重新编写s0.c,s1.c,s2.c的代码

以下是 `s0.c`, `s1.c` 和 `s2.c` 的重新编写版本，保持原有功能的同时，进行了适当的优化和注释：

### s0.c: 初始状态设置进程

#include <sys/types.h>
#include <sys/ipc.h>
#include <sys/sem.h>
#include <signal.h>
#include <stdio.h>
#include <string.h>
#include <stdlib.h>

#define SEM_FILE "sem_name.tmp"
#define EMPTY_FILE "empty.txt"
#define CLIENT_FILE "pvh"
#define FULL_FILE "full.txt"

void sigint_handler(int);

int semid;
struct sembuf psembuf, vsembuf;

int main(int argc, char *argv[]) {
    int k = 10, buffer = 1;
    char filename[20];
    FILE *fempty, *full, *fp[k];
    key_t key;
    short initarray[3];

    signal(SIGINT, sigint_handler);

    // 创建并打开SEM_FILE
    fempty = fopen(SEM_FILE, "w");
    if (fempty == NULL) {
        perror("Error opening SEM_FILE for writing");
        return 1;
    }

    // 生成键值
    key = ftok(SEM_FILE, 'a');
    printf("Key = %u\n", key);
    if (key == -1) {
        perror("Error generating key");
        return 1;
    }

    // 获取信号量集
    semid = semget(key, 3, 0777 | IPC_CREAT);
    printf("Semaphore ID = %d\n", semid);
    if (semid == -1) {
        perror("Error getting semaphore");
        return 1;
    }

    // 初始化信号量
    initarray[0] = buffer;   // 缓冲池
    initarray[1] = k;        // 空缓冲区
    initarray[2] = 0;        // 满缓冲区
    if (semctl(semid, 0, SETALL, initarray) == -1) {
        perror("Error initializing semaphores");
        return 1;
    }

    // 验证初始化
    short outarray[3];
    if (semctl(semid, 0, GETALL, outarray) == -1) {
        perror("Error getting semaphore values");
        return 1;
    }
    printf("Semaphore initial values: %d, %d, %d\n", outarray[0], outarray[1], outarray[2]);

    // 关闭SEM_FILE
    fclose(fempty);

    // 创建EMPTY_FILE和FULL_FILE
    fempty = fopen(EMPTY_FILE, "w");
    full = fopen(FULL_FILE, "w");

    if (fempty == NULL || full == NULL) {
        perror("Error opening files for writing");
        return 1;
    }

    // 创建k个空文件并将文件名写入EMPTY_FILE
    for (int i = 0; i < k; i++) {
        sprintf(filename, "%s%03d.txt", CLIENT_FILE, i);
        fp[i] = fopen(filename, "w");
        if (fp[i] == NULL) {
            perror("Error creating client file");
            return 1;
        }
        fclose(fp[i]);
        fprintf(fempty, "%s\n", filename);
    }

    fclose(full);
    fclose(fempty);

    // 再次验证信号量值
    if (semctl(semid, 0, GETALL, outarray) == -1) {
        perror("Error getting semaphore values");
        return 1;
    }
    printf("Semaphore values: %d, %d, %d\n", outarray[0], outarray[1], outarray[2]);

    getchar();
    return 0;
}

void sigint_handler(int sig) {
    if (semctl(semid, 0, IPC_RMID, 0) == -1) {
        perror("Error removing semaphore");
    }
    exit(0);
}

### s1.c: 写者进程

#include <sys/types.h>
#include <sys/ipc.h>
#include <sys/sem.h>
#include <signal.h>
#include <stdio.h>
#include <string.h>
#include <unistd.h>

#define SEM_FILE "sem_name.tmp"
#define EMPTY_FILE "empty.txt"
#define FULL_FILE "full.txt"

int semid;
unsigned int count;
struct sembuf psembuf[2], vsembuf[2];

typedef struct {
    char str[100];
    char num[6];
} Msg;

int main(int argc, char *argv[]) {
    int k = 10, area = 0, first = 1, second = 2;
    char emptyname[20], restname[k * 20];
    FILE *fempty, *full;
    key_t key;
    short outarray[3];
    Msg msg;

    // 初始化
    memset(emptyname, 0x00, 20);
    memset(restname, 0x00, k * 20);
    memset(msg.str, 0x00, sizeof(msg.str));
    memset(msg.num, 0x00, sizeof(msg.num));

    // 生成键值
    key = ftok(SEM_FILE, 'a');
    printf("Key = %u\n", key);
    if (key == -1) {
        perror("Error generating key");
        return 1;
    }

    // 获取信号量集
    semid = semget(key, 3, 0777);
    printf("Semaphore ID = %d\n", semid);
    if (semid == -1) {
        perror("Error getting semaphore");
        return 1;
    }

