我使用 WKURLSchemeHandler 来处理一些内部请求（如主页、网页恢复等）。有时，当我拨打
urlSchemeTask.didReceive(urlResponse)EXC_BAD_ACCESS这是调用堆栈：
* thread #1, queue = 'com.apple.main-thread', stop reason = EXC_BAD_ACCESS (code=1, address=0x0)
frame #0: 0x00000001a7dd23a0 JavaScriptCore`WTF::StringImpl::hashSlowCase() const + 92
frame #1: 0x00000001a7d8266c JavaScriptCore`WTF::HashTable<WTF::Packed<WTF::StringImpl*>, WTF::Packed<WTF::StringImpl*>, WTF::IdentityExtractor, WTF::DefaultHash<WTF::Packed<WTF::StringImpl*>>, WTF::HashTraits<WTF::Packed<WTF::StringImpl*>>, WTF::HashTraits<WTF::Packed<WTF::StringImpl*>>>::lookupForWriting(WTF::Packed<WTF::StringImpl*> const&) + 88
frame #2: 0x00000001a7d82594 JavaScriptCore`WTF::HashTable<WTF::Packed<WTF::StringImpl*>, WTF::Packed<WTF::StringImpl*>, WTF::IdentityExtractor, WTF::DefaultHash<WTF::Packed<WTF::StringImpl*>>, WTF::HashTraits<WTF::Packed<WTF::StringImpl*>>, WTF::HashTraits<WTF::Packed<WTF::StringImpl*>>>::expand(WTF::Packed<WTF::StringImpl*>*) + 324
frame #3: 0x00000001a7d835e8 JavaScriptCore`WTF::HashTableAddResult<WTF::HashTableIterator<WTF::Packed<WTF::StringImpl*>, WTF::Packed<WTF::StringImpl*>, WTF::IdentityExtractor, WTF::DefaultHash<WTF::Packed<WTF::StringImpl*>>, WTF::HashTraits<WTF::Packed<WTF::StringImpl*>>, WTF::HashTraits<WTF::Packed<WTF::StringImpl*>>>> WTF::HashTable<WTF::Packed<WTF::StringImpl*>, WTF::Packed<WTF::StringImpl*>, WTF::IdentityExtractor, WTF::DefaultHash<WTF::Packed<WTF::StringImpl*>>, WTF::HashTraits<WTF::Packed<WTF::StringImpl*>>, WTF::HashTraits<WTF::Packed<WTF::StringImpl*>>>::addPassingHashCode<WTF::HashSetTranslatorAdapter<WTF::UCharBufferTranslator>, WTF::HashTranslatorCharBuffer<char16_t> const&, WTF::HashTranslatorCharBuffer<char16_t> const&>(WTF::HashTranslatorCharBuffer<char16_t> const&, WTF::HashTranslatorCharBuffer<char16_t> const&) + 692
frame #4: 0x00000001a7d8034c JavaScriptCore`WTF::AtomStringImpl::add(char16_t const*, unsigned int) + 240
frame #5: 0x00000001a7d83e3c JavaScriptCore`WTF::AtomStringImpl::add(__CFString const*) + 332
frame #6: 0x00000001aa7b5010 WebCore`WebCore::ResourceResponse::platformLazyInit(WebCore::ResourceResponseBase::InitLevel) + 336
frame #7: 0x00000001a9f020ec WebKit`void WebCore::ResourceResponseBase::encode<IPC::Encoder>(IPC::Encoder&) const + 124
frame #8: 0x00000001aa250a58 WebKit`bool WebKit::AuxiliaryProcessProxy::send<Messages::WebPage::URLSchemeTaskDidReceiveResponse>(Messages::WebPage::URLSchemeTaskDidReceiveResponse&&, unsigned long long, WTF::OptionSet<IPC::SendOption>) + 268
frame #9: 0x00000001aa22c380 WebKit`WebKit::WebURLSchemeTask::didReceiveResponse(WebCore::ResourceResponse const&) + 192
frame #10: 0x00000001aa106554 WebKit`WTF::Detail::CallableWrapper<-[WKURLSchemeTaskImpl didReceiveResponse:]::$_1, WebKit::WebURLSchemeTask::ExceptionType>::call() + 52
frame #11: 0x00000001aa0fa7e4 WebKit`-[WKURLSchemeTaskImpl didReceiveResponse:] + 100
* frame #12: 0x0000000104dab348 Browser`InternalSchemeHandler.webView(webView=0x000000010c853600, urlSchemeTask=__C.WKURLSchemeTask @ 0x000000016dd7c818, self=0x00000002808efe70) at InternalSchemeHandler.swift:98:27
