我从几个NSURLDownload简单NSURLRequest的 HTTP 开始（例如 3 个线程，每个线程有 3 或 5 次下载）。线程是这样运行的：
- (void)threadSelector:(id)obj
{
NSAutoreleasePool * pool = [[NSAutoreleasePool alloc] init];
while (![downloaderThread isCancelled])
{
NSDate * sec = [NSDate dateWithTimeIntervalSinceNow:1];
[[NSRunLoop currentRunLoop] runMode:NSRunLoopCommonModes beforeDate:sec];
[[NSRunLoop currentRunLoop] runMode:NSDefaultRunLoopMode beforeDate:sec];
[NSThread sleepUntilDate:sec];
}
[pool drain];
}
以及带有频繁 Ajax 请求的 WebKit UI（主线程）。
在某些时候，网络变得无响应：所有请求都返回错误 -1001“请求超时”。之后，即使NSURLConnection是来自主线程的 simple s 也会超时。
这只发生在 Yosemite 上（在 4 台 Yosemite 机器和几台装有旧操作系统的 Mac 上测试）。
此外，它消耗 150-170% 的 CPU（dtrace 顶级消费者：psynch_mutexwait、psynch_mutexdrop、kevent64）。里面有一些互斥锁NSURLConnectionLoader。
不知道如何超出此处的帖子限制（30k 字符）...这是我的连接加载程序线程示例的一部分，当它挂起时：
783 Thread_378163: com.apple.NSURLConnectionLoader
+ 782 thread_start (in libsystem_pthread.dylib) + 13 [0x7fff948654b1]
+ ! 782 _pthread_start (in libsystem_pthread.dylib) + 176 [0x7fff94867279]
+ ! 782 _pthread_body (in libsystem_pthread.dylib) + 131 [0x7fff948672fc]
+ ! 782 __NSThread__main__ (in Foundation) + 1345 [0x7fff92df7b7a]
+ ! 782 +[NSURLConnection(Loader) _resourceLoadLoop:] (in CFNetwork) + 434 [0x7fff962c1d20]
+ ! 782 CFRunLoopRunSpecific (in CoreFoundation) + 296 [0x7fff9294e838]
+ ! 782 __CFRunLoopRun (in CoreFoundation) + 927 [0x7fff9294ee1f]
+ ! 782 __CFRunLoopDoSources0 (in CoreFoundation) + 476 [0x7fff9294f8bc]
+ ! 782 __CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE0_PERFORM_FUNCTION__ (in CoreFoundation) + 17 [0x7fff9295d661]
+ ! 782 _cfstream_shared_signalEventSync (in CoreFoundation) + 477 [0x7fff929da29d]
+ ! 782 _signalEventSync (in CoreFoundation) + 180 [0x7fff9299cbb4]
+ ! 782 CFNetworkReadStream::_readStreamClientCallBackCallBack(__CFReadStream*, unsigned long, void*) (in CFNetwork) + 53 [0x7fff96364f61]
+ ! 782 HTTPNetStreamInfo::_readStreamClientCallBack(__CFReadStream*, unsigned long) (in CFNetwork) + 185 [0x7fff962d80fd]
+ ! 782 CFReadStreamRead (in CoreFoundation) + 413 [0x7fff9298f60d]
+ ! 782 HTTPNetStreamInfo::_streamImpl_Read(__CFReadStream*, unsigned char*, long, CFStreamError*, unsigned char*) (in CFNetwork) + 410 [0x7fff962d70be]
+ ! 782 CoreStreamBase::_streamInterface_Read(unsigned char*, long) (in CFNetwork) + 157 [0x7fff9622cc27]
+ ! 782 HTTPReadFilter::_streamImpl_Read(unsigned char*, long, CFStreamError*, unsigned char*) (in CFNetwork) + 478 [0x7fff9624dd3e]
+ ! 782 HTTPReadFilter::doPlainRead(StreamReader*, unsigned char*, long, CFStreamError*, unsigned char*) (in CFNetwork) + 281 [0x7fff9624dff3]
