4 * Copyright (C) 2008 Adam Williams <broadcast at earthling dot net>
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
16 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, write to the Free Software
18 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
22 #include "bcsignals.h"
28 Sema::Sema(int init_value, const char *title)
30 sem_init(&sem, 0, init_value);
32 this->init_value = init_value;
38 UNSET_ALL_LOCKS(this);
42 void Sema::lock(const char *location)
44 SET_LOCK(this, title, location);
58 sem_getvalue(&sem, &result);
65 sem_init(&sem, 0, init_value);
92 Sema::Sema(int id, int number)
96 if((semid = semget(IPC_PRIVATE, number, IPC_CREAT | 0777)) < 0) perror("Sema::Sema");
97 for(int i = 0; i < number; i++) unlock(i);
99 bc_enter_sema_id(semid);
114 if(semctl(semid, 0, IPC_RMID, arg) < 0) perror("Sema::~Sema");
115 bc_remove_sema_id(semid);
120 int Sema::lock(int number)
124 // decrease the semaphore
125 sop.sem_num = number;
128 if(semop(semid, &sop, 1) < 0) perror("Sema::lock");
132 int Sema::unlock(int number)
136 // decrease the semaphore
137 sop.sem_num = number;
140 if(semop(semid, &sop, 1) < 0) perror("Sema::unlock");
144 int Sema::get_value(int number)
146 return semctl(semid, number, GETVAL, arg);