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Erlang Compiler Stack Reference Regression
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-module(stack_test). | |
-export([ | |
run/0 | |
]). | |
run() -> | |
run(7500, 0.0008). | |
run(Depth, BranchChance) -> | |
rand:seed(exrop, {1647,841737,351137}), | |
Tree = node(Depth, BranchChance), | |
erlang:garbage_collect(), | |
MPid = spawn_mem_sampler(self(), 500), | |
T1 = erlang:monotonic_time(), | |
visit(Tree, sets:new()), | |
T2 = erlang:monotonic_time(), | |
Max = get_max_mem(MPid), | |
unlink(MPid), | |
exit(MPid, kill), | |
{deltaT(T2, T1), Max}. | |
visit([], Seen) -> | |
{sets:add_element(rand:uniform(), Seen), ignore1, ignore2}; | |
visit(Children, Seen0) -> | |
Seen1 = sets:add_element(rand:uniform(), Seen0), | |
lists:foldl(fun(Child, Acc) -> | |
{SeenAcc, Ignore1, Ignore2} = Acc, | |
{NewSeenAcc, _, _} = visit(Child, SeenAcc), | |
{NewSeenAcc, Ignore1, Ignore2} | |
end, {Seen1, ignore1, ignore2}, Children). | |
node(0, _) -> | |
[]; | |
node(Depth, BranchChance) -> | |
case rand:uniform() < BranchChance of | |
true -> | |
[ | |
node(Depth - 1, BranchChance), | |
node(Depth - 1, BranchChance) | |
]; | |
false -> | |
[node(Depth - 1, BranchChance)] | |
end. | |
deltaT(T0, T1) -> | |
erlang:convert_time_unit(T0 - T1, native, millisecond). | |
spawn_mem_sampler(Pid, DtMsec) -> | |
spawn_link(fun() -> mem_sampler(Pid, DtMsec, mem_mb(Pid)) end). | |
mem_sampler(Pid, DtMsec, Max0) -> | |
timer:sleep(DtMsec), | |
Max = max(mem_mb(Pid), Max0), | |
receive | |
{get_mem, From} -> | |
From ! {mem_max, Max} | |
after 0 -> | |
ok | |
end, | |
mem_sampler(Pid, DtMsec, Max). | |
mem_mb(Pid) -> | |
{memory, Words} = erlang:process_info(Pid, memory), | |
Bytes = Words * erlang:system_info(wordsize), | |
Bytes / (1024 * 1024). | |
get_max_mem(Pid) -> | |
Pid ! {get_mem, self()}, | |
receive {mem_max, Max} -> Max end. |
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