多任务互斥与同步(互斥锁, 读写锁, 条件变量, 信号量, 命名信号量)

day7/condition.c

@@ -0,0 +1,83 @@
+#include <stdio.h>
+#include <pthread.h>
+#include <unistd.h>
+
+// 条件变量实例
+
+// 互斥锁和条件变量的初始化
+pthread_mutex_t mutex = PTHREAD_MUTEX_INITIALIZER;
+pthread_cond_t cond = PTHREAD_COND_INITIALIZER;
+
+void *producer_task(void *data)
+{
+    int *n = (int *)data;
+    while (1)
+    {
+        pthread_mutex_lock(&mutex);
+
+        while (*n == 10) // 只要资源为 10 ，就等待
+        {
+            // 条件变量等待后，会自动释放 mutex 锁
+            pthread_cond_wait(&cond, &mutex);
+        }
+
+        (*n)++;
+        printf("生产线程(%ld)生产了 %d 个产品\n", pthread_self(), *n);
+
+        // 发出通知，让等待消费的线程恢复（条件满足）
+        pthread_cond_broadcast(&cond);
+
+        pthread_mutex_unlock(&mutex);
+        // usleep(200 * 1000);
+        sleep(1);
+    }
+
+    pthread_exit(NULL);
+}
+
+void *consumer_task(void *data)
+{
+    int *n = (int *)data;
+    while (1)
+    {
+        pthread_mutex_lock(&mutex);
+        while (*n == 0) // 只要资源为 0 ，就等待
+        {
+            // 条件变量等待后，会自动释放 mutex 锁
+            pthread_cond_wait(&cond, &mutex);
+        }
+        printf("消费者(%ld) 消费了 %d 产品\n", pthread_self(), *n);
+        (*n)--;
+        pthread_mutex_unlock(&mutex);
+        // usleep(200 * 1000);
+        sleep(1);
+    }
+    pthread_exit(NULL);
+}
+
+int main(int argc, char const *argv[])
+{
+    int num = 3; // 3 个产品
+    pthread_t threads[10];
+    // 创建 2 个生产线程
+    for (int i = 0; i < 8; i++)
+    {
+        pthread_create(&threads[i], NULL, producer_task, &num);
+    }
+
+    // 创建 3 个消费者线程
+    for (int i = 8; i < 10; i++)
+    {
+        pthread_create(&threads[i], NULL, consumer_task, &num);
+    }
+
+    for (int i = 0; i < 10; i++)
+    {
+        pthread_join(threads[i], NULL);
+    }
+
+    pthread_mutex_destroy(&mutex);
+    pthread_cond_destroy(&cond);
+
+    return 0;
+}

day7/mutex_1.c

@@ -0,0 +1,58 @@
+#include <stdio.h>
+#include <pthread.h>
+#include <unistd.h>
+
+// 定义两把锁
+pthread_mutex_t mutex1, mutex2;
+
+void *task1(void *data)
+{
+    char *taskName = (char *)data;
+    pthread_mutex_lock(&mutex1);
+    printf("%s 获取锁 1 成功, 等待 1 秒后获取锁 2\n", taskName);
+    sleep(1);
+    pthread_mutex_lock(&mutex2);
+    printf("%s 获取锁 2 成功\n", taskName);
+    printf("%s\n", taskName);
+
+    // 释放锁
+    pthread_mutex_unlock(&mutex2);
+    pthread_mutex_unlock(&mutex1);
+    return NULL;
+}
+
+void *task2(void *data)
+{
+    char *taskName = (char *)data;
+    pthread_mutex_lock(&mutex1);
+    printf("%s 获取锁 1 成功, 等待 1 秒后获取锁 2\n", taskName);
+    sleep(1);
+    pthread_mutex_lock(&mutex2);
+    printf("%s 获取锁 2 成功\n", taskName);
+    printf("%s\n", taskName);
+
+    // 释放锁
+    pthread_mutex_unlock(&mutex2);
+    pthread_mutex_unlock(&mutex1);
+    return NULL;
+}
+
+int main(int argc, char const *argv[])
+{
+    // 动态初始化锁
+    pthread_mutex_init(&mutex1, NULL);
+    pthread_mutex_init(&mutex2, NULL);
+
+    // 创建线程
+    pthread_t tid1, tid2;
+    pthread_create(&tid1, NULL, task1, "hello");
+    pthread_create(&tid2, NULL, task2, "world");
+    pthread_join(tid1, NULL);
+    pthread_join(tid2, NULL);
+
+    // 销毁锁
+    pthread_mutex_destroy(&mutex1);
+    pthread_mutex_destroy(&mutex2);
+
+    return 0;
+}

