WebThread 中的 iOS uiwebview 崩溃

Question

我正在寻求一些建议或帮助诊断我所看到的崩溃。目前，我认为这可能是一个 webkit 错误，但一切皆有可能，所以请提供您可能有的任何见解:

Incident Identifier: AEB8EE37-E5D4-4975-97F4-2B2038AC225ACrashReporter Key:   92349a05395ea832c40c49c9e48997c1d65a2371Hardware Model:      iPad3,3Process:             Touch [242]Path:                /var/mobile/Applications/4D2CAEEE-D0F8-4BB4-989A-F8623C877C78/Touch.app/TouchIdentifier:          StayinFrontTouchVersion:             3.2.40 (3.2.40)Code Type:           ARM (Native)Parent Process:      launchd [1]Date/Time:           2014-04-30 15:26:46.137 +1200OS Version:          iOS 7.1.1 (11D201)Report Version:      104Exception Type:  EXC_BAD_ACCESS (SIGSEGV)Exception Subtype: KERN_INVALID_ADDRESS at 0x00000258Triggered by Thread:  2Thread 0:0   libsystem_kernel.dylib          0x3a2ffa58 mach_msg_trap + 201   libsystem_kernel.dylib          0x3a2ff854 mach_msg + 442   CoreFoundation                  0x2f06e896 __CFRunLoopServiceMachPort + 1503   CoreFoundation                  0x2f06d002 __CFRunLoopRun + 8504   CoreFoundation                  0x2efd7f0a CFRunLoopRunSpecific + 5185   CoreFoundation                  0x2efd7cee CFRunLoopRunInMode + 1026   GraphicsServices                0x33f0a65e GSEventRunModal + 1347   UIKit                           0x31923168 UIApplicationMain + 11328   Touch                           0x000c064a 0xbd000 + 138989   Touch                           0x000bf854 0xbd000 + 10324Thread 1:0   libsystem_kernel.dylib          0x3a2ff808 kevent64 + 241   libdispatch.dylib               0x3a241078 _dispatch_mgr_invoke + 2282   libdispatch.dylib               0x3a240dfe _dispatch_mgr_thread$VARIANT$mp + 34Thread 2 name:  WebThreadThread 2 Crashed:0   WebCore                         0x37584302 WebCore::SubresourceLoader::didReceiveResponse(WebCore::ResourceResponse const&) + 261   WebCore                         0x377f751c WebCore::DocumentLoader::substituteResourceDeliveryTimerFired(WebCore::Timer*) + 2122   WebCore                         0x374ad3f4 WebCore::ThreadTimers::sharedTimerFiredInternal() + 1323   WebCore                         0x374ad346 WebCore::timerFired(__CFRunLoopTimer*, void*) + 224   CoreFoundation                  0x2f06f1b4 __CFRUNLOOP_IS_CALLING_OUT_TO_A_TIMER_CALLBACK_FUNCTION__ + 125   CoreFoundation                  0x2f06edca __CFRunLoopDoTimer + 7786   CoreFoundation                  0x2f06d166 __CFRunLoopRun + 12067   CoreFoundation                  0x2efd7f0a CFRunLoopRunSpecific + 5188   CoreFoundation                  0x2efd7cee CFRunLoopRunInMode + 1029   WebCore                         0x3753a116 RunWebThread(void*) + 41410  libsystem_pthread.dylib         0x3a37b916 _pthread_body + 13811  libsystem_pthread.dylib         0x3a37b886 _pthread_start + 9812  libsystem_pthread.dylib         0x3a379aa0 thread_start + 4Thread 3 name:  com.apple.NSURLConnectionLoaderThread 3:0   libsystem_kernel.dylib          0x3a2ffa58 mach_msg_trap + 201   libsystem_kernel.dylib          0x3a2ff854 mach_msg + 442   CoreFoundation                  0x2f06e896 __CFRunLoopServiceMachPort + 1503   CoreFoundation                  0x2f06cfbc __CFRunLoopRun + 7804   CoreFoundation                  0x2efd7f0a CFRunLoopRunSpecific + 5185   CoreFoundation                  0x2efd7cee CFRunLoopRunInMode + 1026   Foundation                      0x2fa17082 +[NSURLConnection(Loader) _resourceLoadLoop:] + 3147   Foundation                      0x2fa8ca5a __NSThread__main__ + 10588   libsystem_pthread.dylib         0x3a37b916 _pthread_body + 1389   libsystem_pthread.dylib         0x3a37b886 _pthread_start + 9810  libsystem_pthread.dylib         0x3a379aa0 thread_start + 4Thread 4:0   libsystem_kernel.dylib          0x3a2ffa58 mach_msg_trap + 201   libsystem_kernel.dylib          0x3a2ff854 mach_msg + 442   CoreFoundation                  0x2f06e896 __CFRunLoopServiceMachPort + 1503   CoreFoundation                  0x2f06cfbc __CFRunLoopRun + 7804   CoreFoundation                  0x2efd7f0a CFRunLoopRunSpecific + 5185   CoreFoundation                  0x2efd7cee CFRunLoopRunInMode + 1026   libAVFAudio.dylib               0x2e04f44c GenericRunLoopThread::Entry(void*) + 1247   libAVFAudio.dylib               0x2e0437bc CAPThread::Entry(CAPThread*) + 1768   libsystem_pthread.dylib         0x3a37b916 _pthread_body + 1389   libsystem_pthread.dylib         0x3a37b886 _pthread_start + 9810  libsystem_pthread.dylib         0x3a379aa0 thread_start + 4Thread 5 name:  JavaScriptCore::BlockFreeThread 5:0   libsystem_kernel.dylib          0x3a311f2c __psynch_cvwait + 241   libsystem_pthread.dylib         0x3a37af22 _pthread_cond_wait + 5182   libsystem_pthread.dylib         0x3a37bd60 pthread_cond_wait + 363   JavaScriptCore                  0x30004ee4 JSC::BlockAllocator::blockFreeingThreadMain() + 