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109 lines
3.1 KiB
109 lines
3.1 KiB
/* |
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* Copyright (C) 2008 The Android Open Source Project |
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* |
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* Licensed under the Apache License, Version 2.0 (the "License"); |
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* you may not use this file except in compliance with the License. |
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* You may obtain a copy of the License at |
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* |
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* http://www.apache.org/licenses/LICENSE-2.0 |
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* |
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* Unless required by applicable law or agreed to in writing, software |
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* distributed under the License is distributed on an "AS IS" BASIS, |
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
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* See the License for the specific language governing permissions and |
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* limitations under the License. |
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*/ |
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/* |
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* System utilities. |
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*/ |
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#ifndef LIBDEX_SYSUTIL_H_ |
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#define LIBDEX_SYSUTIL_H_ |
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#include <sys/types.h> |
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/* |
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* System page size. Normally you're expected to get this from |
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* sysconf(_SC_PAGESIZE) or some system-specific define (usually PAGESIZE |
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* or PAGE_SIZE). If we use a simple #define the compiler can generate |
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* appropriate masks directly, so we define it here and verify it as the |
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* VM is starting up. |
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* |
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* Must be a power of 2. |
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*/ |
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#ifdef PAGE_SHIFT |
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#define SYSTEM_PAGE_SIZE (1<<PAGE_SHIFT) |
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#else |
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#define SYSTEM_PAGE_SIZE 4096 |
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#endif |
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/* |
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* Use this to keep track of mapped segments. |
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*/ |
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struct MemMapping { |
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void* addr; /* start of data */ |
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size_t length; /* length of data */ |
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void* baseAddr; /* page-aligned base address */ |
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size_t baseLength; /* length of mapping */ |
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}; |
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/* |
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* Copy a map. |
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*/ |
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void sysCopyMap(MemMapping* dst, const MemMapping* src); |
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/* |
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* Map a file (from fd's current offset) into a shared, read-only memory |
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* segment that can be made writable. (In some cases, such as when |
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* mapping a file on a FAT filesystem, the result may be fully writable.) |
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* |
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* On success, "pMap" is filled in, and zero is returned. |
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*/ |
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int sysMapFileInShmemWritableReadOnly(int fd, MemMapping* pMap); |
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/* |
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* Map part of a file into a shared, read-only memory segment. |
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* |
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* On success, "pMap" is filled in, and zero is returned. |
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*/ |
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int sysMapFileSegmentInShmem(int fd, off_t start, size_t length, |
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MemMapping* pMap); |
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/* |
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* Create a private anonymous mapping, useful for large allocations. |
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* |
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* On success, "pMap" is filled in, and zero is returned. |
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*/ |
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int sysCreatePrivateMap(size_t length, MemMapping* pMap); |
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/* |
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* Change the access rights on one or more pages. If "wantReadWrite" is |
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* zero, the pages will be made read-only; otherwise they will be read-write. |
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* |
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* Returns 0 on success. |
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*/ |
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int sysChangeMapAccess(void* addr, size_t length, int wantReadWrite, |
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MemMapping* pmap); |
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/* |
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* Release the pages associated with a shared memory segment. |
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* |
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* This does not free "pMap"; it just releases the memory. |
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*/ |
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void sysReleaseShmem(MemMapping* pMap); |
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/* |
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* Write until all bytes have been written. |
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* |
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* Returns 0 on success, or an errno value on failure. |
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*/ |
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int sysWriteFully(int fd, const void* buf, size_t count, const char* logMsg); |
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/* |
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* Copy the given number of bytes from one fd to another. Returns |
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* 0 on success, -1 on failure. |
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*/ |
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int sysCopyFileToFile(int outFd, int inFd, size_t count); |
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#endif // LIBDEX_SYSUTIL_H_
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