iOS WebView WTF 崩溃

Question

有人遇到下面的崩溃吗？

0 WebKitLegacy 0x000000018f766884 std::__1::unique_ptr&lt;WTF::Function&lt;void ()&gt;, std::__1::default_delete&lt;WTF::Function&lt;void ()&gt; &gt; &gt; WTF::MessageQueue&lt;WTF::Function&lt;void ()&gt; &gt;::waitForMessageFilteredWithTimeout&lt;WTF::MessageQueue&lt;WTF::Function&lt;void ()&gt; &gt;::waitForMessage()::'lambda'(WTF::Function&lt;void ()&gt; const&amp;)&gt;(WTF::MessageQueueWaitResult&amp;, WTF::MessageQueue&lt;WTF::Function&lt;void ()&gt; &gt;::waitForMessage()::'lambda'(WTF::Function&lt;void ()&gt; const&amp;)&amp;&amp;, double) + 192
1 WebKitLegacy 0x000000018f765e68 WebCore::StorageThread::threadEntryPoint() + 68
5 JavaScriptCore 0x000000018dabf35c WTF::threadEntryPoint(void*) + 212
6 JavaScriptCore 0x000000018dabf26c WTF::wtfThreadEntryPoint(void*) + 24
8 libsystem_pthread.dylib 0x0000000188c9f860 __pthread_body + 240
9 libsystem_pthread.dylib 0x0000000188c9f770 __pthread_body
10 libsystem_pthread.dylib 0x0000000188c9cdbc start_wqthread + 0

Answer 1

停止加载 webView 并在离开视图之前删除 delegate。

Before releasing an instance of UIWebView for which you have set a delegate, you must first set its delegate property to nil. This can be done, in your dealloc method.

尝试将 WebView 的委托设置为 nil 并停止在 ViewController 的 viewWillUnload 方法中加载 WebView：

- (void)viewWillUnload {

    [webView setDelegate:nil];
    [webView stopLoading];
}

Answer 2

最后，我发现这个崩溃与localstorage线程有关。当我们在JavaScript中调用window.localStorage时，会触发webkit创建一个localstorage线程，当所有的UIWebView实例dealloc时，该线程会被销毁。事实上，localstorage 线程会比 UIWebView 实例更晚被销毁，这会导致野指针崩溃。因此，您可以创建一个执行 "window.localstorage.setItem(x,x)" 并且从不销毁它的 UIWebView 实例，或者您可以使用 WKWebView.

Answer 3

我已经通过创建静态 UIWebView 实例解决了这个问题。

+ (void)load {
    if ([UIDevice isIOS10]) {
        static UIWebView *storageCrashFixWebView = nil;
        static dispatch_once_t onceToken;
        dispatch_once(&onceToken, ^{
            storageCrashFixWebView = [[UIWebView alloc] initWithFrame:CGRectZero];
            [storageCrashFixWebView loadHTMLString:@"<script>window.localStorage</script>" baseURL:nil];
        });
    }
}

当我在 std::__1::unique_ptr<WTF::Function<void ()>, std::__1::default_delete<WTF::Function<void ()> > > WTF::MessageQueue<WTF::Function<void ()> >::waitForMessageFilteredWithTimeout<WTF::MessageQueue<WTF::Function<void ()> >::waitForMessage()::'lambda'(WTF::Function<void ()> const&)>(WTF::MessageQueueWaitResult&, WTF::MessageQueue<WTF::Function<void ()> >::waitForMessage()::'lambda'(WTF::Function<void ()> const&)&&, double) 设置符号断点时，它会在最后一个使用 localStorage 的 UIWebView 被销毁时中断。

iOS WebView WTF 崩溃

iOS WebView WTF crash

crash

uiwebview

ios