+ ! 782 CFReadStreamRead (in CoreFoundation) + 413 [0x7fff9298f60d]
+ ! 564 SocketStream::read(__CFReadStream*, unsigned char*, long, CFStreamError*, unsigned char*) (in CFNetwork) + 569 [0x7fff962e14d9]
+ ! : 541 CFRunLoopRunSpecific (in CoreFoundation) + 296 [0x7fff9294e838]
+ ! : | 205 __CFRunLoopRun (in CoreFoundation) + 1371 [0x7fff9294efdb]
+ ! : | + 199 __CFRunLoopServiceMachPort (in CoreFoundation) + 212 [0x7fff9294fb14]
+ ! : | + ! 195 mach_msg (in libsystem_kernel.dylib) + 55 [0x7fff9942769f]
+ ! : | + ! : 195 mach_msg_trap (in libsystem_kernel.dylib) + 10 [0x7fff9942852e]
+ ! : | + ! 4 mach_msg (in libsystem_kernel.dylib) + 57,279 [0x7fff994276a1,0x7fff9942777f]
+ ! : | + 4 __CFRunLoopServiceMachPort (in CoreFoundation) + 227 [0x7fff9294fb23]
+ ! : | + ! 3 voucher_mach_msg_revert (in libsystem_kernel.dylib) + 0,7,... [0x7fff99417bee,0x7fff99417bf5,...]
+ ! : | + ! 1 voucher_mach_msg_revert (in libdispatch.dylib) + 1 [0x7fff90bcef86]
+ ! : | + 2 __CFRunLoopServiceMachPort (in CoreFoundation) + 401,192 [0x7fff9294fbd1,0x7fff9294fb00]
+ ! : | 124 __CFRunLoopRun (in CoreFoundation) + 927 [0x7fff9294ee1f]
+ ! : | + 90 __CFRunLoopDoSources0 (in CoreFoundation) + 269 [0x7fff9294f7ed]
+ ! : | + ! 90 __CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE0_PERFORM_FUNCTION__ (in CoreFoundation) + 17 [0x7fff9295d661]
+ ! : | + ! 88 __CFSocketPerformV0 (in CoreFoundation) + 768 [0x7fff9299c340]
+ ! : | + ! : 85 SocketStream::_SocketCallBack_stream(__CFSocket*, unsigned long, __CFData const*, void const*, void*) (in CFNetwork) + 70 [0x7fff9622b2fa]
+ ! : | + ! : | 78 SocketStream::socketCallback(__CFSocket*, unsigned long, __CFData const*, void const*) (in CFNetwork) + 211 [0x7fff9622b409]
+ ! : | + ! : | + 77 SocketStream::dispatchSignalFromSocketCallbackUnlocked(SocketStreamSignalHolder*) (in CFNetwork) + 44 [0x7fff9622ba12]
+ ! : | + ! : | + ! 59 CFRunLoopWakeUp (in CoreFoundation) + 75 [0x7fff9293b1ab]
+ ! : | + ! : | + ! : 58 __psynch_mutexwait (in libsystem_kernel.dylib) + 10 [0x7fff9942d162]
+ ! : | + ! : | + ! : 1 _pthread_mutex_lock (in libsystem_pthread.dylib) + 484 [0x7fff94865822]
+ ! : | + ! : | + ! 12 CFRunLoopWakeUp (in CoreFoundation) + 171 [0x7fff9293b20b]
+ ! : | + ! : | + ! : 11 mach_msg (in libsystem_kernel.dylib) + 55 [0x7fff9942769f]
+ ! : | + ! : | + ! : | 11 mach_msg_trap (in libsystem_kernel.dylib) + 10 [0x7fff9942852e]
+ ! : | + ! : | + ! : 1 mach_msg (in libsystem_kernel.dylib) + 0 [0x7fff99427668]
