在模拟器中的模态控制器中键入UITextField时，应用程序会卡住

Question

I have a very, very weird effect here using Monotouch 5.2.5 running my app in debug mode in iPad Simulator 5.0.

I have built a universal view controller in Interface Builder. It has a UITextField and a UITextView in it.

If I push that controller on my navigation stack I can use it just fine. However, if I present it modally, I can type a view characters in either one of the input fields, then the app gets stuck. No input anymore, no crash, nothing in the console log. It just hangs. This is reproducible every time.

I have put a breakpoint in the finalizer of the controller: not getting called. Also if I add another custom control into the controller which inherits from UITextField , I can use that one without issues.

EDIT:

• It is crashing on the Simulator only
• It is working in the Simulator if I disable auto correction on the input fields!

Here's the output of GDB - however I have no idea what it can tell me:

(gdb) thread apply all backtrace

Thread 11 (process 65850):
#0  0x97d30c76 in semaphore_timedwait_trap ()
#1  0x0020c185 in mono_sem_timedwait (sem=0x2f52c8, timeout_ms=2000, alertable=1) at mono-semaphore.c:76
#2  0x001cc404 in async_invoke_thread (data=0x0) at threadpool.c:1497
#3  0x001d1e16 in start_wrapper_internal [inlined] () at :784
#4  0x001d1e16 in start_wrapper (data=0x9c56770) at threads.c:832
#5  0x00203cfa in thread_start_routine (args=0xe222a70) at wthreads.c:287
#6  0x001aeb20 in gc_start_thread (arg=0x9c563a0) at sgen-gc.c:6196
#7  0x9c596ed9 in _pthread_start ()
#8  0x9c59a6de in thread_start ()

Thread 10 (process 65850):
#0  0x97d32bb2 in __semwait_signal ()
#1  0x9c54b7b9 in nanosleep$UNIX2003 ()
#2  0x00202ed7 in SleepEx (ms=500, alertable=1) at wthreads.c:1027
#3  0x001c92d7 in monitor_thread (unused=0x0) at threadpool.c:781
#4  0x001d1e16 in start_wrapper_internal [inlined] () at :784
#5  0x001d1e16 in start_wrapper (data=0x9c57180) at threads.c:832
#6  0x00203cfa in thread_start_routine (args=0xe2229f4) at wthreads.c:287
#7  0x001aeb20 in gc_start_thread (arg=0x9c56770) at sgen-gc.c:6196
#8  0x9c596ed9 in _pthread_start ()
#9  0x9c59a6de in thread_start ()

Thread 9 (process 65850):
#0  0x97d3283e in __psynch_cvwait ()
#1  0x9c59ae21 in _pthread_cond_wait ()
#2  0x9c54b42c in pthread_cond_wait$UNIX2003 ()
#3  0x001ef302 in _wapi_handle_timedwait_signal_handle (handle=0x10f, timeout=0x0, alertable=1, poll=0) at handles.c:1655
#4  0x001ef348 in _wapi_handle_wait_signal_handle (handle=0x10f, alertable=1) at handles.c:1598
#5  0x00200e58 in WaitForSingleObjectEx (handle=0x131, timeout=4294967295, alertable=1) at wait.c:203
#6  0x001d081d in ves_icall_System_Threading_WaitHandle_WaitOne_internal (this=0xc6a2ed8, handle=0x10f, ms=-1, exitContext=0) at threads.c:1665
#7  0x12f9bf7e in ?? ()
#8  0x12f9b9e4 in ?? ()
#9  0x12f9b4d3 in ?? ()
#10 0x12f99a40 in ?? ()
#11 0x12f972be in ?? ()
#12 0x099eaa50 in ?? ()
#13 0x00010222 in mono_jit_runtime_invoke (method=0xe356e14, obj=0xc6a2fb0, params=0xb06daf34, exc=0x0) at mini.c:5797
#14 0x00171f6e in mono_runtime_invoke (method=0xe356e14, obj=0xc6a2fb0, params=0xb06daf34, exc=0x0) at object.c:2757
#15 0x001720ac in mono_runtime_delegate_invoke (delegate=0xc6a2fb0, params=0xb06daf34, exc=0x0) at object.c:3422
#16 0x001d1e42 in start_wrapper_internal [inlined] () at :790
#17 0x001d1e42 in start_wrapper (data=0x9c58de0) at threads.c:832
#18 0x00203cfa in thread_start_routine (args=0xe222690) at wthreads.c:287
#19 0x001aeb20 in gc_start_thread (arg=0x9c587f0) at sgen-gc.c:6196
#20 0x9c596ed9 in _pthread_start ()
#21 0x9c59a6de in thread_start ()

