microbit-dal/source/MicroBitListener.cpp

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/**
* Class definition for a MicroBitListener.
*
* MicroBitListener holds all the information related to a single event handler required
* to match and fire event handlers to incoming events.
*/
#include "mbed.h"
#include "MicroBit.h"
/**
* Constructor.
* Create a new Message Bus Listener.
* @param id The ID of the component you want to listen to.
* @param value The event ID you would like to listen to from that component
* @param handler A function pointer to call when the event is detected.
*/
microbit: Added configurable concurrency modes for MicroBitMessageBus handlers. MessageBus handlers can now have one of four concurrency modes for the eventuality of an event being raised whilst a previous event is still being processed. An additional (optional) parameter is provided to the listen() functions to allow this to be selected on a per event handler basis. The permissable options are: MESSAGE_BUS_LISTENER_REENTRANT: The event handler is fired with the new event, regardless of whether or not a previous event is still be processed by that handler. MESSAGE_BUS_LISTENER_QUEUE_IF_BUSY: The new event is queued until such a time as the previous event has completed execution. The new event is then processed. This option does not preclude the processing of the new event by other event handlers. MESSAGE_BUS_LISTENER_DROP_IF_BUSY: The new event is dropped, and will never be processed the the event handler. This option does not preclude the processing of the new event by other event handlers. MESSAGE_BUS_LISTENER_NONBLOCKING: The event handler is self-declaring that it never blocks. This flag is used purely for optimisation, as it permits direct execution of the event hadnelr without inducing any overhead from the scheduler. In addition, the following minor revisions were made in this release: * Cleanup of the #include dependencies contained in the microbit-dal .h files * Bugfix to the scheduler block on event matching code. * Introduced a MICROBIT_ID_ALERT MessageBus channel, for general purpose eventing using nonces.
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MicroBitListener::MicroBitListener(uint16_t id, uint16_t value, void (*handler)(MicroBitEvent), uint16_t flags)
{
this->id = id;
this->value = value;
this->cb = handler;
this->cb_arg = NULL;
microbit: Added configurable concurrency modes for MicroBitMessageBus handlers. MessageBus handlers can now have one of four concurrency modes for the eventuality of an event being raised whilst a previous event is still being processed. An additional (optional) parameter is provided to the listen() functions to allow this to be selected on a per event handler basis. The permissable options are: MESSAGE_BUS_LISTENER_REENTRANT: The event handler is fired with the new event, regardless of whether or not a previous event is still be processed by that handler. MESSAGE_BUS_LISTENER_QUEUE_IF_BUSY: The new event is queued until such a time as the previous event has completed execution. The new event is then processed. This option does not preclude the processing of the new event by other event handlers. MESSAGE_BUS_LISTENER_DROP_IF_BUSY: The new event is dropped, and will never be processed the the event handler. This option does not preclude the processing of the new event by other event handlers. MESSAGE_BUS_LISTENER_NONBLOCKING: The event handler is self-declaring that it never blocks. This flag is used purely for optimisation, as it permits direct execution of the event hadnelr without inducing any overhead from the scheduler. In addition, the following minor revisions were made in this release: * Cleanup of the #include dependencies contained in the microbit-dal .h files * Bugfix to the scheduler block on event matching code. * Introduced a MICROBIT_ID_ALERT MessageBus channel, for general purpose eventing using nonces.
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this->flags = flags;
this->next = NULL;
}
/**
* Constructor.
* Create a new parameterised Message Bus Listener.
* @param id The ID of the component you want to listen to.
* @param value The event ID you would like to listen to from that component.
* @param handler A function pointer to call when the event is detected.
* @param arg An additional argument to pass to the event handler function.
*/
microbit: Added configurable concurrency modes for MicroBitMessageBus handlers. MessageBus handlers can now have one of four concurrency modes for the eventuality of an event being raised whilst a previous event is still being processed. An additional (optional) parameter is provided to the listen() functions to allow this to be selected on a per event handler basis. The permissable options are: MESSAGE_BUS_LISTENER_REENTRANT: The event handler is fired with the new event, regardless of whether or not a previous event is still be processed by that handler. MESSAGE_BUS_LISTENER_QUEUE_IF_BUSY: The new event is queued until such a time as the previous event has completed execution. The new event is then processed. This option does not preclude the processing of the new event by other event handlers. MESSAGE_BUS_LISTENER_DROP_IF_BUSY: The new event is dropped, and will never be processed the the event handler. This option does not preclude the processing of the new event by other event handlers. MESSAGE_BUS_LISTENER_NONBLOCKING: The event handler is self-declaring that it never blocks. This flag is used purely for optimisation, as it permits direct execution of the event hadnelr without inducing any overhead from the scheduler. In addition, the following minor revisions were made in this release: * Cleanup of the #include dependencies contained in the microbit-dal .h files * Bugfix to the scheduler block on event matching code. * Introduced a MICROBIT_ID_ALERT MessageBus channel, for general purpose eventing using nonces.
