C++进程间通信之共享内存

// ServerCom.cpp : Defines the entry point for the console application.
//

#include "stdafx.h"

#include <stdio.h>
#include <windows.h>
#pragma endregion
#define MAP_PREFIX          L"Local\\"
#define MAP_NAME            L"SampleMap"
#define FULL_MAP_NAME       MAP_PREFIX MAP_NAME

// Max size of the file mapping object.
#define MAP_SIZE            65536

// File offset where the view is to begin.
#define VIEW_OFFSET         0

// The number of bytes of a file mapping to map to the view. All bytes of the
// view must be within the maximum size of the file mapping object (MAP_SIZE).
// If VIEW_SIZE is 0, the mapping extends from the offset (VIEW_OFFSET) to
// the end of the file mapping.
#define VIEW_SIZE           1024

// Unicode string message to be written to the mapped view. Its size in byte
// must be less than the view size (VIEW_SIZE).
#define MESSAGE             L"Message from the first process."

int _tmain(int argc, _TCHAR* argv[])
{
HANDLE hMapFile = NULL;
PVOID pView = NULL;

// Create the file mapping object.
hMapFile = CreateFileMapping(
INVALID_HANDLE_VALUE,   // Use paging file - shared memory
NULL,                   // Default security attributes
PAGE_READWRITE,         // Allow read and write access
0,                      // High-order DWORD of file mapping max size
MAP_SIZE,               // Low-order DWORD of file mapping max size
FULL_MAP_NAME           // Name of the file mapping object
);
if (hMapFile == NULL)
{
wprintf(L"CreateFileMapping failed w/err 0x%08lx\n", GetLastError());
goto Cleanup;
}
wprintf(L"The file mapping (%s) is created\n", FULL_MAP_NAME);

// Map a view of the file mapping into the address space of the current
// process.
pView = MapViewOfFile(
hMapFile,               // Handle of the map object
FILE_MAP_ALL_ACCESS,    // Read and write access
0,                      // High-order DWORD of the file offset
VIEW_OFFSET,            // Low-order DWORD of the file offset
VIEW_SIZE               // The number of bytes to map to view
);
if (pView == NULL)
{
wprintf(L"MapViewOfFile failed w/err 0x%08lx\n", GetLastError());
goto Cleanup;
}
wprintf(L"The file view is mapped\n");

// Prepare a message to be written to the view.
PWSTR pszMessage = MESSAGE;
DWORD cbMessage = (wcslen(pszMessage) + 1) * sizeof(*pszMessage);

// Write the message to the view.
memcpy_s(pView, VIEW_SIZE, pszMessage, cbMessage);

wprintf(L"This message is written to the view:\n\"%s\"\n",
pszMessage);

// Wait to clean up resources and stop the process.
wprintf(L"Press ENTER to clean up resources and quit");
getchar();

Cleanup:

if (hMapFile)
{
if (pView)
{
// Unmap the file view.
UnmapViewOfFile(pView);
pView = NULL;
}
// Close the file mapping object.
CloseHandle(hMapFile);
hMapFile = NULL;
}

return 0;
}

// ClientCom.cpp : Defines the entry point for the console application.
//

#include "stdafx.h"
#include <stdio.h>
#include <windows.h>
#pragma endregion
#define MAP_PREFIX          L"Local\\"
#define MAP_NAME            L"SampleMap"
#define FULL_MAP_NAME       MAP_PREFIX MAP_NAME

// File offset where the view is to begin.
#define VIEW_OFFSET         0

// The number of bytes of a file mapping to map to the view. All bytes of the
// view must be within the maximum size of the file mapping object. If
// VIEW_SIZE is 0, the mapping extends from the offset (VIEW_OFFSET) to the
// end of the file mapping.
#define VIEW_SIZE           1024

int _tmain(int argc, _TCHAR* argv[])
{
HANDLE hMapFile = NULL;
PVOID pView = NULL;

// Try to open the named file mapping identified by the map name.
hMapFile = OpenFileMapping(
FILE_MAP_READ,          // Read access
FALSE,                  // Do not inherit the name
FULL_MAP_NAME           // File mapping name
);
if (hMapFile == NULL)
{
wprintf(L"OpenFileMapping failed w/err 0x%08lx\n", GetLastError());
goto Cleanup;
}
wprintf(L"The file mapping (%s) is opened\n", FULL_MAP_NAME);

// Map a view of the file mapping into the address space of the current
// process.
pView = MapViewOfFile(
hMapFile,               // Handle of the map object
FILE_MAP_READ,          // Read access
0,                      // High-order DWORD of the file offset
VIEW_OFFSET,            // Low-order DWORD of the file offset
VIEW_SIZE               // The number of bytes to map to view
);
if (pView == NULL)
{
wprintf(L"MapViewOfFile failed w/err 0x%08lx\n", GetLastError());
goto Cleanup;
}
wprintf(L"The file view is mapped\n");

// Read and display the content in view.
wprintf(L"Read from the file mapping:\n\"%s\"\n", (PWSTR)pView);

// Wait to clean up resources and stop the process.
wprintf(L"Press ENTER to clean up resources and quit");
getchar();

Cleanup:

if (hMapFile)
{
if (pView)
{
// Unmap the file view.
UnmapViewOfFile(pView);
pView = NULL;
}
// Close the file mapping object.
CloseHandle(hMapFile);
hMapFile = NULL;
}

return 0;
}