iPhone与tcpConnWorkQueue EXC_BAD_ACCESS崩溃

Question

我有以下堆栈跟踪:

Crashed: tcpConnWorkQueue (Not main thread)
EXC_BAD_ACCESS KERN_INVALID_ADDRESS at 0xf000000c
0 libobjc.A.dylib    objc_msgSend + 5
1 CoreFoundation     CFRelease + 560
2 libdispatch.dylib  _dispatch_call_block_and_release + 10
3 libdispatch.dylib  _dispatch_queue_drain + 374
4 libdispatch.dylib  _dispatch_queue_invoke + 42
5 libdispatch.dylib  _dispatch_root_queue_drain + 76
6 libdispatch.dylib  _dispatch_worker_thread2 + 56
7 libsystem_pthread.dylib    _pthread_wqthread + 298

所有其他堆栈看起来与我的代码无关.这个堆栈跟踪意味着什么？我在哪里可以查找代码中的错误,可能会导致这样的错误？

主线程堆栈如下所示:

Thread : com.apple.main-thread
0  QuartzCore                     0x2fedef34 CA::Render::Object::unref() const + 35
1  QuartzCore                     0x2fedda73 CA::Context::commit_layer(CA::Layer*, unsigned int, unsigned int, void*) + 142
2  QuartzCore                     0x2fedda73 CA::Context::commit_layer(CA::Layer*, unsigned int, unsigned int, void*) + 142
3  QuartzCore                     0x2fedaa23 CA::Layer::commit_if_needed(CA::Transaction*, void (*)(CA::Layer*, unsigned int, unsigned int, void*), void*) + 314
4  QuartzCore                     0x2feda9c1 CA::Layer::commit_if_needed(CA::Transaction*, void (*)(CA::Layer*, unsigned int, unsigned int, void*), void*) + 216
5  QuartzCore                     0x2feda9c1 CA::Layer::commit_if_needed(CA::Transaction*, void (*)(CA::Layer*, unsigned int, unsigned int, void*), void*) + 216
6  QuartzCore                     0x2feda9c1 CA::Layer::commit_if_needed(CA::Transaction*, void (*)(CA::Layer*, unsigned int, unsigned int, void*), void*) + 216
7  QuartzCore                     0x2feda9c1 CA::Layer::commit_if_needed(CA::Transaction*, void (*)(CA::Layer*, unsigned int, unsigned int, void*), void*) + 216
8  QuartzCore                     0x2feda9c1 CA::Layer::commit_if_needed(CA::Transaction*, void (*)(CA::Layer*, unsigned int, unsigned int, void*), void*) + 216
9  QuartzCore                     0x2feda9c1 CA::Layer::commit_if_needed(CA::Transaction*, void (*)(CA::Layer*, unsigned int, unsigned int, void*), void*) + 216
10 QuartzCore                     0x2feda9c1 CA::Layer::commit_if_needed(CA::Transaction*, void (*)(CA::Layer*, unsigned int, unsigned int, void*), void*) + 216
11 QuartzCore                     0x2feda9c1 CA::Layer::commit_if_needed(CA::Transaction*, void (*)(CA::Layer*, unsigned int, unsigned int, void*), void*) + 216
12 QuartzCore                     0x2feda9c1 CA::Layer::commit_if_needed(CA::Transaction*, void (*)(CA::Layer*, unsigned int, unsigned int, void*), void*) + 216
13 QuartzCore                     0x2feda9c1 CA::Layer::commit_if_needed(CA::Transaction*, void (*)(CA::Layer*, unsigned int, unsigned int, void*), void*) + 216
14 QuartzCore                     0x2feda9c1 CA::Layer::commit_if_needed(CA::Transaction*, void (*)(CA::Layer*, unsigned int, unsigned int, void*), void*) + 216
15 QuartzCore                     0x2feda9c1 CA::Layer::commit_if_needed(CA::Transaction*, void (*)(CA::Layer*, unsigned int, unsigned int, void*), void*) + 216
16 QuartzCore                     0x2feda9c1 CA::Layer::commit_if_needed(CA::Transaction*, void (*)(CA::Layer*, unsigned int, unsigned int, void*), void*) + 216
17 QuartzCore                     0x2feda9c1 CA::Layer::commit_if_needed(CA::Transaction*, void (*)(CA::Layer*, unsigned int, unsigned int, void*), void*) + 216
18 QuartzCore                     0x2fed8d41 CA::Context::commit_transaction(CA::Transaction*) + 1048
19 QuartzCore                     0x2fed881f CA::Transaction::commit() + 314
20 QuartzCore                     0x2ff2d929 CA::Display::DisplayLink::dispatch_items(unsigned long long, unsigned long long, unsigned long long) + 516
21 IOMobileFramebuffer            0x32b5d76d IOMobileFramebufferVsyncNotifyFunc + 104
22 IOKit                          0x2e7b4be5 IODispatchCalloutFromCFMessage + 248
23 CoreFoundation                 0x2da92b81 __CFMachPortPerform + 136
24 CoreFoundation                 0x2da9d777 __CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE1_PERFORM_FUNCTION__ + 34
25 CoreFoundation                 0x2da9d713 __CFRunLoopDoSource1 + 346
26 CoreFoundation                 0x2da9bedf __CFRunLoopRun + 1406
27 CoreFoundation                 0x2da06471 CFRunLoopRunSpecific + 524
28 CoreFoundation                 0x2da06253 CFRunLoopRunInMode + 106
29 GraphicsServices               0x327402eb GSEventRunModal + 138
30 UIKit                          0x302bb845 UIApplicationMain + 1136

Answer 1

第 1 级的堆栈跟踪显示 aCFRelease已被调用，但0xf000000c根据内核，您的地址无效，从而导致错误访问异常。在最常见的情况下，当消息发送到已释放的对象时，就会发生这种情况。

这种类型的崩溃通常在对象第一次释放和第二次释放之间存在时间滞后。但是，您的代码会在屏幕更新时触发，因为您有一个0x2ff2d929 CA::Display::DisplayLink::dispatch_items. 屏幕经常更新，因此应该经常调用。

您+ (CADisplayLink *)displayLinkWithTarget:(id)target selector:(SEL)sel在程序中的任何地方使用过吗？你有- (void)invalidate电话吗？

用户界面可能从一种用例（例如玩基于显示计时器的屏幕更新的游戏）切换到另一种用例（例如在游戏结束时呈现菜单选项）。当这种切换发生时，代码假设将失效，因此您必须取消回调，否则当事情设置不正确时（您在实际显示菜单时绘制游戏框架），您会得到最终回调。

当您在启用“僵尸”的情况下运行程序时（“架构”部分中的一个复选框，则任何已发布的对象都会成为“僵尸”）-它会徘徊等待对该对象进行调用。当有任何调用进入时，它知道这是一个编程错误并中止。然后，您可以回顾该对象的分配历史记录，以查看它首次分配和释放的位置，以识别双重释放错误。