{
    $Id$
    This file is part of the Free Pascal run time library.
    Copyright (c) 2002 by Peter Vreman,
    member of the Free Pascal development team.

    Linux (pthreads) threading support implementation

    See the file COPYING.FPC, included in this distribution,
    for details about the copyright.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

 **********************************************************************}
{$mode objfpc}
{$ifdef linux}
{$define dynpthreads} // Useless on BSD, since they are in libc
{$endif}

unit cthreads;
interface
{$S-}

{$ifndef dynpthreads}
{$ifndef BSD}
 {$linklib c}
 {$linklib pthread}
{$else}
 // Link reentrant libc with pthreads
 {$linklib c_r}
{$endif}
{$endif}

Procedure SetCThreadManager;

implementation

Uses 
  systhrds,
  BaseUnix,
  unix
{$ifdef dynpthreads}  
  ,dl
{$endif}
  ;

{*****************************************************************************
                             Generic overloaded
*****************************************************************************}

{ Include OS specific parts. }
{$i pthread.inc}

{*****************************************************************************
                             Threadvar support
*****************************************************************************}

{$ifdef HASTHREADVAR}
    const
      threadvarblocksize : dword = 0;

    var
      TLSKey : pthread_key_t;

    procedure CInitThreadvar(var offset : dword;size : dword);
      begin
        offset:=threadvarblocksize;
        inc(threadvarblocksize,size);
      end;

    function CRelocateThreadvar(offset : dword) : pointer;
      begin
        CRelocateThreadvar:=pthread_getspecific(tlskey)+Offset;
      end;


    procedure CAllocateThreadVars;
      var
        dataindex : pointer;
      begin
        { we've to allocate the memory from system  }
        { because the FPC heap management uses      }
        { exceptions which use threadvars but       }
        { these aren't allocated yet ...            }
        { allocate room on the heap for the thread vars }
        DataIndex:=Pointer(Fpmmap(nil,threadvarblocksize,3,MAP_PRIVATE+MAP_ANONYMOUS,-1,0));
        FillChar(DataIndex^,threadvarblocksize,0);
        pthread_setspecific(tlskey,dataindex);
      end;


    procedure CReleaseThreadVars;
      begin
        {$ifdef ver1_0}
        Fpmunmap(longint(pthread_getspecific(tlskey)),threadvarblocksize);
        {$else}
        Fpmunmap(pointer(pthread_getspecific(tlskey)),threadvarblocksize);
        {$endif}
      end;

{ Include OS independent Threadvar initialization }

{$endif HASTHREADVAR}


{*****************************************************************************
                            Thread starting
*****************************************************************************}

    type
      pthreadinfo = ^tthreadinfo;
      tthreadinfo = record
        f : tthreadfunc;
        p : pointer;
        stklen : cardinal;
      end;

    procedure DoneThread;
      begin
        { Release Threadvars }
{$ifdef HASTHREADVAR}
        CReleaseThreadVars;
{$endif HASTHREADVAR}
      end;


    function ThreadMain(param : pointer) : pointer;cdecl;
      var
        ti : tthreadinfo;
{$ifdef DEBUG_MT}
        // in here, don't use write/writeln before having called
        // InitThread! I wonder if anyone ever debugged these routines,
        // because they will have crashed if DEBUG_MT was enabled!
        // this took me the good part of an hour to figure out
        // why it was crashing all the time!
        // this is kind of a workaround, we simply write(2) to fd 0
        s: string[100]; // not an ansistring
{$endif DEBUG_MT}
      begin
{$ifdef DEBUG_MT}
        s := 'New thread started, initing threadvars'#10;
        fpwrite(0,s[1],length(s));
{$endif DEBUG_MT}
{$ifdef HASTHREADVAR}
        { Allocate local thread vars, this must be the first thing,
          because the exception management and io depends on threadvars }
        CAllocateThreadVars;
{$endif HASTHREADVAR}
        { Copy parameter to local data }
{$ifdef DEBUG_MT}
        s := 'New thread started, initialising ...'#10;
        fpwrite(0,s[1],length(s));
{$endif DEBUG_MT}
        ti:=pthreadinfo(param)^;
        dispose(pthreadinfo(param));
        { Initialize thread }
        InitThread(ti.stklen);
        { Start thread function }
{$ifdef DEBUG_MT}
        writeln('Jumping to thread function');
{$endif DEBUG_MT}
        ThreadMain:=pointer(ti.f(ti.p));
        DoneThread;
	pthread_detach(pointer(pthread_self));
      end;


    function CBeginThread(sa : Pointer;stacksize : dword;
                         ThreadFunction : tthreadfunc;p : pointer;
                         creationFlags : dword; var ThreadId : DWord) : DWord;
      var
        ti : pthreadinfo;
        thread_attr : pthread_attr_t;
      begin
{$ifdef DEBUG_MT}
        writeln('Creating new thread');
{$endif DEBUG_MT}
        { Initialize multithreading if not done }
        if not IsMultiThread then
         begin
{$ifdef HASTHREADVAR}
          { We're still running in single thread mode, setup the TLS }
           pthread_key_create(@TLSKey,nil);
           InitThreadVars(@CRelocateThreadvar);
{$endif HASTHREADVAR}
           IsMultiThread:=true;
         end;
        { the only way to pass data to the newly created thread
          in a MT safe way, is to use the heap }
        new(ti);
        ti^.f:=ThreadFunction;
        ti^.p:=p;
        ti^.stklen:=stacksize;
        { call pthread_create }
{$ifdef DEBUG_MT}
        writeln('Starting new thread');
{$endif DEBUG_MT}
        pthread_attr_init(@thread_attr);
        pthread_attr_setinheritsched(@thread_attr, PTHREAD_EXPLICIT_SCHED);
        
