Changeset 245076 in webkit

Timestamp:

May 8, 2019 4:37:59 PM (5 years ago)

Author:

dbates@webkit.org

Message:

[Legacy WebKit] REGRESSION (r238078): Crash in hardwareKeyboardAvailabilityChangedCallback()
​https://bugs.webkit.org/show_bug.cgi?id=197724
<rdar://problem/49725959>

Reviewed by Tim Horton.

Speculative fix for race condition. Between the time we receive a kGSEventHardwareKeyboardAvailabilityChangedNotification
notification and when we schedule execution to run on the WebThread the WebView that notification
was for may no longer exist. Take out a weak ptr on the WebView when we receive the notification
and check that we still have it once we are running on the WebThread.

• WebView/WebHTMLView.mm:

(hardwareKeyboardAvailabilityChangedCallback):

Location:

trunk/Source/WebKitLegacy/mac

Files:

• ChangeLog (modified) (1 diff)
• WebView/WebHTMLView.mm (modified) (2 diffs)

trunk/Source/WebKitLegacy/mac/ChangeLog

@@ +1 @@
+2019-05-08  Daniel Bates  <dabates@apple.com>
+
+        [Legacy WebKit] REGRESSION (r238078): Crash in hardwareKeyboardAvailabilityChangedCallback()
+        https://bugs.webkit.org/show_bug.cgi?id=197724
+        <rdar://problem/49725959>
+
+        Reviewed by Tim Horton.
+
+        Speculative fix for race condition. Between the time we receive a kGSEventHardwareKeyboardAvailabilityChangedNotification
+        notification and when we schedule execution to run on the WebThread the WebView that notification
+        was for may no longer exist. Take out a weak ptr on the WebView when we receive the notification
+        and check that we still have it once we are running on the WebThread.
+
+        * WebView/WebHTMLView.mm:
+        (hardwareKeyboardAvailabilityChangedCallback):
+
 2019-05-08  Timothy Hatcher  <timothy@apple.com>
 

trunk/Source/WebKitLegacy/mac/WebView/WebHTMLView.mm

@@ -147 +147 @@
 #import <wtf/RunLoop.h>
 #import <wtf/SystemTracing.h>
+#import <wtf/WeakObjCPtr.h>
 
 #if PLATFORM(MAC)
@@ -821 +822 @@
 {
     ASSERT(observer);
+    auto weakWebView = WeakObjCPtr<WebHTMLView>((__bridge WebHTMLView *)observer);
     WebThreadRun(^{
-        WebHTMLView *webView = (__bridge WebHTMLView *)observer;
-        if (Frame* coreFrame = core([webView _frame]))
-            coreFrame->eventHandler().capsLockStateMayHaveChanged();
+        if (auto webView = weakWebView.get()) {
+            if (auto* coreFrame = core([webView _frame]))
+                coreFrame->eventHandler().capsLockStateMayHaveChanged();
+        }
     });
 }