service_runtime/linux/condition_variable.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
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  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
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  29  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  30  */
  31
  32
  33 #ifndef NATIVE_CLIENT_SERVICE_RUNTIME_LINUX_CONDITION_VARIABLE_H_
  34 #define NATIVE_CLIENT_SERVICE_RUNTIME_LINUX_CONDITION_VARIABLE_H_
  35
  36 #include <pthread.h>
  37 #include "native_client/service_runtime/linux/lock.h"
  38 #include "native_client/service_runtime/time.h"
  39
  40 #define INFINITE            0xFFFFFFFF  // Infinite timeout
  41
  42 namespace NaCl {
  43
  44 class Lock;
  45
  46 class ConditionVariable {
  47  public:
  48   ConditionVariable();
  49
  50   ~ConditionVariable();
  51
  52   // We provide two variants of TimedWait:
  53   // the first one takes relative time as an argument.
  54   int TimedWaitRel(Lock& user_lock, TimeDelta max_time);
  55   // The second TimedWait takes absolute time
  56   int TimedWaitAbs(Lock& user_lock, TimeTicks abs_time);
  57   void Wait(Lock& user_lock) {
  58     // Default to "wait forever" timing, which means have to get a Signal()
  59     // or Broadcast() to come out of this wait state.
  60     TimedWaitRel(user_lock, TimeDelta::FromMilliseconds(INFINITE));
  61   }
  62
  63
  64   // Broadcast() revives all waiting threads.
  65   void Broadcast();
  66   // Signal() revives one waiting thread.
  67   void Signal();
  68
  69  private:
  70   pthread_cond_t  cv_;
  71   DISALLOW_EVIL_CONSTRUCTORS(ConditionVariable);
  72 };
  73
  74 }  // namespace NaCl
  75
  76 #endif  // NATIVE_CLIENT_SERVICE_RUNTIME_LINUX_CONDITION_VARIABLE_H_