| ------------------------------------------------------------------------------ |
| -- -- |
| -- 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) 1991-1994, Florida State University -- |
| -- Copyright (C) 1995-2003, Ada Core Technologies -- |
| -- -- |
| -- 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. -- |
| -- Extensive contributions were provided by Ada Core Technologies, Inc. -- |
| -- -- |
| ------------------------------------------------------------------------------ |
| |
| -- 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; |
