libdill: Structured Concurrency for C

NAME

suffix_attach_mem - creates SUFFIX protocol on top of underlying socket

SYNOPSIS

#include <libdill.h>

int suffix_attach_mem(
    int s,
    const void* suffix,
    size_t suffixlen,
    struct suffix_storage* mem);

DESCRIPTION

SUFFIX is a message-based protocol that delimits messages by specific byte sequences. For example, many protocols are line-based, with individual messages separated by CR+LF sequence.

This function instantiates SUFFIX protocol on top of the underlying protocol.

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

s: Handle of the underlying socket. It must be a bytestream protocol.

suffix: The delimiter byte sequence.

suffixlen: The size of the delimiter, in bytes.

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

The socket can be cleanly shut down using suffix_detach function.

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

ERRORS

EBADF: Invalid handle.
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.
EPROTO: Underlying socket is not a bytestream socket.

EXAMPLE

        int s = tcp_connect(&addr, -1);
        s = suffix_attach(s, "
", 2);
        msend(s, "ABC", 3, -1);
        char buf[256];
        ssize_t sz = mrecv(s, buf, sizeof(buf), -1);
        s = suffix_detach(s, -1);
        tcp_close(s);