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      1 /*
      2  * Copyright (c) 2001, 2010, Oracle and/or its affiliates. All rights reserved.
      3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
      4  *
      5  * This code is free software; you can redistribute it and/or modify it
      6  * under the terms of the GNU General Public License version 2 only, as
      7  * published by the Free Software Foundation.  Oracle designates this
      8  * particular file as subject to the "Classpath" exception as provided
      9  * by Oracle in the LICENSE file that accompanied this code.
     10  *
     11  * This code is distributed in the hope that it will be useful, but WITHOUT
     12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
     13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
     14  * version 2 for more details (a copy is included in the LICENSE file that
     15  * accompanied this code).
     16  *
     17  * You should have received a copy of the GNU General Public License version
     18  * 2 along with this work; if not, write to the Free Software Foundation,
     19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
     20  *
     21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
     22  * or visit www.oracle.com if you need additional information or have any
     23  * questions.
     24  */
     25 
     26 #include "jni.h"
     27 #include "jni_util.h"
     28 #include "jvm.h"
     29 #include "jlong.h"
     30 #include <sys/mman.h>
     31 #include <stddef.h>
     32 #include <stdlib.h>
     33 
     34 #include "JNIHelp.h"
     35 
     36 #define NATIVE_METHOD(className, functionName, signature) \
     37 { #functionName, signature, (void*)(Java_java_nio_ ## className ## _ ## functionName) }
     38 
     39 JNIEXPORT jboolean JNICALL
     40 Java_java_nio_MappedByteBuffer_isLoaded0(JNIEnv *env, jobject obj, jlong address,
     41                                          jlong len, jint numPages)
     42 {
     43     jboolean loaded = JNI_TRUE;
     44     int result = 0;
     45     int i = 0;
     46     void *a = (void *) jlong_to_ptr(address);
     47 #ifdef __linux__
     48     unsigned char *vec = (unsigned char *)malloc(numPages * sizeof(char));
     49 #else
     50     char *vec = (char *)malloc(numPages * sizeof(char));
     51 #endif
     52 
     53     if (vec == NULL) {
     54         JNU_ThrowOutOfMemoryError(env, NULL);
     55         return JNI_FALSE;
     56     }
     57 
     58     result = mincore(a, (size_t)len, vec);
     59     if (result == -1) {
     60         JNU_ThrowIOExceptionWithLastError(env, "mincore failed");
     61         free(vec);
     62         return JNI_FALSE;
     63     }
     64 
     65     for (i=0; i<numPages; i++) {
     66         if (vec[i] == 0) {
     67             loaded = JNI_FALSE;
     68             break;
     69         }
     70     }
     71     free(vec);
     72     return loaded;
     73 }
     74 
     75 
     76 JNIEXPORT void JNICALL
     77 Java_java_nio_MappedByteBuffer_load0(JNIEnv *env, jobject obj, jlong address,
     78                                      jlong len)
     79 {
     80     char *a = (char *)jlong_to_ptr(address);
     81     int result = madvise((caddr_t)a, (size_t)len, MADV_WILLNEED);
     82     if (result == -1) {
     83         JNU_ThrowIOExceptionWithLastError(env, "madvise failed");
     84     }
     85 }
     86 
     87 
     88 JNIEXPORT void JNICALL
     89 Java_java_nio_MappedByteBuffer_force0(JNIEnv *env, jobject obj, jobject fdo,
     90                                       jlong address, jlong len)
     91 {
     92     void* a = (void *)jlong_to_ptr(address);
     93     int result = msync(a, (size_t)len, MS_SYNC);
     94     if (result == -1) {
     95         JNU_ThrowIOExceptionWithLastError(env, "msync failed");
     96     }
     97 }
     98 
     99 
    100 static JNINativeMethod gMethods[] = {
    101   NATIVE_METHOD(MappedByteBuffer, isLoaded0, "(JJI)Z"),
    102   NATIVE_METHOD(MappedByteBuffer, load0, "(JJ)V"),
    103   NATIVE_METHOD(MappedByteBuffer, force0, "(Ljava/io/FileDescriptor;JJ)V"),
    104 };
    105 
    106 void register_java_nio_MappedByteBuffer(JNIEnv* env) {
    107   jniRegisterNativeMethods(env, "java/nio/MappedByteBuffer", gMethods, NELEM(gMethods));
    108 }
    109