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): 作业1,2,3,4修订

day7/homework/h1_2.c

@@ -0,0 +1,85 @@
+#include <stdio.h>
+#include <pthread.h>
+
+pthread_mutex_t mutex;
+pthread_cond_t condition;
+int max_number;
+int current_number;
+
+void *print_odd(void *arg)
+{
+    while (1)
+    {
+        pthread_mutex_lock(&mutex);
+        while (current_number % 2 == 0)
+        { // 等待偶数线程通知
+            pthread_cond_wait(&condition, &mutex);
+        }
+        if (current_number > max_number)
+        { // 达到最大值时退出
+            pthread_mutex_unlock(&mutex);
+            break;
+        }
+        printf("%d", current_number);
+        if (current_number != max_number)
+            printf("、");
+        else if (current_number == max_number)
+            printf("\n");
+        fflush(stdout);
+
+        current_number++;
+        pthread_cond_signal(&condition); // 通知偶数线程
+        pthread_mutex_unlock(&mutex);
+    }
+    return NULL;
+}
+
+void *print_even(void *arg)
+{
+    while (1)
+    {
+        pthread_mutex_lock(&mutex);
+        while (current_number % 2 != 0)
+        { // 等待奇数线程通知
+            pthread_cond_wait(&condition, &mutex);
+        }
+        if (current_number > max_number)
+        { // 达到最大值时退出
+            pthread_mutex_unlock(&mutex);
+            break;
+        }
+        printf("%d", current_number);
+        if (current_number != max_number)
+            printf("、");
+        else if (current_number == max_number)
+            printf("\n");
+        fflush(stdout);
+
+        current_number++;
+        pthread_cond_signal(&condition); // 通知奇数线程
+        pthread_mutex_unlock(&mutex);
+    }
+    return NULL;
+}
+
+int main()
+{
+    printf("请输入指定的最大值: ");
+    scanf("%d", &max_number);
+
+    pthread_mutex_init(&mutex, NULL);
+    pthread_cond_init(&condition, NULL);
+    current_number = 1;
+
+    pthread_t odd_thread, even_thread;
+    pthread_create(&odd_thread, NULL, print_odd, NULL);
+    pthread_create(&even_thread, NULL, print_even, NULL);
+
+    pthread_join(odd_thread, NULL);
+    pthread_join(even_thread, NULL);
+
+    pthread_mutex_destroy(&mutex);
+    pthread_cond_destroy(&condition);
+
+    return 0;
+}

day7/homework/h2.c

@@ -63,5 +63,7 @@ int main(int argc, char const *argv[])
     pthread_join(t1, NULL);
     pthread_join(t2, NULL);
 
+    pthread_rwlock_destroy(&rwlock); // 销毁读写锁
+
     return 0;
 }

day7/homework/h2_2.c

@@ -59,5 +59,8 @@ int main(int argc, char const *argv[])
     pthread_join(t1, NULL);
     pthread_join(t2, NULL);
 
+    pthread_cond_destroy(&cond);   // 销毁条件变量
+    pthread_mutex_destroy(&mutex); // 销毁互斥锁
+
     return 0;
 }

day7/homework/h3.c

@@ -36,7 +36,7 @@ int main(int argc, char const *argv[])
 
     printf("现在的 number = %d\n", number);
 