day7/named_sem_1.c

@@ -0,0 +1,45 @@
+#include <sys/stat.h>
+#include <sys/wait.h>
+#include <fcntl.h>
+#include <semaphore.h>
+#include <stdio.h>
+#include <unistd.h>
+
+// 命名信号实例
+
+void printer(char *msg)
+{
+    while (*msg)
+    {
+        printf("%c", *msg++); // 打印字符
+        fflush(stdout);       // 刷新控制台
+        sleep(1);
+    }
+}
+
+int main(int argc, char const *argv[])
+{
+    // 命名信号
+    sem_t *sem = sem_open("mysem", O_CREAT | O_RDWR, 0644, 1);
+
+    int pid = fork();
+    if (pid == 0) // 子进程
+    {
+        sem_wait(sem);
+        printer("disen666");
+        sem_post(sem);
+        _exit(0);
+    }
+    else if (pid > 0) // 父进程
+    {
+        sem_wait(sem);
+        printer("jack888");
+        sem_post(sem);
+        wait(NULL); // 等待子进程退出
+
+        printf("\n---over---\n");
+        sem_close(sem);      // 关闭信号量
+        sem_unlink("mysem"); // 删除信号量文件
+    }
+    return 0;
+}

day7/named_sem_2.c

@@ -0,0 +1,48 @@
+#include <sys/stat.h>
+#include <sys/wait.h>
+#include <fcntl.h>
+#include <semaphore.h>
+#include <stdio.h>
+#include <unistd.h>
+
+// 命名信号实例
+
+void printer(char *msg)
+{
+    while (*msg)
+    {
+        printf("%c", *msg++); // 打印字符
+        fflush(stdout);       // 刷新控制台
+        sleep(1);
+    }
+}
+
+int main(int argc, char const *argv[])
+{
+    // 命名信号
+    sem_t *sem1 = sem_open("mysem1", O_CREAT | O_RDWR, 0644, 1);
+    sem_t *sem2 = sem_open("mysem2", O_CREAT | O_RDWR, 0644, 0);
+
+    int pid = fork();
+    if (pid == 0) // 子进程
+    {
+        sem_wait(sem1);
+        printer("disen666");
+        sem_post(sem2);
+        _exit(0);
+    }
+    else if (pid > 0) // 父进程
+    {
+        sem_wait(sem2);
+        printer("jack888");
+        sem_post(sem1);
+
+        wait(NULL); // 等待子进程退出
+        printf("\n---over---\n");
+        sem_close(sem1);      // 关闭信号量
+        sem_close(sem2);      // 关闭信号量
+        sem_unlink("mysem1"); // 删除信号量文件
+        sem_unlink("mysem2"); // 删除信号量文件
+    }
+    return 0;
+}

day7/named_sem_3.c

@@ -0,0 +1,34 @@
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <semaphore.h>
+#include <stdio.h>
+#include <unistd.h>
+#include <sys/wait.h>
+
+// 无血缘关系的进程的互斥
+void printer(char *msg)
+{
+    while (*msg)
+    {
+        printf("%c", *msg++);
+        fflush(stdout);
+        sleep(1);
+    }
+}
+
+int main(int argc, char const *argv[])
+{
+    // 打开信号量文件
+    sem_t *sem = sem_open("mysem", O_CREAT | O_RDWR, 0666, 1);
+
+    sem_wait(sem);
+#ifdef DISEN
+    printer("disen666\n");
+#else
+    printer("jack888\n");
+#endif
+    sem_post(sem);
+    sem_close(sem);
+
+    return 0;
+}

