linux c全局变量

// file1.c
static int global_var = 10;

// file2.c
static int global_var = 20;

// global_var.h
extern int global_var;

// global_var.c
int global_var = 0;

// main.c
#include "global_var.h"

void init_global_var() {
    global_var = 10;
}

int main() {
    init_global_var();
    return 0;
}

#include <pthread.h>

int global_var = 0;
pthread_mutex_t mutex;

void* thread_func(void* arg) {
    pthread_mutex_lock(&mutex);
    global_var++;
    pthread_mutex_unlock(&mutex);
    return NULL;
}

int main() {
    pthread_t thread1, thread2;
    pthread_mutex_init(&mutex, NULL);
    pthread_create(&thread1, NULL, thread_func, NULL);
    pthread_create(&thread2, NULL, thread_func, NULL);
    pthread_join(thread1, NULL);
    pthread_join(thread2, NULL);
    pthread_mutex_destroy(&mutex);
    return 0;
}