service_runtime/nacl_sync_queue.h

   1 /*
   2  * Copyright 2008, Google Inc.
   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 are
   7  * 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
  12  * copyright notice, this list of conditions and the following disclaimer
  13  * in the documentation and/or other materials provided with the
  14  * distribution.
  15  *     * Neither the name of Google Inc. nor the names of its
  16  * contributors may be used to endorse or promote products derived from
  17  * this software without specific prior written permission.
  18  *
  19  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  20  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  21  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  22  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  23  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  24  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  25  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  26  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  27  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  28  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  29  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  30  */
  31
  32 /*
  33  * NaCl service runtime workqueue.
  34  */
  35
  36 #ifndef NATIVE_CLIENT_SERVICE_RUNTIME_NACL_SYNC_QUEUE_H_
  37 #define NATIVE_CLIENT_SERVICE_RUNTIME_NACL_SYNC_QUEUE_H_
  38
  39 #include "native_client/service_runtime/nacl_sync.h"
  40 #include "native_client/service_runtime/nacl_closure.h"
  41
  42 /**
  43  * This module implements a thread-safe queue.
  44  *
  45  * It internally uses nacl_sync_checked, so any failure returns from
  46  * synchronization objects will result in a fatal error.
  47  */
  48
  49 struct NaClSyncQueueItem;  /* opaque */
  50
  51 struct NaClSyncQueue {
  52   struct NaClMutex          mu;
  53   struct NaClCondVar        cv;  /* wake on not empty */
  54   struct NaClSyncQueueItem  *head;
  55   struct NaClSyncQueueItem  **insert_pt;
  56   int                       quit;
  57 };
  58
  59 int NaClSyncQueueEmpty(struct NaClSyncQueue *nsqp);
  60
  61 /*
  62  * Placement new style constructor for a NaClSyncQueue object.
  63  */
  64 int NaClSyncQueueCtor(struct NaClSyncQueue *nsqp);
  65
  66 void NaClSyncQueueDtor(struct NaClSyncQueue *nsqp);
  67
  68 void NaClSyncQueueInsert(struct NaClSyncQueue *nsqp,
  69                          void                 *item);
  70
  71 /*
  72  * Tell blocked threads to unblock.
  73  */
  74 void NaClSyncQueueQuit(struct NaClSyncQueue *nsqp);
  75
  76 /*
  77  * Block waiting for a work queue item, or until NaClSyncQueueQuit is
  78  * invoked on the work queue, in which case NULL is returned.  Note
  79  * that the NaClSyncQueue may not be empty.  Before the dtor is
  80  * invoked on the queue, all enqueued work items must be freed.
  81  */
  82 void *NaClSyncQueueDequeue(struct NaClSyncQueue *nsqp);
  83
  84 #endif