/*
* Copyright (c) 2001, 2010, Oracle and/or its affiliates. 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. Oracle designates this
* particular file as subject to the "Classpath" exception as provided
* by Oracle 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
* or visit www.oracle.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, jint numPages)
{
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 void JNICALL
Java_java_nio_MappedByteBuffer_load0(JNIEnv *env, jobject obj, jlong address,
jlong len)
{
// no madvise available
}
JNIEXPORT void JNICALL
Java_java_nio_MappedByteBuffer_force0(JNIEnv *env, jobject obj, jobject fdo,
jlong address, jlong len)
{
void *a = (void *) jlong_to_ptr(address);
BOOL 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);
/**
* FlushViewOfFile only initiates the writing of dirty pages to disk
* so we have to call FlushFileBuffers to and ensure they are written.
*/
if (result != 0) {
// by right, the jfieldID initialization should be in a static
// initializer but we do it here instead to avoiding needing to
// load nio.dll during startup.
static jfieldID handle_fdID;
HANDLE h;
if (handle_fdID == NULL) {
jclass clazz = (*env)->FindClass(env, "java/io/FileDescriptor");
if (clazz == NULL)
return; // exception thrown
handle_fdID = (*env)->GetFieldID(env, clazz, "handle", "J");
}
h = jlong_to_ptr((*env)->GetLongField(env, fdo, handle_fdID));
result = FlushFileBuffers(h);
if (result == 0 && GetLastError() == ERROR_ACCESS_DENIED) {
// read-only mapping
result = 1;
}
}
if (result == 0) {
JNU_ThrowIOExceptionWithLastError(env, "Flush failed");
}
}