n64-emu/third_party/parallel-rdp-standalone/util/arena_allocator.cpp
2023-08-06 14:03:29 +09:00

71 lines
2 KiB
C++

/* Copyright (c) 2017-2023 Hans-Kristian Arntzen
*
* 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 the rights to use, copy, modify, merge, publish,
* distribute, sublicense, 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 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 NONINFRINGEMENT.
* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS 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.
*/
#include "arena_allocator.hpp"
#include "bitops.hpp"
#include <assert.h>
namespace Util
{
void LegionAllocator::allocate(uint32_t num_blocks, uint32_t &out_mask, uint32_t &out_offset)
{
assert(NumSubBlocks >= num_blocks);
assert(num_blocks != 0);
uint32_t block_mask;
if (num_blocks == NumSubBlocks)
block_mask = ~0u;
else
block_mask = ((1u << num_blocks) - 1u);
uint32_t mask = free_blocks[num_blocks - 1];
uint32_t b = trailing_zeroes(mask);
assert(((free_blocks[0] >> b) & block_mask) == block_mask);
uint32_t sb = block_mask << b;
free_blocks[0] &= ~sb;
update_longest_run();
out_mask = sb;
out_offset = b;
}
void LegionAllocator::free(uint32_t mask)
{
assert((free_blocks[0] & mask) == 0);
free_blocks[0] |= mask;
update_longest_run();
}
void LegionAllocator::update_longest_run()
{
uint32_t f = free_blocks[0];
longest_run = 0;
while (f)
{
free_blocks[longest_run++] = f;
f &= f >> 1;
}
}
}