Mercurial > repos > blastem
view arena.c @ 1442:59e1dbb795a7
Update README in anticipation of 0.5.1 release
author | Michael Pavone <pavone@retrodev.com> |
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date | Fri, 25 Aug 2017 20:12:21 -0700 |
parents | 4b8ab2d82aee |
children |
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/* Copyright 2015 Michael Pavone This file is part of BlastEm. BlastEm is free software distributed under the terms of the GNU General Public License version 3 or greater. See COPYING for full license text. */ #include <stdlib.h> #include <stdint.h> #include "arena.h" struct arena { void **used_blocks; void **free_blocks; size_t used_count; size_t used_storage; size_t free_count; size_t free_storage; }; #define DEFAULT_STORAGE_SIZE 8 static arena *current_arena; arena *get_current_arena() { if (!current_arena) { current_arena = calloc(1, sizeof(arena)); } return current_arena; } arena *set_current_arena(arena *a) { arena *tmp = current_arena; current_arena = a; return tmp; } arena *start_new_arena() { arena *tmp = current_arena; current_arena = NULL; return tmp; } void track_block(void *block) { arena *cur = get_current_arena(); if (cur->used_count == cur->used_storage) { if (cur->used_storage) { cur->used_storage *= 2; } else { cur->used_storage = DEFAULT_STORAGE_SIZE; } cur->used_blocks = realloc(cur->used_blocks, cur->used_storage * sizeof(void *)); } cur->used_blocks[cur->used_count++] = block; } void mark_all_free() { arena *cur = get_current_arena(); if (!cur->free_blocks) { cur->free_blocks = cur->used_blocks; cur->free_storage = cur->used_storage; cur->free_count = cur->used_count; cur->used_count = cur->used_storage = 0; cur->used_blocks = NULL; } else { if (cur->free_storage < cur->used_count + cur->free_count) { cur->free_storage = cur->used_count + cur->free_count; cur->free_blocks = realloc(cur->free_blocks, cur->free_storage * sizeof(void*)); } for (; cur->used_count > 0; cur->used_count--) { cur->free_blocks[cur->free_count++] = cur->used_blocks[cur->used_count-1]; } } } void *try_alloc_arena() { if (!current_arena || !current_arena->free_count) { return NULL; } void *ret = current_arena->free_blocks[--current_arena->free_count]; track_block(ret); return ret; }