Crash when playing automation constraint

[lossius]

Here are the steps that led to this crash:

1. Opened i-score
2. Added a minuit device with standard settings, connected to max. In max I had j.minuit_device.maxhelp and dbap=.maxhelp open
3. Made a new constraint by double-clicking in the time canvas (not sure what the middle window is called)
4. Added an automation, connecting to /mydbap/sources/source.1/gain, and set start value to -12 and end value to 0
5. Hit play from the play menu
6. The automation starts out, and I can see that messages are pushed to Max, but after a while I got the crash. The crash seems to be reproducible.

https://gist.github.com/lossius/1b840fd9f69e96ec4a7a

[jcelerier]

Paging @theod ; this part crashed :

• 13

Thread 7 Crashed:
0 org.i-score 0x00000001039953e9 JamomaAddress::setValue(OSSIA::Value const_) + 25
1 org.i-score 0x0000000103994afe JamomaAddress::pushValue(OSSIA::Value const_) + 30
2 org.i-score 0x0000000103987c39 JamomaState::launch() const + 41
3 org.i-score 0x0000000103987c39 JamomaState::launch() const + 41
4 org.i-score 0x000000010394269a std::__1::__function::__func<void ()(OSSIA::TimeValue const&, OSSIA::TimeValue const&, std::__1::shared_ptrOSSIA::StateElement), std::__1::allocator<void ()(OSSIA::TimeValue const&, OSSIA::TimeValue const&, std::__1::shared_ptrOSSIA::StateElement)>, void (OSSIA::TimeValue const&, OSSIA::TimeValue const&, std::__1::shared_ptrOSSIA::StateElement)>::operator()(OSSIA::TimeValue const&, OSSIA::TimeValue const&, std::__1::shared_ptrOSSIA::StateElement&&) + 58
5 org.i-score 0x000000010398840b JamomaTimeConstraint::ClockCallback(OSSIA::TimeValue const&, OSSIA::TimeValue const&, unsigned char) + 75
6 org.i-score 0x000000010397ca77 JamomaClock::tick() + 743
7 org.i-score 0x000000010397c669 JamomaClock::threadCallback() + 41
8 org.i-score 0x000000010397cf81 void* std::__1::__thread_proxy<std::__1::tuple<void (JamomaClock::)(), JamomaClock> >(void*) + 113
9 libsystem_pthread.dylib 0x00007fff8c5b005a _pthread_body + 131
10 libsystem_pthread.dylib 0x00007fff8c5affd7 _pthread_start + 176
11 libsystem_pthread.dylib 0x00007fff8c5ad3ed thread_start + 13

[theod]

ouch ! malloc error : pointer being freed was not allocated !
I've put a malloc break point in Xcode but maybe @jcelerier you have a trick figure out this kind of bug ?

[jcelerier]

Mhh... On linux I use valgrind but it doesn't works in OS X (but I think that Xcode has some kind of facilities to detect such problems.)

Maybe (just maybe) a pointer is deleted manually somewhere while being part of a shared_ptr (like some std::shared_ptrOSSIA::Value) ?

[theod]

thanks for the tip !
however Value are never passed using shared_ptr (at least inside the API).
are you doing this into i-score ?

[theod]

I'm suspecting a memory conflict due to the listening.
I'll make some tests next week by closing the listening to see if it continue to crash.

[jcelerier]

I just checked but there are no shared_ptr in iscore either. Could it happen for a same Value to be shared between two states (e.g. when taking the states of the child processes) and then having the first State being deleted which would make the Value in the other state invalid ?

[theod]

adding a mutex to protect from multithreading access resolved the problem. @lossius could you test this on the next release before to close ?

[lossius]

Hi, this seems to work without crashing now, although I notice other issues, but I'll report them separately.