#define JEMALLOC_TCACHE_C_
#include "jemalloc/internal/jemalloc_preamble.h"
#include "jemalloc/internal/jemalloc_internal_includes.h"
#include "jemalloc/internal/assert.h"
#include "jemalloc/internal/mutex.h"
#include "jemalloc/internal/size_classes.h"
/******************************************************************************/
/* Data. */
bool opt_tcache = true;
ssize_t opt_lg_tcache_max = LG_TCACHE_MAXCLASS_DEFAULT;
cache_bin_info_t *tcache_bin_info;
static unsigned stack_nelms; /* Total stack elms per tcache. */
unsigned nhbins;
size_t tcache_maxclass;
tcaches_t *tcaches;
/* Index of first element within tcaches that has never been used. */
static unsigned tcaches_past;
/* Head of singly linked list tracking available tcaches elements. */
static tcaches_t *tcaches_avail;
/* Protects tcaches{,_past,_avail}. */
static malloc_mutex_t tcaches_mtx;
/******************************************************************************/
size_t
tcache_salloc(tsdn_t *tsdn, const void *ptr) {
return arena_salloc(tsdn, ptr);
}
void
tcache_event_hard(tsd_t *tsd, tcache_t *tcache) {
szind_t binind = tcache->next_gc_bin;
cache_bin_t *tbin;
if (binind < NBINS) {
tbin = tcache_small_bin_get(tcache, binind);
} else {
tbin = tcache_large_bin_get(tcache, binind);
}
if (tbin->low_water > 0) {
/*
* Flush (ceiling) 3/4 of the objects below the low water mark.
*/
if (binind < NBINS) {
tcache_bin_flush_small(tsd, tcache, tbin, binind,
tbin->ncached - tbin->low_water + (tbin->low_water
>> 2));
/*
* Reduce fill count by 2X. Limit lg_fill_div such that
* the fill count is always at least 1.
*/
cache_bin_info_t *tbin_info = &tcache_bin_info[binind];
if ((tbin_info->ncached_max >>
(tcache->lg_fill_div[binind] + 1)) >= 1) {
tcache->lg_fill_div[binind]++;
}
} else {
tcache_bin_flush_large(tsd, tbin, binind, tbin->ncached
- tbin->low_water + (tbin->low_water >> 2), tcache);
}
} else if (tbin->low_water < 0) {
/*
* Increase fill count by 2X for small bins. Make sure
* lg_fill_div stays greater than 0.
*/
if (binind < NBINS && tcache->lg_fill_div[binind] > 1) {
tcache->lg_fill_div[binind]--;
}
}
tbin->low_water = tbin->ncached;
tcache->next_gc_bin++;
if (tcache->next_gc_bin == nhbins) {
tcache->next_gc_bin = 0;
}
}
void *
tcache_alloc_small_hard(tsdn_t *tsdn, arena_t *arena, tcache_t *tcache,
cache_bin_t *tbin, szind_t binind, bool *tcache_success) {
void *ret;
assert(tcache->arena != NULL);
arena_tcache_fill_small(tsdn, arena, tcache, tbin, binind,
config_prof ? tcache->prof_accumbytes : 0);
if (config_prof) {
tcache->prof_accumbytes = 0;
}
ret = cache_bin_alloc_easy(tbin, tcache_success);
return ret;
}
void
tcache_bin_flush_small(tsd_t *tsd, tcache_t *tcache, cache_bin_t *tbin,
szind_t binind, unsigned rem) {
bool merged_stats = false;
assert(binind < NBINS);
assert((cache_bin_sz_t)rem <= tbin->ncached);
arena_t *arena = tcache->arena;
assert(arena != NULL);
unsigned nflush = tbin->ncached - rem;
VARIABLE_ARRAY(extent_t *, item_extent, nflush);
/* Look up extent once per item. */
for (unsigned i = 0 ; i < nflush; i++) {
item_extent[i] = iealloc(tsd_tsdn(tsd), *(tbin->avail - 1 - i));
}
while (nflush > 0) {
/* Lock the arena bin associated with the first object. */
extent_t *extent = item_extent[0];
arena_t *bin_arena = extent_arena_get(extent);
bin_t *bin = &bin_arena->bins[binind];
if (config_prof && bin_arena == arena) {
if (arena_prof_accum(tsd_tsdn(tsd), arena,
tcache->prof_accumbytes)) {
prof_idump(tsd_tsdn(tsd));
}
tcache->prof_accumbytes = 0;
}
malloc_mutex_lock(tsd_tsdn(tsd), &bin->lock);
if (config_stats && bin_arena == arena) {
assert(!merged_stats);
merged_stats = true;
bin->stats.nflushes++;
bin->stats.nrequests += tbin->tstats.nrequests;
tbin->tstats.nrequests = 0;
}
unsigned ndeferred = 0;
for (unsigned i = 0; i < nflush; i++) {
void *ptr = *(tbin->avail - 1 - i);
extent = item_extent[i];
assert(ptr != NULL && extent != NULL);
if (extent_arena_get(extent) == bin_arena) {
arena_dalloc_bin_junked_locked(tsd_tsdn(tsd),
bin_arena, extent, ptr);
} else {
/*
* This object was allocated via a different
* arena bin than the one that is currently
* locked. Stash the object, so that it can be
* handled in a future pass.
