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Improve merge work computation

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This commit is contained in:
Kresten Krab Thorup 2012-04-26 01:00:01 +02:00
parent 5d95070669
commit e147dd9d1e
1 changed files with 27 additions and 20 deletions
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47
src/hanoi_level.erl
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@ -31,14 +31,14 @@
-include("src/hanoi.hrl").
%%
%% Manages a "pair" of hanoi index (or rathern, 0, 1 or 2), and governs
%% the process of injecting/merging parent trees into this pair.
%% Manages 0..2 of hanoi index file, and governs all aspects of
%% merging, lookup, folding, etc. for these files
%%
%%
%% For now, we use plain_fsm, because we *want* selective receive to postpone
%% pending injects while we're merging. That's a lot simpler than maintaining
%% to corresponding merge queue.
%% DESIGN: uses plain_fsm, because we *want* selective receive to
%% postpone pending injects while we're merging. That's a lot simpler
%% than maintaining to corresponding merge queue.
%%
-behavior(plain_fsm).
@ -52,7 +52,7 @@
-record(state, {
a, b, c, next, dir, level, inject_done_ref, merge_pid, folding = [],
step_next_ref, step_caller, step_merge_ref,
opts = [], owner, work_done=0
opts = [], owner, work_in_progress=0, work_done=0
}).
@ -279,7 +279,11 @@ main_loop(State = #state{ next=Next }) ->
State#state.step_next_ref == undefined
->
WorkLeftHere = max(0,total_unmerged(State) - State#state.work_done),
if State#state.b =/= undefined ->
WorkLeftHere = max(0, (2 * ?BTREE_SIZE(State#state.level)) - State#state.work_done);
true ->
WorkLeftHere = 0
end,
WorkToDoHere = min(WorkLeftHere, HowMuch),
DelegateWork = max(0,HowMuch - WorkToDoHere),
@ -294,35 +298,37 @@ main_loop(State = #state{ next=Next }) ->
if (State#state.merge_pid == undefined)
orelse (WorkToDoHere =< 0) ->
MergeRef = undefined,
NewWorkDone = State#state.work_done;
MergeRef = undefined;
true ->
MergePID = State#state.merge_pid,
MergeRef = monitor(process, MergePID),
MergePID ! {step, {self(), MergeRef}, WorkToDoHere},
NewWorkDone = State#state.work_done + WorkToDoHere
MergePID ! {step, {self(), MergeRef}, WorkToDoHere}
end,
if (Next =:= undefined) andalso (MergeRef =:= undefined) ->
%% nothing to do ... just return OK
State2 = reply_step_ok(State#state { step_caller = StepFrom }),
main_loop(State2#state { work_done = NewWorkDone });
main_loop(State2);
true ->
main_loop(State#state{ step_next_ref=DelegateRef,
step_caller=StepFrom,
step_merge_ref=MergeRef,
work_done = NewWorkDone
work_in_progress = WorkToDoHere
})
end;
{MRef, step_done} when MRef == State#state.step_merge_ref ->
demonitor(MRef, [flush]),
case State#state.step_next_ref of
State1 = State#state{ work_done = State#state.work_done + State#state.work_in_progress,
work_in_progress = 0 },
case State1#state.step_next_ref of
undefined ->
State2 = reply_step_ok(State);
State2 = reply_step_ok(State1);
_ ->
State2 = State
State2 = State1
end,
main_loop(State2#state{ step_merge_ref=undefined });
@ -338,7 +344,7 @@ main_loop(State = #state{ next=Next }) ->
State2 = State
end,
main_loop(State2#state{ step_merge_ref=undefined });
main_loop(State2#state{ step_merge_ref=undefined, work_in_progress=0 });
?REPLY(MRef, ok)
@ -573,10 +579,11 @@ reply_step_ok(State) ->
total_unmerged(State) ->
Files =
(if State#state.b == undefined -> 0; true -> 1 end)
+ (if State#state.c == undefined -> 0; true -> 1 end),
(if State#state.b == undefined -> 0; true -> 2 end)
% + (if State#state.c == undefined -> 0; true -> 1 end)
,
Files * ?BTREE_SIZE( State#state.level ).
Files * 1 * ?BTREE_SIZE( State#state.level ).