    // 设置P操作和V操作
    psembuf[0].sem_op = -1;
    psembuf[0].sem_flg = SEM_UNDO;
    vsembuf[0].sem_op = 1;
    vsembuf[0].sem_flg = SEM_UNDO;

    psembuf[1].sem_op = -1;
    psembuf[1].sem_flg = SEM_UNDO;
    vsembuf[1].sem_op = 1;
    vsembuf[1].sem_flg = SEM_UNDO;

    // 验证初始化
    if (semctl(semid, 0, GETALL, outarray) == -1) {
        perror("Error getting semaphore values");
        return 1;
    }
    printf("Semaphore initial values: %d, %d, %d\n", outarray[0], outarray[1], outarray[2]);

    for (count = 0;; count++) {
        psembuf[0].sem_num = area;
        psembuf[1].sem_num = first;

        // P操作
        if (semop(semid, psembuf, 2) == -1) {
            perror("Error in P operation");
            return 1;
        }

        // 验证信号量值
        if (semctl(semid, 0, GETALL, outarray) == -1) {
            perror("Error getting semaphore values");
            return 1;
        }
        printf("After P, semaphore values: %d, %d, %d\n", outarray[0], outarray[1], outarray[2]);

        // 读取EMPTY_FILE中的空缓冲区名称
        fempty = fopen(EMPTY_FILE, "r");
        full = fopen(FULL_FILE, "a");
        fread(emptyname, sizeof(char), 10, fempty);
        fwrite(emptyname, strlen(emptyname), sizeof(char), full);
        fclose(full);

        int i = 0;
        while (!feof(fempty)) {
            fread(restname + i * 10, sizeof(char), 10, fempty);
            i++;
        }
        printf("Rest restname: (%s)\n", restname);
        fclose(fempty);

        // 更新EMPTY_FILE
        fempty = fopen(EMPTY_FILE, "w");
        fwrite(restname, strlen(restname), sizeof(char), fempty);
        fclose(fempty);

        memset(restname, 0x00, sizeof(restname));

        // 构建消息
        sprintf(msg.str, "Hello, I am Writer_ pid: %d, msg_no: %d", getpid(), count);
        sprintf(msg.num, "%03d", 0); // 假设初始读者数量为0

        // 写入空缓冲区
        fempty = fopen(emptyname, "w");
        fwrite(msg.str, strlen(msg.str), sizeof(char), fempty);
        fwrite(msg.num, strlen(msg.num), sizeof(char), fempty);
        fclose(fempty);

        printf("%s\n", msg.str);
        printf("%s\n", msg.num);

        // 验证信号量值
        if (semctl(semid, 0, GETALL, outarray) == -1) {
            perror("Error getting semaphore values");
            return 1;
        }
        printf("Semaphore values: %d, %d, %d\n", outarray[0], outarray[1], outarray[2]);

        // 如果满缓冲区计数为0，唤醒读者
        if (outarray[2] == 0) {
            vsembuf[1].sem_num = second;
            vsembuf[0].sem_num = area;
            if (semop(semid, vsembuf, 2) == -1) {
                perror("Error in V operation");
                return 1;
            }
            if (semctl(semid, 0, GETALL, outarray) == -1) {
                perror("Error getting semaphore values");
                return 1;
            }
            printf("After V area and reader, semaphore values: %d, %d, %d\n", outarray[0], outarray[1], outarray[2]);
        } else {
            vsembuf[0].sem_num = area;
            if (semop(semid, vsembuf, 1) == -1) {
                perror("Error in V operation");
                return 1;
            }
            if (semctl(semid, 0, GETALL, outarray) == -1) {
                perror("Error getting semaphore values");
                return 1;
            }
            printf("After V area, semaphore values: %d, %d, %d\n", outarray[0], outarray[1], outarray[2]);
        }
    }

    return 0;
}

### s2.c: 读者进程

#include <sys/types.h>
#include <sys/ipc.h>
#include <sys/sem.h>
#include <signal.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <unistd.h>

#define SEM_FILE "sem_name.tmp"
#define EMPTY_FILE "empty.txt"
#define FULL_FILE "full.txt"
#define MAX_MSG_NUM 10000

int semid;
unsigned int count;
struct sembuf psembuf[2], vsembuf[2];

typedef struct {
    char str[100];
    char num[6];
} Msg;

int main(int argc, char *argv[]) {
    int k = 10, n = 2, area = 0, first = 2, second = 1, msg_no = 0, readers = n, receive_msg_no = 0, has_read = 0, empty_add_num = 0;
    int Read = 0;
    char emptyname[20], restname[k * 20];
    FILE *fempty, *full, *fp;
    key_t key;
    Msg msg;
    char receive_msg[MAX_MSG_NUM][100];
    short outarray[3];

