Connection management

Functions
int	amxp_connection_add (int fd, amxp_fd_cb_t reader, const char *uri, uint32_t type, void *priv)
	Adds a file descriptor (fd) to the list of fds that must be watched. More...
int	amxp_connection_wait_write (int fd, amxp_fd_cb_t can_write_cb)
	Adds a watcher to check if a fd is ready for write. More...
int	amxp_connection_remove (int fd)
	Removes the fd from the connection list. More...
amxp_connection_t *	amxp_connection_get (int fd)
	Gets the connection data for a file descriptor. More...
amxp_connection_t *	amxp_connection_get_first (uint32_t type)
	Gets the first connection of the given type. More...
amxp_connection_t *	amxp_connection_get_next (amxp_connection_t *con, uint32_t type)
	Gets the next connection data for a file descriptor. More...
int	amxp_connection_set_el_data (int fd, void *el_data)
	Sets event-loop data. More...
amxc_llist_t *	amxp_connection_get_connections (void)
	Get a list of the current connections of the application. More...
amxc_llist_t *	amxp_connection_get_listeners (void)
	Get of the current listen sockets of the application. More...

Detailed Description

Function Documentation

amxp_connection_add()

int amxp_connection_add	(	int	fd,
		amxp_fd_cb_t	reader,
		const char *	uri,
		uint32_t	type,
		void *	priv
	)

Adds a file descriptor (fd) to the list of fds that must be watched.

This function will trigger the signal "connection-added" or "listen-added" depending on the type given.

If the type given is "AMXP_CONNECTION_LISTEN" the fd will be added to the list of listen fds and the signal "listen-added" is triggered.

A callback function must be given. This callback function is called whenever data is available for read.

Parameters

fd	the fd that must be watched
reader	the read callback function, is called when data is available for read
uri	(option, can be NULL) a uri representing the fd
type	one of AMXP_CONNECTION_BUS, AMXP_CONNECTION_LISTEN, AMXP_CONNECTION_CUSTOM
priv	private data, will be passed to the callback function

Returns

Returns 0 when success, any other value indicates failure.

Definition at line 129 of file amxp_connections.c.

                                    {
    int retval = -1;
    amxp_connection_t* con = NULL;
 
    when_null(reader, exit);
    when_true(fd < 0, exit);
 
    retval = amxp_can_add_connection(fd, type);
    when_failed(retval, exit);
 
    retval = -1;
    con = (amxp_connection_t*) calloc(1, sizeof(amxp_connection_t));
    when_null(con, exit);
 
    con->uri = uri == NULL ? NULL : strdup(uri);
    con->fd = fd;
    con->priv = priv;
    con->type = type;
 
    retval = amxp_connection_add_impl(con, reader);
 
exit:
    if(retval != 0) {
        free(con);
    }
    return retval;
}

amxp_connection_get()

amxp_connection_t* amxp_connection_get

(

int

fd

)

Gets the connection data for a file descriptor.

Searches the connection data for the given fd. The connection data is stored in the amxp_connection_t structure.

Parameters

fd	the fd associated with the connection

Returns

returns pointer to the connection data or NULL if no data is found.

Definition at line 212 of file amxp_connections.c.

                                               {
    amxp_connection_t* con = NULL;
 
    con = amxp_connection_get_internal(&connections, fd);
    if(con != NULL) {
        goto exit;
    }
    con = amxp_connection_get_internal(&listeners, fd);
 
exit:
    return con;
}

amxp_connection_get_connections()

amxc_llist_t* amxp_connection_get_connections

(

void

)

Get a list of the current connections of the application.

At runtime an application can be connected to a number of sockets. This function retrieves a list of sockets the app is connected to.

Returns

A list with all active socket connections.

Definition at line 279 of file amxp_connections.c.

                                                    {
    return &connections;
}

amxp_connection_get_first()

amxp_connection_t* amxp_connection_get_first

(

uint32_t

type

)

Gets the first connection of the given type.

Parameters

type	one of AMXP_CONNECTION_BUS, AMXP_CONNECTION_LISTEN, AMXP_CONNECTION_CUSTOM

Returns

returns pointer to the connection data or NULL if no data is found.

Definition at line 225 of file amxp_connections.c.

                                                            {
    amxp_connection_t* con = NULL;
 
    amxc_llist_for_each(it, &connections) {
        con = amxc_llist_it_get_data(it, amxp_connection_t, it);
        if(con->type == type) {
            break;
        }
        con = NULL;
    }
 
    return con;
}

amxp_connection_get_listeners()

amxc_llist_t* amxp_connection_get_listeners

(

void

)

Get of the current listen sockets of the application.

