/*
 * Copyright (C) 2007 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 __IPCLINUX_CONDITION_H__
#define __IPCLINUX_CONDITION_H__

#include <stdint.h>
#include <sys/types.h>
#include <time.h>
#include <pthread.h>
#include <utils/Mutex.h>

namespace EyeseeLinux
{

/*
 * Condition variable class.  The implementation is system-dependent.
 *
 * Condition variables are paired up with mutexes.  Lock the mutex,
 * call wait(), then either re-wait() if things aren't quite what you want,
 * or unlock the mutex and continue.  All threads calling wait() must
 * use the same mutex for a given Condition.
 */
class Condition
{
public:
    enum {
        PRIVATE = 0,
        SHARED = 1
    };

    Condition();
    Condition(int type);
    ~Condition();
    // Wait on the condition variable.  Lock the mutex before calling.
    status_t wait(Mutex& mutex);
    // same with relative timeout
    status_t waitRelative(Mutex& mutex, int64_t reltime);
    // Signal the condition variable, allowing one thread to continue.
    void signal();
    // Signal the condition variable, allowing all threads to continue.
    void broadcast();

private:
    pthread_cond_t mCond;
};


inline Condition::Condition() {
    pthread_cond_init(&mCond, NULL);
}
inline Condition::Condition(int type) {
    if (type == SHARED) {
        pthread_condattr_t attr;
        pthread_condattr_init(&attr);
        pthread_condattr_setpshared(&attr, PTHREAD_PROCESS_SHARED);
        pthread_cond_init(&mCond, &attr);
        pthread_condattr_destroy(&attr);
    } else {
        pthread_cond_init(&mCond, NULL);
    }
}
inline Condition::~Condition() {
    pthread_cond_destroy(&mCond);
}
inline status_t Condition::wait(Mutex& mutex) {
    return -pthread_cond_wait(&mCond, &mutex.mMutex);
}
inline status_t Condition::waitRelative(Mutex& mutex, int64_t reltime)
{
    struct timespec ts;
    clock_gettime(CLOCK_REALTIME, &ts);
    ts.tv_sec += reltime/1000000000;
    ts.tv_nsec+= reltime%1000000000;
    if (ts.tv_nsec >= 1000000000) {
        ts.tv_nsec -= 1000000000;
        ts.tv_sec  += 1;
    }
    return -pthread_cond_timedwait(&mCond, &mutex.mMutex, &ts);
}
inline void Condition::signal() {
    pthread_cond_signal(&mCond);
}
inline void Condition::broadcast() {
    pthread_cond_broadcast(&mCond);
}

}; /* namespace EyeseeLinux */

#endif /* __IPCLINUX_CONDITION_H__ */