linux c語言實現佇列及用於生產者消費者模型
阿新 • • 發佈：2019-01-29
c語言沒有佇列的資料結構，需要自己實現
多執行緒與cpu時間片
top中的idle是通過idle thread來計算了。簡單的說，當時鍾中斷到來時，kernel會判斷當前執行的是否是idle thread並維護一個統計值。在idle thread中的次數越多，說明系統越空閒，反之系統繁忙。
//myqueue.h #ifndef __MYQUEUE_H__ #define __MYQUEUE_H__ #include <stdio.h> #include <stdlib.h> #define TRUE 1 #define FALSE 0 #define DBG(...) printf("myqueue %s, %d: ",__FUNCTION__,__LINE__);printf(__VA_ARGS__) #define MAXCNTBUF 1024*12 typedef struct Point2D { int len; unsigned char buf[MAXCNTBUF ]; }ElemType; typedef struct { ElemType **rear; ElemType *front; int len; int size; pthread_mutex_t locker; pthread_cond_t notEmpty; pthread_cond_t notFull; }ArrQueue; ArrQueue *CreateQueue( int nLen) ; void DestroyQueue( ArrQueue *pQueue ); void ClearQueue( ArrQueue *pQueue ); int GetLength( ArrQueue *pQueue ); int GetSize( ArrQueue *pQueue ); int IsEmpty( ArrQueue *pQueue ); int GetHead( ArrQueue *pQueue, ElemType **pe ); int EnQueue( ArrQueue *pQueue, ElemType *pe ); int DeQueue( ArrQueue *pQueue, ElemType **pe ); void ForEachQueue( ArrQueue *pQueue, void (*func)(ElemType *pe) ); #endif
//muqueue.c #include "myqueue.h" ArrQueue *CreateQueue( int nLen ) { ArrQueue *pQueue = (ArrQueue *)malloc( sizeof(ArrQueue) ); pQueue->rear = (ElemType **)calloc( nLen, sizeof(ElemType **) ); pQueue->front = pQueue->rear[0]; pQueue->len = 0; pQueue->size = nLen; pthread_mutex_init(&pQueue->locker,NULL); pthread_cond_init(&pQueue->notEmpty,NULL); pthread_cond_init(&pQueue->notFull,NULL); return pQueue; } void DestroyQueue( ArrQueue *pQueue ) { free( pQueue->rear ); free( pQueue ); pthread_mutex_destroy(&pQueue->locker); pthread_cond_destroy(&pQueue->notEmpty); pthread_cond_destroy(&pQueue->notFull); pQueue = NULL; } void ClearQueue( ArrQueue *pQueue ) { pQueue->front = pQueue->rear[0]; pQueue->len = 0; } int GetLength( ArrQueue *pQueue ) { return pQueue->len; } int GetSize( ArrQueue *pQueue ) { return pQueue->size; } int IsEmpty( ArrQueue *pQueue ) { return pQueue->len == 0 ? TRUE : FALSE; } int IsFull( ArrQueue *pQueue ) { DBG("pQueue->len=%d,pQueue->size=%d\n",pQueue->len,pQueue->size); return pQueue->len == pQueue->size? TRUE : FALSE; } int GetHead( ArrQueue *pQueue, ElemType **pe ) { if( pQueue->len == 0 ) { *pe = NULL; return -1; } *pe = pQueue->rear[pQueue->len-1]; return pQueue->len-1; } int EnQueue( ArrQueue *pQueue, ElemType *pe ) { pthread_mutex_lock(&pQueue->locker); while (IsFull(pQueue)) { DBG("\n"); pthread_cond_wait(&pQueue->notFull, &pQueue->locker); } int i = 0; for( i = pQueue->len; i > 0; --i ) { pQueue->rear[i] = pQueue->rear[i-1]; } pQueue->rear[0] = pe; pQueue->front = pQueue->rear[pQueue->len]; ++pQueue->len; pthread_cond_signal(&pQueue->notEmpty); pthread_mutex_unlock(&pQueue->locker); } int DeQueue( ArrQueue *pQueue, ElemType **pe ) { pthread_mutex_lock(&pQueue->locker); while (IsEmpty(pQueue)) { pthread_cond_wait(&pQueue->notEmpty, &pQueue->locker); } if( pQueue->len == 0 ) { *pe = NULL; return -1; } *pe = pQueue->front; DBG("len= %d,%x \n",(*pe)->len,(*pe)->len); --pQueue->len; pQueue->front = pQueue->rear[pQueue->len-1]; pthread_cond_signal(&pQueue->notFull); pthread_mutex_unlock(&pQueue->locker); return pQueue->len; } void ForEachQueue( ArrQueue *pQueue, void (*func)(ElemType *pe) ) { int i = 0; for( i = 0; i < pQueue->len; ++i ) { func( pQueue->rear[i] ); } }
#include <stdio.h> #include <stdlib.h> #include <string.h> #include <unistd.h> #include <pthread.h> #include <signal.h> #include "myqueue.h" <span style="font-family: Consolas, 'Courier New', Courier, mono, serif; line-height: 18px; background-color: rgb(248, 248, 248);">ArrQueue m_pque;</span> void getqueue() { ElemType *elememt; while(1) { usleep(1000*20); DeQueue( m_pque, &elememt ); if(elememt==NULL) { printf("fdafsaf"); DBG("d ReadOneNaluFromQueue elememt==NULL \n"); } int jj=0; DBG("elememt.len=%d ,0x%x:",elememt->len,elememt->len); for(jj=0;jj<10;jj++) printf("%x ",elememt->buf[jj]); printf("\n"); free( elememt); } } void sendtoqueue() { HI_S32 i; int j=0; ElemType *elememt=NULL; static int ii=0; while(1) { system("free"); elememt=(ElemType *)malloc(sizeof(ElemType)); if(elememt==NULL) { printf("0 malloc(sizeof(ElemType))"); exit(0); } memset(elememt,0,sizeof(ElemType)); elememt->buf[0]=ii; elememt->len=ii++; int jj=0; DBG("elememt.len=%d ,0x%x:",elememt->len,elememt->len); for(jj=0;jj<10;jj++) printf("%x ",elememt->buf[jj]); printf("\n"); EnQueue( m_pque, elememt ); } } /****************************************************************************** * function : main() * Description : video venc sample ******************************************************************************/ int main(int argc, char *argv[]) { #if 0 m_pque = CreateQueue( 20 ); #if 1 pthread_t td; int ret =pthread_create(&td,NULL,getqueue,NULL); if(ret!=0){ printf("create thread err\n"); } pthread_t td2; ret =pthread_create(&td2,NULL,sendtoqueue,NULL); if(ret!=0){ printf("create thread err\n"); } #endif while(1) sleep(1);
多執行緒與cpu時間片
top中的idle是通過idle thread來計算了。簡單的說，當時鍾中斷到來時，kernel會判斷當前執行的是否是idle thread並維護一個統計值。在idle thread中的次數越多，說明系統越空閒，反之系統繁忙。