1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
|
------------------------------------------------------------------------------
-- --
-- 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;
|
