Linux下多线程的实现与控制1.在main线程中创建两个新的线程，其中一个线程用于卖票，一个线程用于补票，假设原始票数5张，只有当票都买完，才补票。编写代码

在Linux环境下，可以使用POSIX线程库(pthreads)或C++11标准中的`std::thread`来实现多线程。这里是一个简单的示例，使用`pthread_create`函数创建两个线程，模拟卖票和补票操作：

#include <stdio.h>
#include <stdlib.h>
#include <pthread.h>

#define TOTAL_TICKETS 5

void* sell_tickets(void* arg) {
    int tickets = TOTAL_TICKETS;
    while (tickets > 0) {
        printf("Ticket sold: %d\n", tickets);
        tickets--;
        // 模拟售票操作，实际应用中可能会有更复杂的逻辑
        pthread_mutex_lock(&ticket_mutex); // 锁定票务资源
        if (tickets == 0) {
            printf("All tickets sold, starting to replenish.\n");
            pthread_cond_signal(&replenish_condition); // 发送信号通知补票线程
        }
        pthread_mutex_unlock(&ticket_mutex); // 解锁
    }
    return NULL;
}

void* replenish_tickets(void* arg) {
    pthread_mutex_lock(&ticket_mutex); // 等待卖票线程结束并释放锁
    printf("Replenishing tickets...\n");
    while (TRUE) {
        pthread_cond_wait(&replenish_condition, &ticket_mutex); // 等待信号
        if (TOTAL_TICKETS < tickets + 1) { // 当所有票售完后，开始补票
            break;
        }
        // 补充票务，实际应用中可能需要持久化处理
        TOTAL_TICKETS++;
        printf("Tickets replenished to: %d\n", TOTAL_TICKETS);
    }
    pthread_mutex_unlock(&ticket_mutex);
    return NULL;
}

int main() {
    pthread_t sell_thread, replenish_thread;
    pthread_mutex_t ticket_mutex = PTHREAD_MUTEX_INITIALIZER;
    pthread_cond_t replenish_condition = PTHREAD_COND_INITIALIZER;

    if (pthread_create(&sell_thread, NULL, sell_tickets, NULL)) {
        perror("Error creating sell thread");
        exit(1);
    }

    if (pthread_create(&replenish_thread, NULL, replenish_tickets, NULL)) {
        perror("Error creating replenish thread");
        exit(1);
    }

    pthread_join(sell_thread, NULL);
    pthread_join(replenish_thread, NULL);

    printf("Threads finished, exiting.\n");

    return 0;
}