While an application is running, it can have a list of of open listen sockets that other applications can connect to.

Returns

A list with all open listen sockets.

Definition at line 283 of file amxp_connections.c.

                                                  {
    return &listeners;
}

amxp_connection_get_next()

amxp_connection_t* amxp_connection_get_next	(	amxp_connection_t *	con,
		uint32_t	type
	)

Gets the next connection data for a file descriptor.

Parameters

con	starting point reference
type	one of AMXP_CONNECTION_BUS, AMXP_CONNECTION_LISTEN, AMXP_CONNECTION_CUSTOM

Returns

returns pointer to the connection data or NULL if no data is found.

Definition at line 239 of file amxp_connections.c.

                                                           {
    amxc_llist_it_t* it = NULL;
    when_null(con, exit);
    when_true(con->it.llist != &connections, exit);
 
    it = amxc_llist_it_get_next(&con->it);
    con = NULL;
    while(it) {
        con = amxc_llist_it_get_data(it, amxp_connection_t, it);
        if(con->type == type) {
            break;
        }
        con = NULL;
        it = amxc_llist_it_get_next(it);
    }
 
exit:
    return con;
}

amxp_connection_remove()

int amxp_connection_remove

(

int

fd

)

Removes the fd from the connection list.

This function triggers the signal "connection-deleted".

Event-loop implementations can connect to this signal and when it is triggered remove the watchers for the given fd.

Parameters

fd	the fd that must be watched

Returns

Returns 0 when success, any other value indicates failure.

Definition at line 186 of file amxp_connections.c.

                                   {
    int retval = -1;
    amxp_connection_t* con = NULL;
    amxc_var_t var_fd;
    const char* signal = "connection-deleted";
 
    amxc_var_init(&var_fd);
 
    con = amxp_connection_get_internal(&connections, fd);
    if(con == NULL) {
        signal = "listen-deleted";
        con = amxp_connection_get_internal(&listeners, fd);
    }
    when_null(con, exit);
 
    amxc_var_set(fd_t, &var_fd, fd);
    amxp_sigmngr_trigger_signal(NULL, signal, &var_fd);
    amxc_llist_it_clean(&con->it, amxp_connection_free);
 
    retval = 0;
 
exit:
    amxc_var_clean(&var_fd);
    return retval;
}

amxp_connection_set_el_data()

int amxp_connection_set_el_data	(	int	fd,
		void *	el_data
	)

Sets event-loop data.

This function is typically used by event-loop implementations to set event-loop specific data for the connection

Parameters

fd	the fd that must be watched
el_data	some event loop data

Returns

Returns 0 when success, any other value indicates failure.

Definition at line 260 of file amxp_connections.c.

                                               {
    int retval = -1;
    amxp_connection_t* con = NULL;
 
    con = amxp_connection_get_internal(&connections, fd);
    if(con == NULL) {
        con = amxp_connection_get_internal(&listeners, fd);
    }
 
    when_null(con, exit);
    con->el_data = el_data;
 
    retval = 0;
 
exit:
    return retval;
}

amxp_connection_wait_write()

int amxp_connection_wait_write	(	int	fd,
		amxp_fd_cb_t	can_write_cb
	)

Adds a watcher to check if a fd is ready for write.

It can happen that a fd is not ready for write. Most of the time the write fails with error code EAGAIN or EWOULDBLOCK. Whenever this happens it is possible to indicate to the event-loop implementation that the fd must be watched and a callback must be called as soon as the fd is available again for writing.

Another use case for this function is a asynchronous connect.

This function will trigger the signal "connection-wait-write". Event-loop implementations can connect to this signal, to add a watcher for the fd.

Typically when the fd is ready for write the watcher is removed.

Note

Before calling this function make sure the fd is added to the list of connections using amxp_connection_add

Parameters

fd	the fd that must be watched
can_write_cb	a callback function called when the socket is available for write

Returns

Returns 0 when success, any other value indicates failure.

Definition at line 161 of file amxp_connections.c.

                                                          {
    int retval = -1;
    amxp_connection_t* con = NULL;
    amxc_var_t var_fd;
    const char* signal = "connection-wait-write";
 
    amxc_var_init(&var_fd);
    when_true(fd < 0, exit);
    when_null(can_write_cb, exit);
 
    con = amxp_connection_get_internal(&connections, fd);
    when_null(con, exit);
 
    amxc_var_set(fd_t, &var_fd, fd);
    amxp_sigmngr_trigger_signal(NULL, signal, &var_fd);
    con->can_write = can_write_cb;
 
    retval = 0;
 
exit:
    amxc_var_clean(&var_fd);
    return retval;
}