利用Event和MapFile进程共享信息

工作过程:


进程一, 建立映射文件,填写数据,并发出Event的信号;


进程二,打开映射文件,收到Event的信号时读取数据.

#include <windows.h>
#include <string.h>
#include <iostream>
using namespace std;

#define FILE_SIZE 1024

static HANDLE hMapFile;
static LPVOID lpMapAddress;
static LPCTSTR g_szEventName="EventName";

void Write(char* data){
    if(lpMapAddress!=NULL){
        memset(lpMapAddress,0,FILE_SIZE);
        sprintf((char*)lpMapAddress,"%s",data);
    }
}

void Read(){
    if(lpMapAddress!=NULL){
        printf("%s\n",lpMapAddress);
    }
}


void Process1(){//写数据
hMapFile = CreateFileMapping(
    INVALID_HANDLE_VALUE,               // Current file handle. 
    NULL,                              // Default security. 
    PAGE_READWRITE,                    // Read/write permission. 
    0,                                 // Max. object size. 
    FILE_SIZE,                         // Size of hFile. 
    "MyFileMappingObject");            // Name of mapping object. 
 
if (hMapFile == NULL) 
{ 
    printf("Could not create file-mapping object."); 
    return ;
} 

//
lpMapAddress = MapViewOfFile(hMapFile, // Handle to mapping object. 
    FILE_MAP_ALL_ACCESS,               // Read/write permission 
    0,                                 // Max. object size. 
    0,                                 // Size of hFile. 
    FILE_SIZE);                                // Map entire file. 
 
if (lpMapAddress == NULL) 
{ 
    printf("Could not map view of file."); 
    return ;
} 
::Sleep(10000);
//Write data
HANDLE hEvent=::OpenEvent(
        EVENT_MODIFY_STATE,
        FALSE,
        g_szEventName);

while(hEvent!=NULL){
        scanf("%s",lpMapAddress);
        ::SetEvent(hEvent);
}
::CloseHandle(hEvent);
hEvent=INVALID_HANDLE_VALUE;

}

void Process2(){//读数据
hMapFile = OpenFileMapping(FILE_MAP_ALL_ACCESS, // Read/write permission. 
    FALSE,                             // Do not inherit the name
    "MyFileMappingObject");            // of the mapping object. 
 
if (hMapFile == NULL) 
{ 
    printf("Could not open file-mapping object.\n"); 
    return;
} 
 
lpMapAddress = MapViewOfFile(hMapFile, // Handle to mapping object. 
    FILE_MAP_ALL_ACCESS,               // Read/write permission. 
    0,                                 // Max. object size. 
    0,                                    // Size of hFile. 
    FILE_SIZE);                                // Map entire file. 
 
if (lpMapAddress == NULL) 
{ 
    printf("Could not map view of file.\n"); 
    return;
} 

//Wait for data
HANDLE hEvent=::CreateEvent(
        NULL,
        TRUE,
        FALSE,
        g_szEventName);

while(hEvent!=NULL){
        ::WaitForSingleObject(hEvent,INFINITE);
        ::ResetEvent(hEvent);
        ::Read();
    }
::CloseHandle(hEvent);
hEvent=INVALID_HANDLE_VALUE;
}

void main(){
    int flag;
    cin>>flag;
    if(flag==1){
        Process1();
    }
    else if(flag==2){
        Process2();
    }
}