dragon.native.event

The Dragon native event is an object that is used for signaling between threads or processes.

One thread or process signals an event and the other waits. When the waiting thread is signalled, the waiting thread is activated.

Classes

Event

This class implements Event objects with a Dragon channel.

class Event

Bases: object

This class implements Event objects with a Dragon channel. The event sends and receives bytes of the message with the respective functions set and clear. Wait is the function that waits for bytes to be written into the channel

__init__(m_uid: int = 4611686018427387904): Initialize an event object :param m_uid: memory pool to create the channel in, defaults to _DEF_MUID :type m_uid: int, optional

set() → None

Set the event.

Set writes a messsage into the channel.

Returns:: None
Return type:: NoneType

is_set() → bool

Returns if the event has been set. Polls the channel for the message.

Returns:: Results from a channel poll with a timeout set to 0.
Return type:: bool

wait(timeout: float | None = None) → bool

Wait for the timeout to elapse and poll for the message in the channel.

Parameters:: timeout (float, optional) – how long to block in seconds, defaults to None
Returns:: if the event has been set
Return type:: bool

clear() → None

Clears the event once the message from the channel has been received.

Clear receives a messsage from the channel

Returns:: None
Return type:: NoneType

destroy()

Destroys the underlying Dragon resources so the space can be re-used.

Destroys underlying Dragon resource. Only do this when you know all references to the object have been deleted.

Returns:: None
Return type:: NoneType