libdill: Structured Concurrency for C

NAME

tcp_listen_mem - starts listening for incoming TCP connections

SYNOPSIS

#include <libdill.h>

int tcp_listen_mem(
    const struct ipaddr* addr,
    int backlog,
    struct tcp_listener_storage* mem);

DESCRIPTION

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

This function starts listening for incoming connections. The connections can be accepted using tcp_accept function.

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

addr: IP address to listen on.

backlog: Maximum number of connections that can be kept open without accepting them.

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

The socket can be closed either by hclose or tcp_close. Both ways are equivalent.

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

RETURN VALUE

In case of success the function returns newly created socket. In case of error it returns -1 and sets errno to one of the values below.

ERRORS

EADDRINUSE: The specified address is already in use.
EADDRNOTAVAIL: The specified address is not available from the local machine.
EINVAL: Invalid argument.
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.

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);