kernel/generic/include/synch/waitq.h

   1 /*
   2  * Copyright (c) 2001-2004 Jakub Jermar
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  *
   9  * - Redistributions of source code must retain the above copyright
  10  *   notice, this list of conditions and the following disclaimer.
  11  * - Redistributions in binary form must reproduce the above copyright
  12  *   notice, this list of conditions and the following disclaimer in the
  13  *   documentation and/or other materials provided with the distribution.
  14  * - The name of the author may not be used to endorse or promote products
  15  *   derived from this software without specific prior written permission.
  16  *
  17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  18  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  19  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  20  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  21  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  22  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  23  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  24  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  25  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  26  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  27  */
  28
  29 /** @addtogroup sync
  30  * @{
  31  */
  32 /** @file
  33  */
  34
  35 #ifndef KERN_WAITQ_H_
  36 #define KERN_WAITQ_H_
  37
  38 #include <arch/types.h>
  39 #include <typedefs.h>
  40 #include <synch/spinlock.h>
  41 #include <synch/synch.h>
  42 #include <adt/list.h>
  43
  44 #define WAKEUP_FIRST    0
  45 #define WAKEUP_ALL      1
  46
  47 /** Wait queue structure. */
  48 struct waitq {
  49
  50         /** Lock protecting wait queue structure.
  51          *
  52          * Must be acquired before T.lock for each T of type thread_t.
  53          */
  54         SPINLOCK_DECLARE(lock);
  55
  56         int missed_wakeups;     /**< Number of waitq_wakeup() calls that didn't find a thread to wake up. */
  57         link_t head;            /**< List of sleeping threads for wich there was no missed_wakeup. */
  58 };
  59
  60 #define waitq_sleep(wq) \
  61         waitq_sleep_timeout((wq),SYNCH_NO_TIMEOUT,SYNCH_FLAGS_NONE)
  62
  63 extern void waitq_initialize(waitq_t *wq);
  64 extern int waitq_sleep_timeout(waitq_t *wq, uint32_t usec, int flags);
  65 extern ipl_t waitq_sleep_prepare(waitq_t *wq);
  66 extern int waitq_sleep_timeout_unsafe(waitq_t *wq, uint32_t usec, int flags);
  67 extern void waitq_sleep_finish(waitq_t *wq, int rc, ipl_t ipl);
  68 extern void waitq_wakeup(waitq_t *wq, bool all);
  69 extern void _waitq_wakeup_unsafe(waitq_t *wq, bool all);
  70 extern void waitq_interrupt_sleep(thread_t *t);
  71
  72 #endif
  73
  74 /** @}
  75  */