/****************************************************************************
* examples/cpuhog/cpuhog_main.c
*
* Copyright (C) 2014 Gregory Nutt. All rights reserved.
* Authors: Gregory Nutt <gnutt@nuttx.org>
* Bob Doiron
*
* 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.
*
****************************************************************************/
/****************************************************************************
* Example usage:
*
* NuttShell (NSH)
* nsh> cpuhog > /dev/ttyS1 &
* cpuhog [5:50]
* nsh> cpuhog > /dev/ttyS2 &
* cpuhog [7:50]
* nsh> cpuhog &
* cpuhog [8:50]
* nsh> cpuhog 2
* ps
* PID PRI SCHD TYPE NP STATE CPU NAME
* 0 0 FIFO TASK READY 0.9% Idle Task()
* 1 192 FIFO KTHREAD WAITSIG 0.0% work()
* 2 200 FIFO KTHREAD WAITSIG 0.0% wdog()
* 3 100 FIFO TASK RUNNING 0.0% init()
* 5 50 RR TASK WAITSEM 27.7% cpuhog(20009c70, 20009c80)
* 7 50 RR TASK WAITSEM 30.3% cpuhog(20008c00, 20008c10)
* 8 50 RR TASK READY 41.7% cpuhog()
* nsh>
*
****************************************************************************/
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/config.h>
#include <stdint.h>
#include <stdio.h>
#include <unistd.h>
#include <nuttx/clock.h>
#include <nuttx/arch.h>
#include <semaphore.h>
#include <errno.h>
#include <fcntl.h>
#include <sys/stat.h>
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
#define CPUHOG_FIFO_FNAME "/dev/cpuhogfifo"
/****************************************************************************
* Private Data
****************************************************************************/
static struct state_s
{
volatile bool initialized;
sem_t sem;
int count;
} g_state;
/****************************************************************************
* Public Functions
****************************************************************************/
#ifdef CONFIG_BUILD_KERNEL
int main(int argc, FAR char *argv[])
#else
int cpuhog_main(int argc, char *argv[])
#endif
{
int id = -1;
char buf[256];
int fd = -1;
if (!g_state.initialized)
{
sem_init(&g_state.sem, 0, 1);
mkfifo(CPUHOG_FIFO_FNAME, 0666);
g_state.count = 0;
g_state.initialized = true;
printf("cpuhog initialized\n");
}
while(1)
{
/* To test semaphore interaction (debugging system crashes...) */
while (sem_wait(&g_state.sem) != 0)
{
ASSERT(errno == EINTR);
}
/* Burn some inside semlock */
up_udelay(3000);
sem_post(&g_state.sem);
/* Unassigned */
if (id == -1)
{
id = g_state.count++;
printf("cpuhog %d", id);
if (id == 0)
{
printf(": consumer\n");
fd = open(CPUHOG_FIFO_FNAME, O_RDONLY);
}
else if (id == 1)
{
printf(": producer\n");
fd = open(CPUHOG_FIFO_FNAME, O_WRONLY);
}
else
{
printf("\n");
}
}
/* Consumer */
else if (id == 0)
{
if (read(fd, buf, sizeof(buf)) > 0)
{
printf("-");
}
else
{
perror("fifo: ");
}
}
/* Producer */
else if (id == 1)
{
if (write(fd, buf, sizeof(buf)) > 0)
{
printf("+");
}
else
{
perror("fifo: ");
}
}
/* Otherwise just a cpu burner */
else
{
/* Burn some outside semlock */
up_udelay(3000);
}
fflush(stdout);
}
return 0;
}
