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 /* 18 * System utilities. 19 */ 20 #ifndef _LIBDEX_SYSUTIL 21 #define _LIBDEX_SYSUTIL 22 23 #include <sys/types.h> 24 25 /* 26 * System page size. Normally you're expected to get this from 27 * sysconf(_SC_PAGESIZE) or some system-specific define (usually PAGESIZE 28 * or PAGE_SIZE). If we use a simple #define the compiler can generate 29 * appropriate masks directly, so we define it here and verify it as the 30 * VM is starting up. 31 * 32 * Must be a power of 2. 33 */ 34 #define SYSTEM_PAGE_SIZE 4096 35 36 /* 37 * Use this to keep track of mapped segments. 38 */ 39 typedef struct MemMapping { 40 void* addr; /* start of data */ 41 size_t length; /* length of data */ 42 43 void* baseAddr; /* page-aligned base address */ 44 size_t baseLength; /* length of mapping */ 45 } MemMapping; 46 47 /* 48 * Copy a map. 49 */ 50 void sysCopyMap(MemMapping* dst, const MemMapping* src); 51 52 /* 53 * Load a file into a new shared memory segment. All data from the current 54 * offset to the end of the file is pulled in. 55 * 56 * The segment is read-write, allowing VM fixups. (It should be modified 57 * to support .gz/.zip compressed data.) 58 * 59 * On success, "pMap" is filled in, and zero is returned. 60 */ 61 int sysLoadFileInShmem(int fd, MemMapping* pMap); 62 63 /* 64 * Map a file (from fd's current offset) into a shared, 65 * read-only memory segment. 66 * 67 * On success, "pMap" is filled in, and zero is returned. 68 */ 69 int sysMapFileInShmemReadOnly(int fd, MemMapping* pMap); 70 71 /* 72 * Map a file (from fd's current offset) into a shared, read-only memory 73 * segment that can be made writable. (In some cases, such as when 74 * mapping a file on a FAT filesystem, the result may be fully writable.) 75 * 76 * On success, "pMap" is filled in, and zero is returned. 77 */ 78 int sysMapFileInShmemWritableReadOnly(int fd, MemMapping* pMap); 79 80 /* 81 * Like sysMapFileInShmemReadOnly, but on only part of a file. 82 */ 83 int sysMapFileSegmentInShmem(int fd, off_t start, size_t length, 84 MemMapping* pMap); 85 86 /* 87 * Create a private anonymous mapping, useful for large allocations. 88 * 89 * On success, "pMap" is filled in, and zero is returned. 90 */ 91 int sysCreatePrivateMap(size_t length, MemMapping* pMap); 92 93 /* 94 * Change the access rights on one or more pages. If "wantReadWrite" is 95 * zero, the pages will be made read-only; otherwise they will be read-write. 96 * 97 * Returns 0 on success. 98 */ 99 int sysChangeMapAccess(void* addr, size_t length, int wantReadWrite, 100 MemMapping* pmap); 101 102 /* 103 * Release the pages associated with a shared memory segment. 104 * 105 * This does not free "pMap"; it just releases the memory. 106 */ 107 void sysReleaseShmem(MemMapping* pMap); 108 109 /* 110 * Write until all bytes have been written. 111 * 112 * Returns 0 on success, or an errno value on failure. 113 */ 114 int sysWriteFully(int fd, const void* buf, size_t count, const char* logMsg); 115 116 #endif /*_DALVIK_SYSUTIL*/ 117
