内存乒乓缓存机制和消息分发机制的C代码实现
用C代码实现乒乓内存缓冲机制,具体实用价值,帮助您提高内存响应速度与及时数据的处理。unsigned long writeunsigned long greadunsigned long overflowST TWTMSG QUEUE:/ Helper macros for accessing Msg queues. *#define tWt QUEUE EMPty(a)(((g->write==(q)->gread)? 1: 0)#define twt_ QUeUe full(a)(((((q)->qwrite +1% TIMEWEIGHT TASKQUEUE SIZED)==(q)->gread)?1: 0)米 generate a Msg entity*正常返回消息体的指针,异常返回NULLT TWTMSG* generateMsg(tT-TWTMSG* pmSg=nULL,if(NULL =-(ptMsg malloc(sizeof(T TWTMSG)))return NULL;memset(ptMsg, 0, sizeof(T TWTMSG)return pmSg;destroy a Msgvoid destroy Msg(t TWTMSG ptMsgif(NULL ptMsg->pfDestroyMsg)pt Msg->pfDestroy Msg(ptMsg->pvMsg)if (NULL != pt Msg)free(pmSgfree a Msg Queuevoid freeTWTMsg Que(T TWTMSG QUEUE* ptMsgQif(NULL =ptMsg Afree(ptMsg Q);Init a Msg QT TWTMSG QUEUE* initTWTMsg QueoT TWTMSG QUEUE pmSg Q= NULlif (NULL ==(ptMsgQ malloc(sizeof(T_ TWTMSG QUeue)goto ErrRetmemset(ptMsgQ, 0, sizeof(T TWTMSG QUEUE))return pmSg Q;Errretprintf( initTWTMsg Que Fail! ")freeTWTMsgQue(ptMsg Q)return nullPop a pvMsg packet from a msg packet queues param g is the packet queue from which to pop the pbuf@return pointer to pvMsg packet if available, NULl otherwiseT TWTMSG* TWTMsg Get(T_ TWTMSG QUEUE aT TWTMSG*//*加锁if(TWT_ QUEUE_ EMPTY(a))iReturn a NUll pointer if the queue is emptypmSg=NULL;else is The queue is not empty so return the next frame from itand adjust the read pointer accordinglypmSg=g->pvMsglq >greadg->gread =((q->gread +1)% TIMEWEIGHT_TASKQUEUE_ SIZE)/*解锁return(pmSg);Push a pmSg packet onto a pvMsg packet queue@param p is the pmsg to push onto the packet queue@param g is the packet queue.W @return 0 if successful, -1 if q is fullnt TWTMsg Send(T tWTMSg*p, T TWTMSG QUEUE *qint ret/if(!TWT_ QUEUE FULL(al)iThe queue isn t full so we add the new frame at the currentw write position and move the write pointer.g->pvMsgla->write]=pg- >write =((q->qwrite+1)% TIMEWEIGHT TASKQUEUE SIZE;ret =oThe stack is full so we are throwing away this value. Keep trackof the number of times this happensg->overflow++ret =-1://*解锁return(ret)**米**米来米***来米*半米*米*半米*米求***半*米米求半**米求半**半求半和*米*//消息分发机制//*算法是//*正常返回0,出错返回-1水米米******水*米*水**米*半*水米米冰半**水水*水米米半米冰水*米水水*水*米水水extern int RecToFile MsgProc(T_ MSG_ REC2 FILE* ptMsg);int DispatchMsg(T TWTMSG *ptMsgitif(NULl = ptMsg goto ErrRet/*dispatch msg*/switch(ptMsg->en Msg Type)case TWT PINgPoNgBuff recRecTo File Msg Procl(TMSG_REC2FE) (pmSg->pMsg);/*处理消息*/destroy Msg( pmSg;/*消毁消息breakdefault.printf("Dispatch Msg Msgtype Error! n")break.return 0ErrRetprintf("Dispatch Msg Fail! ";return-1./*buff size*/#defineP| NGPONG_ BUFF BSIZE0X20000//10*1024*1024/*10M*/*ping pong buff*///chargacPINGBUFF[PINGPONG BUFF BSIZE]; /* Ping Buff*///chargacPONGBUFF[PINGPONG_ BUFF BSIZE] *Pong Buff*/水米米*********米*水**米*半*水米米水**冰水*水米米半半水半米冰水*米水水*水*米米//*释放 ping pong buff/必然成功//*无返回木***木*水****本**水*水水*水****本水**水水****水水***本***米*水void Destroy