mingw-w64-libraries/winpthreads/tests/pthread_mutex/robust-errorcheck-state-recoverable.c

/*
   Copyright (c) 2026 mingw-w64 project

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   The above copyright notice and this permission notice shall be included in
   all copies or substantial portions of the Software.

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   IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
   FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
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   DEALINGS IN THE SOFTWARE.
*/

#include "test.h"

/**
 * Test Summary:
 *
 * Main thread M creates robust error checking mutex L,
 * then it creates threads A, B and C.
 *
 * A locks L.
 *
 * While A holds L, B enter wait state in order to lock L.
 *
 * While B is blocked waiting for L to be released,
 * A terminates but does not release L.
 *
 * B gains ownership for L and is notified that state protected by L
 * may be inconsistent; call to `pthread_mutex_lock` must return `EOWNERDEAD`.
 *
 * After B locks L, C enters wait state in order to lock L.
 *
 * B calls `pthread_mutex_consistent` to mark that state protected by L is
 * consistent and then unlocks L.
 *
 * C gains ownership for L and then unlocks L.
 *
 * M waits for A, B and C to return, and then destroys L.
 */

static LONG Started = FALSE;
static LONG Locked  = FALSE;
static LONG Lock    = FALSE;
static LONG Blocked = FALSE;

static void *ThreadA (void *arg) {
  pthread_mutex_t *mutex = arg;

  while (!Started) {
    YieldProcessor ();
  }
  assert (pthread_mutex_lock (mutex) == 0);
  InterlockedExchange (&Locked, TRUE);
  /**
   * Give B time to enter wait state.
   */
  Sleep (10);

  return arg;
}

static void *ThreadB (void *arg) {
  pthread_mutex_t *mutex = arg;

  InterlockedExchange (&Started, TRUE);
  while (!Locked) {
    YieldProcessor ();
  }
  assert (pthread_mutex_lock (mutex) == EOWNERDEAD);
  InterlockedExchange (&Lock, TRUE);
  while (!Blocked) {
    YieldProcessor ();
  }
  /**
   * Give C time to enter wait state.
   */
  Sleep (10);
  assert (pthread_mutex_lock (mutex) == EDEADLK);
  assert (pthread_mutex_consistent (mutex) == 0);
  assert (pthread_mutex_unlock (mutex) == 0);

  return arg;
}

static void *ThreadC (void *arg) {
  pthread_mutex_t *mutex = arg;

  while (!Lock) {
    YieldProcessor ();
  }
  InterlockedExchange (&Blocked, TRUE);
  assert (pthread_mutex_lock (mutex) == 0);
  assert (pthread_mutex_unlock (mutex) == 0);

  return arg;
}

int main (void)
{
  pthread_mutexattr_t mutexAttr;
  pthread_mutex_t mutex;
  pthread_t threadA;
  pthread_t threadB;
  pthread_t threadC;
  void *result;

  assert (pthread_mutexattr_init (&mutexAttr) == 0);
  assert (pthread_mutexattr_settype (&mutexAttr, PTHREAD_MUTEX_ERRORCHECK) == 0);
  assert (pthread_mutexattr_setrobust (&mutexAttr, PTHREAD_MUTEX_ROBUST) == 0);
  assert (pthread_mutex_init (&mutex, &mutexAttr) == 0);
  assert (pthread_create (&threadA, NULL, ThreadA, &mutex) == 0);
  assert (pthread_create (&threadB, NULL, ThreadB, &mutex) == 0);
  assert (pthread_create (&threadC, NULL, ThreadC, &mutex) == 0);
  assert (pthread_join (threadA, &result) == 0);
  assert (result == &mutex);
  assert (pthread_join (threadB, &result) == 0);
  assert (result == &mutex);
  assert (pthread_join (threadC, &result) == 0);
  assert (result == &mutex);
  assert (pthread_mutex_destroy (&mutex) == 0);
  assert (pthread_mutexattr_destroy (&mutexAttr) == 0);

  return 0;
}