        // will fail under linux -- apparently unimplemented
        pthread_attr_setscope(@thread_attr, PTHREAD_SCOPE_PROCESS);

        // don't create detached, we need to be able to join (waitfor) on
        // the newly created thread!
        //pthread_attr_setdetachstate(@thread_attr, PTHREAD_CREATE_DETACHED);
        if pthread_create(@threadid, @thread_attr, @ThreadMain,ti) <> 0 then begin
          threadid := 0;
        end;
        CBeginThread:=threadid;
{$ifdef DEBUG_MT}
        writeln('BeginThread returning ',BeginThread);
{$endif DEBUG_MT}
      end;


    procedure CEndThread(ExitCode : DWord);
      begin
        DoneThread;
        pthread_detach(pointer(pthread_self));
        pthread_exit(pointer(ExitCode));
      end;


    function  CSuspendThread (threadHandle : dword) : dword;
    begin
      {$Warning SuspendThread needs to be implemented}
    end;

    function  CResumeThread  (threadHandle : dword) : dword;
    begin
      {$Warning ResumeThread needs to be implemented}
    end;

    procedure CThreadSwitch;  {give time to other threads}
    begin
      {extern int pthread_yield (void) __THROW;}
      {$Warning ThreadSwitch needs to be implemented}
    end;

    function  CKillThread (threadHandle : dword) : dword;
    begin
      pthread_detach(pointer(threadHandle));
      CKillThread := pthread_cancel(Pointer(threadHandle));
    end;

    function  CWaitForThreadTerminate (threadHandle : dword; TimeoutMs : longint) : dword;  {0=no timeout}
    var
      LResultP: Pointer;
      LResult: DWord;
    begin
      LResult := 0;
      LResultP := @LResult;
      pthread_join(Pointer(threadHandle), @LResultP);
      CWaitForThreadTerminate := LResult;
    end;

    function  CThreadSetPriority (threadHandle : dword; Prio: longint): boolean; {-15..+15, 0=normal}
    begin
      {$Warning ThreadSetPriority needs to be implemented}
    end;


    function  CThreadGetPriority (threadHandle : dword): Integer;
    begin
      {$Warning ThreadGetPriority needs to be implemented}
    end;

    function  CGetCurrentThreadId : dword;
    begin
      CGetCurrentThreadId:=dword(pthread_self);
    end;


{*****************************************************************************
                          Delphi/Win32 compatibility
*****************************************************************************}

    procedure CInitCriticalSection(var CS);
    
    Var
      P : PRTLCriticalSection;
    
      begin
         P:=PRTLCriticalSection(@CS);
         With p^ do
           begin
           m_spinlock:=0;
           m_count:=0;
           m_owner:=nil;
           m_kind:=1;
           m_waiting.head:=nil;
           m_waiting.tail:=nil;
           end;
         pthread_mutex_init(P,NIL);
      end;

    procedure CEnterCriticalSection(var CS);
      begin
         pthread_mutex_lock(@CS);
      end;

    procedure CLeaveCriticalSection(var CS);
      begin
         pthread_mutex_unlock(@CS);
      end;

    procedure CDoneCriticalSection(var CS);
      begin
         pthread_mutex_destroy(@CS);
      end;


{*****************************************************************************
                           Heap Mutex Protection
*****************************************************************************}

    var
      HeapMutex : pthread_mutex_t;

    procedure PThreadHeapMutexInit;
      begin
         pthread_mutex_init(@heapmutex,nil);
      end;

    procedure PThreadHeapMutexDone;
      begin
         pthread_mutex_destroy(@heapmutex);
      end;

    procedure PThreadHeapMutexLock;
      begin
         pthread_mutex_lock(@heapmutex);
      end;

    procedure PThreadHeapMutexUnlock;
      begin
         pthread_mutex_unlock(@heapmutex);
      end;

    const
      PThreadMemoryMutexManager : TMemoryMutexManager = (
        MutexInit : @PThreadHeapMutexInit;
        MutexDone : @PThreadHeapMutexDone;
        MutexLock : @PThreadHeapMutexLock;
        MutexUnlock : @PThreadHeapMutexUnlock;
      );

    procedure InitHeapMutexes;
      begin
        SetMemoryMutexManager(PThreadMemoryMutexManager);
      end;