2015-09-11 15:39:38 +00:00
MicroBitListener::MicroBitListener(uint16_t id, uint16_t value, void (*handler)(MicroBitEvent, void *), void* arg, uint16_t flags)
{
this->id = id;
this->value = value;
this->cb_param = handler;
this->cb_arg = arg;
microbit: Added configurable concurrency modes for MicroBitMessageBus handlers. MessageBus handlers can now have one of four concurrency modes for the eventuality of an event being raised whilst a previous event is still being processed. An additional (optional) parameter is provided to the listen() functions to allow this to be selected on a per event handler basis. The permissable options are: MESSAGE_BUS_LISTENER_REENTRANT: The event handler is fired with the new event, regardless of whether or not a previous event is still be processed by that handler. MESSAGE_BUS_LISTENER_QUEUE_IF_BUSY: The new event is queued until such a time as the previous event has completed execution. The new event is then processed. This option does not preclude the processing of the new event by other event handlers. MESSAGE_BUS_LISTENER_DROP_IF_BUSY: The new event is dropped, and will never be processed the the event handler. This option does not preclude the processing of the new event by other event handlers. MESSAGE_BUS_LISTENER_NONBLOCKING: The event handler is self-declaring that it never blocks. This flag is used purely for optimisation, as it permits direct execution of the event hadnelr without inducing any overhead from the scheduler. In addition, the following minor revisions were made in this release: * Cleanup of the #include dependencies contained in the microbit-dal .h files * Bugfix to the scheduler block on event matching code. * Introduced a MICROBIT_ID_ALERT MessageBus channel, for general purpose eventing using nonces.
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this->flags = flags | MESSAGE_BUS_LISTENER_PARAMETERISED;
this->next = NULL;
}
/**
* Destructor. Ensures all resources used by this listener are freed.
*/
MicroBitListener::~MicroBitListener()
{
if(this->flags & MESSAGE_BUS_LISTENER_METHOD)
delete cb_method;
}
microbit: Added configurable concurrency modes for MicroBitMessageBus handlers. MessageBus handlers can now have one of four concurrency modes for the eventuality of an event being raised whilst a previous event is still being processed. An additional (optional) parameter is provided to the listen() functions to allow this to be selected on a per event handler basis. The permissable options are: MESSAGE_BUS_LISTENER_REENTRANT: The event handler is fired with the new event, regardless of whether or not a previous event is still be processed by that handler. MESSAGE_BUS_LISTENER_QUEUE_IF_BUSY: The new event is queued until such a time as the previous event has completed execution. The new event is then processed. This option does not preclude the processing of the new event by other event handlers. MESSAGE_BUS_LISTENER_DROP_IF_BUSY: The new event is dropped, and will never be processed the the event handler. This option does not preclude the processing of the new event by other event handlers. MESSAGE_BUS_LISTENER_NONBLOCKING: The event handler is self-declaring that it never blocks. This flag is used purely for optimisation, as it permits direct execution of the event hadnelr without inducing any overhead from the scheduler. In addition, the following minor revisions were made in this release: * Cleanup of the #include dependencies contained in the microbit-dal .h files * Bugfix to the scheduler block on event matching code. * Introduced a MICROBIT_ID_ALERT MessageBus channel, for general purpose eventing using nonces.
2015-09-11 15:39:38 +00:00
/**
* Queues and event up to be processed.
* @param e The event to queue
*/
void MicroBitListener::queue(MicroBitEvent e)
{
MicroBitEventQueueItem *q = new MicroBitEventQueueItem(e);
MicroBitEventQueueItem *p = evt_queue;
if (evt_queue == NULL)
evt_queue = q;
else
{
while (p->next != NULL)
p = p->next;
p->next = q;
}
}