Hi.
I'm porting my Delphi app to Mac OS X. Fortunately my core classes compile
fine with freepascal, so I can produce dylib and use it from Cocoa application.
To make binaries I use fpc 2.0.4 for powerpc version and fpc 2.1.1 for intel
version (2.1.1 snapshot downloaded on August 2, 2006 from lazarus section).
Recently I started to test performance and found that rtl spends quite a lot of
time on array finalization. If you look into rtti.inc file you may see that it
walks on array and trying to finalize each item even though it may need no
finalization at all. Same with dynamic arrays. And with dynamic arrays similar
problem may happen if rtl needs to add reference to each item in array but of
cource it could be that items are not reference counted, so it will walk on
array and will call appropriate function which just have nothing to do. To
solve this issue I added function into "rtti.inc" which determines is data type
dynamic (and therefore needs finalization and could be refrence counted) or
not. It just recursively checks data types and returns TRUE if data type needs
finalization. Then in ArrayRTTI and fpc_finalize_array I call this function to
check is it neccessary to finalize each item or not. I added this function to
"aliases.inc" and use it from "dynarr.inc" too - there two places where
int_addref() function called for each array item, so, before doing this now for
me it checks is that neccessary or not.
Perhaps the best way is to include some kind of attribute into type info
and determine at compile time is data type has any dynamic part or not. Perhaps
compiler may even not generate finalization calls for records (I don't know -
maybe this is already done in compiler). But this could be much bigger amount
of work
I can provide more info if you need. And I think that even such change is
already better than nothing...
Best regards.
Vlad.
Here is the code of my procedure:
--------------------------------------------------------------------
function fpc_is_dyn_type( TypeInfo:Pointer ): boolean;[Public,Alias :
'FPC_IS_DYN_TYPE']; compilerproc;
var
Temp : pbyte;
namelen : byte;
count,
size,
i : SizeInt;
info : pointer;
begin
case PByte(TypeInfo)^ of
tkAstring, tkWstring, tkInterface, tkVariant, tkDynArray:
Result := true;
tkArray :
begin
Temp:=PByte(TypeInfo);
inc(Temp);
{ Skip Name }
namelen:=Temp^;
inc(temp,namelen+1);
temp:=aligntoptr(temp);
{ Skip Element size and count }
inc(Temp,2*sizeof(sizeint));
Result := fpc_is_dyn_type(PPointer(Temp)^);
end;
tkObject,
tkRecord:
begin
Temp:=PByte(TypeInfo);
inc(Temp);
{ Skip Name }
namelen:=Temp^;
inc(temp,namelen+1);
temp:=aligntoptr(temp);
{ Skip size }
inc(Temp,4);
{ Element count }
count:=PLongint(Temp)^;
inc(Temp,sizeof(longint));
{ Process elements }
for i:=1 to count Do
begin
Info:=PPointer(Temp)^;
{ Skip offset }
inc(Temp,sizeof(Info)+sizeof(longint));
if fpc_is_dyn_type(Info) then
begin
Result := true;
exit;
end;
end;
Result := false;
end;
else
Result := false;
end;
end;
----------------------------------------------------------------------
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