/*
 * The contents of this file are subject to the Netscape Public License
 * Version 1.0 (the "NPL"); you may not use this file except in
 * compliance with the NPL.  You may obtain a copy of the NPL at
 * http://www.mozilla.org/NPL/
 *
 * Software distributed under the NPL is distributed on an "AS IS" basis,
 * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the NPL
 * for the specific language governing rights and limitations under the
 * NPL.
 *
 * The Initial Developer of this code under the NPL is Netscape
 * Communications Corporation.  Portions created by Netscape are
 * Copyright (C) 1998 Netscape Communications Corporation.  All Rights
 * Reserved.
 */

/*
	MRJMonitor.cpp
	
	Provides a C++ interface to Java monitors.
	
	by Patrick C. Beard.
 */

#include "MRJMonitor.h"
#include "MRJSession.h"

MRJMonitor::MRJMonitor(MRJSession* session, jobject monitor)
	:	mSession(session), mMonitor(NULL), mWaitMethod(NULL), mNotifyMethod(NULL), mNotifyAllMethod(NULL)
{
	JNIEnv* env = mSession->getCurrentEnv();
	jclass javaLangObject = env->FindClass("java/lang/Object");
	if (javaLangObject != NULL) {
		// look up method IDs.
		mWaitMethod = env->GetMethodID(javaLangObject, "wait", "()V");
		mTimedWaitMethod = env->GetMethodID(javaLangObject, "wait", "(J)V");
		mNotifyMethod = env->GetMethodID(javaLangObject, "notify", "()V");
		mNotifyAllMethod = env->GetMethodID(javaLangObject, "notifyAll", "()V");
		
		Boolean allocateMonitor = (monitor == NULL);
		if (allocateMonitor)
			monitor = env->AllocObject(javaLangObject);
		
		if (monitor != NULL)
			mMonitor = env->NewGlobalRef(monitor);

		if (allocateMonitor)
			env->DeleteLocalRef(monitor);

		env->DeleteLocalRef(javaLangObject);
	}
}

MRJMonitor::~MRJMonitor()
{
	if (mMonitor != NULL) {
		JNIEnv* env = mSession->getCurrentEnv();
		env->DeleteGlobalRef(mMonitor);
		mMonitor = NULL;
	}
}

void MRJMonitor::enter()
{
	JNIEnv* env = mSession->getCurrentEnv();
	env->MonitorEnter(mMonitor);
}

void MRJMonitor::exit()
{
	JNIEnv* env = mSession->getCurrentEnv();
	env->MonitorExit(mMonitor);
}

void MRJMonitor::wait()
{
	if (mMonitor != NULL && mWaitMethod != NULL) {
		JNIEnv* env = mSession->getCurrentEnv();
		env->MonitorEnter(mMonitor);
		env->CallVoidMethod(mMonitor, mWaitMethod);
		env->MonitorExit(mMonitor);
	}
}

void MRJMonitor::wait(long long millis)
{
	if (mMonitor != NULL && mWaitMethod != NULL) {
		JNIEnv* env = mSession->getCurrentEnv();
		env->MonitorEnter(mMonitor);
		env->CallVoidMethod(mMonitor, mTimedWaitMethod, jlong(millis));
		env->MonitorExit(mMonitor);
	}
}

void MRJMonitor::notify()
{
	if (mMonitor != NULL && mNotifyMethod != NULL) {
		JNIEnv* env = mSession->getCurrentEnv();
		env->MonitorEnter(mMonitor);
		env->CallVoidMethod(mMonitor, mNotifyMethod);
		env->MonitorExit(mMonitor);
	}
}

void MRJMonitor::notifyAll()
{
	if (mMonitor != NULL && mNotifyAllMethod != NULL) {
		JNIEnv* env = mSession->getCurrentEnv();
		env->MonitorEnter(mMonitor);
		env->CallVoidMethod(mMonitor, mNotifyAllMethod);
		env->MonitorExit(mMonitor);
	}
}