+ ! : | + ! : | + ! 6 CFRunLoopWakeUp (in CoreFoundation) + 193 [0x7fff9293b221]
+ ! : | + ! : | + ! 4 mach_msg_destroy (in libsystem_kernel.dylib) + 34 [0x7fff9942796c]
+ ! : | + ! : | + ! | 4 mach_msg_destroy_port (in libsystem_kernel.dylib) + 155 [0x7fff99427b03]
+ ! : | + ! : | + ! | 4 mach_port_deallocate (in libsystem_kernel.dylib) + 17 [0x7fff9942bdec]
+ ! : | + ! : | + ! | 4 _kernelrpc_mach_port_deallocate_trap (in libsystem_kernel.dylib) + 10 [0x7fff9942849e]
+ ! : | + ! : | + ! 1 mach_msg_destroy (in libsystem_kernel.dylib) + 51 [0x7fff9942797d]
+ ! : | + ! : | + ! | 1 mach_msg_destroy_port (in libsystem_kernel.dylib) + 0 [0x7fff99427a68]
+ ! : | + ! : | + ! 1 mach_msg_destroy (in libsystem_kernel.dylib) + 38 [0x7fff99427970]
+ ! : | + ! : | + 1 SocketStream::dispatchSignalFromSocketCallbackUnlocked(SocketStreamSignalHolder*) (in CFNetwork) + 35 [0x7fff9622ba09]
+ ! : | + ! : | + 1 CFRunLoopSourceSignal (in CoreFoundation) + 0 [0x7fff929575a0]
+ ! : | + ! : | 2 SocketStream::socketCallback(__CFSocket*, unsigned long, __CFData const*, void const*) (in CFNetwork) + 92 [0x7fff9622b392]
+ ! : | + ! : | + 1 OSAtomicCompareAndSwapPtrBarrier$VARIANT$mp (in libsystem_platform.dylib) + 8 [0x7fff9766f348]
+ ! : | + ! : | + 1 pthread_mutex_lock (in libsystem_pthread.dylib) + 0 [0x7fff94865637]
+ ! : | + ! : | 2 SocketStream::socketCallback(__CFSocket*, unsigned long, __CFData const*, void const*) (in CFNetwork) + 195 [0x7fff9622b3f9]
+ ! : | + ! : | + 1 SocketStream::prepareSignalFromSocketCallbackLocked(SocketStreamSignalHolder*) (in CFNetwork) + 281 [0x7fff9622b8f9]
+ ! : | + ! : | + ! 1 CFRunLoopSourceGetContext (in CoreFoundation) + 1 [0x7fff9293dfe1]
+ ! : | + ! : | + 1 SocketStream::prepareSignalFromSocketCallbackLocked(SocketStreamSignalHolder*) (in CFNetwork) + 297 [0x7fff9622b909]
+ ! : | + ! : | + 1 OSAtomicCompareAndSwapPtrBarrier$VARIANT$mp (in libsystem_platform.dylib) + 8 [0x7fff9766f348]
+ ! : | + ! : | 2 SocketStream::socketCallback(__CFSocket*, unsigned long, __CFData const*, void const*) (in CFNetwork) + 203 [0x7fff9622b401]
+ ! : | + ! : | + 2 pthread_mutex_unlock (in libsystem_pthread.dylib) + 63 [0x7fff94865be2]
+ ! : | + ! : | + 2 OSAtomicCompareAndSwapPtrBarrier$VARIANT$mp (in libsystem_platform.dylib) + 8 [0x7fff9766f348]
+ ! : | + ! : | 1 SocketStream::socketCallback(__CFSocket*, unsigned long, __CFData const*, void const*) (in CFNetwork) + 148 [0x7fff9622b3ca]
+ ! : | + ! : | 1 SocketStream::socketCallbackReadLocked(SocketStreamSignalHolder*) (in CFNetwork) + 49 [0x7fff9622c227]
