crash when [VCSimpleSession endRtmpSession] is called

[zhifeng-huang]

It keeps crashing when I call [VCSimpleSession endRtmpSession]. The crash point is in RTMPSession::~RTMPSession().

Error message:
malloc: *** error for object 0x1742d4c00: pointer being freed was not allocated
*** set a breakpoint in malloc_error_break to debug

Backtrace:

• thread glsl filters in video compositor #1: tid = 0x1541d, 0x0000000197acf270 libsystem_kernel.dylib__pthread_kill + 8, queue = 'com.apple.main-thread', stop reason = signal SIGABRT frame #0: 0x0000000197acf270 libsystem_kernel.dylib__pthread_kill + 8
  frame glsl filters in video compositor #1: 0x0000000197b6d228 libsystem_pthread.dylibpthread_kill + 112 frame #2: 0x0000000197a46b18 libsystem_c.dylibabort + 112
  frame aac encoder should be able to handle an arbitrary number of samples #3: 0x0000000197afc2fc libsystem_malloc.dylibfree + 512 frame #4: 0x0000000196b019b8 libc++.1.dylibstd::__1::basic_string<char, std::__1::char_traits, std::__1::allocator >::~basic_string() + 36
  frame move from "layer name" to z-Index for video #5: 0x00000001006d9c98 EdCastvideocore::RTMPSession::~RTMPSession(this=0x000000013027f800) + 352 at RTMPSession.cpp:93 frame #6: 0x00000001006da630 EdCastvideocore::RTMPSession::~RTMPSession(this=0x000000013027f800) + 28 at RTMPSession.cpp:83
  frame Update video sources to properly register/unregister with mixer #7: 0x00000001006da664 EdCastvideocore::RTMPSession::~RTMPSession(this=0x000000013027f800) + 28 at RTMPSession.cpp:83 frame #8: 0x000000010071e630 EdCaststd::__1::__shared_ptr_pointer<videocore::RTMPSession*, std::__1::default_deletevideocore::RTMPSession, std::__1::allocatorvideocore::RTMPSession >::__on_zero_shared() [inlined] std::__1::default_deletevideocore::RTMPSession::operator(this=0x0000000174625ad8, this=0x0000000174625ad8, this=0x0000000174625ad8, this=0x0000000174625ad8, this=0x0000000174625ad8, _ptr=0x000000013027f800)(videocore::RTMPSession) const + 148 at memory:2426
  frame display camera after the view was loaded #9: 0x000000010071e60c EdCaststd::__1::__shared_ptr_pointer<videocore::RTMPSession_, std::__1::default_deletevideocore::RTMPSession, std::__1::allocatorvideocore::RTMPSession >::__on_zero_shared(this=0x0000000174625ac0) + 112 at memory:3669 frame #10: 0x0000000196afd764 libc++.1.dylibstd::__1::__shared_weak_count::__release_shared() + 64
  frame building VideoCore as a static library #11: 0x00000001007141e8 EdCaststd::__1::shared_ptrvideocore::IOutputSession::~shared_ptr(this=0x000000016fdc5c08) + 60 at memory:4448 frame #12: 0x00000001007140c4 EdCaststd::__1::shared_ptrvideocore::IOutputSession::~shared_ptr(this=0x000000016fdc5c08) + 28 at memory:4446
  frame Use CocoaPods rather than git submodules and dumping stuff in lib/include. #13: 0x000000010070b758 EdCast-[VCSimpleSession endRtmpSession] [inlined] std::__1::shared_ptrvideocore::IOutputSession::reset(this=0x000000012f57c070) + 200 at memory:4577 frame #14: 0x000000010070b690 EdCast-[VCSimpleSession endRtmpSession](self=0x000000012f57bf70, _cmd=0x00000001009410a7) + 1364 at VCSimpleSession.mm:600
  • frame Fix cocoapod namespace collision #15: 0x0000000100709c20 EdCast-[VCSimpleSession dealloc](self=0x000000012f57bf70, _cmd=0x000000018bb6dd0d) + 76 at VCSimpleSession.mm:448 frame #16: 0x000000010003e0f4 EdCast-[ECStreamViewController .cxx_destruct](self=0x000000012f5f6260, _cmd=0x0000000000000000) + 68 at ECStreamViewController.m:24
    frame z-index and transformation matrices #17: 0x0000000197346b1c libobjc.A.dylibobject_cxxDestructFromClass(objc_object*, objc_class*) + 148 frame #18: 0x0000000197353f38 libobjc.A.dylibobjc_destructInstance + 92
    frame Switch to MIT or BSD license #19: 0x0000000197353f90 libobjc.A.dylibobject_dispose + 28 frame #20: 0x000000018b6d4d64 UIKit-[UIResponder dealloc] + 116
    frame Add a preview layer to CameraSource #21: 0x000000018b52198c UIKit-[UIViewController dealloc] + 1912 frame #22: 0x000000018ba8dc20 UIKit-[_UIFullscreenPresentationController _setPresentedViewController:] + 56
    frame use device orientation rather than status bar orientation #23: 0x000000018b69a66c UIKit-[UIPresentationController dealloc] + 40 frame #24: 0x000000018ba8d3f0 UIKit-[_UIFullscreenPresentationController dealloc] + 100
    frame Documentation. #25: 0x000000018b69a3a8 UIKit__destroy_helper_block_354 + 40 frame #26: 0x00000001979e1910 libsystem_blocks.dylib_Block_release + 256
    frame Some means of creating a graph more easily. #27: 0x000000018b4bfac8 UIKit-[_UIViewControllerTransitionContext dealloc] + 160 frame #28: 0x000000018b4bfa18 UIKit-[_UIViewControllerOneToOneTransitionContext dealloc] + 196
    frame AudioMixer setSourceGain does not work #29: 0x000000018b4be024 UIKit-[UITransitionView _didCompleteTransition:] + 1076 frame #30: 0x000000018b3d3c0c UIKit-[UIViewAnimationState sendDelegateAnimationDidStop:finished:] + 188
    frame Fix for readme #31: 0x000000018b3d3b14 UIKit-[UIViewAnimationState animationDidStop:finished:] + 104 frame #32: 0x000000018acf8f64 QuartzCoreCA::Layer::run_animation_callbacks(void*) + 296
    frame Stability of RTMP Session #33: 0x00000001016c8df0 libdispatch.dylib_dispatch_client_callout + 16 frame #34: 0x00000001016cd75c libdispatch.dylib_dispatch_main_queue_callback_4CF + 1056
    frame Video toolbox #14 #35: 0x0000000186ba1fa4 CoreFoundation__CFRUNLOOP_IS_SERVICING_THE_MAIN_DISPATCH_QUEUE__ + 12 frame #36: 0x0000000186ba004c CoreFoundation__CFRunLoopRun + 1492
    frame Bandwidth adaptation #37: 0x0000000186acd0a4 CoreFoundationCFRunLoopRunSpecific + 396 frame #38: 0x000000018fc6f5a4 GraphicsServicesGSEventRunModal + 168
    frame configurable audio sample rate and channel count #39: 0x000000018b4023c0 UIKitUIApplicationMain + 1488 frame #40: 0x000000010013c208 EdCastmain(argc=1, argv=0x000000016fdc79e8) + 172 at main.m:20
    frame RTMPSession::write() (intermittently) called after RTMPSession::~RTMPSession() #41: 0x00000001979b6a08 libdyld.dylib`start + 4

