调用deleteQueue:
LoadBalancer.exe中0x00007FF8E378169C (ucrtbased.dll)抛出异常:0xC0000005:访问冲突读取位置0xffffffffffffffffffffff .
创建队列函数:
queue_t* createQueue(unsigned capacity){
queue_t* queue = (queue_t*)malloc(sizeof(queue_t));
if (queue == NULL)
{
return NULL;
}
queue->capacity = capacity;
queue->array = (char**)malloc(sizeof(char*) * queue->capacity);
queue->size = 0;
queue->front = 0;
queue->rear = -1;
InitializeCriticalSection(&(queue->cs));
return queue;
}
排队:
void enqueue(queue_t* queue, char* string){
EnterCriticalSection(&(queue->cs));
if (isFull(queue)) {
LeaveCriticalSection(&(queue->cs));
return;
}
queue->rear = (queue->rear + 1) % queue->capacity;
queue->size = queue->size + 1;
char* ptr = (char*)malloc(strlen(string)+1);
memcpy(ptr, string, strlen(string)+1);
queue->array[queue->rear] = ptr;
LeaveCriticalSection(&(queue->cs));
return;
}
删除队列功能:
void deleteQueue(queue_t* queue){
DeleteCriticalSection(&(queue->cs));
if (queue != NULL)
{
for (int i = 0; i < queue->capacity; i++) {
free(queue->array[i]);
}
free(queue->array);
free(queue);
}
}
我应该释放指针,以及在dequeue程序中断与相同的异常?
char* dequeue(queue_t* queue){
EnterCriticalSection(&(queue->cs));
if (isEmpty(queue)) {
LeaveCriticalSection(&(queue->cs));
return NULL;
}
char* temp = queue->array[queue->front];
queue->front = (queue->front + 1) % queue->capacity;
queue->size = queue->size - 1;
LeaveCriticalSection(&(queue->cs));
return temp;
}
对于初学者,您分配了一个值不确定的指针数组。
queue->array = (char**)malloc(sizeof(char*) * queue->capacity);
在函数deleteQueue
for (int i = 0; i < queue->capacity; i++) {
free(queue->array[i]);
}
可以调用未定义的行为。应该用空指针初始化数组。例如,不使用函数malloc
,可以使用函数calloc
。
其次,在函数dequeue
中,在该语句之后
char* temp = queue->array[queue->front];
你应该写
queue->array[queue->front] = NULL;
释放返回的字符串是用户的责任。