day7/named_sem_4.c

@@ -0,0 +1,38 @@
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <semaphore.h>
+#include <stdio.h>
+#include <unistd.h>
+#include <sys/wait.h>
+
+// 无血缘关系的进程的同步
+void printer(char *msg)
+{
+    while (*msg)
+    {
+        printf("%c", *msg++);
+        fflush(stdout);
+        sleep(1);
+    }
+}
+
+int main(int argc, char const *argv[])
+{
+    // 打开信号量文件
+    sem_t *sem1 = sem_open("mysem1", O_CREAT | O_RDWR, 0666, 1);
+    sem_t *sem2 = sem_open("mysem2", O_CREAT | O_RDWR, 0666, 0);
+
+#ifdef DISEN
+    sem_wait(sem2);
+    printer("disen666\n");
+    sem_post(sem1);
+#else
+    sem_wait(sem1);
+    printer("jack888\n");
+    sem_post(sem2);
+#endif
+
+    sem_close(sem1);
+    sem_close(sem2);
+    return 0;
+}

day7/nomutex.c

@@ -0,0 +1,28 @@
+#include <stdio.h>
+#include <pthread.h>
+#include <unistd.h>
+
+void *printer(void *data)
+{
+    char *msg = (char *)data;
+    while (*msg)
+    {
+        printf("%c", *msg++);
+        fflush(stdout);
+        sleep(1);
+    }
+    return NULL;
+}
+
+int main(int argc, char const **argv)
+{
+    pthread_t tid1, tid2;
+    pthread_create(&tid1, NULL, printer, "disen666\0");
+    pthread_create(&tid2, NULL, printer, "lucy888\0");
+
+    pthread_join(tid1, NULL);
+    pthread_join(tid2, NULL);
+    printf("---over---\n");
+
+    return 0;
+}

day7/nomutex_2.c

@@ -0,0 +1,42 @@
+#include <stdio.h>
+#include <pthread.h>
+#include <unistd.h>
+
+// 静态初始化互斥锁
+// pthread_mutex_t mutex = PTHREAD_MUTEX_INITIALIZER;
+// 动态初始化锁-定义锁
+pthread_mutex_t mutex;
+
+void *printer(void *data)
+{
+
+    char *msg = (char *)data;
+    pthread_mutex_lock(&mutex); // 申请上锁，可能阻塞
+    while (*msg)
+    {
+        printf("%c", *msg++);
+        fflush(stdout);
+        usleep(200 * 1000);
+    }
+    pthread_mutex_unlock(&mutex); // 不解锁，就会发生死锁
+    return NULL;
+}
+
+int main(int argc, char const **argv)
+{
+    // 动态初始化锁-初始化
+    pthread_mutex_init(&mutex, NULL);
+
+    pthread_t tid1, tid2;
+    pthread_create(&tid1, NULL, printer, "disen666\n");
+    pthread_create(&tid2, NULL, printer, "lucy888\n");
+
+    pthread_join(tid1, NULL);
+    pthread_join(tid2, NULL);
+    printf("\n---over---\n");
+
+    // 销毁互斥锁
+    pthread_mutex_destroy(&mutex);
+
+    return 0;
+}

