A handler for Proton messaging events. More...
#include <messaging_handler.hpp>
Public Member Functions | |
virtual void | on_container_start (container &) |
The container event loop is starting. | |
virtual void | on_container_stop (container &) |
The container event loop is stopping. | |
virtual void | on_message (delivery &, message &) |
A message is received. | |
virtual void | on_sendable (sender &) |
A message can be sent. | |
virtual void | on_transport_open (transport &) |
The underlying network transport is open. | |
virtual void | on_transport_close (transport &) |
The underlying network transport has closed. | |
virtual void | on_transport_error (transport &) |
The underlying network transport has closed with an error condition. | |
virtual void | on_connection_open (connection &) |
The remote peer opened the connection. | |
virtual void | on_connection_close (connection &) |
The remote peer closed the connection. | |
virtual void | on_connection_error (connection &) |
The remote peer closed the connection with an error condition. | |
virtual void | on_session_open (session &) |
The remote peer opened the session. | |
virtual void | on_session_close (session &) |
The remote peer closed the session. | |
virtual void | on_session_error (session &) |
The remote peer closed the session with an error condition. | |
virtual void | on_receiver_open (receiver &) |
The remote peer opened the link. | |
virtual void | on_receiver_detach (receiver &) |
The remote peer detached the link. | |
virtual void | on_receiver_close (receiver &) |
The remote peer closed the link. | |
virtual void | on_receiver_error (receiver &) |
The remote peer closed the link with an error condition. | |
virtual void | on_sender_open (sender &) |
The remote peer opened the link. | |
virtual void | on_sender_detach (sender &) |
The remote peer detached the link. | |
virtual void | on_sender_close (sender &) |
The remote peer closed the link. | |
virtual void | on_sender_error (sender &) |
The remote peer closed the link with an error condition. | |
virtual void | on_tracker_accept (tracker &) |
The receiving peer accepted a transfer. | |
virtual void | on_tracker_reject (tracker &) |
The receiving peer rejected a transfer. | |
virtual void | on_tracker_release (tracker &) |
The receiving peer released a transfer. | |
virtual void | on_tracker_settle (tracker &) |
The receiving peer settled a transfer. | |
virtual void | on_delivery_settle (delivery &) |
The sending peer settled a transfer. | |
virtual void | on_sender_drain_start (sender &) |
**Unsettled API** - The receiving peer has requested a drain of remaining credit. | |
virtual void | on_receiver_drain_finish (receiver &) |
**Unsettled API** - The credit outstanding at the time of the drain request has been consumed or returned. | |
virtual void | on_connection_wake (connection &) |
**Unsettled API** - An event that can be triggered from another thread. | |
virtual void | on_error (const error_condition &) |
Fallback error handling. |
A handler for Proton messaging events.
Subclass and override the event-handling member functions.
Event handling functions can always use the objects passed as arguments.
Thread-safety**: To be safe for both single- and multi-threaded use, a handler **must not** directly use objects belonging to another connection. See mt_page and proton::work_queue for safe ways to communicate. We recommend writing safe handlers to avoid mysterious failures if the handler is ever used in a multi-threaded container.
Single-threaded only**: An application is single-threaded if it calls container::run() exactly once, and does not make proton calls from any other thread. In this case a handler can use objects belonging to another connection, but it must call connection::wake() on the other connection before returning. Such a handler will fail mysteriously if the container is run with multiple threads.
#### Close and error handling
There are several objects that have `on_X_close` and `on_X_error` functions. They are called as follows:
By default, if you do not implement `on_X_error`, it will call `on_error`. If you do not implement `on_error` it will throw a `protonerror` exception, which may not be what you want but does help to identify forgotten error handling quickly.
#### Resource cleanup
Every `on_X_open` event is paired with an `on_X_close` event which can clean up any resources created by the open handler. In particular this is still true if an error is reported with an `on_X_error` event. The error-handling logic doesn't have to manage resource clean up. It can assume that the close event will be along to handle it.
virtual void on_container_start | ( | container & | ) | [virtual] |
The container event loop is starting.
This is the first event received after calling `containerrun()`.
virtual void on_container_stop | ( | container & | ) | [virtual] |
virtual void on_transport_error | ( | transport & | ) | [virtual] |
virtual void on_sender_drain_start | ( | sender & | ) | [virtual] |
**Unsettled API** - The receiving peer has requested a drain of remaining credit.
virtual void on_receiver_drain_finish | ( | receiver & | ) | [virtual] |
**Unsettled API** - The credit outstanding at the time of the drain request has been consumed or returned.
virtual void on_connection_wake | ( | connection & | ) | [virtual] |
**Unsettled API** - An event that can be triggered from another thread.
This event is triggered by a call to `connectionwake()`. It is used to notify the application that something needs attention.
Thread-safety** - The application handler and the triggering thread must use some form of thread-safe state or communication to tell the handler what it needs to do. See `protonwork_queue` for an easier way to execute code safely in the handler thread.