Time Viewpoint

State Dynamics ViewpointAlgorithm Viewpoint

The Time Viewpoint focuses on the specific requirements and constraints of real-time event-driven systems, ensuring that they meet timing and performance criteria. This design viewpoint frames the following design concerns:

• time management mechanisms
• system clock tick rates
• concurrency
• performance

Time Event Life Cycle

SDS_QP_TELC

Time Event Life Cycle

Model Kind

The time event life cycle is illustrated with UML state diagram.

Figure SDS-TE-LIFE: Time Event Life Cycle

Figure SDS-TE-LIFE illustrates the time event life cycle:

[0] Time Event constructed but disarmed.

[1a] the armX() operation with the 'interval' argument of 0 arms a one-shot time event

[1b] the armX() operation with the 'interval' argument of non-zero arms a periodic time event

[2] a one-shot Time Event is automatically disarmed after it expires

[3a] a one-shot Time Event can be disarmed while it is armed and still timing out (the disarm() operation returns 'true').

[3b] a periodic Time Event can be disarmed when it is armed (the disarm() operation returns 'true')

[3c] an already disarmed Time Event can be disarmed (the disarm() operation returns 'false')

[4a] a one-shot Time Event can be rearmed while it is armed and still timing out (the rearm() operation returns 'true').

[4b] a periodic Time Event can be rearmed while it is armed (the rearm() operation returns 'true').

[4c] a disarmed Time Event can be rearmed (the rearm() operation returns 'false').

[5a] arming an already armed one-shot Time Event is NOT allowed (QP framework asserts)

[5b] arming an already armed periodic Time Event is NOT allowed (QP framework asserts)

Backward Traceability

Forward Traceability (truncated to 2 level(s))

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State Dynamics ViewpointAlgorithm Viewpoint