[Bug] client subscribe hang

[haolujun]

Search before asking

• I searched in the issues and found nothing similar.

Version

pulsar: 2.10.0. OS: Linux 4.19.160-0419160-generic x86_64.

Minimal reproduce step

when I close the old consumer and client, and make new client and subcribe, then sometimes hang.

What did you expect to see?

expect success

What did you see instead?

`
#0 0x00007f31b5565ad3 in futex_wait_cancelable (private=, expected=0, futex_word=0x5607e2a0af90) at ../sysdeps/unix/sysv/linux/futex-internal.h:88

#1 __pthread_cond_wait_common (abstime=0x0, mutex=0x5607e2a0af40, cond=0x5607e2a0af68) at pthread_cond_wait.c:502

#2 __pthread_cond_wait (cond=0x5607e2a0af68, mutex=0x5607e2a0af40) at pthread_cond_wait.c:655

#3 0x00007f319e5d68bc in std::condition_variable::wait(std::unique_lockstd::mutex&) () from /usr/lib/x86_64-linux-gnu/libstdc++.so.6

#4 0x00007f314ed9b173 in pulsar::Client::subscribe(std::__cxx11::basic_string<char, std::char_traits, std::allocator > const&, std::__cxx11::basic_string<char, std::char_traits, std::allocator > const&, pulsar::ConsumerConfiguration const&, pulsar::Consumer&) () from /usr/local/lib/python3.7/site-packages/xdl/dataset2/_dataset2_pyext.cpython-37m-x86_64-linux-gnu.so
`

Anything else?

when I close the old consumer and client, and make new client and subcribe, then sometimes hang.

Are you willing to submit a PR?

• I'm willing to submit a PR!

[BewareMyPower]

It seems that you're using Python clients. What's the client version? Could it be reproduced with the latest Python client (3.6.1)?

[haolujun]

oh, I don't use python client. I use cpp client in pybind. So, you can see somthing with python in stack. The python version is 3.7.13.

[BewareMyPower]

Could it be reproduce it via a simple C++ application? What's the C++ client version you're using? The pre-built binaries or you built from source? It's recommended to use vcpkg to install now.