/*
 * Copyright (c) 2004, Bull S.A..  All rights reserved.
 * Created by: Sebastien Decugis

 * This program is free software; you can redistribute it and/or modify it
 * under the terms of version 2 of the GNU General Public License as
 * published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it would be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program; if not, write the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.

 * This sample test aims to check the following assertion:
 *
 * If the mutex type is PTHREAD_MUTEX_RECURSIVE,
 * then the mutex maintains the concept of a lock count.
 * When a thread successfully acquires a mutex for the first time,
 * the lock count is set to one. Every time a thread relocks this mutex,
 * the lock count is incremented by one.
 * Each time the thread unlocks the mutex,
 * the lock count is decremented by one.
 * When the lock count reaches zero,
 * the mutex becomes available and others threads can acquire it.

 * The steps are:
 * ->Create a mutex with recursive attribute
 * ->Create a threads
 * ->Parent locks the mutex twice, unlocks once.
 * ->Child attempts to lock the mutex.
 * ->Parent unlocks the mutex.
 * ->Parent unlocks the mutex (shall fail)
 * ->Child unlocks the mutex.
 */

 /*
  * - adam.li@intel.com 2004-05-13
  *   Add to PTS. Please refer to http://nptl.bullopensource.org/phpBB/
  *   for general information
  */

/********************************************************************************************/
/****************************** standard includes *****************************************/
/********************************************************************************************/
#include <pthread.h>
#include <unistd.h>
#include <stdio.h>
#include <stdlib.h>
#include <stdarg.h>
#include <semaphore.h>		/* for synchronization */
#include <errno.h>

/********************************************************************************************/
/******************************   Test framework   *****************************************/
/********************************************************************************************/
#include "../testfrmw/testfrmw.h"
#include "../testfrmw/testfrmw.c"
 /* This header is responsible for defining the following macros:
  * UNRESOLVED(ret, descr);
  *    where descr is a description of the error and ret is an int (error code for example)
  * FAILED(descr);
  *    where descr is a short text saying why the test has failed.
  * PASSED();
  *    No parameter.
  *
  * Both three macros shall terminate the calling process.
  * The testcase shall not terminate in any other maneer.
  *
  * The other file defines the functions
  * void output_init()
  * void output(char * string, ...)
  *
  * Those may be used to output information.
  */

/********************************************************************************************/
/********************************** Configuration ******************************************/
/********************************************************************************************/
#ifndef VERBOSE
#define VERBOSE 1
#endif

/********************************************************************************************/
/***********************************    Test case   *****************************************/
/********************************************************************************************/
static pthread_mutex_t mtx;
static sem_t sem;

/** child thread function **/
static void *threaded(void *arg PTS_ATTRIBUTE_UNUSED)
{
	int ret;
	/* Try to lock the mutex once. The call must fail here. */
	ret = pthread_mutex_trylock(&mtx);
	if (ret == 0) {
		FAILED("Child first trylock succeeded");
	}
#if VERBOSE >1
	output("[thrd] Try to lock the mutex.... failed (normal)\n");
#endif

	/* Free the parent thread and lock the mutex (must success) */
	if ((ret = sem_post(&sem))) {
		UNRESOLVED(errno, "1st post sem in child failed");
	}

	if ((ret = pthread_mutex_lock(&mtx))) {
		UNRESOLVED(ret, "Child lock failed");
	}
#if VERBOSE >1
	output("[thrd] Successfully locked the mutex\n");
#endif

	/* Wait for the parent to let us go on */
	if ((ret = sem_post(&sem))) {
		UNRESOLVED(errno, "2nd post sem in child failed");
	}

	/* Unlock and exit */
	if ((ret = pthread_mutex_unlock(&mtx))) {
		UNRESOLVED(ret, "Unlock in child failed");
	}
#if VERBOSE >1
	output("[thrd] Unlocked the mutex, ready to terminate.\n");
#endif

	return NULL;
}

/** parent thread function **/
int main(void)
{
	int ret;
	int i;
	pthread_mutexattr_t ma;
	pthread_t child;

	output_init();

#if VERBOSE >1
	output("Initialize the PTHREAD_MUTEX_RECURSIVE mutex\n");
#endif

	/* Initialize the semaphore */
	if ((ret = sem_init(&sem, 0, 0))) {
		UNRESOLVED(ret, "Sem init failed");
	}

	/* We initialize the recursive mutex */
	if ((ret = pthread_mutexattr_init(&ma))) {
		UNRESOLVED(ret, "Mutex attribute init failed");
	}

	if ((ret = pthread_mutexattr_settype(&ma, PTHREAD_MUTEX_RECURSIVE))) {
		UNRESOLVED(ret, "Set type RECURSIVE failed");
	}

	if ((ret = pthread_mutex_init(&mtx, &ma))) {
		UNRESOLVED(ret, "Recursive mutex init failed");
	}

	if ((ret = pthread_mutexattr_destroy(&ma))) {
		UNRESOLVED(ret, "Mutex attribute destroy failed");
	}

	/* -- The mutex is now ready for testing -- */

	/* First, we lock it twice and unlock once */
	if ((ret = pthread_mutex_lock(&mtx))) {
		UNRESOLVED(ret, "First lock failed");
	}

	if ((ret = pthread_mutex_lock(&mtx))) {
		FAILED("Second lock failed");
	}

	if ((ret = pthread_mutex_unlock(&mtx))) {
		FAILED("First unlock failed");
	}
#if VERBOSE >1
	output
	    ("The mutex has been locked twice and unlocked once, start the thread now.\n");
#endif

	/* Here this thread owns the mutex and the internal count is "1" */

	/* We create the child thread */
	if ((ret = pthread_create(&child, NULL, threaded, NULL))) {
		UNRESOLVED(ret, "Unable to create child thread");
	}

	/* then wait for child to be ready */
	if ((ret = sem_wait(&sem))) {
		UNRESOLVED(errno, "Wait sem in child failed");
	}
#if VERBOSE >1
	output("[main] unlock the mutex.\n");
#endif

	/* We can now unlock the mutex */
	if ((ret = pthread_mutex_unlock(&mtx))) {
		FAILED("Second unlock failed");
	}

	/* We wait for the child to lock the mutex */
	if ((ret = sem_wait(&sem))) {
		UNRESOLVED(errno, "Wait sem in child failed");
	}

	/* Then, try to unlock the mutex (owned by the child or unlocked) */
	ret = pthread_mutex_unlock(&mtx);
	if (ret == 0) {
		FAILED("Unlock of unowned mutex succeeds");
	}

	/* Everything seems OK here */
	if ((ret = pthread_join(child, NULL))) {
		UNRESOLVED(ret, "Child join failed");
	}

	/* Simple loop to double-check */
#if VERBOSE >1
	output("[main] joined the thread.\n");
	output("Lock & unlock the mutex 50 times.\n");
#endif

	for (i = 0; i < 50; i++) {
		if ((ret = pthread_mutex_lock(&mtx))) {
			FAILED("Lock failed in loop");
		}
	}
	for (i = 0; i < 50; i++) {
		if ((ret = pthread_mutex_unlock(&mtx))) {
			FAILED("Unlock failed in loop");
		}
	}

	ret = pthread_mutex_unlock(&mtx);
	if (ret == 0) {
		FAILED("Unlock succeeds after the loop");
	}
#if VERBOSE >1
	output("Everything went OK; destroy the mutex.\n");
#endif
	/* The test passed, we destroy the mutex */
	if ((ret = pthread_mutex_destroy(&mtx))) {
		UNRESOLVED(ret, "Final mutex destroy failed");
	}

	PASSED;
}