src/bin/release.c

   1 // ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~
   2 //
   3 //  Copyright (c) 2004, OpenBeOS
   4 //
   5 //  This software is part of the OpenBeOS distribution and is covered
   6 //  by the OpenBeOS license.
   7 //
   8 //
   9 //  File:        release.c
  10 //  Author:      Jérôme Duval (korli@chez.com)
  11 //  Description: release a semaphore.
  12 //
  13 // ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~
  14
  15 #include <stdio.h>
  16 #include <stdlib.h>
  17 #include <string.h>
  18 #include <OS.h>
  19
  20 static int usage(char *prog)
  21 {
  22         printf("usage: release [-f] [-c count] semaphore_number\n");
  23         printf("warning: this can be hazardous...\n");
  24         exit(1);
  25 }
  26
  27
  28 int main(int argc, char **argv)
  29 {
  30         int count = 1;
  31         bool force = false;
  32         sem_id semid = -1;
  33         status_t err;
  34         team_id teamid = -1;
  35
  36         int i;
  37         if (argc < 2 || argc > 5)
  38                 usage("release");
  39         for (i = 1; i < argc; i++) {
  40                 if (strncmp(argv[i], "-f", 2) == 0) {
  41                         force = true;
  42                 } else if (strncmp(argv[i], "-c", 2) == 0) {
  43                         i++;
  44                         if (i < argc) {
  45                                 count = strtol(argv[i], NULL, 10);
  46                         } else
  47                                 usage("release");
  48                 } else {
  49                         semid = strtol(argv[i], NULL, 10);
  50                 }
  51         }
  52
  53         if (semid <=0)
  54                 usage("release");
  55
  56         if (force) {
  57                 sem_info sinfo;
  58                 thread_info tinfo;
  59                 get_sem_info(semid, &sinfo);
  60                 teamid = sinfo.team;
  61                 get_thread_info(find_thread(NULL), &tinfo);
  62                 set_sem_owner(semid, tinfo.team);
  63         }
  64
  65         printf("releasing semaphore %d\n", (int)semid);
  66         err = release_sem_etc(semid, count, 0);
  67
  68         if (err < B_OK) {
  69                 fprintf(stderr, "release_sem failed: %s\n", strerror(err));
  70                 return 1;
  71         } else if (force) {
  72                 set_sem_owner(semid, teamid);
  73         }
  74
  75         return 0;
  76 }