+ ! : | + ! : 1 OSAtomicCompareAndSwapPtrBarrier$VARIANT$mp (in libsystem_platform.dylib) + 8 [0x7fff9766f348]
+ ! : | + ! : 1 SocketStream::_SocketCallBack_stream(__CFSocket*, unsigned long, __CFData const*, void const*, void*) (in CFNetwork) + 53 [0x7fff9622b2e9]
+ ! : | + ! : | 1 CFRetain (in CoreFoundation) + 27 [0x7fff928e309b]
+ ! : | + ! : 1 SocketStream::_SocketCallBack_stream(__CFSocket*, unsigned long, __CFData const*, void const*, void*) (in CFNetwork) + 1 [0x7fff9622b2b5]
+ ! : | + ! 1 __CFSocketPerformV0 (in CoreFoundation) + 33 [0x7fff9299c061]
+ ! : | + ! : 1 __psynch_mutexwait (in libsystem_kernel.dylib) + 10 [0x7fff9942d162]
+ ! : | + ! 1 __CFSocketPerformV0 (in CoreFoundation) + 471 [0x7fff9299c217]
+ ! : | + ! 1 __psynch_mutexdrop (in libsystem_kernel.dylib) + 10 [0x7fff9942d14a]
+ ! : | + 21 __CFRunLoopDoSources0 (in CoreFoundation) + 143 [0x7fff9294f76f]
+ ! : | + ! 21 __psynch_mutexdrop (in libsystem_kernel.dylib) + 10 [0x7fff9942d14a]
+ ! : | + 9 __CFRunLoopDoSources0 (in CoreFoundation) + 108 [0x7fff9294f74c]
+ ! : | + ! 9 CFSetApplyFunction (in CoreFoundation) + 186 [0x7fff9293c1da]
+ ! : | + ! 5 CFBasicHashApply (in CoreFoundation) + 128 [0x7fff92920c30]
+ ! : | + ! : 4 __CFSetApplyFunction_block_invoke (in CoreFoundation) + 18 [0x7fff9293c232]
+ ! : | + ! : | 4 __CFRunLoopCollectSources0 (in CoreFoundation) + 22,1 [0x7fff9294f986,0x7fff9294f971]
+ ! : | + ! : 1 __CFSetApplyFunction_block_invoke (in CoreFoundation) + 1 [0x7fff9293c221]
+ ! : | + ! 3 CFBasicHashApply (in CoreFoundation) + 79 [0x7fff92920bff]
+ ! : | + ! : 3 CFBasicHashGetBucket (in CoreFoundation) + 8,323,... [0x7fff9290abb8,0x7fff9290acf3,...]
+ ! : | + ! 1 CFBasicHashApply (in CoreFoundation) + 84 [0x7fff92920c04]
+ ! : | + 2 __CFRunLoopDoSources0 (in CoreFoundation) + 591 [0x7fff9294f92f]
+ ! : | + ! 2 _pthread_mutex_lock (in libsystem_pthread.dylib) + 20,729 [0x7fff94865652,0x7fff94865917]
+ ! : | + 1 DYLD-STUB$$pthread_mutex_unlock (in CoreFoundation) + 0 [0x7fff92aa44a6]
+ ! : | + 1 __CFRunLoopDoSources0 (in CoreFoundation) + 203 [0x7fff9294f7ab]
+ ! : | + 1 pthread_mutex_lock (in libsystem_pthread.dylib) + 0 [0x7fff94865637]
+ ! : | 81 __CFRunLoopRun (in CoreFoundation) + 1492 [0x7fff9294f054]
+ ! : | + 80 __psynch_mutexwait (in libsystem_kernel.dylib) + 10 [0x7fff9942d162]
+ ! : | + 1 _pthread_mutex_lock (in libsystem_pthread.dylib) + 218 [0x7fff94865718]
+ ! : | 32 __CFRunLoopRun (in CoreFoundation) + 1234 [0x7fff9294ef52]
