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comparison packages/devs/wallclock/current/src/emulate.cxx @ 0:3111d98ba7b3 ecos-v1_1-release

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Initial commit of eCos version 1.1
author jlarmour
date Tue, 11 May 1999 11:16:07 +0000
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children 443894e2e912
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-1:000000000000 0:3111d98ba7b3
1 //==========================================================================
2 //
3 // devs/wallclock/emulate.cxx
4 //
5 // Wallclock emulation implementation
6 //
7 //==========================================================================
8 //####COPYRIGHTBEGIN####
9 //
10 // -------------------------------------------
11 // The contents of this file are subject to the Cygnus eCos Public License
12 // Version 1.0 (the "License"); you may not use this file except in
13 // compliance with the License. You may obtain a copy of the License at
14 // http://sourceware.cygnus.com/ecos
15 //
16 // Software distributed under the License is distributed on an "AS IS"
17 // basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See the
18 // License for the specific language governing rights and limitations under
19 // the License.
20 //
21 // The Original Code is eCos - Embedded Cygnus Operating System, released
22 // September 30, 1998.
23 //
24 // The Initial Developer of the Original Code is Cygnus. Portions created
25 // by Cygnus are Copyright (C) 1998 Cygnus Solutions. All Rights Reserved.
26 // -------------------------------------------
27 //
28 //####COPYRIGHTEND####
29 //==========================================================================
30 //#####DESCRIPTIONBEGIN####
31 //
32 // Author(s): nickg
33 // Contributors: nickg
34 // Date: 1998-07-14
35 // Purpose: Wallclock emulation
36 //
37 //####DESCRIPTIONEND####
38 //
39 //==========================================================================
40
41 #include <pkgconf/wallclock.h> // Wallclock device config
42
43 #include <cyg/infra/cyg_type.h> // Common type definitions and support
44 #include <cyg/hal/hal_diag.h> // HAL diagnostic output
45
46 #include <cyg/devs/wallclock.hxx>
47
48 #include <cyg/kernel/sched.hxx>
49 #include <cyg/kernel/clock.hxx>
50
51 #include <cyg/kernel/sched.inl>
52
53 #ifdef CYGIMP_WALLCLOCK_EMULATE
54
55 /*---------------------------------------------------------------------------*/
56 // Local static variables
57
58 static Cyg_WallClock wallclock_instance CYG_INIT_PRIORITY( CLOCK );
59
60 static cyg_tick_count epoch_ticks;
61
62 static cyg_uint32 epoch_time_stamp;
63
64 Cyg_WallClock *Cyg_WallClock::wallclock;
65
66 /*---------------------------------------------------------------------------*/
67 // Constructor
68
69 Cyg_WallClock::Cyg_WallClock()
70 {
71 // install instance pointer
72 wallclock = &wallclock_instance;
73 }
74
75 /*---------------------------------------------------------------------------*/
76 // Returns the current timestamp. This may involve reading the
77 // hardware, so it may take anything up to a second to complete.
78
79 cyg_uint32 Cyg_WallClock::get_current_time()
80 {
81 Cyg_Clock::cyg_resolution res = Cyg_Clock::real_time_clock->get_resolution();
82
83 Cyg_Scheduler::lock();
84
85 cyg_tick_count diff = Cyg_Clock::real_time_clock->current_value()
86 - epoch_ticks;
87
88 diff = ( diff * res.dividend ) / ( res.divisor * 1000000000LL ) ;
89
90 Cyg_Scheduler::unlock();
91
92 return epoch_time_stamp + diff;
93 }
94
95 /*---------------------------------------------------------------------------*/
96 // Sets the value of the timestamp relative to now. This may involve
97 // writing to the hardware, so it may take anything up to a second to
98 // complete.
99 void Cyg_WallClock::set_current_time( cyg_uint32 time_stamp )
100 {
101 Cyg_Scheduler::lock();
102
103 epoch_time_stamp = time_stamp;
104 epoch_ticks = Cyg_Clock::real_time_clock->current_value();
105
106 Cyg_Scheduler::unlock();
107 }
108
109 /*---------------------------------------------------------------------------*/
110
111 #endif
112 /*---------------------------------------------------------------------------*/
113 /* End of devs/wallclock/emulate.cxx */