win32/unix : IPC + inter-process synchronization

IPC(进程间通信)包括以下一种方法：

• 管道 ： pipe(只能有亲缘关系的进程之间)， FIFO命名管道

windows:http://bbs.pediy.com/showthread.php?threadid=26252

 

 

• 油槽
• socket

• 共享内存: 以下代码是unix/win32的代码。包含进程互斥

OPPOS.h

/** OPPOS* 定义运维平台的系统*///平台定义//#define OPP_WIN32#define OPP_LINUX//#define OPP_UNIX//编译器定义//#define CC_VC#define CC_GCC

 

 

CShareMemory.h

#ifndef _CSHAREMEMORY_H_#define _CSHAREMEMORY_H_/************************************************************************//* //共享内存操作类//析构函数里的内存回收问题如何使用：//linux下string类型不允许typedef struct _Shared{int index;char msg[4096];}ShareMemoryTest;windows:CShareMemory<ShareMemoryTest> g_smdt("test");g_smdt->index = num;g_smdt->msg = strMsg;unix: 用posix共享内存方式CShareMemory<ShareMemoryTest> g_smdt("myshm2");手动删除 /dev/shm下的共享内存的命令：取得ipc信息：ipcs [-m|-q|-s]-m 输出有关共享内存(shared memory)的信息-q 输出有关信息队列(message queue)的信息-s 输出有关“遮断器”(semaphore)的信息%ipcs -m删除ipcipcrm -m|-q|-s shm_id*//************************************************************************/#include "OPPOS.h"#ifndef OPP_WIN32#include <stdio.h>#include <unistd.h>#include <sys/types.h>#include <sys/mman.h>#include <fcntl.h> /* for O_* constants */#include <string.h>using namespace std;#else#include <Windows.h>#endif//共享内存操作类template<class ShareMemoryDataType>class CShareMemory{public:CShareMemory();CShareMemory(char* name);~CShareMemory();bool createShareMemory(char* name);//用的时候需要加锁ShareMemoryDataType *operator->();//用的时候需要加锁ShareMemoryDataType* getData();private:charm_strSharedName[260];//共享内存标识名unsigned longm_dwMaxDataSize;//共享内存的最大值ShareMemoryDataType*m_pData;//共享内存中存放的数据boolm_bCreated;//共享内存是否已经被打开#ifdef OPP_WIN32HANDLEm_hFileMapping;//共享内存文件的句柄#endif};template<class ShareMemoryDataType>CShareMemory<ShareMemoryDataType>::CShareMemory(){m_pData = NULL;#ifdef OPP_WIN32m_hFileMapping = NULL;#endif}template<class ShareMemoryDataType>CShareMemory<ShareMemoryDataType>::CShareMemory(char* name){CShareMemory();createShareMemory(name);}template<class ShareMemoryDataType>CShareMemory<ShareMemoryDataType>::~CShareMemory(){#ifdef OPP_WIN32if(m_pData){//把映射对象从当前应用程序的地址空间unmapUnmapViewOfFile(m_pData);m_pData = NULL;}if(m_hFileMapping){CloseHandle(m_hFileMapping);}#elseif(m_pData != NULL){//释放映射对象munmap(m_pData, 128);}//删除共享内存shm_unlink(m_strSharedName);#endif}template<class ShareMemoryDataType>ShareMemoryDataType *CShareMemory<ShareMemoryDataType>::operator->(){return m_pData;}template<class ShareMemoryDataType>ShareMemoryDataType* CShareMemory<ShareMemoryDataType>::getData(){return m_pData;}template<class ShareMemoryDataType>bool CShareMemory<ShareMemoryDataType>::createShareMemory(char* name){m_dwMaxDataSize = sizeof(ShareMemoryDataType);strcpy(m_strSharedName, name);///////////////////////////////////////////////////////////////////////////#ifdef OPP_WIN32//创建文件映射内核对象m_hFileMapping = CreateFileMappingA(INVALID_HANDLE_VALUE,NULL,// 默认的安全属性PAGE_READWRITE,// 可读写文件的数据0,// size: high 32-bits；对于4GB以下的文件，该参数总是0sizeof(ShareMemoryDataType),// size: low 32-bits；映射文件的字节数name);// 命名该映射对象，用于和其他进程共享该对象if(m_hFileMapping == NULL){int err = GetLastError();return false;}//判断是否第一个访问共享内存的程序m_bCreated = (GetLastError() == ERROR_ALREADY_EXISTS); //// 设置共享内存的访问权限//SetNamedSecurityInfo(name,//SE_KERNEL_OBJECT,//DACL_SECURITY_INFORMATION,//// change only the object's DACL//0,// do not change owner or group//0,// do not change owner or group//(PACL)NULL,//no DACL specified - allows everyone access //NULL);// do not change SACL系统访问控制列表//将一个文件映射对象映射到当前应用程序的地址空间m_pData = (ShareMemoryDataType*)MapViewOfFile(m_hFileMapping,FILE_MAP_READ | FILE_MAP_WRITE,//可以读写文件0,// high offset: map from0,// low offset: beginning0); // default: map entire fileif(m_pData == NULL){CloseHandle(m_hFileMapping);return false;}//如果是第一个创建共享内存的程序，则初始化if (!m_bCreated) memset(m_pData, '/0', m_dwMaxDataSize); #else//在目录/dev/shm/下创建共享内存int fd = shm_open(name, O_CREAT | O_RDWR, 0777);if (fd == -1){perror("shm_open");return false;}const size_t regionSize = sysconf(_SC_PAGE_SIZE);//页得整数倍int dataSize = sizeof(ShareMemoryDataType);int num = dataSize / regionSize;num += 1;int memSize = num * regionSize;//共享内存大小int r = ftruncate(fd, memSize);//将文件映射进内存m_pData = (ShareMemoryDataType*)mmap(0,//映射区的开始位置memSize,//映射区的长度PROT_READ | PROT_WRITE,//期望的内存保护类型MAP_SHARED,//映射对象的类型fd,//文件描述符0);//被映射对象内容的起点#endifreturn true;}#endif