Function CInitThreads : Boolean;

begin
  Writeln('Entering InitThreads.');
{$ifndef dynpthreads} 
  Result:=True;
{$else}  
  Result:=LoadPthreads;
{$endif}  
  Writeln('InitThreads : ',Result);
end;

Function CDoneThreads : Boolean;

begin
{$ifndef dynpthreads}
  Result:=True;
{$else}  
  Result:=UnloadPthreads;
{$endif}
end;


Var
  CThreadManager : TThreadManager; 

Procedure SetCThreadManager;

begin
  With CThreadManager do
    begin
    InitManager            :=@CInitThreads;
    DoneManager            :=@CDoneThreads;
    BeginThread            :=@CBeginThread;
    EndThread              :=@CEndThread;
    SuspendThread          :=@CSuspendThread;
    ResumeThread           :=@CResumeThread;
    KillThread             :=@CKillThread;
    ThreadSwitch           :=@CThreadSwitch;
    WaitForThreadTerminate :=@CWaitForThreadTerminate;
    ThreadSetPriority      :=@CThreadSetPriority;
    ThreadGetPriority      :=@CThreadGetPriority;
    GetCurrentThreadId     :=@CGetCurrentThreadId;
    InitCriticalSection    :=@CInitCriticalSection;
    DoneCriticalSection    :=@CDoneCriticalSection;
    EnterCriticalSection   :=@CEnterCriticalSection;
    LeaveCriticalSection   :=@CLeaveCriticalSection;
{$ifdef hasthreadvar}
    InitThreadVar          :=@CInitThreadVar;
    RelocateThreadVar      :=@CRelocateThreadVar;
    AllocateThreadVars     :=@CAllocateThreadVars;
    ReleaseThreadVars      :=@CReleaseThreadVars;
{$endif}    
    end;
  SetThreadManager(CThreadManager);
  InitHeapMutexes;
end;

initialization
  SetCThreadManager;
end.
{
  $Log$
  Revision 1.5  2003-12-16 09:43:04  daniel
    * Use of 0 instead of nil fixed

  Revision 1.4  2003/11/29 17:34:14  michael
  + Removed dummy variable from SetCthreadManager

  Revision 1.3  2003/11/27 20:24:53  michael
  + Compiles on BSD too now

  Revision 1.2  2003/11/27 20:16:59  michael
  + Make works with 1.0.10 too

  Revision 1.1  2003/11/26 20:10:59  michael
  + New threadmanager implementation

  Revision 1.20  2003/11/19 10:54:32  marco
   * some simple restructures

  Revision 1.19  2003/11/18 22:36:12  marco
   * Last patch was ok, problem was somewhere else. Moved *BSD part of pthreads to freebsd/pthreads.inc

  Revision 1.18  2003/11/18 22:35:09  marco
   * Last patch was ok, problem was somewhere else. Moved *BSD part of pthreads to freebsd/pthreads.inc

  Revision 1.17  2003/11/17 10:05:51  marco
   * threads for FreeBSD. Not working tho

  Revision 1.16  2003/11/17 08:27:50  marco
   * pthreads based ttread from Johannes Berg

  Revision 1.15  2003/10/01 21:00:09  peter
    * GetCurrentThreadHandle renamed to GetCurrentThreadId

  Revision 1.14  2003/10/01 20:53:08  peter
    * GetCurrentThreadId implemented

  Revision 1.13  2003/09/20 12:38:29  marco
   * FCL now compiles for FreeBSD with new 1.1. Now Linux.

  Revision 1.12  2003/09/16 13:17:03  marco
   * Wat cleanup, ouwe syscalls nu via baseunix e.d.

  Revision 1.11  2003/09/16 13:00:02  marco
   * small BSD gotcha removed (typing mmap params)

  Revision 1.10  2003/09/15 20:08:49  marco
   * small fixes. FreeBSD now cycles

  Revision 1.9  2003/09/14 20:15:01  marco
   * Unix reform stage two. Remove all calls from Unix that exist in Baseunix.

  Revision 1.8  2003/03/27 17:14:27  armin
  * more platform independent thread routines, needs to be implemented for unix

  Revision 1.7  2003/01/05 19:11:32  marco
   * small changes originating from introduction of Baseunix to FreeBSD

  Revision 1.6  2002/11/11 21:41:06  marco
   * syscall.inc -> syscallo.inc

  Revision 1.5  2002/10/31 13:45:21  carl
    * threadvar.inc -> threadvr.inc

  Revision 1.4  2002/10/26 18:27:52  marco
   * First series POSIX calls commits. Including getcwd.

  Revision 1.3  2002/10/18 18:05:06  marco
   * $I pthread.inc instead of pthreads.inc

  Revision 1.2  2002/10/18 12:19:59  marco
   * Fixes to get the generic *BSD RTL compiling again + fixes for thread
     support. Still problems left in fexpand. (inoutres?) Therefore fixed
     sysposix not yet commited

  Revision 1.1  2002/10/16 06:22:56  michael
  Threads renamed from threads to systhrds

  Revision 1.1  2002/10/14 19:39:17  peter
    * threads unit added for thread support

}