+ ! : | + 30 __psynch_mutexdrop (in libsystem_kernel.dylib) + 10 [0x7fff9942d14a]
+ ! : | + 1 pthread_mutex_unlock (in libsystem_pthread.dylib) + 63 [0x7fff94865be2]
+ ! : | + ! 1 OSAtomicCompareAndSwapPtrBarrier$VARIANT$mp (in libsystem_platform.dylib) + 8 [0x7fff9766f348]
+ ! : | + 1 pthread_mutex_unlock (in libsystem_pthread.dylib) + 133 [0x7fff94865c28]
+ ! : | 30 __CFRunLoopRun (in CoreFoundation) + 2549 [0x7fff9294f475]
+ ! : | + 28 dispatch_source_cancel (in libdispatch.dylib) + 54 [0x7fff90bbae63]
+ ! : | + ! 26 _dispatch_queue_wakeup_with_qos_slow (in libdispatch.dylib) + 563 [0x7fff90bc15f8]
+ ! : | + ! : 25 _dispatch_queue_wakeup_global_slow (in libdispatch.dylib) + 60 [0x7fff90bb2eac]
+ ! : | + ! : | 22 __workq_kernreturn (in libsystem_kernel.dylib) + 10 [0x7fff9942d946]
+ ! : | + ! : | 3 _pthread_workqueue_addthreads (in libsystem_pthread.dylib) + 55,1 [0x7fff94869674,0x7fff9486963e]
+ ! : | + ! : 1 _dispatch_queue_wakeup_global_slow (in libdispatch.dylib) + 4 [0x7fff90bb2e74]
+ ! : | + ! 2 _dispatch_queue_wakeup_with_qos_slow (in libdispatch.dylib) + 1,0 [0x7fff90bc13c6,0x7fff90bc13c5]
+ ! : | + 2 dispatch_source_cancel (in libdispatch.dylib) + 57,46 [0x7fff90bbae66,0x7fff90bbae5b]
+ ! : | 18 __CFRunLoopRun (in CoreFoundation) + 660 [0x7fff9294ed14]
+ ! : | + 18 _dispatch_resume_slow (in libdispatch.dylib) + 14 [0x7fff90bb2a8e]
+ ! : | + 18 _dispatch_queue_wakeup_with_qos_slow (in libdispatch.dylib) + 563 [0x7fff90bc15f8]
+ ! : | + 18 _dispatch_queue_wakeup_with_qos_slow (in libdispatch.dylib) + 30 [0x7fff90bc13e3]
+ ! : | + 18 _dispatch_mgr_wakeup (in libdispatch.dylib) + 34 [0x7fff90bb2ba3]
+ ! : | + 17 kevent64 (in libsystem_kernel.dylib) + 10 [0x7fff9942e22e]
+ ! : | + 1 _dispatch_kq_update (in libdispatch.dylib) + 208 [0x7fff90bb2c77]
+ ! : | + 1 kevent64 (in libsystem_kernel.dylib) + 20 [0x7fff9942e238]
+ ! : | 16 __CFRunLoopRun (in CoreFoundation) + 1605 [0x7fff9294f0c5]
+ ! : | + 14 CFAbsoluteTimeGetCurrent (in CoreFoundation) + 19 [0x7fff92932903]
+ ! : | + 2 CFAbsoluteTimeGetCurrent (in CoreFoundation) + 19 [0x7fff92932903]
+ ! : | + 2 gettimeofday (in libsystem_c.dylib) + 1 [0x7fff9a6b10ee]
+ ! : | 7 __CFRunLoopRun (in CoreFoundation) + 439 [0x7fff9294ec37]
+ ! : | + 4 dispatch_source_create (in libdispatch.dylib) + 467 [0x7fff90bb2337]
+ ! : | + ! 3 _dispatch_barrier_async_f_slow (in libdispatch.dylib) + 34 [0x7fff90bb2654]
+ ! : | + ! : 3 _dispatch_alloc_continuation_alloc (in libdispatch.dylib) + 1,28,... [0x7fff90bbe075,0x7fff90bbe090,...]
