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Copy pathMappedMemoryUtils.c
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126 lines (111 loc) · 4.17 KB
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/*
* Copyright (c) 2001, 2024, 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_MappedMemoryUtils.h"
#include <assert.h>
#include <sys/mman.h>
#include <stddef.h>
#include <stdlib.h>
/* Output type for mincore(2) */
#ifdef __linux__
typedef unsigned char mincore_vec_t;
#else
typedef char mincore_vec_t;
#endif
jboolean JNICALL MappedMemoryUtils_isLoaded0(JNIEnv *env, jobject obj, jlong address,
jlong len, jlong numPages)
{
jboolean loaded = JNI_TRUE;
int result = 0;
long i = 0;
void *a = (void *) jlong_to_ptr(address);
mincore_vec_t* vec = NULL;
/* Include space for one sentinel byte at the end of the buffer
* to catch overflows. */
vec = (mincore_vec_t*) malloc(numPages + 1);
if (vec == NULL) {
JNU_ThrowOutOfMemoryError(env, NULL);
return JNI_FALSE;
}
vec[numPages] = '\x7f'; /* Write sentinel. */
result = mincore(a, (size_t)len, vec);
assert(vec[numPages] == '\x7f'); /* Check sentinel. */
if (result == -1) {
JNU_ThrowIOExceptionWithLastError(env, "mincore failed");
free(vec);
return JNI_FALSE;
}
for (i=0; i<numPages; i++) {
if (vec[i] == 0) {
loaded = JNI_FALSE;
break;
}
}
free(vec);
return loaded;
}
void JNICALL MappedMemoryUtils_load0(JNIEnv *env, jobject obj, jlong address,
jlong len)
{
char *a = (char *)jlong_to_ptr(address);
int result = madvise((caddr_t)a, (size_t)len, MADV_WILLNEED);
if (result == -1) {
JNU_ThrowIOExceptionWithMessageAndLastError(env, "madvise with advise MADV_WILLNEED failed");
}
}
void JNICALL MappedMemoryUtils_unload0(JNIEnv *env, jobject obj, jlong address,
jlong len)
{
char *a = (char *)jlong_to_ptr(address);
int result = madvise((caddr_t)a, (size_t)len, MADV_DONTNEED);
if (result == -1) {
JNU_ThrowIOExceptionWithMessageAndLastError(env, "madvise with advise MADV_DONTNEED failed");
}
}
void JNICALL MappedMemoryUtils_force0(JNIEnv *env, jobject obj, jobject fdo,
jlong address, jlong len)
{
void* a = (void *)jlong_to_ptr(address);
int result = msync(a, (size_t)len, MS_SYNC);
if (result == -1) {
JNU_ThrowIOExceptionWithMessageAndLastError(env, "msync with parameter MS_SYNC failed");
}
}
#define FD "Ljava/io/FileDescriptor;"
static JNINativeMethod methods[] = {
{"isLoaded0", "(JJJ)Z", (void *)&MappedMemoryUtils_isLoaded0},
{"load0", "(JJ)V", (void *)&MappedMemoryUtils_load0},
{"unload0", "(JJ)V", (void *)&MappedMemoryUtils_unload0},
{"force0", "(" FD "JJ)V", (void *)&MappedMemoryUtils_force0},
};
JNIEXPORT void JNICALL
Java_java_nio_MappedMemoryUtils_registerNatives(JNIEnv *env, jclass cls)
{
(*env)->RegisterNatives(env, cls,
methods, sizeof(methods)/sizeof(methods[0]));
}