pthread_create blows up

[jmadsenee]

Hi All,

I am trying to create a thread to monitor digital IO in a modified scope app. I pretty much copied the pthread code from the worker.c. In my code I have:

Code: Select all

void *rp_io_worker_thread(void *args);
pthread_t 		*rp_io_thread_handler = NULL;

...

int ext_io_init(void)
{
    int ret_val;
...
    ret_val = pthread_create(rp_io_thread_handler, NULL, rp_io_worker_thread, NULL);
    if(ret_val != 0)
...
}

void *rp_io_worker_thread(void *args)
{
	rp_ioState_t 			state;

	while(1)
	{
	    usleep(10000);

	    pthread_mutex_lock(&rp_io_ctrl_mutex);
	    state = rp_io_state;
	    pthread_mutex_unlock(&rp_io_ctrl_mutex);

	    if (state == RP_IO_QUIT)
	    	break;
	}

	return 0;
}

Seems like it should be pretty simple... But, if I put a breakpoint right after the pthread_create, it never reaches it, so I can't even look for an error code.

Anyone have any thoughts? Please? It would be greatly appreciated!

John

[Nils Roos]

You don't show it, so the question is: do you allocate memory for the pthread_t ? Because pthread_create assumes that it can write to the pointer it is handed. If it's still NULL - bang, SIGSEV.

[jmadsenee]

Thanks, Nils! You saved my butt again! Dealing with an operating system is SO much more complex than bare metal... I assumed that declaring it -

Code: Select all

pthread_t *rp_io_thread_handler = NULL;

- allocated memory for it. Then the debugger gave me no hint of what went wrong.

Thanks again!

John