/*

 * Copyright 2001-2007 Sun Microsystems, Inc.  All Rights Reserved.

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.  Sun designates this

 * particular file as subject to the "Classpath" exception as provided

 * by Sun in the LICENSE file that accompanied this code.

 *

 * This code is distributed in the hope that it will be useful, but WITHOUT

 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,

 * CA 95054 USA or visit www.sun.com if you need additional information or

 * have any questions.

 */

#include "jni.h"

#include "jni_util.h"

#include "jvm.h"

#include "jlong.h"

#include "java_nio_MappedByteBuffer.h"

#include <stdlib.h>

JNIEXPORT jboolean JNICALL

Java_java_nio_MappedByteBuffer_isLoaded0(JNIEnv *env, jobject obj,

                                        jlong address, jlong len)

{

    jboolean loaded = JNI_FALSE;

    /* Information not available?

    MEMORY_BASIC_INFORMATION info;

    void *a = (void *) jlong_to_ptr(address);

    int result = VirtualQuery(a, &info, (DWORD)len);

    */

    return loaded;

}

JNIEXPORT jint JNICALL

Java_java_nio_MappedByteBuffer_load0(JNIEnv *env, jobject obj, jlong address,

                                     jlong len, jint pageSize)

{

    int *ptr = (int *) jlong_to_ptr(address);

    int pageIncrement = pageSize / sizeof(int);

    jlong numPages = (len + pageSize - 1) / pageSize;

    int i = 0;

    int j = 0;

    /* touch every page */

    for (i=0; i<numPages; i++) {

        j += *((volatile int *)ptr);

        ptr += pageIncrement;

    }

    return j;

}

JNIEXPORT void JNICALL

Java_java_nio_MappedByteBuffer_force0(JNIEnv *env, jobject obj, jlong address,

                                      jlong len)

{

    void *a = (void *) jlong_to_ptr(address);

    int result;

    int retry;

    /*

     * FlushViewOfFile can fail with ERROR_LOCK_VIOLATION if the memory

     * system is writing dirty pages to disk. As there is no way to

     * synchronize the flushing then we retry a limited number of times.

     */

    retry = 0;

    do {

        result = FlushViewOfFile(a, (DWORD)len);

        if ((result != 0) || (GetLastError() != ERROR_LOCK_VIOLATION))

            break;

        retry++;

    } while (retry < 3);

    if (result == 0) {

        JNU_ThrowIOExceptionWithLastError(env, "Flush failed");

    }

}