frame #13: 0x0000000104dabc64 Browser`@objc InternalSchemeHandler.webView(_:start:) at <compiler-generated>:0
frame #14: 0x00000001aa1b8648 WebKit`WebKit::WebURLSchemeHandlerCocoa::platformStartTask(WebKit::WebPageProxy&, WebKit::WebURLSchemeTask&) + 524
frame #15: 0x00000001aa20a0dc WebKit`WebKit::WebURLSchemeHandler::startTask(WebKit::WebPageProxy&, WebKit::WebProcessProxy&, WTF::ObjectIdentifier<WebCore::PageIdentifierType>, WebKit::URLSchemeTaskParameters&&, WTF::CompletionHandler<void (WebCore::ResourceResponse const&, WebCore::ResourceError const&, WTF::Vector<char, 0ul, WTF::CrashOnOverflow, 16ul, WTF::FastMalloc> const&)>&&) + 968
frame #16: 0x00000001aa209cd0 WebKit`WebKit::WebPageProxy::startURLSchemeTaskShared(WTF::Ref<WebKit::WebProcessProxy, WTF::DumbPtrTraits<WebKit::WebProcessProxy>>&&, WTF::ObjectIdentifier<WebCore::PageIdentifierType>, WebKit::URLSchemeTaskParameters&&) + 108
frame #17: 0x00000001aa209c24 WebKit`WebKit::WebPageProxy::startURLSchemeTask(WebKit::URLSchemeTaskParameters&&) + 52
frame #18: 0x00000001aa4d44a8 WebKit`WebKit::WebPageProxy::didReceiveMessage(IPC::Connection&, IPC::Decoder&) + 84824
frame #19: 0x00000001a9ef885c WebKit`IPC::MessageReceiverMap::dispatchMessage(IPC::Connection&, IPC::Decoder&) + 124
frame #20: 0x00000001aa2272f0 WebKit`WebKit::WebProcessProxy::didReceiveMessage(IPC::Connection&, IPC::Decoder&) + 40
frame #21: 0x00000001a9edbdec WebKit`IPC::Connection::dispatchMessage(std::__1::unique_ptr<IPC::Decoder, std::__1::default_delete<IPC::Decoder>>) + 656
frame #22: 0x00000001a9edb6f4 WebKit`IPC::Connection::dispatchIncomingMessages() + 460
frame #23: 0x00000001a7dbe3c8 JavaScriptCore`WTF::RunLoop::performWork() + 484
frame #24: 0x00000001a7dbf0b0 JavaScriptCore`WTF::RunLoop::performWork(void*) + 36
frame #25: 0x000000019db7076c CoreFoundation`__CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE0_PERFORM_FUNCTION__ + 28
frame #26: 0x000000019db70668 CoreFoundation`__CFRunLoopDoSource0 + 208
frame #27: 0x000000019db6f960 CoreFoundation`__CFRunLoopDoSources0 + 268
frame #28: 0x000000019db69a8c CoreFoundation`__CFRunLoopRun + 824
frame #29: 0x000000019db6921c CoreFoundation`CFRunLoopRunSpecific + 600
frame #30: 0x00000001b4be8784 GraphicsServices`GSEventRunModal + 164
frame #31: 0x00000001a05a2200 UIKitCore`-[UIApplication _run] + 1072
frame #32: 0x00000001a05a7a74 UIKitCore`UIApplicationMain + 168
frame #33: 0x000000010221d568 TDMBrowser`main at AppDelegate.swift:32:7
frame #34: 0x000000019d8296c0 libdyld.dylib`start + 4
这是我的
URLSchemeHandler func webView(_ webView: WKWebView, start urlSchemeTask: WKURLSchemeTask) {
if taskDic[ObjectIdentifier(urlSchemeTask)] != false {
taskDic[ObjectIdentifier(urlSchemeTask)] = true
}
guard let url = urlSchemeTask.request.url else {
if taskDic[ObjectIdentifier(urlSchemeTask)] == true {
urlSchemeTask.didFailWithError(InternalPageSchemeHandlerError.badURL)