Thread 8 (process 65850):
#0  0x97d32876 in __psynch_mutexwait ()
#1  0x9c5956af in pthread_mutex_lock ()
#2  0x073a955e in _WebTryThreadLock ()
#3  0x073a9255 in WebRunLoopLock ()
#4  0x011a99ce in __CFRUNLOOP_IS_CALLING_OUT_TO_AN_OBSERVER_CALLBACK_FUNCTION__ ()
#5  0x01140670 in __CFRunLoopDoObservers ()
#6  0x0110c665 in __CFRunLoopRun ()
#7  0x0110bdb4 in CFRunLoopRunSpecific ()
#8  0x0110bccb in CFRunLoopRunInMode ()
#9  0x073a9220 in RunWebThread ()
#10 0x9c596ed9 in _pthread_start ()
#11 0x9c59a6de in thread_start ()

Thread 7 (process 65850):
#0  0x97d32bb2 in __semwait_signal ()
#1  0x9c54b7b9 in nanosleep$UNIX2003 ()
#2  0x9c54b558 in usleep$UNIX2003 ()
#3  0x0021c162 in monotouch_pump_gc ()
#4  0x9c596ed9 in _pthread_start ()
#5  0x9c59a6de in thread_start ()

Thread 6 (process 65850):
#0  0x97d32a9a in recvfrom$UNIX2003 ()
#1  0x9c54b4a2 in recv$UNIX2003 ()
#2  0x00227b41 in recv_uninterrupted ()
#3  0x00227c24 in sdb_recv ()
#4  0x000b005a in transport_recv [inlined] () at :1373
#5  0x000b005a in debugger_thread (arg=0x0) at debugger-agent.c:7799
#6  0x00203cfa in thread_start_routine (args=0xe22232c) at wthreads.c:287
#7  0x001aeb20 in gc_start_thread (arg=0x9c632d0) at sgen-gc.c:6196
#8  0x9c596ed9 in _pthread_start ()
#9  0x9c59a6de in thread_start ()

Thread 5 (process 65850):
#0  0x97d30c5e in semaphore_wait_trap ()
#1  0x0020c21a in mono_sem_wait (sem=Cannot access memory at address 0x0
) at mono-semaphore.c:115
#2  0x0011224a in finalizer_thread (unused=0x0) at gc.c:1070
#3  0x001d1e16 in start_wrapper_internal [inlined] () at :784
#4  0x001d1e16 in start_wrapper (data=0xdb72500) at threads.c:832
#5  0x00203cfa in thread_start_routine (args=0xe222234) at wthreads.c:287
#6  0x001aeb20 in gc_start_thread (arg=0xdb72550) at sgen-gc.c:6196
#7  0x9c596ed9 in _pthread_start ()
#8  0x9c59a6de in thread_start ()

Thread 4 (process 65850):
#0  0x97d30c22 in mach_msg_trap ()
#1  0x97d301f6 in mach_msg ()
#2  0x000de64a in mach_exception_thread (arg=0x0) at mini-darwin.c:132
#3  0x9c596ed9 in _pthread_start ()
#4  0x9c59a6de in thread_start ()

Thread 3 (process 65850):
#0  0x97d32a9a in recvfrom$UNIX2003 ()
#1  0x9c54b4a2 in recv$UNIX2003 ()
#2  0x00227b41 in recv_uninterrupted ()
#3  0x0022933b in monotouch_process_connection ()
#4  0x00228a17 in monotouch_connect_wifi ()
#5  0x002278b7 in monotouch_configure_debugging ()
#6  0x0022bd75 in -[CocoaThreadInitializer entryPoint:] ()
#7  0x017374e6 in -[NSThread main] ()
#8  0x01737457 in __NSThread__main__ ()
#9  0x9c596ed9 in _pthread_start ()
#10 0x9c59a6de in thread_start ()

Thread 2 (process 65850):
#0  0x97d3390a in kevent ()
#1  0x03784373 in _dispatch_mgr_invoke ()
#2  0x03782cd0 in _dispatch_mgr_thread ()

