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/*
* Copyright (C) 2009 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#ifndef ANDROID_MESSAGE_QUEUE_H
#define ANDROID_MESSAGE_QUEUE_H
#include <stdint.h>
#include <errno.h>
#include <sys/types.h>
#include <utils/threads.h>
#include <utils/Timers.h>
#include <utils/List.h>
#include "Barrier.h"
namespace android {
// ---------------------------------------------------------------------------
class MessageBase;
class MessageList
{
List< sp<MessageBase> > mList;
typedef List< sp<MessageBase> > LIST;
public:
inline LIST::iterator begin() { return mList.begin(); }
inline LIST::const_iterator begin() const { return mList.begin(); }
inline LIST::iterator end() { return mList.end(); }
inline LIST::const_iterator end() const { return mList.end(); }
inline bool isEmpty() const { return mList.empty(); }
void insert(const sp<MessageBase>& node);
void remove(LIST::iterator pos);
};
// ============================================================================
class MessageBase :
public LightRefBase<MessageBase>
{
public:
nsecs_t when;
uint32_t what;
int32_t arg0;
MessageBase() : when(0), what(0), arg0(0) { }
MessageBase(uint32_t what, int32_t arg0=0)
: when(0), what(what), arg0(arg0) { }
// return true if message has a handler
virtual bool handler() { return false; }
// waits for the handler to be processed
void wait() const { barrier.wait(); }
// releases all waiters. this is done automatically if
// handler returns true
void notify() const { barrier.open(); }
protected:
virtual ~MessageBase() { }
private:
mutable Barrier barrier;
friend class LightRefBase<MessageBase>;
};
inline bool operator < (const MessageBase& lhs, const MessageBase& rhs) {
return lhs.when < rhs.when;
}
// ---------------------------------------------------------------------------
class MessageQueue
{
typedef List< sp<MessageBase> > LIST;
public:
MessageQueue();
~MessageQueue();
// pre-defined messages
enum {
INVALIDATE = '_upd'
};
sp<MessageBase> waitMessage(nsecs_t timeout = -1);
status_t postMessage(const sp<MessageBase>& message,
nsecs_t reltime=0, uint32_t flags = 0);
status_t invalidate();
void dump(const sp<MessageBase>& message);
private:
status_t queueMessage(const sp<MessageBase>& message,
nsecs_t reltime, uint32_t flags);
void dumpLocked(const sp<MessageBase>& message);
Mutex mLock;
Condition mCondition;
MessageList mMessages;
bool mInvalidate;
sp<MessageBase> mInvalidateMessage;
};
// ---------------------------------------------------------------------------
}; // namespace android
#endif /* ANDROID_MESSAGE_QUEUE_H */
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