newlib-cygwin/winsup/testsuite/winsup.api/pthread/mutex6d.c

/* 
 * mutex6d.c
 *
 * Tests PTHREAD_MUTEX_DEFAULT mutex type.
 * Thread locks mutex twice (recursive lock).
 * The thread should deadlock.
 *
 * Depends on API functions: 
 *      pthread_create()
 *      pthread_mutexattr_init()
 *      pthread_mutexattr_settype()
 *      pthread_mutexattr_gettype()
 *      pthread_mutex_init()
 *	pthread_mutex_lock()
 *	pthread_mutex_unlock()
 */

#include "test.h"

static int lockCount = 0;

static pthread_mutex_t mutex;
static pthread_mutexattr_t mxAttr;

void * locker(void * arg)
{
  assert(pthread_mutex_lock(&mutex) == 0);
  lockCount++;

  /* Should wait here (deadlocked) */
  assert(pthread_mutex_lock(&mutex) == 0);
  lockCount++;
  assert(pthread_mutex_unlock(&mutex) == 0);

  return (void *) 555;
}
 
int
main()
{
  pthread_t t;
  int mxType = -1;

  assert(pthread_mutexattr_init(&mxAttr) == 0);
  assert(pthread_mutexattr_settype(&mxAttr, PTHREAD_MUTEX_DEFAULT) == 0);
  assert(pthread_mutexattr_gettype(&mxAttr, &mxType) == 0);
  assert(mxType == PTHREAD_MUTEX_NORMAL);

  assert(pthread_mutex_init(&mutex, &mxAttr) == 0);

  assert(pthread_create(&t, NULL, locker, NULL) == 0);

  Sleep(1000);

  assert(lockCount == 1);

  /*
   * Should succeed even though we don't own the lock
   * because FAST mutexes don't check ownership.
   */
  assert(pthread_mutex_unlock(&mutex) == 0);

  Sleep (1000);

  assert(lockCount == 2);

  exit(0);

  /* Never reached */
  return 0;
}