*/
*(tbin->avail - 1 - ndeferred) = ptr;
item_extent[ndeferred] = extent;
ndeferred++;
}
}
malloc_mutex_unlock(tsd_tsdn(tsd), &bin->lock);
arena_decay_ticks(tsd_tsdn(tsd), bin_arena, nflush - ndeferred);
nflush = ndeferred;
}
if (config_stats && !merged_stats) {
/*
* The flush loop didn't happen to flush to this thread's
* arena, so the stats didn't get merged. Manually do so now.
*/
bin_t *bin = &arena->bins[binind];
malloc_mutex_lock(tsd_tsdn(tsd), &bin->lock);
bin->stats.nflushes++;
bin->stats.nrequests += tbin->tstats.nrequests;
tbin->tstats.nrequests = 0;
malloc_mutex_unlock(tsd_tsdn(tsd), &bin->lock);
}
memmove(tbin->avail - rem, tbin->avail - tbin->ncached, rem *
sizeof(void *));
tbin->ncached = rem;
if (tbin->ncached < tbin->low_water) {
tbin->low_water = tbin->ncached;
}
}
void
tcache_bin_flush_large(tsd_t *tsd, cache_bin_t *tbin, szind_t binind,
unsigned rem, tcache_t *tcache) {
bool merged_stats = false;
assert(binind < nhbins);
assert((cache_bin_sz_t)rem <= tbin->ncached);
arena_t *arena = tcache->arena;
assert(arena != NULL);
unsigned nflush = tbin->ncached - rem;
VARIABLE_ARRAY(extent_t *, item_extent, nflush);
/* Look up extent once per item. */
for (unsigned i = 0 ; i < nflush; i++) {
item_extent[i] = iealloc(tsd_tsdn(tsd), *(tbin->avail - 1 - i));
}
while (nflush > 0) {
/* Lock the arena associated with the first object. */
extent_t *extent = item_extent[0];
arena_t *locked_arena = extent_arena_get(extent);
UNUSED bool idump;
if (config_prof) {
idump = false;
}
malloc_mutex_lock(tsd_tsdn(tsd), &locked_arena->large_mtx);
for (unsigned i = 0; i < nflush; i++) {
void *ptr = *(tbin->avail - 1 - i);
assert(ptr != NULL);
extent = item_extent[i];
if (extent_arena_get(extent) == locked_arena) {
large_dalloc_prep_junked_locked(tsd_tsdn(tsd),
extent);
}
}
if ((config_prof || config_stats) && locked_arena == arena) {
if (config_prof) {
idump = arena_prof_accum(tsd_tsdn(tsd), arena,
tcache->prof_accumbytes);
tcache->prof_accumbytes = 0;
}
if (config_stats) {
merged_stats = true;
arena_stats_large_nrequests_add(tsd_tsdn(tsd),
&arena->stats, binind,
tbin->tstats.nrequests);
tbin->tstats.nrequests = 0;
}
}
malloc_mutex_unlock(tsd_tsdn(tsd), &locked_arena->large_mtx);
unsigned ndeferred = 0;
for (unsigned i = 0; i < nflush; i++) {
void *ptr = *(tbin->avail - 1 - i);
extent = item_extent[i];
assert(ptr != NULL && extent != NULL);
if (extent_arena_get(extent) == locked_arena) {
large_dalloc_finish(tsd_tsdn(tsd), extent);
} else {
/*
* This object was allocated via a different
* arena than the one that is currently locked.
