/*
 * $Id$
 */

/*
 * Harbour Project source code:
 * XPP compatible classes to manage threads
 *
 * Copyright 2008 Przemyslaw Czerpak <druzus / at / priv.onet.pl>
 * www - http://harbour-project.org
 * special thanks for Pritpal Bedi for class skeleton with info about
 * Xbase++ and to other contributors which I hope will finish and fix
 * this code
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2, or (at your option)
 * any later version.
 *
 * 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.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this software; see the file COPYING.  If not, write to
 * the Free Software Foundation, Inc., 59 Temple Place, Suite 330,
 * Boston, MA 02111-1307 USA (or visit the web site http://www.gnu.org/).
 *
 * As a special exception, the Harbour Project gives permission for
 * additional uses of the text contained in its release of Harbour.
 *
 * The exception is that, if you link the Harbour libraries with other
 * files to produce an executable, this does not by itself cause the
 * resulting executable to be covered by the GNU General Public License.
 * Your use of that executable is in no way restricted on account of
 * linking the Harbour library code into it.
 *
 * This exception does not however invalidate any other reasons why
 * the executable file might be covered by the GNU General Public License.
 *
 * This exception applies only to the code released by the Harbour
 * Project under the name Harbour.  If you copy code from other
 * Harbour Project or Free Software Foundation releases into a copy of
 * Harbour, as the General Public License permits, the exception does
 * not apply to the code that you add in this way.  To avoid misleading
 * anyone as to the status of such modified files, you must delete
 * this exception notice from them.
 *
 * If you write modifications of your own for Harbour, it is your choice
 * whether to permit this exception to apply to your modifications.
 * If you do not wish that, delete this exception notice.
 *
 */

#include "hbclass.ch"
#include "hbthread.ch"

#include "thread.ch"


/*
 * SIGNAL class
 */
CREATE CLASS Signal

   VAR cargo      AS USUAL EXPORTED
   VAR mutex      AS USUAL PROTECTED

EXPORTED:

   METHOD new( ... )
   METHOD wait( nTimeOut )
   METHOD signal()

ENDCLASS

METHOD new( ... ) CLASS SIGNAL
   ::mutex := hb_mutexCreate()
   ::Init( ... )
   RETURN Self

METHOD wait( nTimeOut ) CLASS SIGNAL
   RETURN __ClsSyncWait( ::mutex, nTimeOut )

METHOD signal() CLASS SIGNAL
   __ClsSyncSignal( ::mutex )
   RETURN Self


/*
 * THREAD class
 */

CREATE CLASS Thread

EXPORTED:
   VAR active           AS LOGICAL READONLY  INIT .F.
   VAR atEnd            AS USUAL             INIT NIL
   VAR atStart          AS USUAL             INIT NIL
   VAR cargo            AS USUAL
   VAR deltaTime        AS NUMERIC READONLY  INIT 0
   VAR interval         AS USUAL   READONLY  INIT NIL
   VAR priority         AS NUMERIC READONLY  INIT 0
   VAR result           AS USUAL             INIT NIL
   VAR startCount       AS NUMERIC READONLY  INIT 0
   VAR startTime        AS USUAL   READONLY  INIT NIL
   VAR threadID         AS NUMERIC READONLY  INIT 0

PROTECTED:
   VAR maxStackSize     AS USUAL             INIT 50000

HIDDEN:
   VAR pThreadID        AS USUAL             INIT NIL

EXPORTED:
   METHOD new( ... )

PROTECTED:
   /* METHOD atEnd() */
   /* METHOD atStart() */
   METHOD execute()

EXPORTED:
   METHOD quit( xResult, nRestart )
   METHOD setInterval( nHSeconds )
   METHOD setPriority( nPriority )
   METHOD setStartTime( nSeconds )
   METHOD start( xAction, ... )
   METHOD synchronize( nTimeOut )

   METHOD threadSelf()

ENDCLASS

METHOD new( ... ) CLASS THREAD
   LOCAL nMaxStackSize

   IF PCount() == 1
      nMaxStackSize := hb_PValue( 1 )
      IF HB_ISNUMERIC( nMaxStackSize )
         ::maxStackSize := nMaxStackSize
      ENDIF
      /* TODO: Create new thread here and suspend its execution
       *       Then :START() method only resumes this thread instead
       *       of creating new one.
       *       xBase++ seems to work in such way.
       */

