libdill: Structured Concurrency for C

NAME

tcp_accept_mem - accepts an incoming TCP connection

SYNOPSIS

#include <libdill.h>

int tcp_accept_mem(
    int s,
    struct ipaddr* addr,
    struct tcp_storage* mem,
    int64_t deadline);

DESCRIPTION

TCP protocol is a reliable bytestream protocol for transporting data over network. It is defined in RFC 793.

This function accepts an incoming TCP connection.

This function allows to avoid one dynamic memory allocation by storing the object in user-supplied memory. Unless you are hyper-optimizing use tcp_accept instead.

s: Socket created by tcp_listen.

addr: Out parameter. IP address of the connecting endpoint. Can be NULL.

mem: The structure to store the newly created object in. It must not be deallocated before the object is closed.

deadline: A point in time when the operation should time out, in milliseconds. Use the now function to get your current point in time. 0 means immediate timeout, i.e., perform the operation if possible or return without blocking if not. -1 means no deadline, i.e., the call will block forever if the operation cannot be performed.

The socket can be cleanly shut down using tcp_close function.

This function is not available if libdill is compiled with --disable-sockets option.

RETURN VALUE

In case of success the function returns handle of the new connection. In case of error it returns -1 and sets errno to one of the values below.

ERRORS

EBADF: Invalid handle.
ECANCELED: Current coroutine was canceled.
EMFILE: The maximum number of file descriptors in the process are already open.
ENFILE: The maximum number of file descriptors in the system are already open.
ENOMEM: Not enough memory.
ENOTSUP: The handle does not support this operation.
ETIMEDOUT: Deadline was reached.

EXAMPLE

struct ipaddr addr;
ipaddr_local(&addr, NULL, 5555, 0);
int ls = tcp_listen(&addr, 10);
int s = tcp_accept(ls, NULL, -1);
bsend(s, "ABC", 3, -1);
char buf[3];
brecv(s, buf, sizeof(buf), -1);
tcp_close(s);
tcp_close(ls);