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/*
* Copyright (C) 2008 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
/*
* System utilities.
*/
#ifndef _LIBDEX_SYSUTIL
#define _LIBDEX_SYSUTIL
#include <sys/types.h>
/*
* System page size. Normally you're expected to get this from
* sysconf(_SC_PAGESIZE) or some system-specific define (usually PAGESIZE
* or PAGE_SIZE). If we use a simple #define the compiler can generate
* appropriate masks directly, so we define it here and verify it as the
* VM is starting up.
*
* Must be a power of 2.
*/
#define SYSTEM_PAGE_SIZE 4096
/*
* Use this to keep track of mapped segments.
*/
typedef struct MemMapping {
void* addr; /* start of data */
size_t length; /* length of data */
void* baseAddr; /* page-aligned base address */
size_t baseLength; /* length of mapping */
} MemMapping;
/*
* Copy a map.
*/
void sysCopyMap(MemMapping* dst, const MemMapping* src);
/*
* Load a file into a new shared memory segment. All data from the current
* offset to the end of the file is pulled in.
*
* The segment is read-write, allowing VM fixups. (It should be modified
* to support .gz/.zip compressed data.)
*
* On success, "pMap" is filled in, and zero is returned.
*/
int sysLoadFileInShmem(int fd, MemMapping* pMap);
/*
* Map a file (from fd's current offset) into a shared,
* read-only memory segment.
*
* On success, "pMap" is filled in, and zero is returned.
*/
int sysMapFileInShmemReadOnly(int fd, MemMapping* pMap);
/*
* Map a file (from fd's current offset) into a shared, read-only memory
* segment that can be made writable. (In some cases, such as when
* mapping a file on a FAT filesystem, the result may be fully writable.)
*
* On success, "pMap" is filled in, and zero is returned.
*/
int sysMapFileInShmemWritableReadOnly(int fd, MemMapping* pMap);
/*
* Like sysMapFileInShmemReadOnly, but on only part of a file.
*/
int sysMapFileSegmentInShmem(int fd, off_t start, size_t length,
MemMapping* pMap);
/*
* Create a private anonymous mapping, useful for large allocations.
*
* On success, "pMap" is filled in, and zero is returned.
*/
int sysCreatePrivateMap(size_t length, MemMapping* pMap);
/*
* Change the access rights on one or more pages. If "wantReadWrite" is
* zero, the pages will be made read-only; otherwise they will be read-write.
*
* Returns 0 on success.
*/
int sysChangeMapAccess(void* addr, size_t length, int wantReadWrite,
MemMapping* pmap);
/*
* Release the pages associated with a shared memory segment.
*
* This does not free "pMap"; it just releases the memory.
*/
void sysReleaseShmem(MemMapping* pMap);
/*
* Write until all bytes have been written.
*
* Returns 0 on success, or an errno value on failure.
*/
int sysWriteFully(int fd, const void* buf, size_t count, const char* logMsg);
#endif /*_DALVIK_SYSUTIL*/
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