linux 进程 线程 区别

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

void child_process() {
    printf("Child process\n");
}

int main() {
    pid_t pid = fork();
    if (pid == 0) { // 子进程
        child_process();
    } else if (pid > 0) { // 父进程
        printf("Parent process\n");
    } else {
        perror("fork");
        exit(EXIT_FAILURE);
    }
    return 0;
}

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

void* thread_function(void* arg) {
    printf("Thread running\n");
    return NULL;
}

int main() {
    pthread_t thread;
    int result = pthread_create(&thread, NULL, thread_function, NULL);
    if (result != 0) {
        perror("pthread_create");
        exit(EXIT_FAILURE);
    }
    pthread_join(thread, NULL);
    printf("Thread finished\n");
    return 0;
}

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

int shared_data = 0;
pthread_mutex_t mutex;

void* thread_function(void* arg) {
    for (int i = 0; i < 100000; ++i) {
        pthread_mutex_lock(&mutex);
        shared_data++;
        pthread_mutex_unlock(&mutex);
    }
    return NULL;
}

int main() {
    pthread_t thread1, thread2;
    pthread_mutex_init(&mutex, NULL);

    pthread_create(&thread1, NULL, thread_function, NULL);
    pthread_create(&thread2, NULL, thread_function, NULL);

    pthread_join(thread1, NULL);
    pthread_join(thread2, NULL);

    printf("Shared data: %d\n", shared_data);
    pthread_mutex_destroy(&mutex);
    return 0;
}