LinuxC语言实现生产者和消费者模型

#include <shm.h> int main(int argc,char **argv) { int num; int shmid_goods,shmid_index,semid; char* shmaddr=NULL; int* indexaddr=NULL; int is_noexist=0; num=10; //create a shared memory as goods buffer if((shmid_goods=createshm(".",'s',num))==-1) { if(errno==EEXIST) { if((shmid_goods=openshm(".",'s'))==-1) { exit(1); } } else { perror("create shared memory failed\n"); exit(1); } } //attach the shared memory to the current process if((shmaddr=shmat(shmid_goods,(char*)0,0))==(char*)-1) { perror("attach shared memory error\n"); exit(1); } //create a shared memory as index if((shmid_index=createshm(".",'z',2))==-1) { if(errno==EEXIST) { if((shmid_index=openshm(".",'z'))==-1) { exit(1); } } else { perror("create shared memory failed\n"); exit(1); } } else { is_noexist=1; } //attach the shared memory to the current process if((indexaddr=shmat(shmid_index,(int*)0,0))==(int*)-1) { perror("attach shared memory error\n"); exit(1); } if(is_noexist) { indexaddr[0]=0; indexaddr[1]=0; } //create a semaphore set including 3 semaphores if((semid=createsem(".",'t',3,0))==-1) { if(errno==EEXIST) { if((semid=opensem(".",'t'))==-1) { exit(1); } } else { perror("semget error:"); exit(1); } } else { union semun arg; //seting value for mutex semaphore arg.val=1; if(semctl(semid,0,SETVAL,arg)==-1) { perror("setting semaphore value failed\n"); return -1; } //set value for synchronous semaphore arg.val=num; //the num means that the producer can continue to produce num products if(semctl(semid,1,SETVAL,arg)==-1) { perror("setting semaphore value failed\n"); return -1; } //the last semaphore's value is default //the default value '0' means that the consumer is not use any product now } int goods=0; while(1) { p(semid,2); sleep(1); p(semid,0); //consumer is consuming a product goods=shmaddr[indexaddr[1]]; printf("consumer:%d consumes a product[%d]:%d\n",getpid(),indexaddr[1],goods); indexaddr[1]=(indexaddr[1]+1)%num; v(semid,0); sleep(1); v(semid,1); } }