diff options
| -rw-r--r-- | include/mempool.h | 30 | ||||
| -rw-r--r-- | lib/util/Makemodule.am | 1 | ||||
| -rw-r--r-- | lib/util/mempool.c | 194 |
3 files changed, 225 insertions, 0 deletions
diff --git a/include/mempool.h b/include/mempool.h new file mode 100644 index 0000000..6d3990e --- /dev/null +++ b/include/mempool.h @@ -0,0 +1,30 @@ +/* SPDX-License-Identifier: LGPL-3.0-or-later */ +/* + * mempool.h + * + * Copyright (C) 2021 David Oberhollenzer <goliath@infraroot.at> + */ +#ifndef MEMPOOL_H +#define MEMPOOL_H + +#include "compat.h" + +typedef struct mem_pool_t mem_pool_t; + +#ifdef __cplusplus +extern "C" { +#endif + +mem_pool_t *mem_pool_create(size_t obj_size); + +void mem_pool_destroy(mem_pool_t *mem); + +void *mem_pool_allocate(mem_pool_t *mem); + +void mem_pool_free(mem_pool_t *mem, void *ptr); + +#ifdef __cplusplus +} +#endif + +#endif /* MEMPOOL_H */ diff --git a/lib/util/Makemodule.am b/lib/util/Makemodule.am index 0784898..80bec4f 100644 --- a/lib/util/Makemodule.am +++ b/lib/util/Makemodule.am @@ -2,6 +2,7 @@ libutil_a_SOURCES = include/util.h include/str_table.h include/hash_table.h libutil_a_SOURCES += lib/util/str_table.c lib/util/alloc.c libutil_a_SOURCES += lib/util/rbtree.c include/rbtree.h libutil_a_SOURCES += lib/util/array.c include/array.h +libutil_a_SOURCES += lib/util/mempool.c include/mempool.h libutil_a_SOURCES += lib/util/xxhash.c lib/util/hash_table.c libutil_a_SOURCES += lib/util/fast_urem_by_const.h libutil_a_CFLAGS = $(AM_CFLAGS) diff --git a/lib/util/mempool.c b/lib/util/mempool.c new file mode 100644 index 0000000..dd2d692 --- /dev/null +++ b/lib/util/mempool.c @@ -0,0 +1,194 @@ +/* SPDX-License-Identifier: LGPL-3.0-or-later */ +/* + * mempool.c + * + * Copyright (C) 2021 David Oberhollenzer <goliath@infraroot.at> + */ +#include "mempool.h" + +#include <stdlib.h> +#include <limits.h> +#include <string.h> +#include <assert.h> + +#include <sys/mman.h> + +#define DEF_POOL_SIZE (65536) + +typedef struct pool_t { + struct pool_t *next; + + unsigned char *data; + unsigned char *limit; + + unsigned int *bitmap; + + size_t obj_free; + + unsigned char blob[]; +} pool_t; + +struct mem_pool_t { + size_t obj_size; + size_t pool_size; + size_t bitmap_count; + pool_t *pool_list; +}; + +static size_t pool_size_from_bitmap_count(size_t count, size_t obj_size) +{ + size_t size, byte_count, bit_count; + + size = sizeof(pool_t); + if (size % sizeof(unsigned int)) + size += sizeof(unsigned int) - size % sizeof(unsigned int); + + byte_count = count * sizeof(unsigned int); + bit_count = byte_count * CHAR_BIT; + + size += byte_count; + if (size % obj_size) + size += obj_size - size % obj_size; + + size += bit_count * obj_size; + return size; +} + +static pool_t *create_pool(const mem_pool_t *mem) +{ + unsigned char *ptr; + pool_t *pool; + + ptr = mmap(NULL, mem->pool_size, PROT_READ | PROT_WRITE, + MAP_PRIVATE | MAP_ANONYMOUS, -1, 0); + + if (ptr == MAP_FAILED) + return NULL; + + pool = (pool_t *)ptr; + + ptr = pool->blob; + + if (((intptr_t)ptr) % sizeof(unsigned int)) { + ptr += sizeof(unsigned int); + ptr -= ((intptr_t)ptr) % sizeof(unsigned int); + } + + pool->bitmap = (unsigned int *)ptr; + pool->obj_free = mem->bitmap_count * sizeof(unsigned int) * CHAR_BIT; + + ptr += mem->bitmap_count * sizeof(unsigned int); + + if (((intptr_t)ptr) % mem->obj_size) { + ptr += mem->obj_size; + ptr -= ((intptr_t)ptr) % mem->obj_size; + } + + pool->data = ptr; + pool->limit = pool->data + pool->obj_free * mem->obj_size - 1; + + memset(pool->bitmap, 0, mem->bitmap_count * sizeof(unsigned int)); + return pool; +} + +mem_pool_t *mem_pool_create(size_t obj_size) +{ + mem_pool_t *mem = calloc(1, sizeof(*mem)); + size_t count = 1, total; + + if (mem == NULL) + return NULL; + + for (;;) { + total = pool_size_from_bitmap_count(count, obj_size); + if (total > DEF_POOL_SIZE) + break; + ++count; + } + + --count; + + mem->obj_size = obj_size; + mem->pool_size = DEF_POOL_SIZE; + mem->bitmap_count = count; + return mem; +} + +void mem_pool_destroy(mem_pool_t *mem) +{ + while (mem->pool_list != NULL) { + pool_t *pool = mem->pool_list; + mem->pool_list = pool->next; + + munmap(pool, mem->pool_size); + } + + free(mem); +} + +void *mem_pool_allocate(mem_pool_t *mem) +{ + size_t idx, i, j; + void *ptr = NULL; + pool_t *it; + + for (it = mem->pool_list; it != NULL; it = it->next) { + if (it->obj_free > 0) + break; + } + + if (it == NULL) { + it = create_pool(mem); + if (it == NULL) + return NULL; + + it->next = mem->pool_list; + mem->pool_list = it; + } + + for (i = 0; i < mem->bitmap_count; ++i) { + if (it->bitmap[i] < UINT_MAX) + break; + } + + for (j = 0; j < (sizeof(it->bitmap[i]) * CHAR_BIT); ++j) { + if (!(it->bitmap[i] & (1UL << j))) + break; + } + + idx = i * sizeof(unsigned int) * CHAR_BIT + j; + ptr = it->data + idx * mem->obj_size; + + it->bitmap[i] |= (1UL << j); + it->obj_free -= 1; + + memset(ptr, 0, mem->obj_size); + return ptr; +} + +void mem_pool_free(mem_pool_t *mem, void *ptr) +{ + size_t idx, i, j; + pool_t *it; + + for (it = mem->pool_list; it != NULL; it = it->next) { + if ((unsigned char *)ptr >= it->data && + (unsigned char *)ptr < it->limit) { + break; + } + } + + assert(it != NULL); + + idx = (size_t)((unsigned char *)ptr - it->data); + + assert((idx % mem->obj_size) == 0); + idx /= mem->obj_size; + + i = idx / (sizeof(unsigned int) * CHAR_BIT); + j = idx % (sizeof(unsigned int) * CHAR_BIT); + + assert((it->bitmap[i] & (1 << j)) != 0); + + it->bitmap[i] &= ~(1 << j); +} |