2044   JavaScriptCore                  0x30002538 WTF::wtfThreadEntryPoint(void*) + 125   libsystem_pthread.dylib         0x3a37b916 _pthread_body + 1386   libsystem_pthread.dylib         0x3a37b886 _pthread_start + 987   libsystem_pthread.dylib         0x3a379aa0 thread_start + 4Thread 6 name:  JavaScriptCore::MarkingThread 6:0   libsystem_kernel.dylib          0x3a311f2c __psynch_cvwait + 241   libsystem_pthread.dylib         0x3a37af22 _pthread_cond_wait + 5182   libsystem_pthread.dylib         0x3a37bd60 pthread_cond_wait + 363   JavaScriptCore                  0x301a0406 JSC::GCThread::waitForNextPhase() + 744   JavaScriptCore                  0x301a0460 JSC::GCThread::gcThreadMain() + 485   JavaScriptCore                  0x30002538 WTF::wtfThreadEntryPoint(void*) + 126   libsystem_pthread.dylib         0x3a37b916 _pthread_body + 1387   libsystem_pthread.dylib         0x3a37b886 _pthread_start + 988   libsystem_pthread.dylib         0x3a379aa0 thread_start + 4Thread 7 name:  WebCore: CFNetwork LoaderThread 7:0   libsystem_kernel.dylib          0x3a2ffa58 mach_msg_trap + 201   libsystem_kernel.dylib          0x3a2ff854 mach_msg + 442   CoreFoundation                  0x2f06e896 __CFRunLoopServiceMachPort + 1503   CoreFoundation                  0x2f06cfbc __CFRunLoopRun + 7804   CoreFoundation                  0x2efd7f0a CFRunLoopRunSpecific + 5185   CoreFoundation                  0x2efd7cee CFRunLoopRunInMode + 1026   WebCore                         0x37582b12 WebCore::runLoaderThread(void*) + 2507   JavaScriptCore                  0x30002538 WTF::wtfThreadEntryPoint(void*) + 128   libsystem_pthread.dylib         0x3a37b916 _pthread_body + 1389   libsystem_pthread.dylib         0x3a37b886 _pthread_start + 9810  libsystem_pthread.dylib         0x3a379aa0 thread_start + 4Thread 8 name:  com.apple.CFSocket.privateThread 8:0   libsystem_kernel.dylib          0x3a312434 __select + 201   CoreFoundation                  0x2f072758 __CFSocketManager + 4802   libsystem_pthread.dylib         0x3a37b916 _pthread_body + 1383   libsystem_pthread.dylib         0x3a37b886 _pthread_start + 984   libsystem_pthread.dylib         0x3a379aa0 thread_start + 4Thread 9 name:  WebCore: LocalStorageThread 9:0   libsystem_kernel.dylib          0x3a311f2c __psynch_cvwait + 241   libsystem_pthread.dylib         0x3a37af22 _pthread_cond_wait + 5182   libsystem_pthread.dylib         0x3a37bd60 pthread_cond_wait + 363   JavaScriptCore                  0x30005012 WTF::ThreadCondition::timedWait(WTF::Mutex&, double) + 584   WebCore                         0x3766cf2c WTF::PassOwnPtr > WTF::MessageQueue >::waitForMessageFilteredWithTimeout*)>(WTF::MessageQueueWaitResult&, bool (&)(WTF::Function*), double) + 1045   WebCore                         0x3766ceb2 WebCore::StorageThread::threadEntryPoint() + 1626   JavaScriptCore                  0x30002538 WTF::wtfThreadEntryPoint(void*) + 127   libsystem_pthread.dylib         0x3a37b916 _pthread_body + 1388   libsystem_pthread.dylib         0x3a37b886 _pthread_start + 989   libsystem_pthread.dylib         0x3a379aa0 thread_start + 4Thread 10:0   libsystem_kernel.dylib          0x3a312c70 __workq_kernreturn + 81   libsystem_pthread.dylib         0x3a379bda _pthread_wqthread + 3062   libsystem_pthread.dylib         0x3a379a94 start_wqthread + 4Thread 11:0   libsystem_kernel.dylib          0x3a312c70 __workq_kernreturn + 81   libsystem_pthread.dylib         0x3a379bda _pthread_wqthread + 3062   libsystem_pthread.dylib         0x3a379a94 start_wqthread + 4Thread 12:0   libsystem_kernel.dylib          0x3a312c70 __workq_kernreturn + 81   libsystem_pthread.dylib         0x3a379bda _pthread_wqthread + 3062   libsystem_pthread.dylib         0x3a379a94 start_wqthread + 4Thread 13:0   libsystem_kernel.dylib          0x3a312c70 __workq_kernreturn + 81   libsystem_pthread.dylib         0x3a379bda _pthread_wqthread + 3062   libsystem_pthread.dylib         0x3a379a94 start_wqthread + 4Thread 14:0   libsystem_kernel.dylib          0x3a312c70 __workq_kernreturn + 81   libsystem_pthread.dylib         0x3a379bda _pthread_wqthread + 3062   libsystem_pthread.dylib         0x3a379a94 start_wqthread + 4Thread 15:0   libsystem_kernel.dylib          0x3a312c70 __workq_kernreturn + 81   libsystem_pthread.dylib         0x3a379bda _pthread_wqthread + 3062   libsystem_pthread.dylib         0x3a379a94 start_wqthread + 4Thread 2 crashed with ARM Thread State (32-bit):    r0: 0x00000000    r1: 0x04ee0238      r2: 0x375842e9      r3: 0x019cb6b8    r4: 0x0a916c00    r5: 0x04ee0238      r6: 0x0a916c00      r7: 0x01bbf028    r8: 0x0549ea00    r9: 0x00000002     r10: 0x0549e9c8     r11: 0x03bc3000    ip: 0x3a6c7838    sp: 0x01bbf014      lr: 0x377f751f      pc: 0x37584302  cpsr: 0x20000030Binary Images:...

