代码:
#include <stdio.h> #include <pthread.h> #include <stdlib.h> #include <semaphore.h> #define NUM 5 int queue[NUM]; sem_t blank_number, product_number; void *producer ( void * arg ) { static int p = 0; for ( ;; ) { sem_wait( &blank_number ); queue[p] = rand() % 1000; printf("Product %d \n", queue[p]); p = (p+1) % NUM; sleep ( rand() % 5); sem_post( &product_number ); } } void *consumer ( void * arg ) { static int c = 0; for( ;; ) { sem_wait( &product_number ); printf("Consume %d\n", queue[c]); c = (c+1) % NUM; sleep( rand() % 5 ); sem_post( &blank_number ); } } int main(int argc, char *argv[] ) { pthread_t pid, cid; sem_init( &blank_number, 0, NUM ); sem_init( &product_number, 0, 0); pthread_create( &pid, NULL, producer, NULL); pthread_create( &cid, NULL, consumer, NULL); pthread_join( pid, NULL ); pthread_join( cid, NULL ); sem_destroy( &blank_number ); sem_destroy( &product_number ); return 0; }
运行截图:
代码功能:生产者与消费者资源提供和消耗。
修改后代码:
#include <stdio.h> #include <pthread.h> #include <stdlib.h> #include <semaphore.h> #include <unistd.h> #define NUM 3 int queue[NUM]; sem_t blank_number, product_number,mutex; void *producer ( void * arg ) { static int p = 0; for ( ;; ) { sem_wait( &blank_number ); sem_wait( &mutex); queue[p] = rand() % 1000; printf("Product %d \n", queue[p]); p = (p+1) % NUM; sleep ( rand() % 5); sem_post(&mutex); sem_post( &product_number ); } } void *consumer ( void * arg ) { static int c = 0; for( ;; ) { sem_wait( &product_number ); sem_wait(&mutex); printf("Consume %d\n", queue[c]); c = (c+1) % NUM; sleep( rand() % 5); sem_post(&mutex); sem_post( &blank_number ); } } int main(int argc, char *argv[] ) { pthread_t pid, cid1,cid2,cid3,cid4,cid5; sem_init( &blank_number, 0, NUM ); sem_init( &product_number, 0, 0); sem_init( &mutex, 1, 1); pthread_create( &pid, NULL, producer, NULL); pthread_create( &cid1, NULL, consumer, NULL); pthread_create( &cid2, NULL, consumer, NULL); pthread_create( &cid3, NULL, consumer, NULL); pthread_create( &cid4, NULL, consumer, NULL); pthread_create( &cid5, NULL, consumer, NULL); pthread_join( pid, NULL ); pthread_join( cid1, NULL ); pthread_join( cid2, NULL ); pthread_join( cid3, NULL ); pthread_join( cid4, NULL ); pthread_join( cid5, NULL ); sem_destroy( &blank_number ); sem_destroy( &product_number ); return 0; }
修改代码后运行截图:
标签:同步,thread,int,number,NUM,测试,pthread,sem,NULL From: https://www.cnblogs.com/MRC-/p/16887135.html