Ping Pong Butt(T PINGPONGBUFF USE DES ptPing Pong Butt)nLoopif (NULL = pt Ping pong buffreturnfor (nLoop=0; nLooptIng BuffUse[nLoop]. pcHeadAddr)free(ptPing Pong ->t Ping BuffUse[nLoop]. pcHeadAddr)free(pt Ping pong Buff)/初始化 ping pong buff返回 pign pong buff的描述指针//*正常返回0,出错返回-1水水水水水水水水水木水木水水水水水木水木水水水水水水水水本水水水水水水水水水本水水水水水水水水水水水水水T PINGPONGBUFF USE DES InitPing Pong Buff(unsigned int n BuffSizeT PINGPONGBUFF USE DES* ptBuffDes=NULLintnLoop/*获取buf描述*if NULL==(ptBuffDes=malloc(sizeof(T PINGPONGBUFF USE DES))))goto ErrRetmemset(pt BuffDes, 0, sizeof(T_PINGPONGBUFF USE_ DES));/*分别初始化ping和pong*/for(nLoop=0; nLooptIng BuffUsenLoop pcHeadAddr =malloc n BuffSize))goto Err Ret;ptBuffDes->tIng BuffUselnLoop] nBuffSize nBuffsizeptBuffDes->tPing BuffUse[nLoop]. oFfsetptBuffDes->tPing BuffUsenLoop) eUseStatus-=BUFF WRITEABLE;pt BuffDes->eCurUseIDBUFF PINGreturn pt BuffDesErrretprintf("lnitPing Pong Buff Fail!");DestroyIng Pong Buff(pt BuffDes)turn null平**米**米*米***来米米*米*米*半米*米米米来*半米平**米米求*来*半求半来*米求*和*米*/*Reset ping pong buff//*正常返回0,出错返回-1米米米米水冰米*米米水**米米冰*米水米米米米水米水*水米米来米米x米来米米水冰来来宋来水米来米来冰#define ResetBuffUse(ptBuffuse)pt BuffUse->oFfset0pt BuffUse->eUseStatus BUFF WRITEABLEgenerate a file rec msg*正常返回消息体的指针,异常返回NULLT_MSG_REC2lGK SenFRMSB(T_BUFF_USE_DES *ptBuffUse, REC_FILE_DESLIST *ptFileListRT MSG REC2FILE KE* ptRFMsg= NULL;if(NULL ==(ptRFMsg malloc(sizeof(T_ MSG REC2 FILE)return nUllptRFMsg- >pt BuffUse pt BuffUseptRFMsg->pt Filelist ptFilelist;return ptRFMsg
- 2020-12-03下载
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数学建模大全
充分了解数学建模的相关知识,其中包括各种算法以及MATLAB在数学建模中的具体应用以及相关的程序代码,综合各方面的知识,方便我们了解例如线性规划maxx s.t. Ax>b的Maab标准型为min -cx s.Axcx∑anx,=bi=12,…,mst≥可行解满足约束条件(4)的解x=(x1,x2,…,xn),称为线性规划问题的可行解,而使目标函数(3)达到最大值的可行解叫最优解可行域所有可行解构成的集合称为问题的可行域,记为R14线性规划的图解法101+x2=106z=12图1线性规划的图解示意图图解法简单直观,有助」了解线性规划问题求解的基木原坦。我们先应用图解法来求解例1。对于每一固定的值z,使目标函数值等于z的点构成的直线称为目标函数等位线,当z变动时,我们得到一族平行直线。对于例1,显然等位线截趋于右上方,其上的点具有越大的目标函数值。不难看出,本例的最优解为x*=(2,6),最优目标值26从上面的图解过程可以看出并不难证明以下断言:(1)可行域R可能会出现多种情况。R可能是空集也可能是非空集合,当R非空时,它必定是若干个半平面的交集(除非遇到空间维数的退化)。R既可能是有界区域,也可能是无界区域(2)在R非空,线性规划既可以存在有限最优解,也可以不存在有限最优解(其目标函数值无界)。(3)若线性规划存在有限最优解,则必可找到具有最优目标函数值的可行域R的“顶点”。上述论断可以推广到一般的线性规划问题,区别只在」空问的维数。在一般的n维空间中,满足一线性等式∑a1x=b的点集被称为一个超平面,而满足一线性不等式氵=1∑ax≤b(或∑a1x,≥b)的点集被称为一个半空间(其中(a1…,an)为一n维行向量,b为一实数)。若千个半空间的交集被称为多胞形,有界的多胞形又被称为多面体。易见,线性规划的可行域必为多胞形(为统一起见,空集Φ也被λ为多胞形)。在一般n维空问中,要直接得出多胞形“顶点”概念还有一些困难。二维空间中的顶点可以看成为边界直线的交点,但这一几何概念的推广在一般n维空间中的几何意义并不十分直观。为此,我们将采用另一途径来定义它。定义1称n维空间中的区域R为一凸集,若Vx,x2∈R及元∈(01),有x+(1-4)x2∈R定义2设R为n维空间中的一个凸集,R中的点x被称为R的一个极点,若不存在x、x2∈R及∈(0,1),使得x=4x+(1-4)x2。定义1说明凸集中任意两点的连线必在此凸集中;而定义2说明,若x是凸集R的个极点,则x不能位于R中任意两点的连线上。不难证明,多胞形必为凸集。同样也不难证明,维空间中可行域R的顶点均为R的极点(R也没有其它的极点)1.5求解线性规划的 Matlab解法单纯形法是求解线性规划问题的最常用、最有效的算法之一。这里我们就不介绍单纯形法,有兴趣的读者可以参看其它线性规划书籍。下面我们介绍线性规划的 Matlab解法Matlab中线性规划的标准型为min c rAx shs t.Aeq. x=beb
- 2020-12-01下载
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