id> >();
+    pluginDatabaseClientCount++;
 
     return self;
@@ -652 +657 @@
         _private->hasSpellCheckerDocumentTag = NO;
     }
-
+    
+    [[NSNotificationCenter defaultCenter] removeObserver:self];
+    [WebPreferences _removeReferenceForIdentifier: [self preferencesIdentifier]];
+    pluginDatabaseClientCount--;
+    
+    // Make sure to close both sets of plug-ins databases because plug-ins need an opportunity to clean up files, etc.
+    
+    // Unload the WebView local plug-in database. 
     if (_private->pluginDatabase) {
         [_private->pluginDatabase close];
@@ -658 +670 @@
         _private->pluginDatabase = nil;
     }
-
-    [[NSNotificationCenter defaultCenter] removeObserver:self];
-
-    [WebPreferences _removeReferenceForIdentifier: [self preferencesIdentifier]];
+    
+    // Keep the global plug-in database active until the app terminates to avoid having to reload plug-in bundles.
+    if (!pluginDatabaseClientCount && applicationIsTerminating)
+        [[WebPluginDatabase sharedDatabase] close];
 }
 
@@ -1444 +1456 @@
 // this prevents open source users from crashing when using the Show DOM Tree menu item in Safari
 // FIXME: remove this when it is no longer needed to prevent Safari from crashing
-+(void)initialize
++ (void)initialize
 {
     static BOOL tooLate = NO;
@@ -1450 +1462 @@
         if ([[[NSBundle mainBundle] bundleIdentifier] isEqualToString:@"com.apple.Safari"] && [[NSUserDefaults standardUserDefaults] boolForKey:@"IncludeDebugMenu"])
             [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(_finishedLaunching) name:NSApplicationDidFinishLaunchingNotification object:NSApp];
+        
+        [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(_applicationWillTerminate) name:NSApplicationWillTerminateNotification object:NSApp];
         tooLate = YES;
     }
 }
 
-+(void)_finishedLaunching
++ (void)_applicationWillTerminate
+{   
+    applicationIsTerminating = YES;
+    if (!pluginDatabaseClientCount)
+        [[WebPluginDatabase sharedDatabase] close];
+}
+
++ (void)_finishedLaunching
 {
     [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(_removeDOMTreeMenuItem:) name:NSMenuDidAddItemNotification object:[NSApp mainMenu]];