Pthreads & Signals.

[Anthony Gabrielson]

Okay,
	With the help of several I got it working and clarifed my 
inderstanding on how pthreads work.  So anyway I have it working and if 
anyone is curious I attached it.

Thanks for all the help -

Anthony
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#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <pthread.h>
#include <errno.h>

pthread_mutex_t 	guard_revc;
pthread_cond_t		got_data;

void *thr(void *);

int lock;

int main( int argc, char *argv[] )
{

	pthread_t thread_recv;
	int result;
	lock = 1;
	
	pthread_cond_init( &got_data, NULL );
	pthread_mutex_init( &guard_revc, NULL );
		
	result = pthread_create(&thread_recv, NULL,
						thr, NULL );

	if ( result != 0 ) {
		perror( "pthread_create failed" );
		printf( "%s\n",strerror(result));
		exit ( 3 );
	} 
	
	printf("main: wait cond\n");
	
	while (lock ==  1){
		result = pthread_cond_wait( &got_data, &guard_revc );
		printf("main: got cond %d\n",result);
		lock = 0;
	}
	
	result = pthread_mutex_lock( &guard_revc );
	printf("main: Got Mutex %d\n",result);
	
	result = pthread_mutex_unlock( &guard_revc );
	printf("main: Release Mutex %d\n",result);
	
	result = pthread_cond_signal( &got_data );
	printf("main: send cond %d\n",result);
	
	usleep(1);

	pthread_join(thread_recv,NULL);
	
	return 0;
}

void *thr( void *arg ){

	int result;

	result = pthread_mutex_lock( &guard_revc );
	printf("thr: Got Mutex %d\n",result);
	usleep(1);
	result = pthread_mutex_unlock( &guard_revc );
	printf("thr: Release Mutex %d\n",result);
	result = pthread_cond_signal( &got_data );
	printf("thr: Sent Signal %d\n",result);
	usleep(1);
	while(lock == 0 ){
		result = pthread_cond_wait( &got_data, &guard_revc );
		printf("thr: Got Signal %d\n",result);
		lock = 1;
	}
	pthread_exit( NULL );
}