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Move public callback methods to internal implementation #4

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pentschev opened this issue Apr 3, 2023 · 0 comments
Open

Move public callback methods to internal implementation #4

pentschev opened this issue Apr 3, 2023 · 0 comments
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improvement Improves an existing functionality

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@pentschev
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Perhaps as part of #3 or even before a complete pImpl implementation, callbacks should be moved to an internal object, such that we don't need to keep them as as public members of the public API.
@pentschev pentschev added the improvement Improves an existing functionality label Apr 3, 2023
rapids-bot bot pushed a commit that referenced this issue Nov 28, 2023
@pentschev
Set timeout for closing endpoints in Python (#136)
21abf71 
#123 introduced timeouts to the generic callbacks, preventing failure to acquire lock due to GIL competition. However, those were not exposed to Python and at least one of the reasons it still timeouts is because of that, notice how the default `period=0` (never unblock) is used:

```cpp
Thread 1 (Thread 0x7f36d675f740 (LWP 155586) "pytest"):
#0  futex_wait_cancelable (private=<optimized out>, expected=0, futex_word=0x7fff45058e58) at ../sysdeps/nptl/futex-internal.h:183
#1  __pthread_cond_wait_common (abstime=0x0, clockid=0, mutex=0x7fff45058e08, cond=0x7fff45058e30) at pthread_cond_wait.c:508
#2  __pthread_cond_wait (cond=0x7fff45058e30, mutex=0x7fff45058e08) at pthread_cond_wait.c:647
#3  0x00007f36d43634d4 in std::condition_variable::wait<ucxx::utils::CallbackNotifier::wait(uint64_t)::<lambda()> > (__p=..., __lock=..., this=0x7fff45058e30) at /opt/conda/envs/test/x86_64-conda-linux-gnu/include/c++/11.4.0/condition_variable:103
#4  ucxx::utils::CallbackNotifier::wait (this=this@entry=0x7fff45058e00, period=period@entry=0) at /datasets/pentschev/src/ucxx-deadlock/cpp/src/utils/callback_notifier.cpp:66
#5  0x00007f36d43470e1 in ucxx::Endpoint::close (this=0x7f369c701a90, period=0, maxAttempts=1) at /datasets/pentschev/src/ucxx-deadlock/cpp/src/endpoint.cpp:171
#6  0x00007f36d4753381 in __pyx_pw_4ucxx_4_lib_7libucxx_11UCXEndpoint_9close(_object*, _object* const*, long, _object*) () from /opt/conda/envs/test/lib/python3.10/site-packages/ucxx/_lib/libucxx.cpython-310-x86_64-linux-gnu.so
```

This PR exposes those arguments to Python and specify a default for Python async API `Endpoint.abort()` to prevent such deadlocks from occurring.

Authors:
  - Peter Andreas Entschev (https://github.com/pentschev)

Approvers:
  - Lawrence Mitchell (https://github.com/wence-)

URL: #136
rapids-bot bot pushed a commit that referenced this issue Dec 5, 2023
@pentschev
Use notify_one() in CallbackNotifier (#140)
197a0a9 
It is unclear why but for some reason `notify_all()` is causing futexes never to return in some situations. This occurs very frequently in CI and is also less frequently reproducible locally.