      /* TODO: do not ignore thread stack size set by user in ::maxStackSize */
   ENDIF
   ::Init( ... )
   RETURN Self

METHOD execute() CLASS THREAD
   HB_SYMBOL_UNUSED( Self )
   RETURN NIL

METHOD quit( xResult, nRestart ) CLASS THREAD
   IF hb_threadSelf() == ::pThreadID
      IF PCOUNT() > 0
         ::result := xResult
      ENDIF
      IF !HB_ISNUMERIC( nRestart ) .OR. nRestart != QUIT_RESTART
         ::interval := NIL
      ENDIF
      QUIT
   ENDIF
   RETURN NIL

METHOD setInterval( nHSeconds ) CLASS THREAD
   IF HB_ISNUMERIC( nHSeconds ) .AND. Int( nHSeconds ) >= 0
      ::interval := Int( nHSeconds )
   ELSEIF PCount() > 0 .OR. nHSeconds == NIL
      ::interval := NIL
   ELSE
      /* TODO: RT Error */
      RETURN .F.
   ENDIF
   RETURN .T.

METHOD setPriority( nPriority ) CLASS THREAD
   /* TODO: add thread priority setting */
   IF HB_ISNUMERIC( nPriority )
      ::priority := nPriority
   ENDIF
   RETURN .F.

METHOD setStartTime( nSeconds ) CLASS THREAD
   IF HB_ISNUMERIC( nSeconds )
      IF nSeconds < 0 .OR. nSeconds > 86400
         RETURN .F.
      ENDIF
      ::startTime := nSeconds
   ELSEIF PCount() > 0 .OR. nSeconds == NIL
      ::startTime := NIL
   ELSE
      /* TODO: RT Error */
      RETURN .F.
   ENDIF
   RETURN .T.

METHOD start( xAction, ... ) CLASS THREAD

   IF ::active
      RETURN .F.

   ELSE
      ::pThreadID := hb_threadStart( HB_THREAD_INHERIT_PUBLIC, ;
            {| ... |
               LOCAL nTime

               ThreadObject( Self )

               ::active := .T.
               ::startCount++

               IF HB_ISNUMERIC( ::startTime )
                  nTime := ::startTime - Seconds()
                  IF nTime < 0
                     nTime += 86400
                  ENDIF
                  hb_idleSleep( nTime )
                  ::startTime := NIL
               ENDIF

               ::atStart( ... )
               IF ValType( ::_atStart ) == "B"
                  EVAL( ::_atStart, ... )
               ENDIF

               WHILE .T.

                  nTime := hb_milliSeconds()

                  BEGIN SEQUENCE
                     IF ! Empty( xAction ) .AND. ValType( xAction ) $ "CBS"
                        ::result := DO( xAction, ... )
                     ELSE
                        ::result := ::execute( ... )
                     ENDIF
                  ALWAYS
                     __QUITCANCEL()
                  ENDSEQUENCE

                  nTime := Int( ( hb_milliSeconds() - nTime ) / 10 )
                  ::deltaTime := nTime

                  /* TODO: when ::startTime is set execution is suspended
                   *       but I do not know the exact conditions and how
                   *       it can be resumed
                   */

                  IF !HB_ISNUMERIC( ::interval )
                     EXIT
                  ENDIF

                  nTime := ::interval - ::deltaTime
                  IF nTime > 0
                     hb_idleSleep( nTime / 100 )
                  ENDIF
                  ::startCount++

               ENDDO

               ::atEnd( ... )
               IF ValType( ::_atEnd ) == "B"
                  EVAL( ::_atEnd, ... )
               ENDIF
               ::active := .F.

               RETURN NIL
            }, ... )

      ::threadID := IIF( ::pThreadID == NIL, 0, hb_threadID( ::pThreadID ) )

   ENDIF

RETURN .T.

METHOD synchronize( nTimeOut ) CLASS THREAD
   LOCAL pThreadID := ::pThreadID

   IF hb_threadSelf() != pThreadID
      RETURN hb_threadWait( pThreadID, ;
                            iif( HB_ISNUMERIC( nTimeOut ) .AND. nTimeOut != 0, ;
                            nTimeOut / 100, ) )
   ENDIF
   RETURN .F.

METHOD threadSelf() CLASS THREAD
   RETURN ::pThreadID

/*
METHOD threadID() CLASS THREAD
   LOCAL pThreadID := ::pThreadID
   RETURN IIF( pThreadID == NIL, 0, hb_threadID( pThreadID ) )
*/