+ ! : | + ! 1 dispatch_set_target_queue (in libdispatch.dylib) + 153 [0x7fff90bb240b]
+ ! : | + 2 dispatch_source_create (in libdispatch.dylib) + 156 [0x7fff90bb2200]
+ ! : | + ! 2 _os_object_alloc_realized (in libdispatch.dylib) + 38 [0x7fff90bb0921]
+ ! : | + ! 2 class_createInstance (in libobjc.A.dylib) + 133 [0x7fff8fc52719]
+ ! : | + ! 2 calloc (in libsystem_malloc.dylib) + 49 [0x7fff94b71231]
+ ! : | + ! 2 malloc_zone_calloc (in libsystem_malloc.dylib) + 78 [0x7fff94b6bacb]
+ ! : | + ! 1 szone_malloc_should_clear (in libsystem_malloc.dylib) + 317 [0x7fff94b69f50]
+ ! : | + ! : 1 tiny_malloc_from_free_list (in libsystem_malloc.dylib) + 152 [0x7fff94b6b02c]
+ ! : | + ! 1 szone_malloc_should_clear (in libsystem_malloc.dylib) + 161 [0x7fff94b69eb4]
+ ! : | + 1 dispatch_source_create (in libdispatch.dylib) + 251 [0x7fff90bb225f]
+ ! : | + 1 _dispatch_calloc (in libdispatch.dylib) + 31 [0x7fff90bb2368]
+ ! : | + 1 calloc (in libsystem_malloc.dylib) + 0 [0x7fff94b71200]
+ ! : | 4 __CFRunLoopRun (in CoreFoundation) + 493 [0x7fff9294ec6d]
+ ! : | + 4 __CFTimeIntervalToTSR (in CoreFoundation) + 1,48 [0x7fff92956521,0x7fff92956550]
+ ! : | 3 __CFRunLoopRun (in CoreFoundation) + 2473 [0x7fff9294f429]
+ ! : | + 2 __CFRunLoopModeIsEmpty (in CoreFoundation) + 32,42 [0x7fff9294e910,0x7fff9294e91a]
+ ! : | + 1 __CFRunLoopModeIsEmpty (in CoreFoundation) + 66 [0x7fff9294e932]
+ ! : | + 1 pthread_main_np (in libsystem_pthread.dylib) + 9 [0x7fff94866e34]
+ ! : | 2 __CFRunLoopRun (in CoreFoundation) + 1222 [0x7fff9294ef46]
+ ! : | + 2 pthread_mutex_unlock (in libsystem_pthread.dylib) + 63 [0x7fff94865be2]
+ ! : | + 1 OSAtomicCompareAndSwapPtrBarrier$VARIANT$mp (in libsystem_platform.dylib) + 8 [0x7fff9766f348]
+ ! : | + 1 __mtx_droplock (in libsystem_pthread.dylib) + 1 [0x7fff94865c9b]
+ ! : | 2 __CFRunLoopRun (in CoreFoundation) + 1504 [0x7fff9294f060]
+ ! : | + 2 _pthread_mutex_lock (in libsystem_pthread.dylib) + 191,6 [0x7fff948656fd,0x7fff94865644]
+ ! : | 2 __CFRunLoopRun (in CoreFoundation) + 2508 [0x7fff9294f44c]
+ ! : | + 1 voucher_mach_msg_revert (in libdispatch.dylib) + 1 [0x7fff90bcef86]
+ ! : | + 1 voucher_mach_msg_revert (in libsystem_kernel.dylib) + 16 [0x7fff99417bfe]
+ ! : | 1 DYLD-STUB$$dispatch_release (in CoreFoundation) + 0 [0x7fff92aa40aa]
+ ! : | 1 DYLD-STUB$$dispatch_source_cancel (in CoreFoundation) + 0 [0x7fff92aa40d4]
+ ! : | 1 DYLD-STUB$$dispatch_source_set_event_handler_f (in CoreFoundation) + 0 [0x7fff92aa40f2]
+ ! : | 1 __CFRunLoopRun (in CoreFoundation) + 290 [0x7fff9294eba2]
+ ! : | + 1 _dispatch_runloop_root_queue_get_port_4CF (in libdispatch.dylib) + 0 [0x7fff90bc12a8]
