编程范式--并发编程相关代码
串行式销售模式
#include
void sell (int p, int num) {
while (num > 0) {
printf("售票点#%d售出1张票\n", p);
num--;
}
printf("售票点#%d售罄\n", p);
}
int main (int argc, char const **argv) {
int n = 3;
int x = 12;
for (int i=1; i<=n; i++) {
sell(i, x/n);
}
return 0;
} 并行式销售模式
#include
#include
#include
#include
#include
#include
typedef struct SellInfo {
int id;
int num;
}sellInfo;
void* sell (void* v) {
//申请p指针,指向v的内存
sellInfo* p = (struct SellInfo *) v;
while (p->num > 0) {
printf("售票点#%d售出1张票\n", p->id);
p->num--;
usleep(rand()%120);
}
printf("售票点#%d售罄\n", p->id);
free(p);
}
int main (int argc, char const **argv) {
int n = 3;
int x = 12;
srand(time(NULL));
pthread_t th[3] = {0};
for (int i=1; i<=n; i++) {
sellInfo* p = (struct SellInfo *)malloc(sizeof(struct SellInfo));
p->id = i;
p->num = x / n;
pthread_create(&th[i-1], NULL, sell, p);
}
for (int i=1; i<=n; i++) {
pthread_join(th[i], NULL);
}
return 0;
} 竞争式销售模式
#include
#include
#include
#include
#include
#include
typedef struct SellInfo {
int id;
int num;
}sellInfo;
int total = 120;
pthread_mutex_t mutex;
void* sell (void* v) {
sellInfo* p = (struct SellInfo *) v;
int cur;
while (1) {
pthread_mutex_lock(&mutex);
cur = total;
if (cur <= 0) {
printf("售罄!!!");
pthread_mutex_unlock(&mutex);
break;
}
printf("当前票数为:%d ", cur);
usleep(rand()%90000);
printf("售票点#%d售出一张票\n", p->id);
cur--;
total = cur;
pthread_mutex_unlock(&mutex);
}
free(p);
}
int main (int argc, char const **argv) {
int n = 20;
srand(time(NULL));
pthread_t th[20] = {0};
pthread_mutex_init(&mutex, NULL);
for (int i=0; iid = i + 1;
p->num = 0;
pthread_create(&th[i], NULL, sell, p);
}
for (int i=0; i 协调生产和消费进度
#include
#include
#include
#include
#include
#include
#include
#define N 14
int buf[N] = {-1};
int putin = 0;
int takeout = 0;
sem_t unoccupied;
sem_t occupied;
pthread_mutex_t mutex;
void delay (int len) {
int i = rand() % len;
int x;
while (i > 0) {
x = rand() % len;
while (x > 0) {
x--;
}
i--;
}
}
void producer () {
while (1) {
int d = 1 + rand()%100;
delay(50000);
sem_wait(&unoccupied);
pthread_mutex_lock(&mutex);
buf[putin] = d;
printf("Put %d to the buffer at %d.\n", d, putin);
putin++;
if (putin == N) {
putin = 0;
}
sem_post(&occupied);
pthread_mutex_unlock(&mutex);
}
}
void consumer () {
while (1) {
delay (50000);
sem_wait(&occupied);
pthread_mutex_lock(&mutex);
printf("Take out %d from the buffer at %d.\n", buf[takeout], takeout);
buf[takeout] = -1;
takeout++;
if (takeout == N) {
takeout = 0;
}
sem_post(&unoccupied);
pthread_mutex_unlock(&mutex);
}
}
int main (int argc, char const** argv) {
pthread_t manufacture;
pthread_t customer;
pthread_mutex_init(&mutex, NULL);
pthread_create(&manufacture, NULL, (void*)producer, NULL);
pthread_create(&customer, NULL, (void*)consumer, NULL);
sem_init(&unoccupied, 0, N);
sem_init(&occupied, 0, 0);
pthread_join(customer, NULL);
pthread_join(manufacture, NULL);
sem_destroy(&unoccupied);
sem_destroy(&occupied);
pthread_mutex_destroy(&mutex);
return 0;
} 哲学家就餐问题
#include
#include
#include
#include
#include
#include
#include
#define N 5
sem_t chopsticks[5];
sem_t r;
int philosophers[5] = {0, 1, 2, 3, 4};
void delay (int len) {
int i = rand() % len;
int x;
while (i > 0) {
x = rand() % len;
while (x > 0) {
x--;
}
i--;
}
}
void philosopher (void* arg) {
int i = *(int *)arg;
int left = i;
int right = (i + 1) % N;
while (1) {
printf("哲学家%d正在思考问题\n", i);
delay(50000);
printf("哲学家%d饿了\n", i);
sem_wait(&r);
sem_wait(&chopsticks[left]);
printf("哲学家%d拿起了%d号筷子,现在只有一支筷子,不能进餐\n", i, left);
sem_wait(&chopsticks[right]);
printf("哲学家%d拿起了%d号筷子, 现在有两支筷子,开始进餐\n", i, right);
delay(50000);
sem_post(&r);
sem_post(&chopsticks[left]);
printf("哲学家%d放下了%d号筷子\n", i, left);
sem_post(&chopsticks[right]);
printf("哲学家%d放下了%d号筷子\n", i, right);
}
}
int main (int argc, char **argv) {
srand(time(NULL));
pthread_t PHD[N];
for (int i=0; i