Sven Barth schrieb:
Am 25.08.2010 13:53, schrieb Maik Wojcieszak:
Alexander,
I found something in the lazarus package for vortex :
{ FPC specific thread create function to replace Vortex's thread create.
This is required because FPC doesn't work when C libraries create
their own
threads}
This may lead us to a solution I guess.
Some more background about that would be nice. Is this documented
anywhere ?
Maik
You can read this thread on the fpc-pascal list:
http://www.hu.freepascal.org/lists/fpc-pascal/2010-July/025939.html
Jonas has implemented a possibilty for external C threads to work, but
you need to use a SVN FPC and you need to create at least one thread
in FPC (it can terminate immediatly, it's just needed to initialise
the threading subsystem). (And this fix is *nix only)
If you read this thread carefully, you can notice that I already posted
this here in my first answer to Maik ;-)
I also showed in a test program in a later post that this problem
doesn't seem to exist in the Win32 target, it was just the Darwin
target. Here's again the test program I wrote . I creates a non-FPC
thread and inside that thread it calls back a FPC funtion and object.
This fully works without crashes.
program project1;
{$APPTYPE CONSOLE}
{$mode objfpc}{$H+}
uses
{$IFDEF UNIX}{$IFDEF UseCThreads}
cthreads,
{$ENDIF}{$ENDIF}
Classes,
{ you can add units after this }
windows;
{$R project1.res}
type
TSomeClass = class
public
procedure someMethod();
end;
procedure TSomeClass.someMethod();
begin
writeln('TSomeClass.someMethod called');
end;
var
ThreadID: DWORD; //Thread-ID
ThreadHandle: THandle; //Rückgabewert von CreateThread
someObj: TSomeClass;
procedure someFunc(param: pchar); cdecl;
begin
WriteLn('External is called - ThreadID=', GetCurrentThreadId);
if assigned(param) then writeln('blub');
writeln('param=', param);
someObj.someMethod();
end;
function ExternalThread(zahl: Pointer): LongInt; stdcall;
begin
//Sleep(2000);
someFunc('test');
Result:=0;
end;
begin
WriteLn('Main ThreadID=', GetCurrentThreadId);
someObj:=TSomeClass.create;
WriteLn('Creating external thread');
ThreadHandle:=CreateThread(nil, 0, TFNThreadStartRoutine(@ExternalThread),
nil, 0, ThreadID);
if ThreadHandle = 0 then writeln('ERROR creating external thread');
readln;
WriteLn('Freeing external thread');
if ThreadHandle<>0 then CloseHandle(ThreadHandle);
someObj.free;
end.
--
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