/****************************************************************************
* examples/nxflat/tests/signal/signal.c
*
* Copyright (C) 2009, 2012 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 <sys/types.h>
#include <stdio.h>
#include <stdlib.h>
#include <signal.h>
#include <unistd.h>
#include <string.h>
#include <errno.h>
/****************************************************************************
* Definitions
****************************************************************************/
#define USEC_PER_MSEC 1000
#define MSEC_PER_SEC 1000
#define USEC_PER_SEC (USEC_PER_MSEC * MSEC_PER_SEC)
#define SHORT_DELAY (USEC_PER_SEC / 3)
/****************************************************************************
* Private Data
****************************************************************************/
static int sigusr1_rcvd = 0;
static int sigusr2_rcvd = 0;
/****************************************************************************
* Private Functions
****************************************************************************/
/****************************************************************************
* Name: siguser_action
***************************************************************************/
/* 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 ELF is generated by GCC.
*/
void siguser_action(int signo, siginfo_t *siginfo, void *arg)
{
printf("siguser_action: Received signo=%d siginfo=%p arg=%p\n",
signo, siginfo, arg);
if (signo == SIGUSR1)
{
printf(" SIGUSR1 received\n");
sigusr2_rcvd = 1;
}
else if (signo == SIGUSR2)
{
printf(" SIGUSR2 received\n");
sigusr1_rcvd = 2;
}
else
{
printf(" ERROR: Unexpected signal\n");
}
if (siginfo)
{
printf("siginfo:\n");
printf(" si_signo = %d\n", siginfo->si_signo);
printf(" si_code = %d\n", siginfo->si_code);
printf(" si_value = %d\n", siginfo->si_value.sival_int);
}
}
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: main
****************************************************************************/
int main(int argc, char **argv)
{
struct sigaction act;
struct sigaction oact1;
struct sigaction oact2;
pid_t mypid = getpid();
union sigval sigval;
int status;
printf("Setting up signal handlers from pid=%d\n", mypid);
/* Set up so that siguser_action will respond to SIGUSR1 */
memset(&act, 0, sizeof(struct sigaction));
act.sa_sigaction = siguser_action;
act.sa_flags = SA_SIGINFO;
(void)sigemptyset(&act.sa_mask);
status = sigaction(SIGUSR1, &act, &oact1);
if (status != 0)
{
fprintf(stderr, "Failed to install SIGUSR1 handler, errno=%d\n",
errno);
exit(2);
}
printf("Old SIGUSR1 sighandler at %p\n", oact1.sa_handler);
printf("New SIGUSR1 sighandler at %p\n", siguser_action);
/* Set up so that siguser_action will respond to SIGUSR2 */
status = sigaction(SIGUSR2, &act, &oact2);
if (status != 0)
{
fprintf(stderr, "Failed to install SIGUSR2 handler, errno=%d\n",
errno);
exit(2);
}
printf("Old SIGUSR2 sighandler at %p\n", oact2.sa_handler);
printf("New SIGUSR2 sighandler at %p\n", siguser_action);
printf("Raising SIGUSR1 from pid=%d\n", mypid);
fflush(stdout); usleep(SHORT_DELAY);
/* Send SIGUSR1 to ourselves via kill() */
printf("Kill-ing SIGUSR1 from pid=%d\n", mypid);
status = kill(0, SIGUSR1);
if (status != 0)
{
fprintf(stderr, "Failed to kill SIGUSR1, errno=%d\n", errno);
exit(3);
}
usleep(SHORT_DELAY);
printf("SIGUSR1 raised from pid=%d\n", mypid);
/* Verify that we received SIGUSR1 */
if (sigusr1_rcvd == 0)
{
fprintf(stderr, "SIGUSR1 not received\n");
exit(4);
}
sigusr1_rcvd = 0;
/* Send SIGUSR2 to ourselves */
printf("sigqueue-ing SIGUSR2 from pid=%d\n", mypid);
fflush(stdout); usleep(SHORT_DELAY);
/* Send SIGUSR2 to ourselves via sigqueue() */
sigval.sival_int = 87;
status = sigqueue(mypid, SIGUSR2, sigval);
if (status != 0)
{
fprintf(stderr, "Failed to queue SIGUSR2, errno=%d\n", errno);
exit(5);
}
usleep(SHORT_DELAY);
printf("SIGUSR2 queued from pid=%d, sigval=87\n", mypid);
/* Verify that SIGUSR2 was received */
if (sigusr2_rcvd == 0)
{
fprintf(stderr, "SIGUSR2 not received\n");
exit(6);
}
sigusr2_rcvd = 0;
/* Remove the siguser_action handler and replace the SIGUSR2
* handler with sigusr2_sighandler.
*/
printf("Resetting SIGUSR2 signal handler from pid=%d\n", mypid);
status = sigaction(SIGUSR2, &oact2, &act);
if (status != 0)
{
fprintf(stderr, "Failed to install SIGUSR1 handler, errno=%d\n",
errno);
exit(2);
}
printf("Old SIGUSR1 sighandler at %p\n", act.sa_handler);
printf("New SIGUSR1 sighandler at %p\n", oact1.sa_handler);
/* Verify that the handler that was removed was siguser_action */
if ((void*)act.sa_handler != (void*)siguser_action)
{
fprintf(stderr,
"Old SIGUSR2 signal handler (%p) is not siguser_action (%p)\n",
act.sa_handler, siguser_action);
exit(8);
}
/* Send SIGUSR2 to ourselves via kill() */
printf("Killing SIGUSR2 from pid=%d\n", mypid);
fflush(stdout); usleep(SHORT_DELAY);
status = kill(mypid, SIGUSR2);
if (status != 0)
{
fprintf(stderr, "Failed to kill SIGUSR2, errno=%d\n", errno);
exit(9);
}
usleep(SHORT_DELAY);
printf("SIGUSR2 killed from pid=%d\n", mypid);
/* Verify that SIGUSR2 was received */
if (sigusr2_rcvd == 0)
{
fprintf(stderr, "SIGUSR2 not received\n");
exit(10);
}
sigusr2_rcvd = 0;
return 0;
}