The typical stack trace for the blocked thread is shown below:

```cpp
Thread 6 (Thread 0x7f13ec84f700 (LWP 2823667) "pytest"):
#0  futex_wait (private=<optimized out>, expected=32765, futex_word=0x7ffd5186a874) at ../sysdeps/nptl/futex-internal.h:141
#1  futex_wait_simple (private=<optimized out>, expected=32765, futex_word=0x7ffd5186a874) at ../sysdeps/nptl/futex-internal.h:172
#2  __condvar_quiesce_and_switch_g1 (private=<optimized out>, g1index=<synthetic pointer>, wseq=<optimized out>, cond=0x7ffd5186a860) at pthread_cond_common.c:416
#3  __pthread_cond_broadcast (cond=0x7ffd5186a860) at pthread_cond_broadcast.c:73
#4  0x00007f140fe5f23c in ucxx::BaseDelayedSubmissionCollection<std::function<void ()> >::process() (this=0x560d0effafd0) at /repo/cpp/include/ucxx/delayed_submission.h:154
#5  0x00007f140fe5f399 in ucxx::DelayedSubmissionCollection::processPost (this=<optimized out>) at /repo/cpp/src/delayed_submission.cpp:84
#6  0x00007f140fe7ed71 in ucxx::WorkerProgressThread::progressUntilSync(std::function<bool ()>, bool const&, std::function<void (void*)>, void*, std::shared_ptr<ucxx::DelayedSubmissionCollection>) (progressFunction=..., stop=@0x560d0f6527f8: false, startCallback=..., startCallbackArg=<optimized out>, delayedSubmissionCollection=...) at /opt/conda/envs/test/x86_64-conda-linux-gnu/include/c++/11.4.0/bits/shared_ptr_base.h:1295
#7  0x00007f140fe7f3ee in std::__invoke_impl<void, void (*)(std::function<bool ()>, bool const&, std::function<void (void*)>, void*, std::shared_ptr<ucxx::DelayedSubmissionCollection>), std::function<bool ()>, std::reference_wrapper<bool>, std::function<void (void*)>, void*, std::shared_ptr<ucxx::DelayedSubmissionCollection> >(std::__invoke_other, void (*&&)(std::function<bool ()>, bool const&, std::function<void (void*)>, void*, std::shared_ptr<ucxx::DelayedSubmissionCollection>), std::function<bool ()>&&, std::reference_wrapper<bool>&&, std::function<void (void*)>&&, void*&&, std::shared_ptr<ucxx::DelayedSubmissionCollection>&&) (__f=<optimized out>, __f=<optimized out>) at /opt/conda/envs/test/x86_64-conda-linux-gnu/include/c++/11.4.0/bits/invoke.h:61
#8  std::__invoke<void (*)(std::function<bool ()>, bool const&, std::function<void (void*)>, void*, std::shared_ptr<ucxx::DelayedSubmissionCollection>), std::function<bool ()>, std::reference_wrapper<bool>, std::function<void (void*)>, void*, std::shared_ptr<ucxx::DelayedSubmissionCollection> >(void (*&&)(std::function<bool ()>, bool const&, std::function<void (void*)>, void*, std::shared_ptr<ucxx::DelayedSubmissionCollection>), std::function<bool ()>&&, std::reference_wrapper<bool>&&, std::function<void (void*)>&&, void*&&, std::shared_ptr<ucxx::DelayedSubmissionCollection>&&) (__fn=<optimized out>) at /opt/conda/envs/test/x86_64-conda-linux-gnu/include/c++/11.4.0/bits/invoke.h:96
#9  std::thread::_Invoker<std::tuple<void (*)(std::function<bool ()>, bool const&, std::function<void (void*)>, void*, std::shared_ptr<ucxx::DelayedSubmissionCollection>), std::function<bool ()>, std::reference_wrapper<bool>, std::function<void (void*)>, void*, std::shared_ptr<ucxx::DelayedSubmissionCollection> > >::_M_invoke<0ul, 1ul, 2ul, 3ul, 4ul, 5ul>(std::_Index_tuple<0ul, 1ul, 2ul, 3ul, 4ul, 5ul>) (this=<optimized out>) at /opt/conda/envs/test/x86_64-conda-linux-gnu/include/c++/11.4.0/bits/std_thread.h:259
#10 std::thread::_Invoker<std::tuple<void (*)(std::function<bool ()>, bool const&, std::function<void (void*)>, void*, std::shared_ptr<ucxx::DelayedSubmissionCollection>), std::function<bool ()>, std::reference_wrapper<bool>, std::function<void (void*)>, void*, std::shared_ptr<ucxx::DelayedSubmissionCollection> > >::operator()() (this=<optimized out>) at /opt/conda/envs/test/x86_64-conda-linux-gnu/include/c++/11.4.0/bits/std_thread.h:266
#11 std::thread::_State_impl<std::thread::_Invoker<std::tuple<void (*)(std::function<bool ()>, bool const&, std::function<void (void*)>, void*, std::shared_ptr<ucxx::DelayedSubmissionCollection>), std::function<bool ()>, std::reference_wrapper<bool>, std::function<void (void*)>, void*, std::shared_ptr<ucxx::DelayedSubmissionCollection> > > >::_M_run() (this=<optimized out>) at /opt/conda/envs/test/x86_64-conda-linux-gnu/include/c++/11.4.0/bits/std_thread.h:211
#12 0x00007f140f92fe95 in std::execute_native_thread_routine (__p=<optimized out>) at ../../../../../libstdc++-v3/src/c++11/thread.cc:104
#13 0x00007f1412647609 in start_thread (arg=<optimized out>) at pthread_create.c:477
#14 0x00007f1412412133 in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95
```

Authors:
  - Peter Andreas Entschev (https://github.com/pentschev)

Approvers:
  - Lawrence Mitchell (https://github.com/wence-)

URL: #140
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