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| -rw-r--r-- | src/gallium/auxiliary/util/u_range.h | 89 |
1 files changed, 89 insertions, 0 deletions
diff --git a/src/gallium/auxiliary/util/u_range.h b/src/gallium/auxiliary/util/u_range.h new file mode 100644 index 00000000000..4b1d0d1be52 --- /dev/null +++ b/src/gallium/auxiliary/util/u_range.h @@ -0,0 +1,89 @@ +/* + * Copyright 2013 Marek Olšák <[email protected]> + * + * Permission is hereby granted, free of charge, to any person obtaining a + * copy of this software and associated documentation files (the "Software"), + * to deal in the Software without restriction, including without limitation + * on the rights to use, copy, modify, merge, publish, distribute, sub + * license, and/or sell copies of the Software, and to permit persons to whom + * the Software is furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice (including the next + * paragraph) shall be included in all copies or substantial portions of the + * Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL + * THE AUTHOR(S) AND/OR THEIR SUPPLIERS BE LIABLE FOR ANY CLAIM, + * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR + * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE + * USE OR OTHER DEALINGS IN THE SOFTWARE. */ + +/** + * @file + * 1D integer range, capable of the union and intersection operations. + * + * It only maintains a single interval which is extended when the union is + * done. This implementation is partially thread-safe (readers are not + * protected by a lock). + * + * @author Marek Olšák + */ + +#ifndef U_RANGE_H +#define U_RANGE_H + +#include "os/os_thread.h" + +struct util_range { + unsigned start; /* inclusive */ + unsigned end; /* exclusive */ + + /* for the range to be consistent with multiple contexts: */ + pipe_mutex write_mutex; +}; + + +static INLINE void +util_range_set_empty(struct util_range *range) +{ + range->start = ~0; + range->end = 0; +} + +/* This is like a union of two sets. */ +static INLINE void +util_range_add(struct util_range *range, unsigned start, unsigned end) +{ + if (start < range->start || end > range->end) { + pipe_mutex_lock(range->write_mutex); + range->start = MIN2(start, range->start); + range->end = MAX2(end, range->end); + pipe_mutex_unlock(range->write_mutex); + } +} + +static INLINE boolean +util_ranges_intersect(struct util_range *range, unsigned start, unsigned end) +{ + return MAX2(start, range->start) < MIN2(end, range->end); +} + + +/* Init/deinit */ + +static INLINE void +util_range_init(struct util_range *range) +{ + pipe_mutex_init(range->write_mutex); + util_range_set_empty(range); +} + +static INLINE void +util_range_destroy(struct util_range *range) +{ + pipe_mutex_destroy(range->write_mutex); +} + +#endif |