nuttx-apps/examples/ostest/robust.c

/****************************************************************************
 * examples/ostest/robust.c
 *
 *   Copyright (C) 2017 Gregory Nutt. All rights reserved.
 *   Author: Gregory Nutt <gnutt@nuttx.org>
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 * 3. Neither the name NuttX nor the names of its contributors may be
 *    used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
 * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
 * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
 * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 *
 ****************************************************************************/

/****************************************************************************
 * Included Files
 ****************************************************************************/

#include <nuttx/config.h>

#include <stdio.h>
#include <time.h>
#include <pthread.h>
#include <errno.h>

#include "ostest.h"

/****************************************************************************
 * Private Data
 ****************************************************************************/

static pthread_mutex_t g_robust_mutex;

/****************************************************************************
 * Private Functions
 ****************************************************************************/

static FAR void *robust_waiter(FAR void *parameter)
{
  int status;

  /* Take the mutex */

  printf("robust_waiter: Taking mutex\n");
  status = pthread_mutex_lock(&g_robust_mutex);
  if (status != 0)
    {
       printf("thread_waiter: ERROR: pthread_mutex_lock failed, status=%d\n", status);
    }

  if (status != 0)
    {
       printf("robust_waiter: ERROR: pthread_mutex_lock failed, status=%d\n", status);
    }
  else
    {
      printf("robust_waiter: Exitting with mutex\n");
    }

  sleep(2);
  return NULL;
}

/****************************************************************************
 * Public Functions
 ****************************************************************************/

void robust_test(void)
{
  pthread_attr_t pattr;
  pthread_mutexattr_t mattr;
  pthread_t waiter;
  void *result;
  int nerrors = 0;
  int status;

  /* Initialize the mutex */

  printf("robust_test: Initializing mutex\n");

  status = pthread_mutexattr_init(&mattr);
  if (status != 0)
    {
      printf("robust_test: ERROR: pthread_mutexattr_init failed, status=%d\n",
             status);
      nerrors++;
    }

  status = pthread_mutexattr_setrobust(&mattr, PTHREAD_MUTEX_ROBUST);
  if (status != 0)
    {
      printf("robust_test: ERROR: pthread_mutexattr_setrobust failed, status=%d\n",
             status);
      nerrors++;
    }

  status = pthread_mutex_init(&g_robust_mutex, &mattr);
  if (status != 0)
    {
      printf("robust_test: ERROR: pthread_mutex_init failed, status=%d\n",
             status);
      nerrors++;
    }

  /* Set up pthread attributes */

  printf("robust_test: Starting thread\n");

  status = pthread_attr_init(&pattr);
  if (status != 0)
    {
      printf("robust_test: ERROR: pthread_attr_init failed, status=%d\n",
             status);
      nerrors++;
    }

  status = pthread_attr_setstacksize(&pattr, STACKSIZE);
  if (status != 0)
    {
      printf("robust_test: ERROR: pthread_attr_setstacksize failed, status=%d\n",
             status);
      nerrors++;
    }

  /* Start the robust waiter thread.  It will take the mutex, sleep for two
   * seconds, and exit holding the mutex.
   */

  status = pthread_create(&waiter, &pattr, robust_waiter, NULL);
  if (status != 0)
    {
      printf("robust_test: ERROR: pthread_create failed, status=%d\n", status);
      printf("             ERROR: Terminating test\n");
      nerrors++;
      return;
    }

  /* Wait one second.. the robust waiter should still be waiting */

  sleep(1);

  /* Now try to take the mutex held by the robust waiter.  This should wait
   * one second there fail with EOWNERDEAD.
   */

  status = pthread_mutex_lock(&g_robust_mutex);
  if (status == 0)
    {
      printf("robust_test: ERROR: pthread_mutex_lock succeeded\n");
      nerrors++;
    }
  else if (status != EOWNERDEAD)
    {
      printf("robust_test: ERROR: pthread_mutex_lock failed with %d\n", status);
      printf("             ERROR: expected %d (EOWNERDEAD)\n", EOWNERDEAD);
      nerrors++;
    }

  /* Try again, this should return immediately, still failing with EOWNERDEAD */

  printf("robust_test: Take the lock again\n");
  status = pthread_mutex_lock(&g_robust_mutex);
  if (status == 0)
    {
      printf("robust_test: ERROR: pthread_mutex_lock succeeded\n");
      nerrors++;
    }
  else if (status != EOWNERDEAD)
    {
      printf("robust_test: ERROR: pthread_mutex_lock failed with %d\n", status);
      printf("             ERROR: expected %d (EOWNERDEAD)\n", EOWNERDEAD);
      nerrors++;
    }

  /* Make the mutex consistent and try again.  It should succeed this time. */

  printf("robust_test: Make the mutex consistent again.\n");
  status = pthread_mutex_consistent(&g_robust_mutex);
  if (status != 0)
    {
      printf("robust_test: ERROR: pthread_mutex_consistent failed: %d\n", status);
      nerrors++;
    }

  printf("robust_test: Take the lock again\n");
  status = pthread_mutex_lock(&g_robust_mutex);
  if (status != 0)
    {
      printf("robust_test: ERROR: pthread_mutex_lock failed with: %d\n", status);
      nerrors++;
    }

  /* Then join to the thread to pick up the result (if we don't do this we
   * will have a memory leak!)
   */

  printf("robust_test: Joining\n");
  status = pthread_join(waiter, &result);
  if (status != 0)
    {
      printf("robust_test: ERROR: pthread_join failed, status=%d\n", status);
      nerrors++;
    }
  else
    {
      printf("robust_test: waiter exited with result=%p\n", result);
      if (result != NULL)
        {
          printf("robust_test: ERROR: expected result=%p\n", PTHREAD_CANCELED);
          nerrors++;
        }
    }

  /* Release and destory the mutex then  return success */

  status = pthread_mutex_unlock(&g_robust_mutex);
  if (status != 0)
    {
      printf("robust_test: ERROR: pthread_mutex_unlock failed, status=%d\n", status);
      nerrors++;
    }

  status = pthread_mutex_destroy(&g_robust_mutex);
  if (status != 0)
    {
      printf("robust_test: ERROR: pthread_mutex_unlock failed, status=%d\n", status);
      nerrors++;
    }

  printf("robust_test: Test complete with nerrors=%d\n", nerrors);
}