将参数传递给_beginthread() - 什么是错的？

Question

我有这个代码,我没有得到预期的结果......什么是错的？

typedef struct {
   int data1;
   int data2;
}t;

void foo(int a, int b) {

   Handle handle;
   t arg;
   arg.data1 = a;
   arg.data2 = b;
   handle = (HANDLE) _beginthread( myFunc, 0, (void*) &arg);
}

void myFunc(void *param) {
   t *args = (t*) param;
   int x = args->data1;
   int y = args->data2;
   printf("x=%d, y=%d\n", x, y);
} 

Answer 1

arg是一个定义的局部变量foo- 它会在该函数结束时被销毁,但是myFunc在另一个线程中运行它仍然会尝试访问它.你应该arg在堆上分配并在完成后在线程中销毁它.

void foo(int a, int b) {
   HANDLE handle;
   t *arg;
   arg = (t *)malloc(sizeof(t));
   arg->data1 = a;
   arg->data2 = b;
   handle = (HANDLE) _beginthread( myFunc, 0, (void*) arg);
}

void myFunc(void *param) {
   t *args = (t*) param;
   int x = args->data1;
   int y = args->data2;
   printf("x=%d, y=%d\n", x, y);
   free(args);
}

还要注意HANDLE应该全部上限.