/*
* %CopyrightBegin%
*
* Copyright Ericsson AB 2003-2016. All Rights Reserved.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
* %CopyrightEnd%
*/
/*
* Description: A fast allocator intended for temporary allocation.
* When allocating, only the first block in the free list
* is inspected, if this block doesn't fit a new carrier
* is created. NOTE: this allocator can behave really bad
* if misused.
*
* This module is a callback-module for erl_alloc_util.c
*
* Author: Rickard Green
*/
#ifdef HAVE_CONFIG_H
# include "config.h"
#endif
#include "global.h"
#define GET_ERL_AF_ALLOC_IMPL
#include "erl_afit_alloc.h"
struct AFFreeBlock_t_ {
Block_t block_head;
AFFreeBlock_t *prev;
AFFreeBlock_t *next;
};
#define AF_BLK_SZ(B) MBC_FBLK_SZ(&(B)->block_head)
#define MIN_MBC_SZ (16*1024)
#define MIN_MBC_FIRST_FREE_SZ (4*1024)
/* Prototypes of callback functions */
static Block_t * get_free_block (Allctr_t *, Uint, Block_t *, Uint);
static void link_free_block (Allctr_t *, Block_t *);
static void unlink_free_block (Allctr_t *, Block_t *);
static Eterm info_options (Allctr_t *, char *, int *,
void *arg, Uint **, Uint *);
static void init_atoms (void);
static int atoms_initialized = 0;
void
erts_afalc_init(void)
{
atoms_initialized = 0;
}
Allctr_t *
erts_afalc_start(AFAllctr_t *afallctr,
AFAllctrInit_t *afinit,
AllctrInit_t *init)
{
struct {
int dummy;
AFAllctr_t allctr;
} zero = {0};
/* The struct with a dummy element first is used in order to avoid (an
incorrect) gcc warning. gcc warns if {0} is used as initializer of
a struct when the first member is a struct (not if, for example,
the third member is a struct). */
Allctr_t *allctr = (Allctr_t *) afallctr;
sys_memcpy((void *) afallctr, (void *) &zero.allctr, sizeof(AFAllctr_t));
allctr->mbc_header_size = sizeof(Carrier_t);
allctr->min_mbc_size = MIN_MBC_SZ;
allctr->min_mbc_first_free_size = MIN_MBC_FIRST_FREE_SZ;
allctr->min_block_size = sizeof(AFFreeBlock_t);
allctr->vsn_str = ERTS_ALC_AF_ALLOC_VSN_STR;
/* Callback functions */
allctr->get_free_block = get_free_block;
allctr->link_free_block = link_free_block;
allctr->unlink_free_block = unlink_free_block;
allctr->info_options = info_options;
allctr->get_next_mbc_size = NULL;
allctr->creating_mbc = NULL;
allctr->destroying_mbc = NULL;
allctr->add_mbc = NULL;
allctr->remove_mbc = NULL;
allctr->largest_fblk_in_mbc = NULL;
allctr->init_atoms = init_atoms;
#ifdef ERTS_ALLOC_UTIL_HARD_DEBUG
allctr->check_block = NULL;
allctr->check_mbc = NULL;
#endif
allctr->atoms_initialized = 0;
if (!erts_alcu_start(allctr, init))
return NULL;
return allctr;
}
static Block_t *
get_free_block(Allctr_t *allctr, Uint size, Block_t *cand_blk, Uint cand_size)
{
AFAllctr_t *afallctr = (AFAllctr_t *) allctr;
ASSERT(!cand_blk || cand_size >= size);
if (afallctr->free_list && AF_BLK_SZ(afallctr->free_list) >= size) {
AFFreeBlock_t *res = afallctr->free_list;
afallctr->free_list = res->next;
if (res->next)
res->next->prev = NULL;
return (Block_t *) res;
}
else
return NULL;
}
static void
link_free_block(Allctr_t *allctr, Block_t *block)
{
AFFreeBlock_t *blk = (AFFreeBlock_t *) block;
AFAllctr_t *afallctr = (AFAllctr_t *) allctr;
if (afallctr->free_list && AF_BLK_SZ(afallctr->free_list) > AF_BLK_SZ(blk)) {
blk->next = afallctr->free_list->next;
blk->prev = afallctr->free_list;
afallctr->free_list->next = blk;
}
else {
blk->next = afallctr->free_list;
blk->prev = NULL;
afallctr->free_list = blk;
}
if (blk->next)
blk->next->prev = blk;
}
static void
unlink_free_block(Allctr_t *allctr, Block_t *block)
{
AFFreeBlock_t *blk = (AFFreeBlock_t *) block;
AFAllctr_t *afallctr = (AFAllctr_t *) allctr;
if (blk->prev)
blk->prev->next = blk->next;
else
afallctr->free_list = blk->next;
if (blk->next)
blk->next->prev = blk->prev;
}
static struct {
Eterm as;
Eterm af;
#ifdef DEBUG
Eterm end_of_atoms;
#endif
} am;
static void ERTS_INLINE atom_init(Eterm *atom, char *name)
{
*atom = am_atom_put(name, strlen(name));
}
#define AM_INIT(AM) atom_init(&am.AM, #AM)
static void
init_atoms(void)
{
#ifdef DEBUG
Eterm *atom;
#endif
if (atoms_initialized)
return;
#ifdef DEBUG
for (atom = (Eterm *) &am; atom <= &am.end_of_atoms; atom++) {
*atom = THE_NON_VALUE;
}
#endif
AM_INIT(as);
AM_INIT(af);
#ifdef DEBUG
for (atom = (Eterm *) &am; atom < &am.end_of_atoms; atom++) {
ASSERT(*atom != THE_NON_VALUE);
}
#endif
atoms_initialized = 1;
}
#define bld_uint erts_bld_uint
#define bld_cons erts_bld_cons
#define bld_tuple erts_bld_tuple
static ERTS_INLINE void
add_2tup(Uint **hpp, Uint *szp, Eterm *lp, Eterm el1, Eterm el2)
{
*lp = bld_cons(hpp, szp, bld_tuple(hpp, szp, 2, el1, el2), *lp);
}
static Eterm
info_options(Allctr_t *allctr,
char *prefix,
int *print_to_p,
void *print_to_arg,
Uint **hpp,
Uint *szp)
{
Eterm res = THE_NON_VALUE;
if (print_to_p) {
erts_print(*print_to_p, print_to_arg, "%sas: af\n", prefix);
}
if (hpp || szp) {
if (!atoms_initialized)
erts_exit(ERTS_ERROR_EXIT, "%s:%d: Internal error: Atoms not initialized",
__FILE__, __LINE__);;
res = NIL;
add_2tup(hpp, szp, &res, am.as, am.af);
}
return res;
}
/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *\
* NOTE: erts_afalc_test() is only supposed to be used for testing. *
* *
* Keep alloc_SUITE_data/allocator_test.h updated if changes are made *
* to erts_afalc_test() *
\* */
UWord
erts_afalc_test(UWord op, UWord a1, UWord a2)
{
switch (op) {
default: ASSERT(0); return ~((UWord) 0);
}
}