I did some further investigation into the stack trace and found the code for Subresourceloader here (https://webkit.googlesource.com/WebKit/+/master/Source/WebCore/loader/SubresourceLoader.cpp).

My guess is that m_resource is NULL at this point marked with (****) causing the crash:

void SubresourceLoader::didReceiveResponse(const ResourceResponse& response)
{
    ASSERT(!response.isNull());
    ASSERT(m_state == Initialized);
    // Reference the object in this method since the additional processing can do
    // anything including removing the last reference to this object; one example of this is 3266216.
    Ref<SubresourceLoader> protect(*this);
    if (m_resource->resourceToRevalidate()) {  ****
        if (response.httpStatusCode() == 304) {
            // 304 Not modified / Use local copy
            // Existing resource is ok, just use it updating the expiration time.
            m_resource->setResponse(response);
            memoryCache()->revalidationSucceeded(m_resource, response);
            if (!reachedTerminalState())
                ResourceLoader::didReceiveResponse(response);
            return;
        }
        // Did not get 304 response, continue as a regular resource load.
        memoryCache()->revalidationFailed(m_resource);
    }
...

Answer 1

如果它在重新安装后有效，那么您可以尝试在不缓存的情况下执行 URL 请求，因为我认为这会产生相同的结果:

NSURLRequest *request = [NSURLRequest requestWithURL:url cachePolicy:NSURLRequestReloadIgnoringLocalAndRemoteCacheData timeoutInterval:30];
[webView loadRequest:request];

我猜资源缓存出了点问题。