jack_client_close is locking when the jack server is periodically restarts #395
Description
Hi, i'm working on an application which must automatically reconnect to the jack server. But i'm run into some trouble when started to test it. After several times of restarting the jack server, my application ended up stuck at jack_client_close.
Here's example to reproduce the bug:
#include <jack/jack.h>
#include <unistd.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <pthread.h>
jack_port_t *input_port;
jack_port_t *output_port;
jack_client_t *client;
pthread_spinlock_t spinlock;
int stop = 0;
int process (jack_nframes_t nframes, void *arg) {
jack_default_audio_sample_t *in, *out;
in = (jack_default_audio_sample_t *)jack_port_get_buffer (input_port, nframes);
out = (jack_default_audio_sample_t *)jack_port_get_buffer (output_port, nframes);
memcpy (out, in,
sizeof (jack_default_audio_sample_t) * nframes);
return 0;
}
void jack_shutdown(void *arg) {
pthread_spin_lock(&spinlock);
stop = 1;
pthread_spin_unlock(&spinlock);
}
void silent_jack_error_callback(const char *msg) {}
int main() {
pthread_spin_init(&spinlock, 0);
jack_set_error_function(silent_jack_error_callback);
const char *client_name = "simple";
const char *server_name = NULL;
jack_options_t options = JackNullOption;
jack_status_t status;
while(true){
client = jack_client_open (client_name, JackNoStartServer, &status, server_name);
if (client == NULL) {
fprintf (stderr, "jack_client_open() failed, "
"status = 0x%2.0x\n", status);
if (status & JackServerFailed) {
fprintf (stderr, "Unable to connect to JACK server\n");
}
continue;
}
jack_on_shutdown(client, jack_shutdown, 0);
jack_set_process_callback (client, process, 0);
input_port = jack_port_register (client, "input",
JACK_DEFAULT_AUDIO_TYPE,
JackPortIsInput, 0);
output_port = jack_port_register (client, "output",
JACK_DEFAULT_AUDIO_TYPE,
JackPortIsOutput, 0);
if (jack_activate (client)) {
fprintf (stderr, "cannot activate client");
exit (1);
}
while (1) {
pthread_spin_lock(&spinlock);
if(stop) {
pthread_spin_unlock(&spinlock);
break;
}
pthread_spin_unlock(&spinlock);
}
fprintf (stderr, "stopping\n");
jack_client_close(client);
stop = 0;
fprintf (stderr, "alive\n");
}
return 0;
}
#!/bin/bash
while :
do
jack_control start
sleep 1
jack_control stop
sleep 1
done
Here's stack traces of two non responding threads:
1 pthread_cond_wait * *GLIBC_2.3.2 0x7ffff73cdafc
2 Jack::JackPosixProcessSync::Wait JackPosixProcessSync.cpp 81 0x7ffff7b0350a
3 Jack::JackMessageBuffer::Execute JackMessageBuffer.cpp 104 0x7ffff7afc6a9
4 Jack::JackPosixThread::ThreadHandler JackPosixThread.cpp 59 0x7ffff7b02812
5 start_thread 0x7ffff73c7a9d
6 clone 0x7ffff72f7b23
1 __lll_lock_wait 0x7ffff73d0edc
2 pthread_mutex_lock 0x7ffff73ca336
3 Jack::JackPosixMutex::Lock JackPosixMutex.cpp 112 0x7ffff7b03ef2
4 Jack::JackClient::Close JackClient.cpp 118 0x7ffff7ae0096
5 jack_client_close JackLibAPI.cpp 219 0x7ffff7b0772f
6 monitor jack_input.c 126 0x555555558ede
7 start_thread 0x7ffff73c7a9d
8 clone 0x7ffff72f7b23
Edit:
I tried to add this before jack_client_close:
jack_deactivate(client);
jack_port_unregister(client, input_port);
jack_port_unregister(client, output_port);
Same result.