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70 lines
1.0 KiB
C++
70 lines
1.0 KiB
C++
/*
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* Copyright 2013 Haiku, Inc. All rights reserved.
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* Distributed under the terms of the MIT License.
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*
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* Authors:
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* Paweł Dziepak, pdziepak@quarnos.org
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*/
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#ifndef KERNEL_UTIL_RANDOM_H
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#define KERNEL_UTIL_RANDOM_H
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#include <smp.h>
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#include <SupportDefs.h>
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#define MAX_FAST_RANDOM_VALUE 0x7fff
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#define MAX_RANDOM_VALUE 0x7fffffffu
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static const int kFastRandomShift = 15;
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static const int kRandomShift = 31;
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#ifdef __cplusplus
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extern "C" {
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#endif
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unsigned int fast_random_value(void);
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unsigned int random_value(void);
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#ifdef __cplusplus
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}
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#endif
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#ifdef __cplusplus
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template<typename T>
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T
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fast_get_random()
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{
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size_t shift = 0;
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T random = 0;
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while (shift < sizeof(T) * 8) {
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random |= (T)fast_random_value() << shift;
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shift += kFastRandomShift;
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}
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return random;
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}
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template<typename T>
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T
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get_random()
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{
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size_t shift = 0;
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T random = 0;
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while (shift < sizeof(T) * 8) {
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random |= (T)random_value() << shift;
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shift += kRandomShift;
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}
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return random;
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}
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#endif // __cplusplus
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#endif // KERNEL_UTIL_RANDOM_H
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