* Stash the object, so that it can be handled
* in a future pass.
*/
*(tbin->avail - 1 - ndeferred) = ptr;
item_extent[ndeferred] = extent;
ndeferred++;
}
}
if (config_prof && idump) {
prof_idump(tsd_tsdn(tsd));
}
arena_decay_ticks(tsd_tsdn(tsd), locked_arena, nflush -
ndeferred);
nflush = ndeferred;
}
if (config_stats && !merged_stats) {
/*
* The flush loop didn't happen to flush to this thread's
* arena, so the stats didn't get merged. Manually do so now.
*/
arena_stats_large_nrequests_add(tsd_tsdn(tsd), &arena->stats,
binind, tbin->tstats.nrequests);
tbin->tstats.nrequests = 0;
}
memmove(tbin->avail - rem, tbin->avail - tbin->ncached, rem *
sizeof(void *));
tbin->ncached = rem;
if (tbin->ncached < tbin->low_water) {
tbin->low_water = tbin->ncached;
}
}
void
tcache_arena_associate(tsdn_t *tsdn, tcache_t *tcache, arena_t *arena) {
assert(tcache->arena == NULL);
tcache->arena = arena;
if (config_stats) {
/* Link into list of extant tcaches. */
malloc_mutex_lock(tsdn, &arena->tcache_ql_mtx);
ql_elm_new(tcache, link);
ql_tail_insert(&arena->tcache_ql, tcache, link);
cache_bin_array_descriptor_init(
&tcache->cache_bin_array_descriptor, tcache->bins_small,
tcache->bins_large);
ql_tail_insert(&arena->cache_bin_array_descriptor_ql,
&tcache->cache_bin_array_descriptor, link);
malloc_mutex_unlock(tsdn, &arena->tcache_ql_mtx);
}
}
static void
tcache_arena_dissociate(tsdn_t *tsdn, tcache_t *tcache) {
arena_t *arena = tcache->arena;
assert(arena != NULL);
if (config_stats) {
/* Unlink from list of extant tcaches. */
malloc_mutex_lock(tsdn, &arena->tcache_ql_mtx);
if (config_debug) {
bool in_ql = false;
tcache_t *iter;
ql_foreach(iter, &arena->tcache_ql, link) {
if (iter == tcache) {
in_ql = true;
break;
}
}
assert(in_ql);
}
ql_remove(&arena->tcache_ql, tcache, link);
ql_remove(&arena->cache_bin_array_descriptor_ql,
&tcache->cache_bin_array_descriptor, link);
tcache_stats_merge(tsdn, tcache, arena);
malloc_mutex_unlock(tsdn, &arena->tcache_ql_mtx);
}
tcache->arena = NULL;
}
void
tcache_arena_reassociate(tsdn_t *tsdn, tcache_t *tcache, arena_t *arena) {
tcache_arena_dissociate(tsdn, tcache);
tcache_arena_associate(tsdn, tcache, arena);
}
bool
tsd_tcache_enabled_data_init(tsd_t *tsd) {
/* Called upon tsd initialization. */
tsd_tcache_enabled_set(tsd, opt_tcache);
tsd_slow_update(tsd);
if (opt_tcache) {
/* Trigger tcache init. */
tsd_tcache_data_init(tsd);
}
return false;
}
/* Initialize auto tcache (embedded in TSD). */
static void
tcache_init(tsd_t *tsd, tcache_t *tcache, void *avail_stack) {
memset(&tcache->link, 0, sizeof(ql_elm(tcache_t)));
tcache->prof_accumbytes = 0;
tcache->next_gc_bin = 0;
tcache->arena = NULL;
ticker_init(&tcache->gc_ticker, TCACHE_GC_INCR);
size_t stack_offset = 0;
assert((TCACHE_NSLOTS_SMALL_MAX & 1U) == 0);
memset(tcache->bins_small, 0, sizeof(cache_bin_t) * NBINS);
memset(tcache->bins_large, 0, sizeof(cache_bin_t) * (nhbins - NBINS));
unsigned i = 0;
for (; i < NBINS; i++) {
tcache->lg_fill_div[i] = 1;
stack_offset += tcache_bin_info[i].ncached_max * sizeof(void *);
/*
* avail points past the available space. Allocations will
* access the slots toward higher addresses (for the benefit of
* prefetch).
