| 0,0 → 1,86 |
|---|
| /* |
| * Copyright (C) 2001-2004 Jakub Jermar |
| * All rights reserved. |
| * |
| * Redistribution and use in source and binary forms, with or without |
| * modification, are permitted provided that the following conditions |
| * are met: |
| * |
| * - Redistributions of source code must retain the above copyright |
| * notice, this list of conditions and the following disclaimer. |
| * - 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. |
| * - The name of the author may not be used to endorse or promote products |
| * derived from this software without specific prior written permission. |
| * |
| * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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. |
| */ |
| |
| #include <synch/semaphore.h> |
| #include <synch/waitq.h> |
| #include <synch/spinlock.h> |
| #include <synch/synch.h> |
| #include <arch/asm.h> |
| #include <arch.h> |
| |
| /** Initialize semaphore |
| * |
| * Initialize semaphore. |
| * |
| * @param s Semaphore. |
| * @param val Maximal number of threads allowed to enter critical section. |
| */ |
| void semaphore_initialize(semaphore_t *s, int val) |
| { |
| ipl_t ipl; |
| |
| waitq_initialize(&s->wq); |
| |
| ipl = interrupts_disable(); |
| |
| spinlock_lock(&s->wq.lock); |
| s->wq.missed_wakeups = val; |
| spinlock_unlock(&s->wq.lock); |
| |
| interrupts_restore(ipl); |
| } |
| |
| /** Semaphore down |
| * |
| * Semaphore down. |
| * Conditional mode and mode with timeout can be requested. |
| * |
| * @param s Semaphore. |
| * @param usec Timeout in microseconds. |
| * @param trydown Switches between blocking and non-blocking mode. |
| * |
| * For exact description of possible combinations of |
| * 'usec' and 'trydown', see comment for waitq_sleep_timeout(). |
| * |
| * @return See comment for waitq_sleep_timeout(). |
| */ |
| int _semaphore_down_timeout(semaphore_t *s, __u32 usec, int trydown) |
| { |
| return waitq_sleep_timeout(&s->wq, usec, trydown); |
| } |
| |
| /** Semaphore up |
| * |
| * Semaphore up. |
| * |
| * @param s Semaphore. |
| */ |
| void semaphore_up(semaphore_t *s) |
| { |
| waitq_wakeup(&s->wq, WAKEUP_FIRST); |
| } |