DDS_WaitSetProperty_t Struct Reference

<<extension>> Specifies the DDS_WaitSet behavior for multiple trigger events. More...

Data Fields
DDS_Long	max_event_count
	Maximum number of trigger events to cause a DDS_WaitSet to awaken. More...
struct DDS_Duration_t	max_event_delay
	Maximum delay from occurrence of first trigger event to cause a DDS_WaitSet to awaken. More...

Detailed Description

<<extension>> Specifies the DDS_WaitSet behavior for multiple trigger events.

In simple use, a DDS_WaitSet returns when a single trigger event occurs on one of its attached DDS_Condition (s), or when the timeout maximum wait duration specified in the DDS_WaitSet_wait call expires.

The DDS_WaitSetProperty_t allows configuration of the waiting behavior of a DDS_WaitSet. If no conditions are true at the time of the call to wait, then the max_event_count parameter may be used to configure the WaitSet to wait for max_event_count trigger events to occur before returning, or to wait for up to max_event_delay time from the occurrence of the first trigger event before returning.

The timeout maximum wait duration specified in the DDS_WaitSet_wait call continues to apply.

Entity:

DDS_WaitSet

Properties:

RxO = N/A

Changeable = YES

Field Documentation

max_event_count

DDS_Long DDS_WaitSetProperty_t::max_event_count

Maximum number of trigger events to cause a DDS_WaitSet to awaken.

The DDS_WaitSet will wait until up to max_event_count trigger events have occurred before returning. The DDS_WaitSet may return earlier if either the timeout duration has expired, or max_event_delay has elapsed since the occurrence of the first trigger event. max_event_count may be used to "collect" multiple trigger events for processing at the same time.

[default] 1

[range] >= 1

;

max_event_delay

struct DDS_Duration_t DDS_WaitSetProperty_t::max_event_delay

Maximum delay from occurrence of first trigger event to cause a DDS_WaitSet to awaken.

The DDS_WaitSet will return no later than max_event_delay after the first trigger event. max_event_delay may be used to establish a maximum latency for events reported by the DDS_WaitSet.

Note that DDS_RETCODE_TIMEOUT is not returned if max_event_delay is exceeded. DDS_RETCODE_TIMEOUT is returned only if the timeout duration expires before any trigger events occur.

[default] DDS_DURATION_INFINITE;