/****************************************************************************
* examples/nxflat/tests/mutex/mutex.c
*
* Copyright (C) 2009 Gregory Nutt. All rights reserved.
* Author: Gregory Nutt <spudmonkey@racsa.co.cr>
*
* 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 <stdio.h>
#include <stdlib.h>
#include <pthread.h>
/****************************************************************************
* Private Data
****************************************************************************/
static pthread_mutex_t mut;
static volatile int my_mutex = 0;
static unsigned long nloops[2] = {0, 0};
static unsigned long nerrors[2] = {0, 0};
/****************************************************************************
* Private Functions
****************************************************************************/
/* NOTE: it is necessary for functions that are referred to by function pointers
* pointer to be declared with global scope (at least for ARM). Otherwise,
* a relocation type that is not supported by NXFLAT is generated by GCC.
*/
void thread_func(void *parameter)
{
int my_id = (int)parameter;
int my_ndx = my_id - 1;
volatile int i;
for (;;)
{
if ((pthread_mutex_lock(&mut)) != 0)
{
printf("ERROR thread %d: pthread_mutex_lock failed\n", my_id);
}
if (my_mutex == 1)
{
printf("ERROR thread=%d: "
"my_mutex should be zero, instead my_mutex=%d\n",
my_id, my_mutex);
nerrors[my_ndx]++;
}
my_mutex = 1;
for (i = 0; i < 1000; i++);
my_mutex = 0;
if ((pthread_mutex_unlock(&mut)) != 0)
{
printf("ERROR thread %d: pthread_mutex_unlock failed\n", my_id);
}
nloops[my_ndx]++;
}
}
/****************************************************************************
* Public Functions
****************************************************************************/
int main(int argc, char **argv)
{
pthread_t thread1, thread2;
printf("Starting threads\n");
/* Initialize the mutex */
pthread_mutex_init(&mut, NULL);
/* Start two thread instances */
if ((pthread_create(&thread1, NULL, (void*)&thread_func, (void*)1)) != 0)
{
fprintf(stderr, "Error in thread#1 creation\n");
}
if ((pthread_create(&thread2, NULL, (void*)&thread_func, (void*)2)) != 0)
{
fprintf(stderr, "Error in thread#2 creation\n");
}
printf("Press control-C to terminate the example\n");
pthread_join(thread1, NULL);
pthread_join(thread2, NULL);
return 0;
}