Мне нужно организовать что то вроде shared memory только под Виндовс для интер-процессинг.
После поисков в Гугле, использую File Mapping.
Но ничего не нашла о реализации синхронизации между врайтером и ридером...
Т.е. как ридер дожен узнать, что есть дата.. и т.д.
Вот тут код, как лучше довести его до ума...:
| Код |
#ifndef _SHARED_MEMORY_
#define _SHARED_MEMORY_
#include <windows.h>
#include <stdio.h>
#include <conio.h>
#include <string>
using std::string;
class CSharedMemoryArea
{
public:
CSharedMemoryArea(){}
HRESULT CreateSharedMemoryArea(LPCSTR FileName);
HRESULT OpenSharedMemory(LPCSTR FileName);
HRESULT DestroySharedMemoryArea ();
void WriteOnSharedMemory(int data, int position);
void ReadFromSharedMemory(int *data, int position);
private:
HANDLE m_hFile;
LPINT m_ipView,
m_ipAux;
};
#endif
|
| Код |
// ------------------------------------------------------
// Shared memory functions
// Sample file to create a Shared Memory area...
// ------------------------------------------------------
//#include <stdafx.h>
#include "SharedMemory.h"
//________________________________________________________________
//
HRESULT CSharedMemoryArea::CreateSharedMemoryArea(LPCSTR FileName)
{
m_hFile = CreateFileMapping(INVALID_HANDLE_VALUE,
NULL,
PAGE_READWRITE,
0,
1024 * 4,
FileName);
if (m_hFile == NULL)
{
printf("Unable to create a file. Error %d", GetLastError());
return 0; //@@
}
else
{
if (GetLastError() == ERROR_ALREADY_EXISTS)
{
printf("A file was already created.Error %d", GetLastError());
return 0;
}
}
m_ipView = (LPINT) MapViewOfFile(m_hFile,
FILE_MAP_ALL_ACCESS,
0,
0,
0);
if (m_ipView == NULL)
{
printf("Unable to create a VIEW.Error %d", GetLastError());
return 0;
}
printf("Shared memory has been successfully created....\n");
m_ipAux = m_ipView;
return 1;
}
//__________________________________________________________
//
HRESULT CSharedMemoryArea::OpenSharedMemory(LPCSTR FileName)
{
m_hFile = OpenFileMapping(FILE_MAP_ALL_ACCESS,
FALSE,
FileName);
if (m_hFile == NULL)
{
printf("Unable to open the shared area.\n");
return 0;
}
m_ipView = (LPINT) MapViewOfFile(m_hFile,
FILE_MAP_ALL_ACCESS, //FILE_MAP_WRITE | FILE_MAP_READ,
0,
0,
0);
if (m_ipView == NULL)
{
printf("Unable to create a VIEW. Error %d", GetLastError());
return 0;
}
printf("Shared memory has been successfully openned....\n");
m_ipAux = m_ipView;
return S_OK;
}
//___________________________________________________
//
HRESULT CSharedMemoryArea::DestroySharedMemoryArea ()
{
if (!UnmapViewOfFile(m_ipView))
{
printf("Could not unmap view of file. Error %d ", GetLastError());
}
CloseHandle(m_hFile);
printf("Shared memory has been successfully destroyed....\n");
return 1;
}
//_________________________________________________________________
//
void CSharedMemoryArea::WriteOnSharedMemory(int data, int position)
{
printf("Writing data on the shared area...\n");
m_ipAux[position] = data;
}
//___________________________________________________________________
//
void CSharedMemoryArea::ReadFromSharedMemory(int *data, int position)
{
printf("Reading data on the shared area...\n");
*data = m_ipAux[position];
}
|
Reader
| Код |
// ------------------------------------------------------------
// User.cpp
// This program uses a shared area
// It should run AFTER the other program.
// ------------------------------------------------------------
#include <stdio.h>
#include "SharedMemory.h"
void main(int argc, char* argv[])
{
int i, data;
CSharedMemoryArea cSM;
HRESULT hr;
hr = cSM.OpenSharedMemory("SharedFile");
printf("Reading data from the shared memory area...\n");
for (i=0; i< 100; i++) {
cSM.ReadFromSharedMemory(&data, i);
printf("Data[%d] = %3d\n", i, data);
}
printf("The reading is done.\n");
cSM.DestroySharedMemoryArea ();
printf("The End.");
}
|
Writer
| Код |
// ------------------------------------------------------------
// Creator.cpp
// This program creates a shared area.
// ------------------------------------------------------------
#include <stdio.h>
#include <conio.h>
#include "SharedMemory.h"
void main(int argc, char* argv[])
{
int i;
CSharedMemoryArea cSM;
HRESULT hr;
// creates the area to be shared
hr = cSM.CreateSharedMemoryArea("SharedFile");
printf("Writing data on the shared memory area...\n");
for (i=0; i< 100; i++)
cSM.WriteOnSharedMemory(i*2, i); // performs the writing
printf("The writing is done.\n");
printf("Now you can run the other program to read the shared area.\n");
printf("When you want to close the shared area and finish this program...\n");
printf("Just press a key.\n");
_getch();
cSM.DestroySharedMemoryArea ();
printf("The End.");
}
|
|
См. CreateSemaphore, OpenSemaphore