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 "java_nio_MappedByteBuffer.h"
31#include <assert.h>
32#include <sys/mman.h>
33#include <stddef.h>
34#include <stdlib.h>
35
36#ifdef _AIX
37#include <unistd.h>
38#endif
39
40/* Output type for mincore(2) */
41#ifdef __linux__
42typedef unsigned char mincore_vec_t;
43#else
44typedef char mincore_vec_t;
45#endif
46
47#ifdef _AIX
48static long calculate_number_of_pages_in_range(void* address, size_t len, size_t pagesize) {
49 uintptr_t address_unaligned = (uintptr_t) address;
50 uintptr_t address_aligned = address_unaligned & (~(pagesize - 1));
51 size_t len2 = len + (address_unaligned - address_aligned);
52 long numPages = (len2 + pagesize - 1) / pagesize;
53 return numPages;
54}
55#endif
56
57JNIEXPORT jboolean JNICALL
58Java_java_nio_MappedByteBuffer_isLoaded0(JNIEnv *env, jobject obj, jlong address,
59 jlong len, jint numPages)
60{
61 jboolean loaded = JNI_TRUE;
62 int result = 0;
63 int i = 0;
64 void *a = (void *) jlong_to_ptr(address);
65 mincore_vec_t* vec = NULL;
66
67#ifdef _AIX
68 /* See JDK-8186665 */
69 size_t pagesize = (size_t)sysconf(_SC_PAGESIZE);
70 if ((long)pagesize == -1) {
71 return JNI_FALSE;
72 }
73 numPages = (jint) calculate_number_of_pages_in_range(a, len, pagesize);
74#endif
75
76 /* Include space for one sentinel byte at the end of the buffer
77 * to catch overflows. */
78 vec = (mincore_vec_t*) malloc(numPages + 1);
79
80 if (vec == NULL) {
81 JNU_ThrowOutOfMemoryError(env, NULL);
82 return JNI_FALSE;
83 }
84
85 vec[numPages] = '\x7f'; /* Write sentinel. */
86 result = mincore(a, (size_t)len, vec);
87 assert(vec[numPages] == '\x7f'); /* Check sentinel. */
88
89 if (result == -1) {
90 JNU_ThrowIOExceptionWithLastError(env, "mincore failed");
91 free(vec);
92 return JNI_FALSE;
93 }
94
95 for (i=0; i<numPages; i++) {
96 if (vec[i] == 0) {
97 loaded = JNI_FALSE;
98 break;
99 }
100 }
101 free(vec);
102 return loaded;
103}
104
105
106JNIEXPORT void JNICALL
107Java_java_nio_MappedByteBuffer_load0(JNIEnv *env, jobject obj, jlong address,
108 jlong len)
109{
110 char *a = (char *)jlong_to_ptr(address);
111 int result = madvise((caddr_t)a, (size_t)len, MADV_WILLNEED);
112 if (result == -1) {
113 JNU_ThrowIOExceptionWithLastError(env, "madvise failed");
114 }
115}
116
117
118JNIEXPORT void JNICALL
119Java_java_nio_MappedByteBuffer_force0(JNIEnv *env, jobject obj, jobject fdo,
120 jlong address, jlong len)
121{
122 void* a = (void *)jlong_to_ptr(address);
123 int result = msync(a, (size_t)len, MS_SYNC);
124 if (result == -1) {
125 JNU_ThrowIOExceptionWithLastError(env, "msync failed");
126 }
127}
128