taskDic.removeValue(forKey: ObjectIdentifier(urlSchemeTask))
}
return
}
let path = url.path.starts(with: "/") ? String(url.path.dropFirst()) : url.path
guard let responder = InternalSchemeHandler.responders[path] else {
if taskDic[ObjectIdentifier(urlSchemeTask)] == true {
urlSchemeTask.didFailWithError(InternalPageSchemeHandlerError.noResponder)
taskDic.removeValue(forKey: ObjectIdentifier(urlSchemeTask))
}
return
}
guard let (urlResponse, data) = responder.response(forRequest: urlSchemeTask.request) else {
if taskDic[ObjectIdentifier(urlSchemeTask)] == true {
urlSchemeTask.didFailWithError(InternalPageSchemeHandlerError.responderUnableToHandle)
taskDic.removeValue(forKey: ObjectIdentifier(urlSchemeTask))
}
return
}
if taskDic[ObjectIdentifier(urlSchemeTask)] == true {
urlSchemeTask.didReceive(urlResponse)
urlSchemeTask.didReceive(data)
urlSchemeTask.didFinish()
taskDic.removeValue(forKey: ObjectIdentifier(urlSchemeTask))
}
}
func webView(_ webView: WKWebView, stop urlSchemeTask: WKURLSchemeTask) {
moduleLogger.debug("stop urlSchemeTask: \(urlSchemeTask)")
taskDic[ObjectIdentifier(urlSchemeTask)] = false
}
任何人都可以帮助我避免这次崩溃吗？
您现在可能已经明白了这一点，但您应该使用锁或以其他方式同步对字典的访问，并在获取锁时执行您的needed操作。我自己也遇到过同样的问题。
class TaskRegistry {
private var lock = NSLock()
private var tasks: [ObjectIdentifier: Bool] = [:]
func withStorage(action: (inout [ObjectIdentifier: Bool]) -> Void) {
lock.withLock {
action(storage)
}
}
}
let registry = TaskRegistry()
func webView(_ webView: WKWebView, stop urlSchemeTask: WKURLSchemeTask) {
moduleLogger.debug("stop urlSchemeTask: \(urlSchemeTask)")
registry.withStorage {
$0[ObjectIdentifier(urlSchemeTask)] = false
}
}
func webView(_ webView: WKWebView, start urlSchemeTask: WKURLSchemeTask) {
registry.withStorage {
if $0[ObjectIdentifier(urlSchemeTask)] != false {
$0[ObjectIdentifier(urlSchemeTask)] = true
}
}
guard let url = urlSchemeTask.request.url else {
registry.withStorage {
if $0[ObjectIdentifier(urlSchemeTask)] == true {
urlSchemeTask.didFailWithError(InternalPageSchemeHandlerError.badURL)
$0.removeValue(forKey: ObjectIdentifier(urlSchemeTask))
}
}
return
}
let path = url.path.starts(with: "/") ? String(url.path.dropFirst()) : url.path
guard let responder = InternalSchemeHandler.responders[path] else {
registry.withStorage {
if $0[ObjectIdentifier(urlSchemeTask)] == true {
urlSchemeTask.didFailWithError(InternalPageSchemeHandlerError.noResponder)
$0.removeValue(forKey: ObjectIdentifier(urlSchemeTask))
}
}
return
}
guard let (urlResponse, data) = responder.response(forRequest: urlSchemeTask.request) else {
registry.withStorage {
if $0[ObjectIdentifier(urlSchemeTask)] == true {
urlSchemeTask.didFailWithError(
InternalPageSchemeHandlerError.responderUnableToHandle
)
$0.removeValue(forKey: ObjectIdentifier(urlSchemeTask))
}
}
return
}
registry.withStorage {
if $0[ObjectIdentifier(urlSchemeTask)] == true {
urlSchemeTask.didReceive(urlResponse)
urlSchemeTask.didReceive(data)
urlSchemeTask.didFinish()
$0.removeValue(forKey: ObjectIdentifier(urlSchemeTask))
}
}
}
OSAllocatedUnfairLock