[zhifeng-huang]

The same code is working fine on the simulator.

[zhifeng-huang]

It crashes all the time on a device.

[jgh-]

Which version of VideoCore is this?

[zhifeng-huang]

I am using 0.3.0 from CocoaPods.

[zhifeng-huang]

Should I try a different version?

[jgh-]

Could you add a breakpoint for malloc_error_break and let me know what comes up?

[zhifeng-huang]

I just tried the version 0.2.3.2. It still crashed at the same spot. I am going to add a breakpoint for malloc_error_break now.

[zhifeng-huang]

With the breakpoint at malloc_error_break, I see the following:

#0 0x0000000197b07890 in malloc_error_break ()
#1 0x0000000197afc280 in free ()
#2 0x0000000196b019b8 in std::__1::basic_string<char, std::__1::char_traits, std::__1::allocator >::~basic_string() ()
#3 0x00000001006b9bf8 in videocore::RTMPSession::~RTMPSession() at /Users/zfh/Desktop/edcast-ios/Pods/VideoCore/rtmp/RTMPSession.cpp:93
#4 0x00000001006ba590 in videocore::RTMPSession::~RTMPSession() at /Users/zfh/Desktop/edcast-ios/Pods/VideoCore/rtmp/RTMPSession.cpp:83
#5 0x00000001006ba5c4 in videocore::RTMPSession::~RTMPSession() at /Users/zfh/Desktop/edcast-ios/Pods/VideoCore/rtmp/RTMPSession.cpp:83

libc++.1.dylib`std::__1::basic_string<char, std::__1::char_traits, std::__1::allocator >::~basic_string():
0x196b01994: stp x20, x19, [sp, #-32]!
0x196b01998: stp fp, lr, [sp, #16]
0x196b0199c: add fp, sp, #16
0x196b019a0: mov x19, x0
0x196b019a4: ldrsb w8, [x19, #23]
0x196b019a8: cmp w8, #0
0x196b019ac: b.ge 0x196b019b8 ; std::__1::basic_string<char, std::__1::char_traits, std::__1::allocator >::~basic_string() + 36
0x196b019b0: ldr x0, [x19]
0x196b019b4: bl 0x196b098a4 ; symbol stub for: std::1::collate::hash(char const, char const) const
(stop here) ==> 0x196b019b8: mov x0, x19 <== (stop here)
0x196b019bc: ldp fp, lr, [sp, #16]
0x196b019c0: ldp x20, x19, [sp], #32
0x196b019c4: ret

[jgh-]

I was experiencing a similar crash under certain circumstances. I made a few changes and pushed out 0.3.0.1 - give that one a try.

[zhifeng-huang]

0.3.0.1 is very slow compared to 0.3.0. I even crashed when starting a session with 0.3.0.1.

[zhifeng-huang]

Also, I set the frame rate to be 30fps. However, with 0.3.0.1, Xcode says that FPS is 60. With 0.3.0, Xcode says that FPS is 30, which is what I expect.

[jgh-]

Please test with 0.3.0.3. I made some changes that may have fixed this issue.

[zhifeng-huang]

I just test 0.3.0.3. The crash has been fixed! Thank you for your fast response!

[jgh-]

perfect, glad to hear