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arangodb/lib/BasicsC/memory-map-win32.c

240 lines
7.9 KiB
C

////////////////////////////////////////////////////////////////////////////////
/// @brief memory mapped files in windows
///
/// @file
///
/// DISCLAIMER
///
/// Copyright 2004-2012 triagens GmbH, Cologne, Germany
///
/// 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.
///
/// Copyright holder is triAGENS GmbH, Cologne, Germany
///
/// @author Dr. O
/// @author Copyright 2012, triAGENS GmbH, Cologne, Germany
////////////////////////////////////////////////////////////////////////////////
#include "memory-map.h"
#ifdef TRI_HAVE_WIN32_MMAP
#include "Windows.h"
#include "BasicsC/logging.h"
#include "BasicsC/strings.h"
////////////////////////////////////////////////////////////////////////////////
/// @addtogroup Memory_map
/// @{
////////////////////////////////////////////////////////////////////////////////
int TRI_FlushMMFile(void* fileHandle, void** mmHandle, void* startingAddress, size_t numOfBytesToFlush, int flags) {
// ...........................................................................
// Possible flags to send are (based upon the Ubuntu Linux ASM include files:
// #define MS_ASYNC 1 /* sync memory asynchronously */
// #define MS_INVALIDATE 2 /* invalidate the caches */
// #define MS_SYNC 4 /* synchronous memory sync */
// Note: under windows all flushes are achieved synchronously, however
// under windows, there is no guarentee that the underlying disk hardware
// cache has physically written to disk.
// FlushFileBuffers ensures file written to disk
// ...........................................................................
bool ok = FlushViewOfFile(startingAddress, numOfBytesToFlush);
if (ok && ((flags & MS_SYNC) == MS_SYNC)) {
ok = FlushFileBuffers(fileHandle);
}
if (ok) {
return TRI_ERROR_NO_ERROR;
}
return TRI_ERROR_SYS_ERROR;
}
int TRI_MMFile(void* memoryAddress, size_t numOfBytesToInitialise, int memoryProtection,
int flags, void* fileHandle, void** mmHandle, int64_t offset, void** result) {
DWORD objectProtection = PAGE_READONLY;
DWORD viewProtection = FILE_MAP_READ;
LARGE_INTEGER mmLength;
// ...........................................................................
// Set the high and low order 32 bits for using a 64 bit integer
// ...........................................................................
mmLength.QuadPart = numOfBytesToInitialise;
// ...........................................................................
// There are two steps for mapping a file:
// Create the handle and then bring the memory mapped file into 'view'
// ...........................................................................
// ...........................................................................
// Create the memory-mapped file object. For windows there is no PROT_NONE
// so we assume no execution and only read access
// ...........................................................................
if (fileHandle == NULL) {
fileHandle = INVALID_HANDLE_VALUE; // lives in virtual memory rather than a real file
}
if ((flags & PROT_READ) == PROT_READ) {
if ((flags & PROT_EXEC) == PROT_EXEC) {
if ((flags & PROT_WRITE) == PROT_WRITE) {
objectProtection = PAGE_EXECUTE_READWRITE;
viewProtection = FILE_MAP_ALL_ACCESS | FILE_MAP_EXECUTE;
}
else {
objectProtection = PAGE_EXECUTE_READ;
viewProtection = FILE_MAP_READ | FILE_MAP_EXECUTE;
}
}
else if ((flags & PROT_WRITE) == PROT_WRITE) {
objectProtection = PAGE_READWRITE;
viewProtection = FILE_MAP_ALL_ACCESS;
}
else {
objectProtection = PAGE_READONLY;
}
} // end of PROT_READ
else if ((flags & PROT_EXEC) == PROT_EXEC) {
if ((flags & PROT_WRITE) == PROT_WRITE) {
objectProtection = PAGE_EXECUTE_READWRITE;
viewProtection = FILE_MAP_ALL_ACCESS | FILE_MAP_EXECUTE;
}
else {
objectProtection = PAGE_EXECUTE_READ;
viewProtection = FILE_MAP_READ | FILE_MAP_EXECUTE;
}
} // end of PROT_EXEC
else if ((flags & PROT_WRITE) == PROT_WRITE) {
objectProtection = PAGE_READWRITE;
viewProtection = FILE_MAP_ALL_ACCESS;
}
*mmHandle = CreateFileMapping(fileHandle, NULL, objectProtection, mmLength.HighPart, mmLength.LowPart, NULL);
if (*mmHandle == NULL) {
// we have failure for some reason
// TODO: map the error codes of windows to the TRI_ERROR (see function DWORD WINAPI GetLastError(void) );
return TRI_ERROR_SYS_ERROR;
}
// ........................................................................
// We have a valid handle, now map the view. We let the OS handle where the
// view is placed in memory.
// ........................................................................
*result = MapViewOfFile(*mmHandle, viewProtection, 0, 0, 0);
if (*result == NULL) {
CloseHandle(*mmHandle);
// we have failure for some reason
// TODO: map the error codes of windows to the TRI_ERROR (see function DWORD WINAPI GetLastError(void) );
return TRI_ERROR_SYS_ERROR;
}
return TRI_ERROR_NO_ERROR;
}
int TRI_UNMMFile(void* memoryAddress, size_t numOfBytesToUnMap, void* fileHandle, void** mmHandle) {
bool ok = UnmapViewOfFile(memoryAddress);
ok = (CloseHandle(*mmHandle) && ok);
if (!ok) {
return TRI_ERROR_SYS_ERROR;
}
return TRI_ERROR_NO_ERROR;
}
int TRI_ProtectMMFile(void* memoryAddress, size_t numOfBytesToProtect, int flags, void* fileHandle, void** mmHandle) {
DWORD objectProtection = PAGE_READONLY;
DWORD viewProtection = FILE_MAP_READ;
LARGE_INTEGER mmLength;
// ...........................................................................
// TODO:
// ...........................................................................
if ((flags & PROT_READ) == PROT_READ) {
if ((flags & PROT_EXEC) == PROT_EXEC) {
if ((flags & PROT_WRITE) == PROT_WRITE) {
objectProtection = PAGE_EXECUTE_READWRITE;
viewProtection = FILE_MAP_ALL_ACCESS | FILE_MAP_EXECUTE;
}
else {
objectProtection = PAGE_EXECUTE_READ;
viewProtection = FILE_MAP_READ | FILE_MAP_EXECUTE;
}
}
else if ((flags & PROT_WRITE) == PROT_WRITE) {
objectProtection = PAGE_READWRITE;
viewProtection = FILE_MAP_ALL_ACCESS;
}
else {
objectProtection = PAGE_READONLY;
}
} // end of PROT_READ
else if ((flags & PROT_EXEC) == PROT_EXEC) {
if ((flags & PROT_WRITE) == PROT_WRITE) {
objectProtection = PAGE_EXECUTE_READWRITE;
viewProtection = FILE_MAP_ALL_ACCESS | FILE_MAP_EXECUTE;
}
else {
objectProtection = PAGE_EXECUTE_READ;
viewProtection = FILE_MAP_READ | FILE_MAP_EXECUTE;
}
} // end of PROT_EXEC
else if ((flags & PROT_WRITE) == PROT_WRITE) {
objectProtection = PAGE_READWRITE;
viewProtection = FILE_MAP_ALL_ACCESS;
}
return TRI_ERROR_NO_ERROR;
}
////////////////////////////////////////////////////////////////////////////////
/// @}
////////////////////////////////////////////////////////////////////////////////
#endif
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