+ ! : | 1 __CFRunLoopRun (in CoreFoundation) + 314 [0x7fff9294ebba]
+ ! : | + 1 malloc (in libsystem_malloc.dylib) + 42 [0x7fff94b68395]
+ ! : | + 1 malloc_zone_malloc (in libsystem_malloc.dylib) + 71 [0x7fff94b69877]
+ ! : | + 1 szone_malloc_should_clear (in libsystem_malloc.dylib) + 317 [0x7fff94b69f50]
+ ! : | + 1 tiny_malloc_from_free_list (in libsystem_malloc.dylib) + 149 [0x7fff94b6b029]
+ ! : | 1 __CFRunLoopRun (in CoreFoundation) + 420 [0x7fff9294ec24]
+ ! : | + 1 dispatch_get_global_queue (in libdispatch.dylib) + 193 [0x7fff90bb2049]
+ ! : | 1 __CFRunLoopRun (in CoreFoundation) + 476 [0x7fff9294ec5c]
+ ! : | + 1 CFRetain (in CoreFoundation) + 27 [0x7fff928e309b]
+ ! : | 1 __CFRunLoopRun (in CoreFoundation) + 530 [0x7fff9294ec92]
+ ! : | + 1 _dispatch_barrier_async_f_slow (in libdispatch.dylib) + 34 [0x7fff90bb2654]
+ ! : | + 1 _dispatch_alloc_continuation_alloc (in libdispatch.dylib) + 187 [0x7fff90bbe12f]
+ ! : | 1 __CFRunLoopRun (in CoreFoundation) + 545 [0x7fff9294eca1]
+ ! : | + 1 _dispatch_barrier_async_f_slow (in libdispatch.dylib) + 355 [0x7fff90bb2795]
+ ! : | 1 __CFRunLoopRun (in CoreFoundation) + 557 [0x7fff9294ecad]
+ ! : | + 1 __CFTSRToTimeInterval (in CoreFoundation) + 1 [0x7fff929998c1]
+ ! : | 1 __CFRunLoopRun (in CoreFoundation) + 652 [0x7fff9294ed0c]
+ ! : | + 1 dispatch_source_set_timer (in libdispatch.dylib) + 111 [0x7fff90bb8d60]
+ ! : | + 1 _os_object_retain (in libdispatch.dylib) + 23 [0x7fff90bb0968]
+ ! : | 1 __CFRunLoopRun (in CoreFoundation) + 910 [0x7fff9294ee0e]
+ ! : | + 1 __CFRunLoopDoBlocks (in CoreFoundation) + 27 [0x7fff9294f51b]
+ ! : | 1 __CFRunLoopRun (in CoreFoundation) + 1141 [0x7fff9294eef5]
+ ! : | + 1 pthread_mutex_unlock (in libsystem_pthread.dylib) + 13 [0x7fff94865bb0]
+ ! : | 1 __CFRunLoopRun (in CoreFoundation) + 1857 [0x7fff9294f1c1]
+ ! : | + 1 mach_absolute_time (in libsystem_kernel.dylib) + 28 [0x7fff9942763a]
+ ! : | 1 __CFRunLoopRun (in CoreFoundation) + 1141 [0x7fff9294eef5]
+ ! : 12 CFRunLoopRunSpecific (in CoreFoundation) + 88 [0x7fff9294e768]
+ ! : | 11 __psynch_mutexwait (in libsystem_kernel.dylib) + 10 [0x7fff9942d162]
+ ! : | 1 OSAtomicCompareAndSwapPtrBarrier$VARIANT$mp (in libsystem_platform.dylib) + 8 [0x7fff9766f348]
+ ! : 4 CFRunLoopRunSpecific (in CoreFoundation) + 101 [0x7fff9294e775]
+ ! : | 3 __CFRunLoopFindMode (in CoreFoundation) + 197 [0x7fff9292bd95]
+ ! : | + 3 CFSetGetValue (in CoreFoundation) + 125 [0x7fff92913b8d]
+ ! : | + 3 CFBasicHashFindBucket (in CoreFoundation) + 1,320,... [0x7fff928e6231,0x7fff928e6370,...]
