c - pthread 指针数组

Question

我正在尝试动态分配一个 pthread 指针数组，但得到这个 glibc 错误:

*** glibc detected *** ./test: realloc(): invalid next size: 0x00000000084d2010 ***

代码:

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

int main(int argc, char** argv) {
    pthread_t **threads;
    int i;

    for(i=1;i<100;i++) {
        threads = realloc(threads, sizeof(pthread_t*)*i);
        threads[i] = malloc(sizeof(pthread_t));
    }

   return EXIT_SUCCESS;
}

我做错了什么？

Answer 1

• 您应该初始化线程(重点是我的)。

C11 (n1570), § 7.22.3.5 The realloc function

If ptr is a null pointer, the realloc function behaves like the malloc function for the specified size. Otherwise, if ptr does not match a pointer earlier returned by a memory management function, or if the space has been deallocated by a call to the free or realloc function, the behavior is undefined.

• sizeof(pthread_t *) * i 没有分配足够的内存来访问 thread[i]。您必须分配 ((sizeof(pthread_t *) * (i + 1))。