BlockFlow_test Class Reference

Description

Test:

document the memory management scheme used by the Scheduler.

See also

SchedulerActivity_test

SchedulerUsage_test

Definition at line 81 of file block-flow-test.cpp.

Private Member Functions
void	adjustEpochs ()
void	announceLoad ()
void	handleEpoch ()
void	placeActivity ()
virtual void	run (Arg)
void	simpleUsage ()
void	storageFlow ()

Additional Inherited Members
Public Member Functions inherited from Test
virtual void	run (Arg arg)=0

Member Function Documentation

simpleUsage()

void simpleUsage ( )

inlineprivate

Test:

demonstrate a simple usage scenario

• open new Epoch to allocate an Activity
• clean-up at a future time point

Definition at line 101 of file block-flow-test.cpp.

References BlockFlow< CONF >::AllocatorHandle::create(), BlockFlow< CONF >::discardBefore(), Activity::TICK, and BlockFlow< CONF >::until().

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handleEpoch()

void handleEpoch ( )

inlineprivate

Test:

cover properties and handling of Epochs (low-level)

• demonstrate that each Epoch is placed into an Extent
• verify that both Extent and Epoch access the same memory block
• demonstrate the standard setup and initialisation of an Epoch
• allocate some Activities into the storage and observe free-managment
• detect when the Epoch is filled up
• verify alive / dead decision relative to given deadline

Note

this test covers helpers and implementation structures of BlockFlow, without actually using a BlockFlow instance; rather, the typical handling and low-level bookkeeping aspects are emulated and observed

Definition at line 132 of file block-flow-test.cpp.

placeActivity()

void placeActivity ( )

inlineprivate

Test:

place Activity record into storage

• new Activity without any previously established Epoch
• place Activity into future, expanding the Epoch grid
• locate Activity relative to established Epoch grid
• fill up existing Epoch, causing overflow to next one
• exhaust multiple adjacent Epochs, overflowing to first free one
• exhaust last Epoch, causing setup of new Epoch, with reduced spacing
• use this reduced spacing also for subsequently created Epochs
• clean up obsoleted Epochs, based on given deadline

Definition at line 229 of file block-flow-test.cpp.

References BlockFlow< CONF >::AllocatorHandle::create(), and BlockFlow< CONF >::until().

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adjustEpochs()

void adjustEpochs ( )

inlineprivate

Test:

load based regulation of Epoch spacing

• on overflow, capacity is boosted by a fixed factor
• on clean-up, a moving average of (in hindsight) optimal length is computed and used as the new Epoch spacing

Definition at line 323 of file block-flow-test.cpp.

announceLoad()

void announceLoad ( )

inlineprivate

Test:

announce additional load to reserve additional capacity up-front.

Definition at line 366 of file block-flow-test.cpp.

storageFlow()

void storageFlow ( )

inlineprivate

Test:

investigate progression of epochs under realistic load

• expose the allocator to a load of 200fps for simulated 3 Minutes
• assuming 10 Activities per frame, this means a throughput of 360000 Activities
• run this load exposure under saturation for performance measurement
• use a planning to deadline delay of 500ms, but with ±200ms random spread
• after 250ms (500 steps), »invoke« by accessing and adding the random checksum
• run a comparison of all-pre-allocated ⟷ heap allocated ⟷ Refcount ⟷ BlockFlow

Remarks

This test setup can be used to investigate different load scenarios. In the standard as defined, the BlockFlow allocator is overloaded initially; within 5 seconds, the algorithm should have regulated the Epoch stepping down to accommodate the load peak. As immediate response, excess allocation requests are shifted into later Epochs. To cope with a persisting higher load, the spacing is reduced swiftly, by growing the internal pool with additional heap allocated Extents. In the following balancing phase, the mechanism aims at bringing back the Epoch duration into a narrow corridor, to keep the usage quotient as close as possible to 90%

Definition at line 403 of file block-flow-test.cpp.

Inheritance diagram for BlockFlow_test:

Collaboration diagram for BlockFlow_test:

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

• block-flow-test.cpp