Hi all!
While analyzing my project with valgrind, I discovered that almost a quarter
of the cpu cycle where eaten up by the function fpc_finalize_array. It seams
that fpc_finalize_array calls for every element of the array fpc_finalize. To
illustrate the problem i have written to small test programs:
program DynArray;
{$mode objfpc}{$H+}
var
i: Integer;
aArray: Array of Integer;
begin
SetLength(aArray, 1000000);
for i := 0 to 999999 do
aArray[i] := i;
aArray := nil;
end.
program StaticArray;
{$mode objfpc}{$H+}
var
i: Integer;
aArray: PIntegerArray;
begin
GetMem(aArray, 1000000);
for i := 0 to 999999 do
aArray^[i] := i;
FreeMem(aArray);
end.
According to valgrind:
Total CPU cycles:
DynArray: 32 243 842
StaticArray: 2 107 419
And in the last line (aArray := nil; / FreeMem(aArray);):
DynArray: 22 001 122
StaticArray: 0
In order to avoid the unnecessary calls to fpc_finalize i added the following
line to fpc_finalize_array:
begin
if PByte(typeinfo)^ in [tkAstring, tkWstring, tkArray, tkObject, tkRecord,
tkInterface, tkDynArray, tkVariant] then ...
After that i go:
Total CPU cycles - DynArray: 8 205 710.
As far as I can see this change doesn't cause memory leaks.
Regards Volker
P.S.: I'm using rc_2_2_2.
Index: rtl/inc/rtti.inc
===================================================================
--- rtl/inc/rtti.inc (Revision 11340)
+++ rtl/inc/rtti.inc (Arbeitskopie)
@@ -339,7 +339,8 @@
var
i : longint;
begin
- for i:=0 to count-1 do
- int_finalize(data+size*i,typeinfo);
+ if PByte(typeinfo)^ in [tkAstring, tkWstring, tkArray, tkObject, tkRecord, tkInterface, tkDynArray, tkVariant] then
+ for i:=0 to count-1 do
+ int_finalize(data+size*i,typeinfo);
end;
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