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 <nativehelper/JNIHelp.h>
35 
36 #define NATIVE_METHOD(className, functionName, signature) \
37 { #functionName, signature, (void*)(Java_java_nio_ ## className ## _ ## functionName) }
38 
39 // Android-changed: Use jlong for numPages to support 64-bit address.
40 JNIEXPORT jboolean JNICALL
Java_java_nio_MappedByteBuffer_isLoaded0(JNIEnv * env,jobject obj,jlong address,jlong len,jlong numPages)41 Java_java_nio_MappedByteBuffer_isLoaded0(JNIEnv *env, jobject obj, jlong address,
42                                          jlong len, jlong numPages)
43 {
44 // BEGIN Android-added: Fuchsia holds all pages in memory. http://b/119503290
45 #if defined(__Fuchsia__)
46     return JNI_TRUE;
47 #else
48 // END Android-added: Fuchsia holds all pages in memory. http://b/119503290
49     jboolean loaded = JNI_TRUE;
50     int result = 0;
51     int i = 0;
52     void *a = (void *) jlong_to_ptr(address);
53 #ifdef __linux__
54     // Android-changed: fix mismatched type in sizeof.
55     unsigned char *vec = (unsigned char *)malloc(numPages * sizeof(*vec));
56 #else
57     char *vec = (char *)malloc(numPages * sizeof(*vec));
58 #endif
59 
60     if (vec == NULL) {
61         JNU_ThrowOutOfMemoryError(env, NULL);
62         return JNI_FALSE;
63     }
64 
65     result = mincore(a, (size_t)len, vec);
66     if (result == -1) {
67         JNU_ThrowIOExceptionWithLastError(env, "mincore failed");
68         free(vec);
69         return JNI_FALSE;
70     }
71 
72     for (i=0; i<numPages; i++) {
73         if (vec[i] == 0) {
74             loaded = JNI_FALSE;
75             break;
76         }
77     }
78     free(vec);
79     return loaded;
80 // Android-added: Fuchsia holds all pages in memory. http://b/119503290
81 #endif
82 }
83 
84 
85 JNIEXPORT void JNICALL
Java_java_nio_MappedByteBuffer_load0(JNIEnv * env,jobject obj,jlong address,jlong len)86 Java_java_nio_MappedByteBuffer_load0(JNIEnv *env, jobject obj, jlong address,
87                                      jlong len)
88 {
89     char *a = (char *)jlong_to_ptr(address);
90     int result = madvise((caddr_t)a, (size_t)len, MADV_WILLNEED);
91     if (result == -1) {
92         JNU_ThrowIOExceptionWithLastError(env, "madvise failed");
93     }
94 }
95 
96 
97 JNIEXPORT void JNICALL
Java_java_nio_MappedByteBuffer_force0(JNIEnv * env,jobject obj,jobject fdo,jlong address,jlong len)98 Java_java_nio_MappedByteBuffer_force0(JNIEnv *env, jobject obj, jobject fdo,
99                                       jlong address, jlong len)
100 {
101     void* a = (void *)jlong_to_ptr(address);
102     int result = msync(a, (size_t)len, MS_SYNC);
103     if (result == -1) {
104         JNU_ThrowIOExceptionWithLastError(env, "msync failed");
105     }
106 }
107 
108 
109 static JNINativeMethod gMethods[] = {
110   NATIVE_METHOD(MappedByteBuffer, isLoaded0, "(JJJ)Z"),
111   NATIVE_METHOD(MappedByteBuffer, load0, "(JJ)V"),
112   NATIVE_METHOD(MappedByteBuffer, force0, "(Ljava/io/FileDescriptor;JJ)V"),
113 };
114 
register_java_nio_MappedByteBuffer(JNIEnv * env)115 void register_java_nio_MappedByteBuffer(JNIEnv* env) {
116   jniRegisterNativeMethods(env, "java/nio/MappedByteBuffer", gMethods, NELEM(gMethods));
117 }
118