day7/nomutex_3.c

@@ -0,0 +1,54 @@
+#include <stdio.h>
+#include <pthread.h>
+#include <unistd.h>
+
+// 静态初始化互斥锁
+// pthread_mutex_t mutex = PTHREAD_MUTEX_INITIALIZER;
+// 动态初始化锁-定义锁
+pthread_mutex_t mutex;
+
+void *printer(void *data)
+{
+
+    char *msg = (char *)data;
+    int lock_acquired = 0; // 未获取到锁
+    while (!lock_acquired) // 未获取到锁的时候，循环尝试获取锁，并处理
+    {
+        // trylock 非阻塞锁
+        if (pthread_mutex_trylock(&mutex) == 0) // 如果拿到锁
+        {
+            lock_acquired = 1; // 该状态:已获取到锁
+            while (*msg)       // 当前线程传入的字符串未读取完成时，循环读取
+            {
+                printf("%c", *msg++);
+                fflush(stdout);
+                usleep(200 * 1000);
+            }
+            pthread_mutex_unlock(&mutex); // 读完后，解锁当前进程
+        }
+        else
+        {
+            usleep(100); // 0.1 毫秒后继续尝试获取锁
+        }
+    }
+    return NULL;
+}
+
+int main(int argc, char const **argv)
+{
+    // 动态初始化锁-初始化
+    pthread_mutex_init(&mutex, NULL);
+
+    pthread_t tid1, tid2;
+    pthread_create(&tid1, NULL, printer, "disen666\n");
+    pthread_create(&tid2, NULL, printer, "lucy888\n");
+
+    pthread_join(tid1, NULL);
+    pthread_join(tid2, NULL);
+    printf("\n---over---\n");
+
+    // 销毁互斥锁
+    pthread_mutex_destroy(&mutex);
+
+    return 0;
+}

day7/rwlock_1.c

@@ -0,0 +1,52 @@
+#include <stdio.h>
+#include <pthread.h>
+#include <unistd.h>
+
+// 定义读写锁（需要 GNU99）
+pthread_rwlock_t rwlock = PTHREAD_RWLOCK_INITIALIZER; // 静态初始化读写锁
+
+void *read_task(void *data)
+{
+    int *n = (int *)data;
+
+    while (1)
+    {
+        pthread_rwlock_rdlock(&rwlock); // 申请读锁 rdlock
+        printf("(%ld)线程读取 num: %d\n", pthread_self(), *n);
+        pthread_rwlock_unlock(&rwlock); // 解锁
+        usleep(500 * 1000);
+    }
+    return NULL;
+}
+
+void *write_task(void *data)
+{
+    int *n = (int *)data;
+    while (1)
+    {
+        pthread_rwlock_wrlock(&rwlock); // 申请写锁 wrlock
+        (*n)++;
+        printf("(%ld) 线程写 num: %d\n", pthread_self(), *n);
+        pthread_rwlock_unlock(&rwlock); // 解锁
+        sleep(2);
+    }
+
+    return NULL;
+}
+
+int main(int argc, char const *argv[])
+{
+    int num; // 公共资源
+    pthread_t t1, t2, t3;
+    pthread_create(&t1, NULL, read_task, &num);
+    pthread_create(&t2, NULL, read_task, &num);
+    pthread_create(&t3, NULL, write_task, &num);
+
+    pthread_join(t1, NULL);
+    pthread_join(t2, NULL);
+    pthread_join(t3, NULL);
+
+    pthread_rwlock_destroy(&rwlock); // 销毁读写锁
+
+    return 0;
+}