+ ! : | 1 DYLD-STUB$$pthread_mutex_lock (in CoreFoundation) + 0 [0x7fff92aa44a0]
+ ! : 4 CFRunLoopRunSpecific (in CoreFoundation) + 361 [0x7fff9294e879]
+ ! : | 2 szone_free (in libsystem_malloc.dylib) + 1214,507 [0x7fff94b7002a,0x7fff94b6fd67]
+ ! : | 1 malloc_zone_free (in libsystem_malloc.dylib) + 20 [0x7fff94b6e698]
+ ! : | 1 szone_free (in libsystem_malloc.dylib) + 645 [0x7fff94b6fdf1]
+ ! : | 1 _os_lock_spin_lock (in libsystem_platform.dylib) + 5 [0x7fff97670cca]
+ ! : 2 CFRunLoopRunSpecific (in CoreFoundation) + 394 [0x7fff9294e89a]
+ ! : | 2 pthread_mutex_unlock (in libsystem_pthread.dylib) + 63 [0x7fff94865be2]
+ ! : | 2 __mtx_droplock (in libsystem_pthread.dylib) + 291,94 [0x7fff94865dbd,0x7fff94865cf8]
+ ! : 1 CFRunLoopRunSpecific (in CoreFoundation) + 343 [0x7fff9294e867]
+ ! : 1 pthread_mutex_unlock (in libsystem_pthread.dylib) + 63 [0x7fff94865be2]
+ ! : 1 OSAtomicCompareAndSwapPtrBarrier$VARIANT$mp (in libsystem_platform.dylib) + 0 [0x7fff9766f340]
+ ! 48 SocketStream::read(__CFReadStream*, unsigned char*, long, CFStreamError*, unsigned char*) (in CFNetwork) + 149 [0x7fff962e1335]
+ ! : 42 __sendto (in libsystem_kernel.dylib) + 10,5 [0x7fff9942d4e6,0x7fff9942d4e1]
+ ! : 2 __CFSocketEnableCallBacks (in CoreFoundation) + 826,157 [0x7fff9299bbca,0x7fff9299b92d]
+ ! : 1 CFSocketEnableCallBacks (in CoreFoundation) + 1 [0x7fff9299b841]
+ ! : 1 __CFSocketEnableCallBacks (in CoreFoundation) + 296 [0x7fff9299b9b8]
+ ! : | 1 OSAtomicCompareAndSwapPtrBarrier$VARIANT$mp (in libsystem_platform.dylib) + 0 [0x7fff9766f340]
+ ! : 1 __CFSocketEnableCallBacks (in CoreFoundation) + 592 [0x7fff9299bae0]
+ ! : | 1 CFArrayGetCount (in CoreFoundation) + 28 [0x7fff928f4f6c]
+ ! : 1 __CFSocketEnableCallBacks (in CoreFoundation) + 826 [0x7fff9299bbca]
+ ! : 1 send (in libsystem_c.dylib) + 1 [0x7fff9a72006e]
+ ! 36 SocketStream::read(__CFReadStream*, unsigned char*, long, CFStreamError*, unsigned char*) (in CFNetwork) + 664 [0x7fff962e1538]
+ ! : 36 Schedulables::unschedule(__CFRunLoop*, __CFString const*) (in CFNetwork) + 45 [0x7fff962297e3]
+ ! : 33 CFArrayApplyFunction (in CoreFoundation) + 68 [0x7fff929291e4]
+ ! : | 30 _CFTypeUnscheduleFromRunLoop (in CFNetwork) + 175 [0x7fff9622c91b]
+ ! : | + 23 CFRunLoopRemoveSource (in CoreFoundation) + 510 [0x7fff9294fe0e]
还有一大堆其他的s，里面SocketStream::read有CFRunLoopAddSources，CFRunLoopRemoveSources和CFRunLoopSourceDeallocates。
我想唯一的“不是很好”的事情（从苹果的角度来看）就是这个，但我在那里找不到任何犯罪。