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comparison packages/kernel/current/include/flag.hxx @ 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 #ifndef CYGONCE_KERNEL_FLAG_HXX
2 #define CYGONCE_KERNEL_FLAG_HXX
3
4 //==========================================================================
5 //
6 // flag.hxx
7 //
8 // Flag object class declarations
9 //
10 //==========================================================================
11 //####COPYRIGHTBEGIN####
12 //
13 // -------------------------------------------
14 // The contents of this file are subject to the Cygnus eCos Public License
15 // Version 1.0 (the "License"); you may not use this file except in
16 // compliance with the License. You may obtain a copy of the License at
17 // http://sourceware.cygnus.com/ecos
18 //
19 // Software distributed under the License is distributed on an "AS IS"
20 // basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See the
21 // License for the specific language governing rights and limitations under
22 // the License.
23 //
24 // The Original Code is eCos - Embedded Cygnus Operating System, released
25 // September 30, 1998.
26 //
27 // The Initial Developer of the Original Code is Cygnus. Portions created
28 // by Cygnus are Copyright (C) 1998 Cygnus Solutions. All Rights Reserved.
29 // -------------------------------------------
30 //
31 //####COPYRIGHTEND####
32 //==========================================================================
33 //#####DESCRIPTIONBEGIN####
34 //
35 // Author(s): hmt
36 // Contributors: hmt
37 // Date: 1998-02-10
38 // Purpose: Define Flag class interfaces
39 // Description: The classes defined here provide the APIs for flags.
40 // Usage: #include <cyg/kernel/flag.hxx>
41 //
42 //
43 //####DESCRIPTIONEND####
44 //
45 //==========================================================================
46
47 #include <cyg/kernel/ktypes.h>
48 #include <cyg/infra/cyg_ass.h> // assertion macros
49 #include <cyg/kernel/thread.hxx> // Cyg_Thread
50
51 // -------------------------------------------------------------------------
52
53 // Flag object. This class implements a queue of threads waiting for a
54 // boolean expression of the flag value (an integer) to become true; all
55 // relevant threads are awoken, not just the first. A variant on this is
56 // the single-bit flag, which is implemented by means of default arguments.
57
58 #ifdef CYGIMP_FLAGS_16BIT
59 typedef cyg_uint16 Cyg_FlagValue;
60 #define CYG_FLAGS_SIZE 16
61 #endif
62 #ifdef CYGIMP_FLAGS_32BIT
63 typedef cyg_uint32 Cyg_FlagValue;
64 #define CYG_FLAGS_SIZE 32
65 #endif
66 #ifdef CYGIMP_FLAGS_64BIT
67 typedef cyg_uint64 Cyg_FlagValue;
68 #define CYG_FLAGS_SIZE 64
69 #endif
70
71 #ifndef CYG_FLAGS_SIZE
72 typedef cyg_uint32 Cyg_FlagValue;
73 #define CYG_FLAGS_SIZE 32
74 #endif
75
76
77
78 class Cyg_Flag
79 {
80 private:
81 Cyg_FlagValue value;
82
83 class FlagWaitInfo
84 {
85 public:
86 Cyg_FlagValue allmask; // these are separate words to
87 Cyg_FlagValue anymask; // save time in wakeup.
88 Cyg_FlagValue value_out; // return the value that satisfied
89 cyg_bool do_clear;
90
91 FlagWaitInfo() { value_out = 0; }
92 };
93
94 Cyg_ThreadQueue queue; // Queue of waiting threads
95
96 public:
97
98 CYGDBG_DEFINE_CHECK_THIS
99
100 Cyg_Flag( Cyg_FlagValue init = 0 ); // Constructor
101 ~Cyg_Flag(); // Destructor
102
103 void
104 setbits( Cyg_FlagValue arg = ~0 ); // -OR- the arg in
105 // not inlined; this function awakens affected threads.
106
107 void
108 maskbits( Cyg_FlagValue arg = 0 ); // -AND- it in
109 // this is not inlined because it needs to lock the scheduler;
110 // it only really does value &= arg; nobody can be awoken in consequence.
111
112 typedef cyg_uint8 WaitMode;
113 // These values are chosen to map directly to uITRON for emulation
114 // purposes:
115 static const WaitMode AND = 0; // all specified bits must be set
116 static const WaitMode OR = 2; // any specified bit must be set
117 static const WaitMode CLR = 1; // clear value when satisfied
118 static const WaitMode MASK= 3; // might be useful
119
120 // Wait for a match on our pattern, according to the flags given.
121 // Return the matching value, or zero if interrupted.
122 Cyg_FlagValue
123 wait( Cyg_FlagValue pattern, WaitMode mode );
124
125 // Wait for a match on our pattern, with an absolute timeout.
126 // Return the matching value, or zero if timed out/interrupted.
127 // (zero cannot match any pattern).
128 #ifdef CYGFUN_KERNEL_THREADS_TIMER
129 Cyg_FlagValue
130 wait( Cyg_FlagValue pattern, WaitMode mode,
131 cyg_tick_count abs_timeout );
132 #endif
133 // Test for a match on our pattern, according to the flags given.
134 // Return the matching value if success, else zero.
135 Cyg_FlagValue
136 poll( Cyg_FlagValue pattern, WaitMode mode );
137
138 inline Cyg_FlagValue
139 peek() // Get current value
140 {
141 return value; // NOT atomic wrt threads
142 }
143
144 inline cyg_bool
145 waiting() // Any threads waiting?
146 {
147 return !queue.empty();
148 }
149 };
150
151
152
153 // -------------------------------------------------------------------------
154 #endif // ifndef CYGONCE_KERNEL_FLAG_HXX
155 // EOF flag.hxx