    // 初始化
    memset(emptyname, 0x00, 20);
    memset(restname, 0x00, k * 20);
    memset(msg.str, 0x00, sizeof(msg.str));
    memset(msg.num, 0x00, sizeof(msg.num));
    for (int i = 0; i < MAX_MSG_NUM; i++)
        memset(receive_msg[i], 0x00, 100);

    // 生成键值
    key = ftok(SEM_FILE, 'a');
    printf("Key = %u\n", key);
    if (key == -1) {
        perror("Error generating key");
        return 1;
    }

    // 获取信号量集
    semid = semget(key, 3, 0777);
    printf("Semaphore ID = %d\n", semid);
    if (semid == -1) {
        perror("Error getting semaphore");
        return 1;
    }

    // 设置P操作和V操作
    psembuf[0].sem_op = -1;
    psembuf[0].sem_flg = SEM_UNDO;
    vsembuf[0].sem_op = 1;
    vsembuf[0].sem_flg = SEM_UNDO;

    psembuf[1].sem_op = -1;
    psembuf[1].sem_flg = SEM_UNDO;
    vsembuf[1].sem_op = 1;
    vsembuf[1].sem_flg = SEM_UNDO;

    // 验证初始化
    if (semctl(semid, 0, GETALL, outarray) == -1) {
        perror("Error getting semaphore values");
        return 1;
    }
    printf("Semaphore initial values: %d, %d, %d\n", outarray[0], outarray[1], outarray[2]);

    for (count = 0;; count++) {
        empty_add_num = 0;
        printf("Count = %d, Receive message number = %d\n", count, receive_msg_no);

        psembuf[0].sem_num = area;
        psembuf[1].sem_num = first;

        // P操作
        if (semop(semid, psembuf, 2) == -1) {
            perror("Error in P operation");
            return 1;
        }

        // 验证信号量值
        if (semctl(semid, 0, GETALL, outarray) == -1) {
            perror("Error getting semaphore values");
            return 1;
        }
        printf("After P, semaphore values: %d, %d, %d\n", outarray[0], outarray[1], outarray[2]);

        // 读取FULL_FILE中的满缓冲区名称
        full = fopen(FULL_FILE, "r");
        if (full == NULL) {
            perror("Error opening full file");
            return 1;
        }

        int i = 0;
        memset(restname, 0x00, k * 20);
        size_t bytesRead = fread(restname, sizeof(char), 10, full);

        while (bytesRead > 0) {
            has_read = 0;
            fp = fopen(restname, "r");
            if (fp == NULL) {
                perror("Error opening temp file");
                continue;
            }

            fgets(msg.str, 100, fp);
            fgets(msg.num, 10, fp);

            printf("File: %s, Message: %s\n", restname, msg.str);
            printf("File: %s, Number: %s\n", restname, msg.num);

            for (int j = 0; j < receive_msg_no && !has_read; j++) {
                if (strcmp(receive_msg[j], msg.str) == 0) {
                    printf("The message has been read!\n");
                    has_read = 1;
                }
            }

            if (has_read) {
                memset(restname, 0x00, k * 20);
                bytesRead = fread(restname, sizeof(char), 10, full);
                fclose(fp);
                continue;
            } else {
                strcpy(receive_msg[(receive_msg_no++) % MAX_MSG_NUM], msg.str);
            }

            printf("Message number: %d\n", atoi(msg.num));

            if (atoi(msg.num) == 2495) {
                empty_add_num++;
                printf("I am the last reader for file: %s, I will empty it and add its name to file: %s!\n", restname, EMPTY_FILE);
                printf("%s\n", msg.str);
                printf("%s\n", msg.num);

                fclose(fp);
                fp = fopen(restname, "w");
                if (fp == NULL) {
                    perror("Error opening temp file for writing");
                    continue;
                }
                fclose(fempty);
                fempty = fopen(EMPTY_FILE, "a");
                if (fempty == NULL) {
                    perror("Error opening empty file for appending");
                    continue;
                }
                fwrite(restname, strlen(restname), sizeof(char), fempty);
                fclose(fempty);

                memset(restname, 0x00, k * 20);
                i = 0;
                bytesRead = fread(restname + i * 10, sizeof(char), 10, full);
                while (bytesRead > 0) {
                    i++;
                    bytesRead = fread(restname + i * 10, sizeof(char), 10, full);
                }
                printf("Rest restname: (%s)\n", restname);

                fclose(full);
                full = fopen(FULL_FILE, "w");
                if (full == NULL) {
                    perror("Error opening full file for writing");
                    continue;
                }
                fwrite(restname, strlen(restname),