SysUtil.h revision f6c387128427e121477c1b32ad35cdcaa5101ba3 
1/*
2 * Copyright (C) 2008 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *      http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16/*
17 * System utilities.
18 */
19#ifndef _LIBDEX_SYSUTIL
20#define _LIBDEX_SYSUTIL
21
22#include <sys/types.h>
23
24/*
25 * Use this to keep track of mapped segments.
26 */
27typedef struct MemMapping {
28    void*   addr;           /* start of data */
29    size_t  length;         /* length of data */
30
31    void*   baseAddr;       /* page-aligned base address */
32    size_t  baseLength;     /* length of mapping */
33} MemMapping;
34
35/*
36 * Copy a map.
37 */
38void sysCopyMap(MemMapping* dst, const MemMapping* src);
39
40/*
41 * Load a file into a new shared memory segment.  All data from the current
42 * offset to the end of the file is pulled in.
43 *
44 * The segment is read-write, allowing VM fixups.  (It should be modified
45 * to support .gz/.zip compressed data.)
46 *
47 * On success, "pMap" is filled in, and zero is returned.
48 */
49int sysLoadFileInShmem(int fd, MemMapping* pMap);
50
51/*
52 * Map a file (from fd's current offset) into a shared,
53 * read-only memory segment.
54 *
55 * On success, "pMap" is filled in, and zero is returned.
56 */
57int sysMapFileInShmem(int fd, MemMapping* pMap);
58
59/*
60 * Like sysMapFileInShmem, but on only part of a file.
61 */
62int sysMapFileSegmentInShmem(int fd, off_t start, long length,
63    MemMapping* pMap);
64
65/*
66 * Release the pages associated with a shared memory segment.
67 *
68 * This does not free "pMap"; it just releases the memory.
69 */
70void sysReleaseShmem(MemMapping* pMap);
71
72#endif /*_DALVIK_SYSUTIL*/
73