yssegment.h

电力故障信息采集,主要是针对南自的保护装置,这个程序用在Linux操作系统下

#ifndef YSSEGMENT_H
#define YSSEGMENT_H
#include "ysheader.h"
#include "YsString.h"
#include "yspubfunction.h"
//*********************共享内存类的定义*****************//
class CSegment
{
    public:
    CSegment()
    {
	return;
    }
    ~CSegment()
    {
	return;
    }
    public:
    int m_SegmentQid;						//共享内存的qid
    public:
    int Open_Segment(key_t keyval,int iSize,bool bExcl=false)	//创建一个共享内存
    {
	int shmid=0;
	if(!bExcl)
	{
	    if((shmid=shmget(keyval,iSize,IPC_CREAT|0660))==-1)
		return -1;
	}
	else
	{
	    if((shmid=shmget(keyval,iSize,IPC_CREAT|IPC_EXCL))==-1)
		return -1;
	}
	return shmid;
    }
    
    void *Attach_Segment(int shmid)				//返回内存段连接的地址
    {
	return ((void*)shmat(shmid,0,0));
    }
    
    int  DisAttach_Segment(void* segptr)
    {
	return shmdt((char*)segptr);
    }
    
    void Write_Segment(void *segptr,void *pSrc,int iSize)		//写内存
    {
	memcpy(segptr,pSrc,iSize);
    }
    
    void Read_Segment(void *segptr,void *pDes,int iSize)		//读内存
    {
	memcpy(pDes,segptr,iSize);
    }
    
    void Remove_Segment(int shmid)				//删除内存
    {
	shmctl(shmid,IPC_RMID,0);
    }
    
    void Change_SegmentMode(int shmid,char *mode)		//改变内存模式
    {
	struct shmid_ds myshmds;
	shmctl(shmid,IPC_STAT,&myshmds);
	sscanf(mode,"%ho",&myshmds.shm_perm.mode);
	shmctl(shmid,IPC_SET,&myshmds);
    }
    
    int  WriteSegment(void *pSrc,int iSize,bool bExcl=true)
    {
	int count=0;int shmid=-1;
	if(!pSrc||iSize<=0) return -1;
	while(shmid==-1&&count<10)
	{
	    key_t keyval=_getKeyId();shmid=Open_Segment(keyval,iSize,bExcl);count++;
	}
	if(shmid<0) return -1;
	void* segptr=Attach_Segment(shmid);
	if(!segptr) 
	{
	    Remove_Segment(shmid);return -1;
	}
	Write_Segment(segptr,pSrc,iSize);DisAttach_Segment(segptr);
	return shmid;
    }
    
    void ReadSegment(int shmid,void *pDes,int iSize,bool bDelete=true)
    {
	if(shmid<=0) return;
	void* segptr=Attach_Segment(shmid);
	if(segptr==NULL) return;
	if(pDes==NULL) 
	{
	    Remove_Segment(shmid);DisAttach_Segment(segptr);return;
	}
	Read_Segment(segptr,pDes,iSize);
	if(bDelete)
	    Remove_Segment(shmid);
	DisAttach_Segment(segptr);
    }
};
#endif