Go C + + code for interprocess communication using "Shared memory" in Windows environments---leveraging createfilemapping and mapviewoffile

http://blog.csdn.net/stpeace/article/details/39534361

There are many ways to communicate between processes, the last time we said the most stupid way to "share external memory/files". So, in this article, we're going to learn the "shared memory" way to communicate between processes, which is the fastest method of IPC. In some places, this "shared memory" approach is called a "memory-mapped file" approach.

Let's start by looking at process A's corresponding program:

#include <iostream> #include <windows.h>using namespace std; #define Buf_size 1025char szname[] = " Nameofmappingobject ";    Shared Memory name int main () {//create shared file handle    HANDLE Hmapfile = createfilemapping (        invalid_handle_value,    //physical file handle        NULL,                    //default security level        Page_readwrite,          //readable writable        0,//                       High file size        buf_size,                //status File size        SzName                   //Shared memory name);    Char *pbuf = (char *) mapviewoffile (hmapfile,            //handle to Shared memory        file_map_all_access,//read/write license        0,        0,        buf_size);    while (1)    {cout << "input ..." << Endl;        Char Szinfo[buf_size] = {0};        Gets (Szinfo); Actually gets is not safe        strncpy (PBuf, Szinfo, buf_size-1);p buf[buf_size-1] = '/';    } UnmapViewOfFile (PBUF);    CloseHandle (hmapfile); return 0;}

Then, let's take a look at the program that corresponds to process B:

#include <iostream> #include <windows.h>using namespace std; #define Buf_size 1025char szname[] = " Nameofmappingobject ";    Shared Memory name int main () {//create shared file handle    HANDLE Hmapfile = createfilemapping (        invalid_handle_value,    //physical file handle        NULL,                    //default security level        Page_readwrite,          //readable writable        0,//                       High file size        buf_size,                //status File size        SzName                   //Shared memory name);    Char *pbuf = (char *) mapviewoffile (hmapfile,            //handle to Shared memory        file_map_all_access,//read/write license        0,        0,        buf_size);    while (1)    {        cout << ' Press any button ' to receive data ... ' << Endl;        GetChar (); cout << pBuf << Endl;    } UnmapViewOfFile (PBUF);    CloseHandle (hmapfile); return 0;}

Successively run the above two programs, get the result for ( in the word that should be than, I wrote wrong ):

Go C + + code for interprocess communication using "Shared memory" in Windows environments---leveraging createfilemapping and mapviewoffile