*/
tcache_small_bin_get(tcache, i)->avail =
(void **)((uintptr_t)avail_stack + (uintptr_t)stack_offset);
}
for (; i < nhbins; i++) {
stack_offset += tcache_bin_info[i].ncached_max * sizeof(void *);
tcache_large_bin_get(tcache, i)->avail =
(void **)((uintptr_t)avail_stack + (uintptr_t)stack_offset);
}
assert(stack_offset == stack_nelms * sizeof(void *));
}
/* Initialize auto tcache (embedded in TSD). */
bool
tsd_tcache_data_init(tsd_t *tsd) {
tcache_t *tcache = tsd_tcachep_get_unsafe(tsd);
assert(tcache_small_bin_get(tcache, 0)->avail == NULL);
size_t size = stack_nelms * sizeof(void *);
/* Avoid false cacheline sharing. */
size = sz_sa2u(size, CACHELINE);
void *avail_array = ipallocztm(tsd_tsdn(tsd), size, CACHELINE, true,
NULL, true, arena_get(TSDN_NULL, 0, true));
if (avail_array == NULL) {
return true;
}
tcache_init(tsd, tcache, avail_array);
/*
* Initialization is a bit tricky here. After malloc init is done, all
* threads can rely on arena_choose and associate tcache accordingly.
* However, the thread that does actual malloc bootstrapping relies on
* functional tsd, and it can only rely on a0. In that case, we
* associate its tcache to a0 temporarily, and later on
* arena_choose_hard() will re-associate properly.
*/
tcache->arena = NULL;
arena_t *arena;
if (!malloc_initialized()) {
/* If in initialization, assign to a0. */
arena = arena_get(tsd_tsdn(tsd), 0, false);
tcache_arena_associate(tsd_tsdn(tsd), tcache, arena);
} else {
arena = arena_choose(tsd, NULL);
/* This may happen if thread.tcache.enabled is used. */
if (tcache->arena == NULL) {
tcache_arena_associate(tsd_tsdn(tsd), tcache, arena);
}
}
assert(arena == tcache->arena);
return false;
}
/* Created manual tcache for tcache.create mallctl. */
tcache_t *
tcache_create_explicit(tsd_t *tsd) {
tcache_t *tcache;
size_t size, stack_offset;
size = sizeof(tcache_t);
/* Naturally align the pointer stacks. */
size = PTR_CEILING(size);
stack_offset = size;
size += stack_nelms * sizeof(void *);
/* Avoid false cacheline sharing. */
size = sz_sa2u(size, CACHELINE);
tcache = ipallocztm(tsd_tsdn(tsd), size, CACHELINE, true, NULL, true,
arena_get(TSDN_NULL, 0, true));
if (tcache == NULL) {
return NULL;
}
tcache_init(tsd, tcache,
(void *)((uintptr_t)tcache + (uintptr_t)stack_offset));
tcache_arena_associate(tsd_tsdn(tsd), tcache, arena_ichoose(tsd, NULL));
return tcache;
}
static void
tcache_flush_cache(tsd_t *tsd, tcache_t *tcache) {
assert(tcache->arena != NULL);
for (unsigned i = 0; i < NBINS; i++) {
cache_bin_t *tbin = tcache_small_bin_get(tcache, i);
tcache_bin_flush_small(tsd, tcache, tbin, i, 0);
if (config_stats) {
assert(tbin->tstats.nrequests == 0);
}
}
for (unsigned i = NBINS; i < nhbins; i++) {
cache_bin_t *tbin = tcache_large_bin_get(tcache, i);
tcache_bin_flush_large(tsd, tbin, i, 0, tcache);
