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* prefetch heap status in sysfreemem

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* re-layouted code in sysfreemem_fixed so that the most likely case is on
    the fall-through path
  * moved dec(poc^.used) in sysfreemem_fixed earlier so that it doesn't
    cause a dependency stall for the "if poc^.used<=0" test later

git-svn-id: trunk@15515 -
This commit is contained in:
Jonas Maebe 2010-07-03 12:45:55 +00:00
parent d8707ec5d3
commit 8a891690cc
1 changed files with 34 additions and 25 deletions
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59
rtl/inc/heap.inc
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@ -1059,34 +1059,42 @@ var
chunksize: ptruint;
poc: poschunk;
pmc_next: pmemchunk_fixed;
pocfreelists: pfreelists;
begin
poc := poschunk(pointer(pmc)-(pmc^.size shr fixedoffsetshift));
{ start memory access to poc^.freelists already }
pocfreelists := poc^.freelists;
chunksize := pmc^.size and fixedsizemask;
if loc_freelists <> poc^.freelists then
begin
{ deallocated in wrong thread! add to to-be-freed list of correct thread }
waitfree_fixed(pmc, poc);
exit(chunksize);
end;
dec(loc_freelists^.internal_status.currheapused, chunksize);
{ insert the block in its freelist }
chunkindex := chunksize shr blockshift;
pmc_next := loc_freelists^.fixedlists[chunkindex];
pmc^.prev_fixed := nil;
pmc^.next_fixed := pmc_next;
if assigned(pmc_next) then
pmc_next^.prev_fixed := pmc;
loc_freelists^.fixedlists[chunkindex] := pmc;
{ decrease used blocks count }
dec(poc^.used);
if poc^.used <= 0 then
if loc_freelists = pocfreelists then
begin
{ decrease used blocks count }
if poc^.used<0 then
HandleError(204);
{ osblock can be freed? }
append_to_oslist(poc);
{ decrease used blocks count (well in advance of poc^.used check below,
to avoid stalling due to a dependency) }
dec(poc^.used);
{ insert the block in its freelist }
chunkindex := chunksize shr blockshift;
pmc_next := loc_freelists^.fixedlists[chunkindex];
pmc^.prev_fixed := nil;
pmc^.next_fixed := pmc_next;
if assigned(pmc_next) then
pmc_next^.prev_fixed := pmc;
loc_freelists^.fixedlists[chunkindex] := pmc;
dec(loc_freelists^.internal_status.currheapused, chunksize);
if poc^.used <= 0 then
begin
{ decrease used blocks count }
if poc^.used<0 then
HandleError(204);
{ osblock can be freed? }
append_to_oslist(poc);
end;
end
else
begin
{ deallocated in wrong thread! add to to-be-freed list of correct thread }
waitfree_fixed(pmc, poc);
end;
result := chunksize;
end;
@ -1103,13 +1111,13 @@ begin
exit(chunksize);
end;
dec(loc_freelists^.internal_status.currheapused, chunksize);
{ insert the block in it's freelist }
pmcv^.size := pmcv^.size and (not usedflag);
append_to_list_var(pmcv);
pmcv := try_concat_free_chunk(pmcv);
if (pmcv^.size and (firstblockflag or lastblockflag)) = (firstblockflag or lastblockflag) then
append_to_oslist_var(pmcv);
dec(loc_freelists^.internal_status.currheapused, chunksize);
result := chunksize;
end;
@ -1138,6 +1146,7 @@ begin
{$endif}
{ loc_freelists is a threadvar, so it can be worth it to prefetch }
loc_freelists := @freelists;
prefetch(loc_freelists^.internal_status.currheapused);
{ check if this is a fixed- or var-sized chunk }
if (pmc^.size and fixedsizeflag) = 0 then
result := sysfreemem_var(loc_freelists, pmemchunk_var(p-sizeof(tmemchunk_var_hdr)))