 

CMutex.h

#ifndef _CMUTEX_H_#define _CMUTEX_H_/************************************************************************//* //进程间的互斥类windows:CreateMutexunix: 信号量*//************************************************************************/#include "OPPOS.h"#ifndef OPP_WIN32#include <string.h>#include <stdio.h>#include <semaphore.h>#include <errno.h>#include <sys/types.h>#include <sys/stat.h>#include <fcntl.h>#else#include <Windows.h>#endif#define MUTEXNAMELENGTH 260//进程间的加锁类class CMutex{public:CMutex();CMutex(char* name);~CMutex();void createMyMutex(char* name);void lock();void unlock();private:#ifdef OPP_WIN32HANDLE m_mutex;#elsesem_t *m_sem;char m_semName[MUTEXNAMELENGTH];#endif};#endif

CMutex.cpp

#include "CMutex.h"CMutex::CMutex(){}CMutex::~CMutex(){#ifdef OPP_WIN32WaitForSingleObject(m_mutex, INFINITE);#elsesem_unlink(m_semName);#endif}CMutex::CMutex(char* name){CMutex();createMyMutex(name);}void CMutex::createMyMutex(char* name){#ifdef OPP_WIN32m_mutex = CreateMutexA(NULL, FALSE, name);if(m_mutex == NULL){//create error}#else//create semaphore, semaphore have a name then use in processesm_sem=sem_open(name,O_CREAT|O_RDWR,0777,1);if(m_sem == SEM_FAILED){printf("/nsem_open failed, (%s)/n", strerror(errno));}strcpy(m_semName, name);#endif}void CMutex::lock(){#ifdef OPP_WIN32WaitForSingleObject(m_mutex, INFINITE);#elsesem_wait(m_sem);#endif}void CMutex::unlock(){#ifdef OPP_WIN32ReleaseMutex(m_mutex);#elsesem_post(m_sem);#endif}

 

man.cpp

//#define OPP_LINUX//g++ main.cpp CMutex.cpp -lrt -lpthread -o main#include "CMutex.h"#include "CShareMemory.h"#include <iostream>#include <unistd.h>using namespace std;//linux下string类型不允许typedef struct _Shared{int index;char msg[4096];}ShareMemoryTest;int main(){char* name = "test1234";CMutex mutex(name);CShareMemory<ShareMemoryTest> g_smdt(name);char cString[260];int num;cout<<"start";mutex.lock();cout<<"read";cout<<g_smdt->index<<":::"<<g_smdt->msg;int ii;cin>>ii;cout<<"write";g_smdt->index = 1;for(int i=0; i<5;i++){g_smdt->msg[i] = 'b';}mutex.unlock();//while(1)//{//cout<<"1: set data /n 2: get data /n";//int iChoice=0;//cin>>iChoice;//if(iChoice == 1)//{//mutex.lock();//cout<<"/n input the int: /n";//cin>>num;//cout<<"/n input the string: /n";//cin>>cString;//g_smdt->index = num;//strcpy(g_smdt->msg, cString);//mutex.unlock();//}//else if(iChoice == 2)//{//mutex.lock();//cout<<g_smdt->index<<":::"<<g_smdt->msg<<"/n";//mutex.unlock();//}//else//break;//}system("pause");return 0;}