if (config_stats) {
assert(tbin->tstats.nrequests == 0);
}
}
if (config_prof && tcache->prof_accumbytes > 0 &&
arena_prof_accum(tsd_tsdn(tsd), tcache->arena,
tcache->prof_accumbytes)) {
prof_idump(tsd_tsdn(tsd));
}
}
void
tcache_flush(tsd_t *tsd) {
assert(tcache_available(tsd));
tcache_flush_cache(tsd, tsd_tcachep_get(tsd));
}
static void
tcache_destroy(tsd_t *tsd, tcache_t *tcache, bool tsd_tcache) {
tcache_flush_cache(tsd, tcache);
tcache_arena_dissociate(tsd_tsdn(tsd), tcache);
if (tsd_tcache) {
/* Release the avail array for the TSD embedded auto tcache. */
void *avail_array =
(void *)((uintptr_t)tcache_small_bin_get(tcache, 0)->avail -
(uintptr_t)tcache_bin_info[0].ncached_max * sizeof(void *));
idalloctm(tsd_tsdn(tsd), avail_array, NULL, NULL, true, true);
} else {
/* Release both the tcache struct and avail array. */
idalloctm(tsd_tsdn(tsd), tcache, NULL, NULL, true, true);
}
}
/* For auto tcache (embedded in TSD) only. */
void
tcache_cleanup(tsd_t *tsd) {
tcache_t *tcache = tsd_tcachep_get(tsd);
if (!tcache_available(tsd)) {
assert(tsd_tcache_enabled_get(tsd) == false);
if (config_debug) {
assert(tcache_small_bin_get(tcache, 0)->avail == NULL);
}
return;
}
assert(tsd_tcache_enabled_get(tsd));
assert(tcache_small_bin_get(tcache, 0)->avail != NULL);
tcache_destroy(tsd, tcache, true);
if (config_debug) {
tcache_small_bin_get(tcache, 0)->avail = NULL;
}
}
void
tcache_stats_merge(tsdn_t *tsdn, tcache_t *tcache, arena_t *arena) {
unsigned i;
cassert(config_stats);
/* Merge and reset tcache stats. */
for (i = 0; i < NBINS; i++) {
bin_t *bin = &arena->bins[i];
cache_bin_t *tbin = tcache_small_bin_get(tcache, i);
malloc_mutex_lock(tsdn, &bin->lock);
bin->stats.nrequests += tbin->tstats.nrequests;
malloc_mutex_unlock(tsdn, &bin->lock);
tbin->tstats.nrequests = 0;
}
for (; i < nhbins; i++) {
cache_bin_t *tbin = tcache_large_bin_get(tcache, i);
arena_stats_large_nrequests_add(tsdn, &arena->stats, i,
tbin->tstats.nrequests);
tbin->tstats.nrequests = 0;
}
}
static bool
tcaches_create_prep(tsd_t *tsd) {
bool err;
malloc_mutex_lock(tsd_tsdn(tsd), &tcaches_mtx);
if (tcaches == NULL) {
tcaches = base_alloc(tsd_tsdn(tsd), b0get(), sizeof(tcache_t *)
* (MALLOCX_TCACHE_MAX+1), CACHELINE);
if (tcaches == NULL) {
err = true;
goto label_return;
}
}
if (tcaches_avail == NULL && tcaches_past > MALLOCX_TCACHE_MAX) {
err = true;
goto label_return;
}
err = false;
label_return:
malloc_mutex_unlock(tsd_tsdn(tsd), &tcaches_mtx);
return err;
}
bool
tcaches_create(tsd_t *tsd, unsigned *r_ind) {
witness_assert_depth(tsdn_witness_tsdp_get(tsd_tsdn(tsd)), 0);
bool err;
if (tcaches_create_prep(tsd)) {
err = true;
goto label_return;
}
tcache_t *tcache = tcache_create_explicit(tsd);
if (tcache == NULL) {
err = true;
goto label_return;
}
tcaches_t *elm;
malloc_mutex_lock(tsd_tsdn(tsd), &tcaches_mtx);
