text: /****************************************************************************
   * rmutex.c
   *
   *   Copyright (C) 2008 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.
   *
   ****************************************************************************/
  
  #include <stdio.h>
  #include <pthread.h>
  #include "ostest.h"
  
  #define NTHREADS    3
  #define NLOOPS      3
  #define NRECURSIONS 3
  
  static pthread_mutex_t mut;
  
  static void thread_inner(int id, int level)
  {
    int status;
    if (level < NRECURSIONS)
      {
        /* Take the mutex */
  
        printf("thread_inner[%d, %d]: Locking\n", id, level);
        status = pthread_mutex_lock(&mut);
        if (status != 0)
          {
            printf("thread_inner[%d, %d]: ERROR pthread_mutex_lock failed: %d\n",
                    id, level, status);
          }
        printf("thread_inner[%d, %d]: Locked\n", id, level);
  
        /* Try-lock already locked recursive mutex. */
  
        status = pthread_mutex_trylock(&mut);
        if (status != 0)
          {
            printf("thread_inner[%d, %d]: ERROR pthread_mutex_trylock failed: %d\n",
                    id, level, status);
          }
        else
          {
            /* Unlock the try-lock. */
  
            status = pthread_mutex_unlock(&mut);
            if (status != 0)
              {
                printf("thread_inner[%d, %d]: ERROR pthread_mutex_unlock after try-lock failed: %d\n",
                   id, level, status);
              }
          }
  
        /* Give the other threads a chance */
  
        pthread_yield();
        thread_inner(id, level+1);
        pthread_yield();
  
        /* Unlock the mutex */
  
        printf("thread_inner[%d, %d]: Unlocking\n", id, level);
        status = pthread_mutex_unlock(&mut);
        if (status != 0)
          {
            printf("thread_inner[%d, %d]: ERROR pthread_mutex_unlock failed: %d\n",
                   id, level, status);
          }
        printf("thread_inner[%d, %d]: Unlocked\n", id, level);
        pthread_yield();
      }
  }
  
  static FAR void *thread_outer(FAR void *parameter)
  {
    int i;
  
    printf("thread_outer[%d]: Started\n", (int)((intptr_t)parameter));
    for (i = 0; i < NLOOPS; i++)
      {
        printf("thread_outer[%d]: Loop %d\n", (int)((intptr_t)parameter), i);
        thread_inner((int)((intptr_t)parameter), 0);
      }
  
    printf("thread_outer[%d]: Exitting\n", (int)((intptr_t)parameter));
    pthread_exit(NULL);
    return NULL; /* Non-reachable -- needed for some compilers */
  }
  
  void recursive_mutex_test(void)
  {
    pthread_t thread[NTHREADS];
  #ifdef SDCC
    pthread_addr_t result[NTHREADS];
    pthread_attr_t attr;
  #endif
    pthread_mutexattr_t mattr;
    int type;
    int status;
    int i;
  
    /* Initialize the mutex attributes */
  
    pthread_mutexattr_init(&mattr);
    status = pthread_mutexattr_settype(&mattr, PTHREAD_MUTEX_RECURSIVE);
    if (status != 0)
      {
        printf("recursive_mutex_test: ERROR pthread_mutexattr_settype failed, status=%d\n", status);
      }
  
    status = pthread_mutexattr_gettype(&mattr, &type);
    if (status != 0)
      {
        printf("recursive_mutex_test: ERROR pthread_mutexattr_gettype failed, status=%d\n", status);
      }
    if (type != PTHREAD_MUTEX_RECURSIVE)
      {
        printf("recursive_mutex_test: ERROR pthread_mutexattr_gettype return type=%d\n", type);
      }
  
    /* Initialize the mutex */
  
    printf("recursive_mutex_test: Initializing mutex\n");
    status = pthread_mutex_init(&mut, &mattr);
    if (status != 0)
      {
        printf("recursive_mutex_test: ERROR pthread_mutex_init failed, status=%d\n", status);
      }
  
    /* Start the threads -- all at the same, default priority */
  
    for (i = 0; i < NTHREADS; i++)
      {
        printf("recursive_mutex_test: Starting thread %d\n", i+1);
  #ifdef SDCC
        (void)pthread_attr_init(&attr);
        status = pthread_create(&thread[i], &attr, thread_outer, (pthread_addr_t)((uintptr_t)i+1));
  #else
        status = pthread_create(&thread[i], NULL, thread_outer, (pthread_addr_t)((uintptr_t)i+1));
  #endif
        if (status != 0)
          {
            printf("recursive_mutex_test: ERROR thread#%d creation: %d\n", i+1, status);
          }
      }
  
    /* Wait for all; of the threads to complete */
  
    for (i = 0; i < NTHREADS; i++)
      {
        printf("recursive_mutex_test: Waiting for thread %d\n", i+1);
  #ifdef SDCC
        pthread_join(thread[i], &result[i]);
  #else
        pthread_join(thread[i], NULL);
  #endif
      }
  
    printf("recursive_mutex_test: Complete\n");
  }
  