哲学家就餐问题代码.docVIP

#includestdio.h #includestdlib.h #includestring.h #includepthread.h #includesemaphore.h #includesys/types.h #includeerrno.h #includeunistd.h #includesignal.h #define NUM_THREADS_P 5 /*define the number of philosopher*/ #define CHAIR_NUM 4 #define CHOP_NUM 5 int chairflg[CHAIR_NUM][2],dining_num=0; sem_t chair,chopsticks[CHOP_NUM],mutex,mutex1,print_mutex;// 设定信号量 pthread_t threads_p[NUM_THREADS_P]; /*philosopher*/ void* philosopher_thread(int tid); int main(){ int i; sem_init(chair,0,CHAIR_NUM); /*set the value of semaphores*/ for(i=0;iCHOP_NUM;i++) { sem_init(chopsticks[i],0,1); } sem_init(mutex,0,1); sem_init(mutex1,0,1); sem_init(print_mutex,0,1); for(i=0;i4;i++)chairflg[i][0]=0; /*create the threads*/ for(i=0;iNUM_THREADS_P;i++) pthread_create(threads_p[i],NULL,(void*)philosopher_thread,(void*)(i)); /*wait the threads to exit*/ for(i=0;iNUM_THREADS_P;i++) pthread_join(threads_p[i],NULL); /*destroy the semaphores*/ sem_destroy(chair); sem_destroy(chopsticks[CHOP_NUM]); sem_destroy(mutex); sem_destroy(mutex1); sem_destroy(print_mutex); return 0; } void* philosopher_thread(int tid) { int i; i=tid; sem_wait(chair); sem_wait(mutex); for(i=0;iCHAIR_NUM;i++){ if(chairflg[i][0]==0){ /*the chair is empty*/ chairflg[i][0]=1; chairflg[i][1]=(int)i;/*philosopher(i) toke the chair*/ break; } } dining_num++; sem_post(mutex); sem_wait(chopsticks[i]); printf(philosopher %d get chopstics %d\n,i,i); sem_wait(chopsticks[(i+1)%CHOP_NUM]); printf(philosopher %d get chopstics %d\n,tid,(i+1)%CHOP_NUM); sleep(rand()%3); sem_wait(print_mutex); printf(philosopher %d is dining.when he is dining ,there are %d philosophers at table.\n,(int)i,dining_num); for(i=0;iCHAIR_NUM;i++){ if(chairflg[i][0]==1){ printf(poilosopher %d in chair %d. ,chairflg[i][1],i+1); } } printf(\n\n); sem_post(print_mutex); sleep(rand()%3); s