-    sem_destroy(&sem);
+    sem_destroy(&sem); // 销毁信号量
 
     return 0;
 }

day7/homework/h4.c

@@ -0,0 +1,95 @@
+/*
+编写一个程序, 创建多个线程, 每个线程负责对一个共享数组的不同部分进行排序。要求实现线程间的同步, 确保每个线程在进行排序时不会干扰其他线程的工作。
+*/
+#include <stdio.h>
+#include <pthread.h>
+#include <stdlib.h>
+#include <unistd.h>
+
+typedef struct array_s
+{
+    int *arr;               // 数组元素头指针
+    int start_pos;          // 起始位置
+    int end_pos;            // 结束位置
+    pthread_mutex_t *mutex; // 互斥锁
+} ARRAY;
+
+void *sort(void *data)
+{
+    ARRAY *array = (ARRAY *)data;
+    pthread_mutex_lock(array->mutex); // 线程加锁
+    printf("%ld 线程开始排序\n", pthread_self());
+
+    for (int i = array->start_pos; i < array->end_pos; i++)
+    {
+        for (int j = array->start_pos; j < array->end_pos - i; j++)
+        {
+            if (array->arr[j] > array->arr[j + 1])
+            {
+                array->arr[j] ^= array->arr[j + 1];
+                array->arr[j + 1] ^= array->arr[j];
+                array->arr[j] ^= array->arr[j + 1];
+            }
+        }
+    }
+
+    pthread_mutex_unlock(array->mutex); // 线程解锁
+
+    return NULL;
+}
+
+int main()
+{
+    int arr[9] = {1, 4, 2, 9, 0, 5, 6, 1, 8};
+    pthread_mutex_t mutex;
+    pthread_mutex_init(&mutex, NULL);
+
+    ARRAY array1 = {arr, 0, 2, &mutex};
+    ARRAY array2 = {arr, 3, 5, &mutex};
+    ARRAY array3 = {arr, 6, 8, &mutex};
+
+    pthread_t t1, t2, t3;
+    pthread_create(&t1, NULL, sort, &array1);
+    pthread_create(&t2, NULL, sort, &array2);
+    pthread_create(&t3, NULL, sort, &array3);
+
+    pthread_join(t1, NULL);
+    pthread_join(t2, NULL);
+    pthread_join(t3, NULL);
+
+    // 合并排序结果
+    int merged[9];
+    int i = 0;
+    for (int j = array1.start_pos; j <= array1.end_pos; j++)
+    {
+        merged[i++] = arr[j];
+    }
+    for (int j = array2.start_pos; j <= array2.end_pos; j++)
+    {
+        merged[i++] = arr[j];
+    }
+    for (int j = array3.start_pos; j <= array3.end_pos; j++)
+    {
+        merged[i++] = arr[j];
+    }
+
+    pthread_mutex_unlock(&mutex); // 解锁
+
+    // 创建数组结构和新线程，将合并后的数组进行排序
+    ARRAY arr4 = {merged, 0, 8, &mutex};
+    pthread_t t4;
+    pthread_create(&t4, NULL, sort, &arr4);
+    pthread_join(t4, NULL);
+
+    // 输出排序结果
+    printf("排序后的数组：");
+    for (int i = 0; i < 9; i++)
+    {
+        printf("%d ", merged[i]);
+    }
+    printf("\n");
+
+    pthread_mutex_destroy(&mutex); // 销毁互斥锁
+
+    return 0;
+}

day7/homework/test.c

@@ -0,0 +1,58 @@
+#include <stdio.h>
+#include <pthread.h>
+#include <stdlib.h>
+#include <semaphore.h>
+//设置办理业务的人数
+int num = 5;
+//创建信号量
+sem_t sem;
+//模拟办理业务的过程
+void *get_service(void *arg)
+{
+    int id = *((int *)arg);
+    //信号量成功“减 1”后才能继续执行
+    if (sem_wait(&sem) == 0)
+    {
+        printf("---customer%d 正在办理业务\n", id);
+        sleep(2);
+        printf("---customer%d 已办完业务\n", id);
+        //信号量“加 1”
+        sem_post(&sem);
+    }
+    return 0;
+}
+
+int main()
+{
+    int flag, i, j;
+    //创建 5 个线程代表 5 个人
+    pthread_t customer[5];
+    //初始化信号量
+    sem_init(&sem, 0, 2);
+    for (i = 0; i < num; i++)
+    {
+        flag = pthread_create(&customer[i], NULL, get_service, &i);
+        if (flag != 0)
+        {
+            printf("线程创建失败!\n");
+            return 0;
+        }
+        else
+        {
+            printf("customer%d 来办理业务\n", i);
+        }
+        sleep(1);
+    }
+
+    for (j = 0; j < num; j++)
+    {
+        flag = pthread_join(customer[j], NULL);
+        if (flag != 0)
+        {
+            printf("tid=%d 等待失败！", customer[i]);
+            return 0;
+        }
+    }
+    sem_destroy(&sem);
+    return 0;
+}