c - 在C中为结构的属性设置默认值

Question

我有一个结构(用 C 语言)声明如下:

struct readyQueue
{
    int start;
    int total_CPU_burst;
    int CPU_burst;
    int CPU_bursted;
    int IO_burst;
    int CPU;
    struct readyQueue *next;
};
struct readyQueue *readyStart = NULL;
struct readyQueue *readyRear = NULL;

readyStart = mallow(sizeof(struct readyQueue) * 1);
readyRear = mallow(sizeof(struct readyQueue) * 1);

我想默认设置 readyStart->CPU = -1 , readyRead->CPU = -1, CPUchoose->CPU = -1 这意味着如果我像那样声明新的 readyQueue 结构

struct readyQueue *CPUchoose = NULL;
CPUchoose = mallow(sizeof(struct readyQueue) * 1);

然后CPUchoose->CPU也==-1，我试过这样delare readyQueue

 struct readyQueue
    {
        int start;
        int total_CPU_burst;
        int CPU_burst;
        int CPU_bursted;
        int IO_burst;
        int CPU = -1;
        struct readyQueue *next;
    };

但是当我构建代码时出现错误，谁能帮帮我

Answer 1

创建一个函数来完成它:

struct readyQueue* create_readyQueue()
{
    struct readyQueue* ret = malloc( sizeof( struct readyQueue ) );
    ret->CPU = -1;
    // ...
    return ret;
}

struct readyQueue* CPUchoose = create_readyQueue();

您还必须记住释放内存，因此最好传入一个指向初始化函数的指针。

void init_readyQueue( struct readyQueue* q )
{
   q->CPU = -1;
   // ...
}


struct readyQueue* CPUchoose = malloc( sizeof( struct readyQueue ) );
init_readyQueue( CPUchoose );
// clearer that you are responsible for freeing the memory since you allocate it.