Thread 1 (process 65850):
#0  0x947e7d52 in ?? ()
#1  0x90154973 in CGDataProviderRetain ()
#2  0x9c80364a in CFAllocatorCreate ()
#3  0x9859a3d1 in CGImageReadCreateWithProvider ()
#4  0x9859a291 in CGImageSourceCreateWithDataProvider ()
#5  0x013d4d2f in CGImageCreateWithPNGDataProvider ()
#6  0x073de2a5 in WKGraphicsCreateImageFromBundleWithName ()
#7  0x06c305bd in WebCore::GraphicsContext::drawLineForTextChecking ()
#8  0x06d0ae84 in WebCore::InlineTextBox::paintSpellingOrGrammarMarker ()
#9  0x06d0afb9 in WebCore::InlineTextBox::paintDocumentMarkers ()
#10 0x06d073fc in WebCore::InlineTextBox::paint ()
#11 0x06d003cd in WebCore::InlineFlowBox::paint ()
#12 0x0726124c in WebCore::RootInlineBox::paint ()
#13 0x071bce2a in WebCore::RenderLineBoxList::paint ()
#14 0x07156089 in WebCore::RenderBlock::paintObject ()
#15 0x0715648f in WebCore::RenderBlock::paint ()
#16 0x07155615 in WebCore::RenderBlock::paintChildren ()
#17 0x071560ab in WebCore::RenderBlock::paintObject ()
#18 0x0715648f in WebCore::RenderBlock::paint ()
#19 0x071aa1b0 in WebCore::RenderLayer::paintLayer ()
#20 0x071aa48c in WebCore::RenderLayer::paintLayer ()
#21 0x071ab3bb in WebCore::RenderLayer::paint ()
#22 0x06c03809 in WebCore::FrameView::paintContents ()
#23 0x067b91d0 in -[WebFrame(WebInternal) _drawRect:contentsOnly:] ()
#24 0x067e083c in -[WebHTMLView drawSingleRect:] ()
#25 0x067e0786 in -[WebHTMLView drawRect:] ()
#26 0x073a6c2f in drawCallback ()
#27 0x073e152c in _WKViewDraw ()
#28 0x073e161f in _WKViewDraw ()
#29 0x073e161f in _WKViewDraw ()
#30 0x073e161f in _WKViewDraw ()
#31 0x073e161f in _WKViewDraw ()
#32 0x073e180e in WKViewDisplayRect ()
#33 0x073e2ad0 in WKWindowDrawRect ()
#34 0x07371af0 in WebCore::TileCache::drawLayer ()
#35 0x07376af1 in -[TileLayer drawInContext:] ()
#36 0x0418612d in backing_callback ()
#37 0x040a615d in CABackingStoreUpdate_ ()
#38 0x04185fd2 in CA::Layer::display_ ()
#39 0x04173cf1 in -[CALayer _display] ()
#40 0x0417a281 in CA::Layer::display ()
#41 0x04173d17 in -[CALayer display] ()
#42 0x0417dc5c in CA::Layer::display_if_needed ()
#43 0x04103fb9 in CA::Context::commit_transaction ()
#44 0x04105ea6 in CA::Transaction::commit ()
#45 0x04105580 in CA::Transaction::observer_callback ()
#46 0x011a99ce in __CFRUNLOOP_IS_CALLING_OUT_TO_AN_OBSERVER_CALLBACK_FUNCTION__ ()
#47 0x01140670 in __CFRunLoopDoObservers ()
#48 0x0110c4f6 in __CFRunLoopRun ()
#49 0x0110bdb4 in CFRunLoopRunSpecific ()
#50 0x0110bccb in CFRunLoopRunInMode ()
#51 0x0479d879 in GSEventRunModal ()
#52 0x0479d93e in GSEventRun ()
#53 0x021a4a9b in UIApplicationMain ()
#54 0x0e9e018d in ?? ()
#55 0x0e9de930 in ?? ()
#56 0x0e9de608 in ?? ()
#57 0x0e9de77e in ?? ()
#58 0x00010222 in mono_jit_runtime_invoke (method=0xa3031e4, obj=0x0, params=0xbffff1d8, exc=0x0) at mini.c:5797
#59 0x00171f6e in mono_runtime_invoke (method=0xa3031e4, obj=0x0, params=0xbffff1d8, exc=0x0) at object.c:2757
#60 0x00176294 in mono_runtime_exec_main (method=0xa3031e4, args=0xc69be98, exc=0x0) at object.c:3932
#61 0x00176605 in mono_runtime_run_main (method=0xa3031e4, argc=0, argv=0x2dee80, exc=0x0) at object.c:3562
#62 0x0006b7f5 in mono_jit_exec (domain=0x9d616b0, assembly=0x986b2f0, argc=1, argv=0x2dee80) at driver.c:1122
#63 0x0022bcd0 in main ()

Does anybody have the slightest idea what might be going on here? I will try to isolate the problem now but I'm still hoping somebody can point my in the right direction.

Answer 1

Yes. It's a known bug of the iOS simulator (unrelated to MonoTouch). The workaround is to disable spellcheck (eg #if SIMULATOR) when executing in the simulator.

UITextField Crash in Simulator not in iPhone 4 (4.2)

You can figure out what the app is doing by attaching gdb and getting stack traces for all threads:

gdb program <PID printed to application output on startup>
<gdb output>
(gdb) thread apply all backtrace
<more gdb output>