Segfault with multiple instances for the server #1005
Description
Describe the bug
I launch two instances of the JACK server use the API (jackctl_server_create/open/start(), etc.). If I try to stop the server that was created 2nd before the 1st one, I get SIGSEGV. If I close the 1st server and then the 2nd one, everything is fine. 🤯 In other words, if I do:
- Create & start server1.
- Create & start server2.
- Sleep 1 sec.
- Stop & destroy server2. <-- SIGSEGV in
jackctl_server_stop(). - Stop & destroy server1.
But, if I switch the order of how the servers are stopped, everything is fine:
- Create & start server1.
- Create & start server2.
- Sleep 1 sec.
- Stop & destroy server1. <-- OK
- Stop & destroy server1. <-- OK
Environment
- JACK Version: jackdmp version 1.9.21 tmpdir /dev/shm protocol 9
- Operating System: Ubuntu 24.04
- Installation:
sudo apt install jackd libjack-jackd2-dev
Steps To Reproduce
#include <jack/jack.h>
#include <jack/control.h>
#include <stdio.h>
#include <string.h>
#include <unistd.h>
void set_param(const JSList *params, const char *name, const char *value)
{
for (const JSList *node = params; node; node = node->next)
{
jackctl_parameter_t *param = (jackctl_parameter_t*)node->data;
if (!strcmp(jackctl_parameter_get_name(param), name))
{
jackctl_parameter_value val;
strcpy(val.str, value);
jackctl_parameter_set_value(param, &val);
break;
}
}
}
jackctl_server_t *create_server(const char *server_name, const char *driver_name, const char *device)
{
jackctl_server_t *server = jackctl_server_create(NULL, NULL);
set_param(jackctl_server_get_parameters(server), "name", server_name);
jackctl_driver_t *driver;
for (const JSList *node = jackctl_server_get_drivers_list(server); node; node = node->next)
{
driver = (jackctl_driver_t*)node->data;
if (!strcmp(jackctl_driver_get_name(driver), driver_name)) break;
}
if (device) set_param(jackctl_driver_get_parameters(driver), "device", device);
jackctl_server_open(server, driver);
jackctl_server_start(server);
return server;
}
void kill_server(jackctl_server_t *server)
{
jackctl_server_stop(server);
jackctl_server_close(server);
jackctl_server_destroy(server);
}
int main()
{
jackctl_server_t *server1 = create_server("server1", "alsa", "hw:1");
jackctl_server_t *server2 = create_server("server2", "alsa", "hw:2");
sleep(1);
kill_server(server2);
kill_server(server1);
return 0;
}Compiled with:
g++ -ggdb jack.cpp -o jack -ljack -ljackserverExpected vs. actual behavior
Expected the server to exit, so it can be closed and destroyed.