kopia lustrzana https://github.com/bristol-seds/pico-tracker
74 wiersze
2.5 KiB
C
74 wiersze
2.5 KiB
C
/*
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* Macros for defining and operating on double buffers
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* Copyright (C) 2014 Richard Meadows <richardeoin>
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*
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* Permission is hereby granted, free of charge, to any person obtaining
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* a copy of this software and associated documentation files (the
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* "Software"), to deal in the Software without restriction, including
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* without limitation the rights to use, copy, modify, merge, publish,
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* distribute, sublicense, and/or sell copies of the Software, and to
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* permit persons to whom the Software is furnished to do so, subject to
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* the following conditions:
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*
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* The above copyright notice and this permission notice shall be
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* included in all copies or substantial portions of the Software.
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*
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
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* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
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* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
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* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
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* LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
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* OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
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* WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
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*/
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#ifndef DBUFFER_H
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#define DBUFFER_H
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/**
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* Double buffer implementation for single types
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*/
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#define DBUFFER_T(t) \
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struct { \
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t buffers[2]; \
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uint8_t index; \
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}
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#define DBUFFER_INIT(db_ptr) do{ \
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(db_ptr)->index = 0; } while (0)
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#define DBUFFER_WRITE(db_ptr, val) do { \
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(db_ptr)->buffers[(db_ptr)->index] = val; } while (0)
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#define DBUFFER_SWAP(db_ptr) do { \
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(db_ptr)->index ^= 0x1; } while (0)
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#define DBUFFER_READ(db_ptr) \
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(db_ptr)->buffers[(db_ptr)->index ^ 0x1]
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/**
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* Double buffer implementation for arrays
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*/
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#define ARRAY_DBUFFER_T(t, n) \
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struct { \
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t buffers[2][n]; \
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uint8_t index; \
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}
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#define ARRAY_DBUFFER_INIT DBUFFER_INIT
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/**
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* Functions for the data source. The data source owns the pointer
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* returned by ARRAY_DBUFFER_WRITE_PTR until it calls
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* ARRAY_DBUFFER_SWAP.
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*/
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#define ARRAY_DBUFFER_WRITE_PTR(db_ptr) \
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(db_ptr)->buffers[(db_ptr)->index]
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#define ARRAY_DBUFFER_SWAP DBUFFER_SWAP
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/**
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* Functions for the data sink. The pointer returned by
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* ARRAY_DBUFFER_READ_PTR is immediately invalid unless called in a
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* critical section. This is as the data source could be operating in
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* a higher IRQ context.
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*/
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#define ARRAY_DBUFFER_READ_PTR(db_ptr) \
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(db_ptr)->buffers[(db_ptr)->index ^ 0x1]
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#endif /* DBUFFER_H */
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