------------------------------------------------------------------------------ -- -- -- GNU ADA RUN-TIME LIBRARY (GNARL) COMPONENTS -- -- -- -- S Y S T E M . O S _ I N T E R F A C E -- -- -- -- B o d y -- -- -- -- -- -- Copyright (C) 1991-2002 Florida State University -- -- -- -- GNARL is free software; you can redistribute it and/or modify it under -- -- terms of the GNU General Public License as published by the Free Soft- -- -- ware Foundation; either version 2, or (at your option) any later ver- -- -- sion. GNARL is distributed in the hope that it will be useful, but WITH- -- -- OUT 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 distributed with GNARL; see file COPYING. If not, write -- -- to the Free Software Foundation, 59 Temple Place - Suite 330, Boston, -- -- MA 02111-1307, USA. -- -- -- -- As a special exception, if other files instantiate generics from this -- -- unit, or you link this unit with other files to produce an executable, -- -- this unit does not by itself cause the resulting executable to be -- -- covered by the GNU General Public License. This exception does not -- -- however invalidate any other reasons why the executable file might be -- -- covered by the GNU Public License. -- -- -- -- GNARL was developed by the GNARL team at Florida State University. It is -- -- now maintained by Ada Core Technologies Inc. in cooperation with Florida -- -- State University (http://www.gnat.com). -- -- -- ------------------------------------------------------------------------------ -- This is the OS/2 version of this package pragma Polling (Off); -- Turn off polling, we do not want ATC polling to take place during -- tasking operations. It causes infinite loops and other problems. with Interfaces.OS2Lib.Errors; with Interfaces.OS2Lib.Synchronization; package body System.OS_Interface is use Interfaces; use Interfaces.OS2Lib; use Interfaces.OS2Lib.Synchronization; use Interfaces.OS2Lib.Errors; ----------- -- Yield -- ----------- -- Give up the remainder of the time-slice and yield the processor -- to other threads of equal priority. Yield will return immediately -- without giving up the current time-slice when the only threads -- that are ready have a lower priority. -- ??? Just giving up the current time-slice seems not to be enough -- to get the thread to the end of the ready queue if OS/2 does use -- a queue at all. As a partial work-around, we give up two time-slices. -- This is the best we can do now, and at least is sufficient for passing -- the ACVC 2.0.1 Annex D tests. procedure Yield is begin Delay_For (0); Delay_For (0); end Yield; --------------- -- Delay_For -- --------------- procedure Delay_For (Period : in Duration_In_Millisec) is Result : APIRET; begin pragma Assert (Period >= 0, "GNULLI---Delay_For: negative argument"); -- ??? DosSleep is not the appropriate function for a delay in real -- time. It only gives up some number of scheduled time-slices. -- Use a timer instead or block for some semaphore with a time-out. Result := DosSleep (ULONG (Period)); if Result = ERROR_TS_WAKEUP then -- Do appropriate processing for interrupted sleep -- Can we raise an exception here? null; end if; pragma Assert (Result = NO_ERROR, "GNULLI---Error in Delay_For"); end Delay_For; ----------- -- Clock -- ----------- function Clock return Duration is -- Implement conversion from tick count to Duration -- using fixed point arithmetic. The frequency of -- the Intel 8254 timer chip is 18.2 * 2**16 Hz. Tick_Duration : constant := 1.0 / (18.2 * 2**16); Tick_Count : aliased QWORD; begin -- Read nr of clock ticks since boot time Must_Not_Fail (DosTmrQueryTime (Tick_Count'Access)); return Tick_Count * Tick_Duration; end Clock; end System.OS_Interface;