如何将多个参数传递给c中的客户端服务器的线程？

I want to create a concurrent server to work on multiple client request. So I created a thread function to handle multiple request . My problem is I have a hash table , it is loaded with contents of file initially whenever server start and I have socket descriptor, file descriptor too. So how can I pass to thread function .Is it required structure to store the arguments and pass to thread ?

我想创建一个并发服务器来处理多个客户端请求。所以我创建了一个线程函数来处理多个请求。我的问题是我有一个哈希表,每当服务器启动它时都会加载文件的内容,我也有套接字描述符,文件描述符。那么我怎样才能传递给线程函数。是否需要结构来存储参数并传递给线程?

my code is like this :

我的代码是这样的:

struct UserData
{
    char *username; 
    char *password;

};

struct HashTable
 {
    int size;
    struct UserData *table
 };

int main()
{
 struct HashTable *htable;
  //socket sd to open socket in server
  and a Fd file descriptor to write to file
 // hash table loaded with contents and it is a structure
 /*create thread using pthread*/
 pthread_create(...,fun,..);

 }

 void * fun(void *arg)
 {
  .............
  }

how I declare a structure for passing to thread function including the arguments like socket descriptor (sd) ,file descriptor(fd) and hash table pointer ? will I use mutex to lock when I writing to file (fd) ?

我如何声明一个传递给线程函数的结构,包括socket descriptor(sd),file descriptor(fd)和hash table pointer这样的参数?我写文件(fd)时会使用互斥锁吗?

1 个解决方案

#1

pthread_create() takes a void * as its final argument, which gets passed to your thread entry function, fun() in your case. So you would just need to define a struct that contains all the fields you want to pass:

pthread_create()接受一个void *作为它的最后一个参数,它将被传递给你的线程入口函数fun()。所以你只需要定义一个包含你想要传递的所有字段的结构:

struct ThreadArg {
    int sd; /* socket descriptor */
    int fd; /* file descriptor */
    struct HashTable *ht;
};

Then in your main() you fill it in and pass it to pthread_create():

然后在main()中填写并传递给pthread_create():

...
struct ThreadArg *arg = malloc(sizeof(struct ThreadArg)); /* you should check for NULL */
arg->sd = sd;
arg->fd = fd;
arg->ht = htable;
pthread_create(..., fun, (void *)arg);
...

And in fun() you cast it back:

在fun()中,你把它丢回来:

void *fun(void *arg) {
    struct ThreadArg *thArg = (struct ThreadArg *)arg;
    /* do whatever with thArg->sd, thArg->fd, etc. */
    ...
    /* free the memory when done */
    free(arg);
}

#1