day7/rwlock_2.c

@@ -0,0 +1,97 @@
+#include <stdio.h>
+#include <pthread.h>
+#include <unistd.h>
+#include <string.h>
+
+pthread_rwlock_t rwlock = PTHREAD_RWLOCK_INITIALIZER;
+int money = 1000;  // 存款余额
+int exit_flag = 0; // 退出标志
+
+void *task1(void *data)
+{
+    while (1)
+    {
+        pthread_rwlock_wrlock(&rwlock); // 加写锁
+        // 查询余额
+        printf("存款任务-余额: %d\n", money);
+        usleep(200 * 1000);
+        // 从键盘读取存入的金额
+        printf("请输入存款金额 (输入 0 结束存款): ");
+        fflush(stdout);
+        int m;
+        scanf("%d", &m);
+        if (m == 0)
+        {
+            exit_flag = 1;
+            pthread_rwlock_unlock(&rwlock); // 解锁
+            break;
+        }
+        money += m;
+        // 修改余额并打印结果
+        printf("存款成功, 余额为 %d\n", money);
+        pthread_rwlock_unlock(&rwlock); // 解锁
+    }
+    pthread_exit(NULL);
+}
+
+void *task2(void *data)
+{
+    while (1)
+    {
+        pthread_rwlock_wrlock(&rwlock); // 加写锁
+        // 查询余额
+        printf("取款任务-余额: %d\n", money);
+        usleep(200 * 1000);
+        // 从键盘读取取出的金额
+        printf("请输入取款金额 (输入 0 结束取款): ");
+        fflush(stdout);
+        int m;
+        scanf("%d", &m);
+        if (m == 0)
+        {
+            exit_flag = 1;
+            pthread_rwlock_unlock(&rwlock); // 解锁
+            break;
+        }
+        if (money >= m)
+        {
+            money -= m;
+            // 修改余额并打印结果
+            printf("取款成功, 余额为 %d\n", money);
+        }
+        else
+        {
+            printf("取款失败, 余额不足\n");
+        }
+        pthread_rwlock_unlock(&rwlock); // 解锁
+    }
+    pthread_exit(NULL);
+}
+
+int main(int argc, char const *argv[])
+{
+    while (1)
+    {
+        pthread_t t1, t2;
+        pthread_create(&t1, NULL, task1, NULL);
+        pthread_create(&t2, NULL, task2, NULL);
+
+        while (1)
+        {
+            pthread_rwlock_rdlock(&rwlock);
+            if (exit_flag)
+            {
+                pthread_rwlock_unlock(&rwlock);
+                break;
+            }
+            pthread_rwlock_unlock(&rwlock);
+        }
+
+        pthread_join(t1, NULL);
+        pthread_join(t2, NULL);
+    }
+
+    pthread_rwlock_destroy(&rwlock);
+
+    return 0;
+}

day7/sem_1.c

@@ -0,0 +1,48 @@
+#include <stdio.h>
+#include <pthread.h>
+#include <unistd.h>
+#include <semaphore.h>
+
+// 信号量实例
+
+sem_t sem; // 定义信号量
+
+void *printer(void *data)
+{
+
+    char *msg = (char *)data;
+
+    // P 操作
+    sem_wait(&sem); // 本案例中锁住了控制台
+
+    while (*msg)
+    {
+        printf("%c", *msg++);
+        fflush(stdout);
+        usleep(200 * 1000);
+    }
+
+    // V 操作
+    sem_post(&sem);
+
+    return NULL;
+}
+
+int main(int argc, char const **argv)
+{
+    // 信号量初始化
+    sem_init(&sem, 0, 1);
+
+    pthread_t tid1, tid2;
+    pthread_create(&tid1, NULL, printer, "disen666\n");
+    pthread_create(&tid2, NULL, printer, "lucy888\n");
+
+    pthread_join(tid1, NULL);
+    pthread_join(tid2, NULL);
+    printf("\n---over---\n");
+
+    // 销毁信号量
+    sem_destroy(&sem);
+
+    return 0;
+}

