• 读写者
• 生产者消费者
• 哲学家问题
• 吸烟者问题
• 理发师问题

读写者

读优先 / 写优先

生产者消费者

#include <pthread/pthread.h>
#include <semaphore.h>

#define kBufferSize 2
static pthread_mutex_t lock = PTHREAD_MUTEX_INITIALIZER;
static pthread_cond_t empty = PTHREAD_COND_INITIALIZER;
static pthread_cond_t full = PTHREAD_COND_INITIALIZER;

static int buffer[kBufferSize];
static int count = 0; // 大小为1
static int use = 0;
static int fill = 0;

static void put(int value)
{
    buffer[fill] = value;
    fill = (fill + 1) % kBufferSize;
    count++;
}

static int get()
{
    int tmp = buffer[use];
    use = (use + 1) % kBufferSize;
    count--;
    return tmp;
}


static void *producer(void *arg)
{
    int loops = (int)arg;
    for (int i = 0; i < loops; ++i) {
        pthread_mutex_lock(&lock);
        while (count == kBufferSize) {
            pthread_cond_wait(&empty, &lock);
        }
        
        put(i);
        printf("produce %d \n", i);
        pthread_cond_signal(&full);
        pthread_mutex_unlock(&lock);
    }
    
    return NULL;
}

static void *consumer(void *arg)
{
    int loops = (int)arg;
    for (int i = 0; i < loops; ++i) {
        pthread_mutex_lock(&lock);
        
        while (count == 0) {
            pthread_cond_wait(&full, &lock);
        }
        int tmp = get();
        printf("consume %d \n", tmp);
        pthread_cond_signal(&empty);
        pthread_mutex_unlock(&lock);
    }
    
    return NULL;
}

static int testEntry()
{    
    printf("parent start\n");
    pthread_t p1, p2, c1, c2;
    pthread_create(&p1, NULL, producer, (void *)10);
    pthread_create(&p2, NULL, producer, (void *)10);
    pthread_create(&c1, NULL, consumer, (void *)10);
    pthread_create(&c2, NULL, consumer, (void *)10);
    printf("parent end\n");
    
    return 0;
}

哲学家问题

dining philosopher’s problem

吸烟者问题

cigarette smoker’s problem

理发师问题

sleeping barber problem

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