SchedulerLoadControl_test Class Reference

Description

Test:

verify behaviour patterns relevant for Scheduler load control.

See also

SchedulerCommutator_test

SchedulerService_test

SchedulerStress_test

Definition at line 48 of file scheduler-load-control-test.cpp.

Private Member Functions
void	classifyCapacity ()
void	classifyHorizon ()
void	indicateAverageLoad ()
virtual void	run (Arg)
void	scatteredReCheck ()
void	simpleUsage ()
void	tendNextActivity ()

Additional Inherited Members
Public Member Functions inherited from Test
virtual	~Test ()=default
	this is an interface
lib::Random	makeRandGen ()
	build a dedicated new RandomGen, seeded from the default-Gen
virtual void	run (Arg arg)=0
void	seedRand ()
	draw a new random seed from a common nucleus, and re-seed the default-Gen.
Static Public Member Functions inherited from Test
static string	firstTok (Arg)
	conveniently pick the first token from the argument line
static uint	firstVal (Arg, uint=1)
	conveniently use some number given as argument, with optional default

Member Function Documentation

simpleUsage()

void simpleUsage ( )

inlineprivate

Test:

TODO demonstrate a simple usage scenario

Todo:

WIP 10/23 🔁 define ⟶ 🔁 implement

Definition at line 67 of file scheduler-load-control-test.cpp.

classifyHorizon()

void classifyHorizon ( )

inlineprivate

Test:

verify classification of time horizon for scheduling.

• if the next planned Activity lies beyond the SLEEP_HORIZON, then the current thread can be considered part of the idle capacity
• in a similar way, WORK_HORIZON delineates the zone of repeated incoming Activities from the zone considered part of current active operation
• Activities within the NOW_HORIZON can be awaited by yield-spinning
• and any event from current into the past will be scheduled right away

Definition at line 84 of file scheduler-load-control-test.cpp.

References LoadController::classifyTimeHorizon(), vault::gear::anonymous_namespace{load-controller.hpp}::NEAR_HORIZON, vault::gear::anonymous_namespace{load-controller.hpp}::SLEEP_HORIZON, and vault::gear::anonymous_namespace{load-controller.hpp}::WORK_HORIZON.

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tendNextActivity()

void tendNextActivity ( )

inlineprivate

Test:

verify the mark for tended next head Activity.

Definition at line 113 of file scheduler-load-control-test.cpp.

References LoadController::tendedNext(), and LoadController::tendNext().

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classifyCapacity()

void classifyCapacity ( )

inlineprivate

Test:

verify allocation decision for free capacity

• due and overdue Activities are prioritised
• keep spinning when next Activity to schedule is very close
• otherwise, priority is to tend for the next known Activity
• beyond that, free capacity is redistributed according to horizon
• for incoming free capacity there is a preference to keep it sleeping, to allow for disposing of excess capacity after extended sleep time

Definition at line 157 of file scheduler-load-control-test.cpp.

References LoadController::markIncomingCapacity(), LoadController::markOutgoingCapacity(), vault::gear::anonymous_namespace{load-controller.hpp}::NEAR_HORIZON, Time::NEVER, vault::gear::anonymous_namespace{load-controller.hpp}::SLEEP_HORIZON, LoadController::tendNext(), and vault::gear::anonymous_namespace{load-controller.hpp}::WORK_HORIZON.

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scatteredReCheck()

void scatteredReCheck ( )

inlineprivate

Test:

verify the re-distribution of free capacity by targeted delay

• the implementation uses the next-tended start time as anchor point
• capacity classes which should be scheduled right away will actually never call this function — yet still a sensible value is returned here
• capacity targeted at current work will be redistributed behind the next-tended time, and within a time span corresponding to the work realm
• capacity targeted towards more future work will be distributed within the horizon defined by the sleep-cycle
• especially for capacity sent to sleep, this redistribution works without being shifted behind the next-tended time, since in that case the goal is to produce a random distribution of the »sleeper« callbacks.

• the offset is indeed randomised, using current time for randomisation

  See also

  LoadController::scatteredDelayTime()

Definition at line 235 of file scheduler-load-control-test.cpp.

References Time::ANYTIME, LoadController::scatteredDelayTime(), vault::gear::anonymous_namespace{load-controller.hpp}::SLEEP_HORIZON, LoadController::tendNext(), and vault::gear::anonymous_namespace{load-controller.hpp}::WORK_HORIZON.

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indicateAverageLoad()

void indicateAverageLoad ( )

inlineprivate

Test:

verify fusion of sampled observations to guess average scheduler load

• use a rigged wiring of the load controller to verify calculation based on known values of current concurrency and schedule pressure
• scheduling on average 200µs behind nominal schedule is considered the regular balanced state and thus defined as 100% schedule pressure
• if congestion builds up to 1/10 of WORK_HORIZON, 200% overload is indicated
• on the other hand, if workers appear on average 200µs before the typical balanced state, the resulting headroom is defined to constitute 50% pressure
• the pressure value is multiplied with the degree of concurrency
• the pressure is sampled from the lag (distance of current time to the next activity to schedule), which is observed whenever a worker calls in to retrieve more work.

These calls happen randomly.

Definition at line 288 of file scheduler-load-control-test.cpp.

References LoadController::setCurrentAverageLag(), and vault::gear::test::anonymous_namespace{work-force-test.cpp}::setup().

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Inheritance diagram for SchedulerLoadControl_test:

Collaboration diagram for SchedulerLoadControl_test:

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The documentation for this class was generated from the following file:

• scheduler-load-control-test.cpp