0009016: Create Thread Limit - Free Pascal/Lazarus Bug Tracker

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Category

Severity

Reproducibility

Date Submitted

Last Update

0009016

[FPC] Compiler

block

always

2007-06-06 12:33

2007-09-25 12:56

Reporter

Lionel

View Status

public

Assigned To

Jonas Maebe

Priority

normal

Resolution

fixed

Status

closed

Product Version

2.3.1

Summary

0009016: Create Thread Limit

Description

Hello, there is thread creation limit on linux, i don't try under win32 environment.
With Kylix compiler, no problem.

Additional Information

Very simple sample :

program test_thread;

{$IFDEF FPC}
{$PACKRECORDS C}
{$MODE DELPHI} // Delphi-compatible mode in FreePascal
{$ASMMODE Intel}
{$UNDEF BORLAND}
{$ELSE}
{$APPTYPE CONSOLE}
{$ENDIF}

uses
{$IFDEF FPC}
  cthreads,
{$ENDIF}
  SysUtils,
  Classes;

type
  TTestThread = class(TThread)
  private
    { Déclarations privées }
  protected
    procedure Execute; override;
  end;

const
  MAX_THREAD : integer = 1000;
var
  I : integer;

{ TTestThread }

procedure TTestThread.Execute;
begin
  Writeln('[' + IntToStr(Self.ThreadID) + '] Running...');
  Terminate;
end;

procedure CreateThread;
var
  TestThread : TTestThread;
begin
  TestThread := TTestThread.Create(true);
  TestThread.FreeOnTerminate := true;
  TestThread.Resume;
end;

begin
  try
    for I := 1 to MAX_THREAD do
      begin
        Writeln('Create ' + IntToStr(I) + ' ...');
        CreateThread;
        Sleep(100);
      end;
    Writeln('Finish');
    ReadLn;
  except
    on E: Exception do
      Writeln(E.ClassName, ': ', E.Message);
  end;
end.

Tags

No tags attached.

FPCOldBugId

Fixed in Revision

8430

Attached Files

test_thread [^] (420,296 bytes) 2007-06-06 14:24

Relationships

has duplicate	0009322	closed	Jonas Maebe	With FPC 2.1.5 threads are not freed/reused properly
has duplicate	0010815	closed	Jonas Maebe	EThread, Failed to create new threads.

Notes
(0012986) Marco van de Voort (manager) 2007-06-06 13:25 edited on: 2007-06-06 13:26	I can't test with Kylix, but this sounds awfully like a process limitation. Try to see if it depends on ulimit settings. It could be that Kylix doesn't have this limit because the older thread libs that it uses don't implement the limit checking (I assume the remark about Kylix is on exactly the same machine + account)

(0012987) Lionel (reporter) 2007-06-06 14:24	Yes, it's on same machine. I build the project with : fpc -Mdelphi test_thread.dpr and the limite is here : vvvvvvvvvvvvvvvvvvvvvvvv ........................ Create 380 ... [-1099203680] Running... Create 381 ... [-1090810976] Running... Create 382 ... [-1082418272] Running... Create 383 ... EThread: Failed to create new thread ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ The number of thread is always 383, I have tried the same application on other machine and this the same problem. I've joined compiled application.

(0012988) Lionel (reporter) 2007-06-06 14:29	#ulimit - a core file size (blocks, -c) 0 data seg size (kbytes, -d) unlimited file size (blocks, -f) unlimited pending signals (-i) 16382 max locked memory (kbytes, -l) 32 max memory size (kbytes, -m) unlimited open files (-n) 1024 pipe size (512 bytes, -p) 8 POSIX message queues (bytes, -q) 819200 stack size (kbytes, -s) 8192 cpu time (seconds, -t) unlimited max user processes (-u) unlimited virtual memory (kbytes, -v) unlimited file locks (-x) unlimited

(0012989) Jonas Maebe (manager) 2007-06-06 15:26 edited on: 2007-06-06 15:27	The problem is improper reaping of dead threads under certain circumstances. The error you see is caused by running out of virtual address space, because it's entirely consumed by the stacks allocated for threads which are finished running, but still lingering around.

(0012990) Lionel (reporter) 2007-06-06 15:37	There is a solution to release the thread completely and free virtual adress for another thread ? It's a bug from linux or fpc ? I don't have fpc installed on win32 and I cannot test this. I cannot migrate my application from delphi if the threads are limited at 383. Thank you for your reactvity

(0012991) Jonas Maebe (manager) 2007-06-06 16:10	It's an FPC bug.

Issue History
Date Modified	Username	Field	Change
2007-06-06 12:33	Lionel	New Issue
2007-06-06 12:33	Lionel	Issue Monitored: Lionel
2007-06-06 13:25	Marco van de Voort	Note Added: 0012986
2007-06-06 13:26	Marco van de Voort	Note Edited: 0012986
2007-06-06 14:24	Lionel	Note Added: 0012987
2007-06-06 14:24	Lionel	File Added: test_thread
2007-06-06 14:29	Lionel	Note Added: 0012988
2007-06-06 15:26	Jonas Maebe	Note Added: 0012989
2007-06-06 15:27	Jonas Maebe	Note Edited: 0012989
2007-06-06 15:37	Lionel	Note Added: 0012990
2007-06-06 16:10	Jonas Maebe	Note Added: 0012991
2007-06-06 17:19	Jonas Maebe	Fixed in Revision	=> 7588
2007-06-06 17:19	Jonas Maebe	Status	new => resolved
2007-06-06 17:19	Jonas Maebe	Fixed in Version	=> 2.3.1
2007-06-06 17:19	Jonas Maebe	Resolution	open => fixed
2007-06-06 17:19	Jonas Maebe	Assigned To	=> Jonas Maebe
2007-07-24 18:11	Jonas Maebe	Relationship added	has duplicate 0009322
2007-07-29 16:56	Florian Klämpfl	Status	resolved => closed
2007-09-25 12:56	Jonas Maebe	FPCOldBugId	=> 0
2007-09-25 12:56	Jonas Maebe	FPCTarget	=> -
2007-09-25 12:56	Jonas Maebe	Fixed in Revision	7588 => 8430
2007-09-25 12:56	Jonas Maebe	Fixed in Version	2.3.1 => 2.2.1
2008-02-12 13:19	Jonas Maebe	Relationship added	has duplicate 0010815

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