if (tcaches_avail != NULL) {
elm = tcaches_avail;
tcaches_avail = tcaches_avail->next;
elm->tcache = tcache;
*r_ind = (unsigned)(elm - tcaches);
} else {
elm = &tcaches[tcaches_past];
elm->tcache = tcache;
*r_ind = tcaches_past;
tcaches_past++;
}
malloc_mutex_unlock(tsd_tsdn(tsd), &tcaches_mtx);
err = false;
label_return:
witness_assert_depth(tsdn_witness_tsdp_get(tsd_tsdn(tsd)), 0);
return err;
}
static tcache_t *
tcaches_elm_remove(tsd_t *tsd, tcaches_t *elm) {
malloc_mutex_assert_owner(tsd_tsdn(tsd), &tcaches_mtx);
if (elm->tcache == NULL) {
return NULL;
}
tcache_t *tcache = elm->tcache;
elm->tcache = NULL;
return tcache;
}
void
tcaches_flush(tsd_t *tsd, unsigned ind) {
malloc_mutex_lock(tsd_tsdn(tsd), &tcaches_mtx);
tcache_t *tcache = tcaches_elm_remove(tsd, &tcaches[ind]);
malloc_mutex_unlock(tsd_tsdn(tsd), &tcaches_mtx);
if (tcache != NULL) {
tcache_destroy(tsd, tcache, false);
}
}
void
tcaches_destroy(tsd_t *tsd, unsigned ind) {
malloc_mutex_lock(tsd_tsdn(tsd), &tcaches_mtx);
tcaches_t *elm = &tcaches[ind];
tcache_t *tcache = tcaches_elm_remove(tsd, elm);
elm->next = tcaches_avail;
tcaches_avail = elm;
malloc_mutex_unlock(tsd_tsdn(tsd), &tcaches_mtx);
if (tcache != NULL) {
tcache_destroy(tsd, tcache, false);
}
}
bool
tcache_boot(tsdn_t *tsdn) {
/* If necessary, clamp opt_lg_tcache_max. */
if (opt_lg_tcache_max < 0 || (ZU(1) << opt_lg_tcache_max) <
SMALL_MAXCLASS) {
tcache_maxclass = SMALL_MAXCLASS;
} else {
tcache_maxclass = (ZU(1) << opt_lg_tcache_max);
}
if (malloc_mutex_init(&tcaches_mtx, "tcaches", WITNESS_RANK_TCACHES,
malloc_mutex_rank_exclusive)) {
return true;
}
nhbins = sz_size2index(tcache_maxclass) + 1;
/* Initialize tcache_bin_info. */
tcache_bin_info = (cache_bin_info_t *)base_alloc(tsdn, b0get(), nhbins
* sizeof(cache_bin_info_t), CACHELINE);
if (tcache_bin_info == NULL) {
return true;
}
stack_nelms = 0;
unsigned i;
for (i = 0; i < NBINS; i++) {
if ((bin_infos[i].nregs << 1) <= TCACHE_NSLOTS_SMALL_MIN) {
tcache_bin_info[i].ncached_max =
TCACHE_NSLOTS_SMALL_MIN;
} else if ((bin_infos[i].nregs << 1) <=
TCACHE_NSLOTS_SMALL_MAX) {
tcache_bin_info[i].ncached_max =
(bin_infos[i].nregs << 1);
} else {
tcache_bin_info[i].ncached_max =
TCACHE_NSLOTS_SMALL_MAX;
}
stack_nelms += tcache_bin_info[i].ncached_max;
}
for (; i < nhbins; i++) {
tcache_bin_info[i].ncached_max = TCACHE_NSLOTS_LARGE;
stack_nelms += tcache_bin_info[i].ncached_max;
}
return false;
}
void
tcache_prefork(tsdn_t *tsdn) {
if (!config_prof && opt_tcache) {
malloc_mutex_prefork(tsdn, &tcaches_mtx);
}
}
void
tcache_postfork_parent(tsdn_t *tsdn) {
if (!config_prof && opt_tcache) {
malloc_mutex_postfork_parent(tsdn, &tcaches_mtx);
}
}
void
tcache_postfork_child(tsdn_t *tsdn) {
if (!config_prof && opt_tcache) {
malloc_mutex_postfork_child(tsdn, &tcaches_mtx);
}
}