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/* BeginSourceFile more_steps.c
This file creates a lot of threads which then execute
in parallel, so that wdb can be tested on handling
simultaneous thread events.
To compile:
cc -Ae +DA1.0 -g -o more_steps -lpthread more_steps.c
To run:
more_threads
*/
#include <unistd.h>
#include <stdlib.h>
#include <stdio.h>
#include <assert.h>
#include <pthread.h>
#define TRUE 1
#define FALSE 0
#define N_THREADS 3
#define PHASES 3
typedef enum {
ZERO,
ONE,
TWO,
THREE
} phase_t;
/* Uncomment to turn on debugging output */
/* #define DEBUG */
/* Locks.
*/
int lock_one; /* Main W, others R */
int lock_two; /* ditto */
int lock_end[ N_THREADS ]; /* Main R, others R[i] */
int phase[ N_THREADS ];
/* Routine for each thread to run.
*/
void *spin( vp )
void * vp;
{
int me = (int) vp;
int i;
lock_end[ me ] = TRUE;
phase[ me ] = ONE;
while( lock_one );
phase[ me ] = TWO;
while( lock_two );
phase[ me ] = THREE;
lock_end[ me ] = FALSE;
}
void
do_pass()
{
int i;
pthread_t t[ N_THREADS ];
int err;
int done;
/* Start N_THREADS threads, then join them so
* that they are terminated.
*/
for( i = 0; i < N_THREADS; i++ ) {
err = pthread_create( &t[i], NULL, spin, (void *)i );
if( err != 0 ) {
printf( "== Start/stop, error in thread %d create\n", i );
}
}
/* Do phase 1.
*/
lock_one = FALSE;
/* Do phase 2.
*/
lock_two = FALSE;
/* Be done.
*/
done = 0;
while( !done ) {
/* Be optimistic.
*/
done = 1;
for( i = 0; i < N_THREADS; i++ ) {
if( lock_end[i] ) {
/* Thread "i" is not ready yet.
*/
done = 0;
break;
}
}
}
/* Finish up
*/
for( i = 0; i < N_THREADS; i++ ) {
err = pthread_join(t[i], NULL ); /* Line 105 */
if( err != 0 ) { /* Line 106 */
printf( "== Start/stop, error in thread %d join\n", i );
}
}
i = 10; /* Line 109. Null line for setting bpts on. */
}
main( argc, argv )
int argc;
char **argv;
{
int i;
/* Init
*/
lock_one = TRUE;
lock_two = TRUE;
for( i = 0; i < N_THREADS; i++ ) {
lock_end[i] = TRUE;
phase[i] = ZERO;
}
do_pass();
return(0);
}
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