shmemusr.c

来自「Source code for an Numeric Cmputer」· C语言 代码 · 共 61 行

#include <stdio.h>
#include <signal.h>		/* signal(), SIGINT */
#include <unistd.h>		/* sleep() */
#include "rtapi.h"		/* user-level API to RT Linux */
#include "common.h"		/* shmem structure */

static int module;
static int key = SHMEM_KEY;
static int shmem_id;
static SHMEM_STRUCT *shmem_struct;

static int done = 0;
static void quit(int sig)
{
    done = 1;
}

int main()
{
    int retval;

    module = rtapi_init("SHMEM_USR");
    if (module < 1) {
	rtapi_print_msg(RTAPI_MSG_ERR,
	    "shmemusr main: rtapi_init returned %d\n", module);
	return -1;
    }

    /* allocate the shared memory structure */
    shmem_id = rtapi_shmem_new(key, module, sizeof(SHMEM_STRUCT));
    if (shmem_id < 0) {
	rtapi_print_msg(RTAPI_MSG_ERR,
	    "shmemusr main: rtapi_shmem_new returned %d\n", shmem_id);
	rtapi_exit(module);
	return -1;
    }
    retval = rtapi_shmem_getptr(shmem_id, (void **) &shmem_struct);
    if (retval != RTAPI_SUCCESS) {
	rtapi_print_msg(RTAPI_MSG_ERR,
	    "shmemusr main: rtapi_shmem_getptr returned %d\n", retval);
	rtapi_exit(module);
	return -1;
    }

    signal(SIGINT, quit);
    while (!done) {
	rtapi_print("%lu\n", shmem_struct->heartbeat);
	sleep(1);
    }

    retval = rtapi_shmem_delete(shmem_id, module);
    if (retval != RTAPI_SUCCESS) {
	rtapi_print_msg(RTAPI_MSG_ERR,
	    "shmemusr main: rtapi_free_shmem returned %d\n", retval);
	rtapi_exit(module);
	return -1;
    }

    return rtapi_exit(module);
}