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-- $Id: testes/gengc.lua $
-- See Copyright Notice in file all.lua
print('testing generational garbage collection')
local debug = require"debug"
assert(collectgarbage("isrunning"))
collectgarbage()
local oldmode = collectgarbage("generational")
-- ensure that table barrier evolves correctly
do
local U = {}
-- full collection makes 'U' old
collectgarbage()
assert(not T or T.gcage(U) == "old")
-- U refers to a new table, so it becomes 'touched1'
U[1] = {x = {234}}
assert(not T or (T.gcage(U) == "touched1" and T.gcage(U[1]) == "new"))
-- both U and the table survive one more collection
collectgarbage("step")
assert(not T or (T.gcage(U) == "touched2" and T.gcage(U[1]) == "survival"))
-- both U and the table survive yet another collection
-- now everything is old
collectgarbage("step")
assert(not T or (T.gcage(U) == "old" and T.gcage(U[1]) == "old1"))
-- data was not corrupted
assert(U[1].x[1] == 234)
end
do
-- ensure that 'firstold1' is corrected when object is removed from
-- the 'allgc' list
local function foo () end
local old = {10}
collectgarbage() -- make 'old' old
assert(not T or T.gcage(old) == "old")
setmetatable(old, {}) -- new table becomes OLD0 (barrier)
assert(not T or T.gcage(getmetatable(old)) == "old0")
collectgarbage("step") -- new table becomes OLD1 and firstold1
assert(not T or T.gcage(getmetatable(old)) == "old1")
setmetatable(getmetatable(old), {__gc = foo}) -- get it out of allgc list
collectgarbage("step") -- should not seg. fault
end
do -- bug in 5.4.0
-- When an object aged OLD1 is finalized, it is moved from the list
-- 'finobj' to the *beginning* of the list 'allgc', but that part of the
-- list was not being visited by 'markold'.
local A = {}
A[1] = false -- old anchor for object
-- obj finalizer
local function gcf (obj)
A[1] = obj -- anchor object
assert(not T or T.gcage(obj) == "old1")
obj = nil -- remove it from the stack
collectgarbage("step") -- do a young collection
print(getmetatable(A[1]).x) -- metatable was collected
end
collectgarbage() -- make A old
local obj = {} -- create a new object
collectgarbage("step") -- make it a survival
assert(not T or T.gcage(obj) == "survival")
setmetatable(obj, {__gc = gcf, x = "+"}) -- create its metatable
assert(not T or T.gcage(getmetatable(obj)) == "new")
obj = nil -- clear object
collectgarbage("step") -- will call obj's finalizer
end
do -- another bug in 5.4.0
local old = {10}
collectgarbage() -- make 'old' old
local co = coroutine.create(
function ()
local x = nil
local f = function ()
return x[1]
end
x = coroutine.yield(f)
coroutine.yield()
end
)
local _, f = coroutine.resume(co) -- create closure over 'x' in coroutine
collectgarbage("step") -- make upvalue a survival
old[1] = {"hello"} -- 'old' go to grayagain as 'touched1'
coroutine.resume(co, {123}) -- its value will be new
co = nil
collectgarbage("step") -- hit the barrier
assert(f() == 123 and old[1][1] == "hello")
collectgarbage("step") -- run the collector once more
-- make sure old[1] was not collected
assert(f() == 123 and old[1][1] == "hello")
end
do -- bug introduced in commit 9cf3299fa
local t = setmetatable({}, {__mode = "kv"}) -- all-weak table
collectgarbage() -- full collection
assert(not T or T.gcage(t) == "old")
t[1] = {10}
assert(not T or (T.gcage(t) == "touched1" and T.gccolor(t) == "gray"))
collectgarbage("step") -- minor collection
assert(not T or (T.gcage(t) == "touched2" and T.gccolor(t) == "black"))
collectgarbage("step") -- minor collection
assert(not T or T.gcage(t) == "old") -- t should be black, but it was gray
t[1] = {10} -- no barrier here, so t was still old
collectgarbage("step") -- minor collection
-- t, being old, is ignored by the collection, so it is not cleared
assert(t[1] == nil) -- fails with the bug
end
if T == nil then
(Message or print)('\n >>> testC not active: \z
skipping some generational tests <<<\n')
print 'OK'
return
end
-- ensure that userdata barrier evolves correctly
do
local U = T.newuserdata(0, 1)
-- full collection makes 'U' old
collectgarbage()
assert(T.gcage(U) == "old")
-- U refers to a new table, so it becomes 'touched1'
debug.setuservalue(U, {x = {234}})
assert(T.gcage(U) == "touched1" and
T.gcage(debug.getuservalue(U)) == "new")
-- both U and the table survive one more collection
collectgarbage("step")
assert(T.gcage(U) == "touched2" and
T.gcage(debug.getuservalue(U)) == "survival")
-- both U and the table survive yet another collection
-- now everything is old
collectgarbage("step")
assert(T.gcage(U) == "old" and
T.gcage(debug.getuservalue(U)) == "old1")
-- data was not corrupted
assert(debug.getuservalue(U).x[1] == 234)
end
-- just to make sure
assert(collectgarbage'isrunning')
do print"testing stop-the-world collection"
local step = collectgarbage("param", "stepsize", 0);
collectgarbage("incremental")
assert(collectgarbage("param", "stepsize") == 0)
-- each step does a complete cycle
assert(collectgarbage("step"))
assert(collectgarbage("step"))
-- back to default value
collectgarbage("param", "stepsize", step);
assert(collectgarbage("param", "stepsize") == step)
end
collectgarbage(oldmode)
print('OK')
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