管理人の独り言（プログラミング関連）

1631： ◆adhRKFl5jU：2009/03/12(木) 16:55:55: #ifndef SHAREDMEMORYMANAGER_HPP
#define SHAREDMEMORYMANAGER_HPP

#include <windows.h>
#include <cstring>
#include <string>

#include <stdexcept>

class SharedMemoryManager{
private:
HANDLE m_hMutexRW, m_hMap;
volatile void *m_p;

public:
SharedMemoryManager(std::size_t size, const char *_id){
std::string id(_id);
if(id.length() > MAX_PATH - 5){
throw std::logic_error("_id is too long");
}

m_hMutexRW = CreateMutexA(NULL, FALSE, ("SMMR:" + id).c_str());
if(m_hMutexRW == NULL){
throw std::logic_error("CreateMutexA Error");
}
HANDLE hMutexC = CreateMutexA(NULL, FALSE, ("SMMC:" + id).c_str());
if(hMutexC == NULL){
CloseHandle(m_hMutexRW);
throw std::logic_error("CreateMutexA Error");
}

WaitForSingleObject(hMutexC, INFINITE);

m_hMap = CreateFileMappingA(INVALID_HANDLE_VALUE, NULL, PAGE_READWRITE | SEC_COMMIT, 0, size, ("SMMF" + id).c_str());
if(m_hMap == NULL){
ReleaseMutex(hMutexC);
CloseHandle(hMutexC);
CloseHandle(m_hMutexRW);
throw std::logic_error("CreateFileMappingA Error");
}
bool exist = (GetLastError() == ERROR_ALREADY_EXISTS);

m_p = MapViewOfFile(m_hMap, FILE_MAP_ALL_ACCESS, 0, 0, 0);
if(m_p == NULL){
CloseHandle(m_hMap);
ReleaseMutex(hMutexC);
CloseHandle(hMutexC);
CloseHandle(m_hMutexRW);
throw std::logic_error("MapViewOfFile Error");
}

if(exist == false){
ZeroMemory((void*)m_p, size);
}

ReleaseMutex(hMutexC);
CloseHandle(hMutexC);
}

~SharedMemoryManager(){
UnmapViewOfFile((void*)m_p);
CloseHandle(m_hMap);
CloseHandle(m_hMutexRW);
}

bool ReaderEnter(DWORD timeout = INFINITE){
return WaitForSingleObject(m_hMutexRW, timeout) == WAIT_OBJECT_0;
}
void ReaderLeave(){
ReleaseMutex(m_hMutexRW);
}
bool WriterEnter(DWORD timeout = INFINITE){
return WaitForSingleObject(m_hMutexRW, timeout) == WAIT_OBJECT_0;
}
void WriterLeave(){
ReleaseMutex(m_hMutexRW);
}

volatile void *GetPointer(){
return m_p;
}
operator volatile void *(){
return GetPointer();
}
};

#endif

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