day7/sem_2.c

@@ -0,0 +1,105 @@
+#include <stdio.h>
+#include <pthread.h>
+#include <unistd.h>
+#include <string.h>
+#include <semaphore.h>
+
+// 信号量实例 2 - 存取款
+sem_t sem; // 定义信号量
+
+int money = 1000;  // 存款余额
+int exit_flag = 0; // 退出标志
+
+void *task1(void *data)
+{
+    while (1)
+    {
+        sem_wait(&sem); // P 操作
+        // 查询余额
+        printf("存款任务-余额: %d\n", money);
+        usleep(200 * 1000);
+        // 从键盘读取存入的金额
+        printf("请输入存款金额 (输入 0 结束存款): ");
+        fflush(stdout);
+        int m;
+        scanf("%d", &m);
+        if (m == 0)
+        {
+            exit_flag = 1;
+            sem_post(&sem); // V 操作
+            break;
+        }
+        money += m;
+        // 修改余额并打印结果
+        printf("存款成功, 余额为 %d\n", money);
+        sem_post(&sem); // V 操作
+    }
+    pthread_exit(NULL);
+}
+
+void *task2(void *data)
+{
+    while (1)
+    {
+        sem_wait(&sem); // P 操作
+        // 查询余额
+        printf("取款任务-余额: %d\n", money);
+        usleep(200 * 1000);
+        // 从键盘读取取出的金额
+        printf("请输入取款金额 (输入 0 结束取款): ");
+        fflush(stdout);
+        int m;
+        scanf("%d", &m);
+        if (m == 0)
+        {
+            exit_flag = 1;
+            sem_post(&sem); // V 操作
+            break;
+        }
+        if (money >= m)
+        {
+            money -= m;
+            // 修改余额并打印结果
+            printf("取款成功, 余额为 %d\n", money);
+        }
+        else
+        {
+            printf("取款失败, 余额不足\n");
+        }
+        sem_post(&sem); // V 操作
+    }
+    pthread_exit(NULL);
+}
+
+int main(int argc, char const *argv[])
+{
+    // 初始化信号量
+    sem_init(&sem, 0, 1);
+
+    while (1)
+    {
+        pthread_t t1, t2;
+        pthread_create(&t1, NULL, task1, NULL);
+        pthread_create(&t2, NULL, task2, NULL);
+
+        while (1)
+        {
+            sem_wait(&sem); // P 操作
+
+            if (exit_flag)
+            {
+                sem_post(&sem); // V 操作
+                break;
+            }
+            sem_post(&sem); // V 操作
+        }
+
+        pthread_join(t1, NULL);
+        pthread_join(t2, NULL);
+    }
+
+    // 销毁信号量
+    sem_destroy(&sem);
+
+    return 0;
+}

day7/sem_3.c

@@ -0,0 +1,88 @@
+#include <stdio.h>
+#include <pthread.h>
+#include <unistd.h>
+#include <semaphore.h>
+#include <string.h>
+
+sem_t sem1, sem2; // 信号量
+
+void *task1(void *data)
+{
+    int *money = (int *)data;
+    // 存款任务
+    sem_wait(&sem1);
+
+    //  查询余额
+    printf("存款任务-余额: %d\n", *money);
+    sleep(1);
+    // 从键盘读取存入的金额
+    printf("请输入存款金额: ");
+    fflush(stdout);
+    int m;
+    scanf("%d", &m);
+    *money += m;
+    // 修改余额并打印结果
+    printf("存款成功, 余额为: %d\n", *money);
+    sem_post(&sem2);
+    pthread_exit(NULL);
+}
+
+void *task2(void *data)
+{
+    int *money = (int *)data;
+    // 取款任务
+    sem_wait(&sem2);
+    //  查询余额
+    printf("取款任务-余额: %d\n", *money);
+
+    sleep(1);
+
+    // 从键盘读取取出的金额
+    printf("请输入取款金额: ");
+    fflush(stdout);
+    int m;
+    scanf("%d", &m);
+    if (*money >= m)
+    {
+        *money -= m;
+        // 修改余额并打印结果
+        printf("取款成功, 余额为: %d\n", *money);
+    }
+    else
+    {
+        printf("取款失败，余额不足\n");
+    }
+
+    sem_post(&sem1);
+    pthread_exit(NULL);
+}
+
+int main(int argc, char const *argv[])
+{
+    // 初始化信号量
+    sem_init(&sem1, 0, 1); // 存款的信号量初始化
+    sem_init(&sem2, 0, 0); // 取款的信号量初始化
+
+    int money = 1000; // 存款
+
+    while (1)
+    {
+        printf("输入 exit 退出 , 输入其他内容开始存取款\n");
+        char input[100];
+        scanf("%s", input);
+        if (strncmp(input, "exit", 4) == 0)
+        {
+            break;
+        }
+        pthread_t tid1, tid2;
+        pthread_create(&tid1, NULL, task1, &money);
+        pthread_create(&tid2, NULL, task2, &money);
+
+        pthread_join(tid1, NULL);
+        pthread_join(tid2, NULL);
+    }
+
+    sem_destroy(&sem1);
+    sem_destroy(&sem2);
+    return 0;
+}