探索进程控制块（PCB）的概念与实际应用

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

#define MAX_FILES 10

// 定义进程状态枚举类型
typedef enum {
    READY,
    RUNNING,
    BLOCKED,
    TERMINATED
} ProcessState;

// 定义 PCB 结构体
typedef struct {
    int pid; // 进程 ID
    int ppid; // 父进程 ID
    ProcessState state; // 进程状态
    int priority; // 优先级
    void *memoryBase; // 内存基地址
    size_t memorySize; // 内存大小
    int fileDescriptors[MAX_FILES]; // 打开文件描述符
    int cpuTime; // 已使用的 CPU 时间
} PCB;

// 创建一个新的 PCB
PCB *createPCB(int pid, int ppid, ProcessState state, int priority, void *memoryBase, size_t memorySize) {
    PCB *pcb = (PCB *)malloc(sizeof(PCB));
    if (!pcb) {
        perror("Failed to allocate memory for PCB");
        exit(EXIT_FAILURE);
    }
    pcb->pid = pid;
    pcb->ppid = ppid;
    pcb->state = state;
    pcb->priority = priority;
    pcb->memoryBase = memoryBase;
    pcb->memorySize = memorySize;
    memset(pcb->fileDescriptors, -1, sizeof(pcb->fileDescriptors));
    pcb->cpuTime = 0;
    return pcb;
}

// 打印 PCB 信息
void printPCB(PCB *pcb) {
    if (!pcb) return;
    printf("Process ID: %d\n", pcb->pid);
    printf("Parent Process ID: %d\n", pcb->ppid);
    printf("State: %d\n", pcb->state);
    printf("Priority: %d\n", pcb->priority);
    printf("Memory Base: %p\n", pcb->memoryBase);
    printf("Memory Size: %zu\n", pcb->memorySize);
    printf("CPU Time: %d\n", pcb->cpuTime);
}

int main() {
    PCB *pcb = createPCB(1, 0, READY, 5, (void *)0x1000, 4096);
    printPCB(pcb);
    free(pcb);
    return 0;
}