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comparison packages/kernel/current/include/bitmap.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_BITMAP_HXX
2 #define CYGONCE_KERNEL_BITMAP_HXX
3
4 //==========================================================================
5 //
6 // bitmap.hxx
7 //
8 // Bitmap scheduler class declaration(s)
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): nickg
36 // Contributors: nickg
37 // Date: 1997-09-10
38 // Purpose: Define bitmap scheduler implementation
39 // Description: The classes defined here are used as base classes
40 // by the common classes that define schedulers and thread
41 // things.
42 // Usage: Included according to configuration by
43 // <cyg/kernel/sched.hxx>
44 //
45 //####DESCRIPTIONEND####
46 //
47 //==========================================================================
48
49 #include <cyg/kernel/ktypes.h>
50
51 // -------------------------------------------------------------------------
52 // The macro CYGNUM_KERNEL_SCHED_BITMAP_SIZE contains the number of bits
53 // that the scheduler bitmap should contain. It is derived from the number
54 // of threads that the system is allowed to use during configuration.
55
56 #ifndef CYGNUM_KERNEL_SCHED_BITMAP_SIZE
57 #define CYGNUM_KERNEL_SCHED_BITMAP_SIZE 32
58 #endif
59
60 #if CYGNUM_KERNEL_SCHED_BITMAP_SIZE <= 8
61 typedef cyg_ucount8 cyg_sched_bitmap;
62 #elif CYGNUM_KERNEL_SCHED_BITMAP_SIZE <= 16
63 typedef cyg_ucount16 cyg_sched_bitmap;
64 #elif CYGNUM_KERNEL_SCHED_BITMAP_SIZE <= 32
65 typedef cyg_ucount32 cyg_sched_bitmap;
66 #else
67 #error Bitmaps greater than 32 bits not currently allowed
68 #endif
69
70 // -------------------------------------------------------------------------
71 // Customize the scheduler
72
73 #define CYGIMP_THREAD_PRIORITY 1
74 #define CYG_SCHED_UNIQUE_PRIORITIES 1
75
76 #define CYG_THREAD_MIN_PRIORITY (CYGNUM_KERNEL_SCHED_BITMAP_SIZE-1)
77 #define CYG_THREAD_MAX_PRIORITY 0
78
79 // set default scheduling info value for thread constructors.
80 #define CYG_SCHED_DEFAULT_INFO CYG_THREAD_MAX_PRIORITY
81
82 // -------------------------------------------------------------------------
83 // This class contains the implementation details of the scheduler, and
84 // provides a standard API for accessing it.
85
86 class Cyg_Scheduler_Implementation
87 : public Cyg_Scheduler_Base
88 {
89 friend class Cyg_ThreadQueue_Implementation;
90 friend class Cyg_SchedThread_Implementation;
91
92 cyg_sched_bitmap run_queue;
93
94 Cyg_Thread *thread_table[CYGNUM_KERNEL_SCHED_BITMAP_SIZE];
95
96
97 protected:
98
99 Cyg_Scheduler_Implementation(); // Constructor
100
101 // The following functions provide the scheduler implementation
102 // interface to the Cyg_Scheduler class. These are protected
103 // so that only the scheduler can call them.
104
105 // choose a new thread
106 Cyg_Thread *schedule();
107
108 // make thread schedulable
109 void add_thread(Cyg_Thread *thread);
110
111 // make thread un-schedulable
112 void rem_thread(Cyg_Thread *thread);
113
114 // register thread with scheduler
115 void register_thread(Cyg_Thread *thread);
116
117 // deregister thread
118 void deregister_thread(Cyg_Thread *thread);
119
120 // Test the given priority for uniqueness
121 cyg_bool unique( cyg_priority priority);
122
123 };
124
125 // -------------------------------------------------------------------------
126 // Scheduler thread implementation.
127 // This class provides the implementation of the scheduler specific parts
128 // of each thread.
129
130 class Cyg_SchedThread_Implementation
131 {
132 friend class Cyg_Scheduler_Implementation;
133 friend class Cyg_ThreadQueue_Implementation;
134
135 protected:
136
137 cyg_priority priority; // current thread priority
138
139 Cyg_SchedThread_Implementation(CYG_ADDRWORD sched_info);
140
141 void yield(); // Yield CPU to next thread
142
143 };
144
145 // -------------------------------------------------------------------------
146 // Thread queue implementation.
147 // This class provides the (scheduler specific) implementation of the
148 // thread queue class.
149
150 class Cyg_ThreadQueue_Implementation
151 {
152 cyg_sched_bitmap wait_queue;
153
154 protected:
155
156 // API used by Cyg_ThreadQueue
157
158 Cyg_ThreadQueue_Implementation(); // Constructor
159
160 // Add thread to queue
161 void enqueue(Cyg_Thread *thread);
162
163 // return first thread on queue
164 Cyg_Thread *highpri();
165
166 // remove first thread on queue
167 Cyg_Thread *dequeue();
168
169 // remove specified thread from queue
170 void remove(Cyg_Thread *thread);
171
172 // test if queue is empty
173 cyg_bool empty();
174
175 };
176
177 inline cyg_bool Cyg_ThreadQueue_Implementation::empty()
178 {
179 return wait_queue == 0;
180 }
181
182 // -------------------------------------------------------------------------
183
184 #endif // ifndef CYGONCE_KERNEL_BITMAP_HXX
185 // EOF bitmap.hxx