Cheney's algorithm: Difference between revisions

Revision as of 03:06, 6 April 2016

Revision as of 14:19, 20 April 2016

Line 21:

<source>

initialize() =

tospace = 0

fromspace = N/2

allocPtr = tospace

scanPtr = whatever -- only used during collection

</source>

Line 41 ⟶ 42:

<source>

collect() =

swap( fromspace, tospace )

allocPtr = tospace

rootscanPtr = copy(root)tospace

-- scan every root you've got

ForEach root in the stack -- or elsewhere

rroot = copy(rroot)

EndForEach

-- scan objects in the heap (including objects added by this loop)

While scanPtr points to an object o in the heap

ForEach reference r from o’o

r = copy(r)

EndForEach

scanPtr = scanPtr + o.size() -- points to the next object in the heap, if any

EndWhile

</source>

<source>

copy(o) =

If o has no forwarding address

o’ o' = allocPtr

allocPtr = allocPtr + size(oroot)

copy the contents of o to o’o'

forwarding-address(o) = o’o'

ForEach reference r from o’

r = copy(r)

EndForEach

EndIf

return forwarding-address(o)

</source>