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#include "../autoconfig.h"
#include <sys/types.h>
#include <sys/ipc.h>
#include <sys/sem.h>
#include <errno.h>
#include <getopt.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
static char *progname;
static const key_t key_astribanks = 0xAB11A0;
static int debug;
static int verbose;
static int timeout_seconds = 60;
/* If libc provides no timeout variant: try to do without it: */
#ifndef HAVE_SEMTIMEDOP
#define semtimedop(sem, ops, n, timeout) semop(sem, ops, n)
#endif
static void usage(void)
{
fprintf(stderr, "Usage: %s [-d] [-t <seconds>] [-a|-r|-w]\n", progname);
exit(1);
}
static int absem_get(int createit)
{
int flags = (createit) ? IPC_CREAT | 0644 : 0;
int absem;
if((absem = semget(key_astribanks, 1, flags)) < 0)
absem = -errno;
return absem;
}
static int absem_touch(void)
{
int absem;
if((absem = absem_get(1)) < 0) {
perror(__FUNCTION__);
return absem;
}
if(semctl(absem, 0, SETVAL, 0) < 0) {
perror("SETVAL");
return -errno;
}
if(debug)
fprintf(stderr, "%s: touched absem\n", progname);
if(verbose)
printf("Astribanks initialization is starting\n");
return 0;
}
static int absem_remove(void)
{
int absem;
if((absem = absem_get(0)) < 0) {
if(absem == -ENOENT) {
if(debug)
fprintf(stderr, "%s: absem already removed\n", progname);
return 0;
}
perror(__FUNCTION__);
return absem;
}
if(semctl(absem, 0, IPC_RMID, 0) < 0) {
perror("RMID");
return -errno;
}
if(debug)
fprintf(stderr, "%s: removed absem\n", progname);
if(verbose)
printf("Astribanks initialization is done\n");
return 0;
}
static int absem_wait(void)
{
int absem;
struct sembuf sops;
long now;
long start_wait;
struct timespec timeout;
if((absem = absem_get(0)) < 0) {
perror(__FUNCTION__);
return absem;
}
sops.sem_num = 0;
sops.sem_op = -1;
sops.sem_flg = 0;
start_wait = time(NULL);
timeout.tv_sec = timeout_seconds;
timeout.tv_nsec = 0;
if(semtimedop(absem, &sops, 1, &timeout) < 0) {
switch(errno) {
case EIDRM: /* Removed -- OK */
break;
case EAGAIN: /* Timeout -- Report */
fprintf(stderr, "Astribanks waiting timed out\n");
return -errno;
default: /* Unexpected errors */
perror("semop");
return -errno;
}
/* fall-thgough */
}
now = time(NULL);
if(debug)
fprintf(stderr, "%s: waited on absem %ld seconds\n", progname, now - start_wait);
if(verbose)
printf("Finished after %ld seconds\n", now - start_wait);
return 0;
}
static int absem_detected(void)
{
int absem;
if((absem = absem_get(0)) < 0) {
if(debug)
fprintf(stderr, "%s: absem does not exist\n", progname);
return absem;
}
if(debug)
fprintf(stderr, "%s: absem exists\n", progname);
if(verbose)
printf("Astribanks are initializing...\n");
return 0;
}
int main(int argc, char *argv[])
{
const char options[] = "dvarwt:h";
int val;
progname = argv[0];
while (1) {
int c;
int t;
c = getopt (argc, argv, options);
if (c == -1)
break;
switch (c) {
case 'd':
debug++;
break;
case 'v':
verbose++;
break;
case 't':
t = atoi(optarg);
if(t <= 0) {
fprintf(stderr,
"%s: -t expect a positive number of seconds: '%s'\n",
progname, optarg);
usage();
}
timeout_seconds = t;
break;
case 'a':
if((val = absem_touch()) < 0) {
fprintf(stderr, "%s: Add failed: %d\n", progname, val);
return 1;
}
return 0;
case 'r':
if((val = absem_remove()) < 0) {
fprintf(stderr, "%s: Remove failed: %d\n", progname, val);
return 1;
}
return 0;
case 'w':
if((val = absem_wait()) < 0) {
fprintf(stderr, "%s: Wait failed: %d\n", progname, val);
return 1;
}
return 0;
case 'h':
default:
fprintf(stderr, "Unknown option '%c'\n", c);
usage();
}
}
val = absem_detected();
return (val == 0) ? 0 : 1;
}
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