#define JEMALLOC_CHUNK_C_
#include "jemalloc/internal/jemalloc_internal.h"
/******************************************************************************/
/* Data. */
const char *opt_dss = DSS_DEFAULT;
size_t opt_lg_chunk = LG_CHUNK_DEFAULT;
/* Used exclusively for gdump triggering. */
static size_t curchunks;
static size_t highchunks;
rtree_t chunks_rtree;
/* Various chunk-related settings. */
size_t chunksize;
size_t chunksize_mask; /* (chunksize - 1). */
size_t chunk_npages;
/******************************************************************************/
bool
chunk_register(const void *chunk, const extent_node_t *node)
{
assert(extent_node_addr_get(node) == chunk);
if (rtree_set(&chunks_rtree, (uintptr_t)chunk, node))
return (true);
if (config_prof && opt_prof) {
size_t size = extent_node_size_get(node);
size_t nadd = (size == 0) ? 1 : size / chunksize;
size_t cur = atomic_add_z(&curchunks, nadd);
size_t high = atomic_read_z(&highchunks);
while (cur > high && atomic_cas_z(&highchunks, high, cur)) {
/*
* Don't refresh cur, because it may have decreased
* since this thread lost the highchunks update race.
*/
high = atomic_read_z(&highchunks);
}
if (cur > high && prof_gdump_get_unlocked())
prof_gdump();
}
return (false);
}
void
chunk_deregister(const void *chunk, const extent_node_t *node)
{
bool err;
err = rtree_set(&chunks_rtree, (uintptr_t)chunk, NULL);
assert(!err);
if (config_prof && opt_prof) {
size_t size = extent_node_size_get(node);
size_t nsub = (size == 0) ? 1 : size / chunksize;
assert(atomic_read_z(&curchunks) >= nsub);
atomic_sub_z(&curchunks, nsub);
}
}
/*
* Do first-best-fit chunk selection, i.e. select the lowest chunk that best
* fits.
*/
static extent_node_t *
chunk_first_best_fit(arena_t *arena, extent_tree_t *chunks_szad,
extent_tree_t *chunks_ad, size_t size)
{
extent_node_t key;
assert(size == CHUNK_CEILING(size));
extent_node_init(&key, arena, NULL, size, false);
return (extent_tree_szad_nsearch(chunks_szad, &key));
}
static void *
chunk_recycle(arena_t *arena, extent_tree_t *chunks_szad,
extent_tree_t *chunks_ad, bool cache, void *new_addr, size_t size,
size_t alignment, bool *zero, bool dalloc_node)
{
void *ret;
extent_node_t *node;
size_t alloc_size, leadsize, trailsize;
bool zeroed;
assert(new_addr == NULL || alignment == chunksize);
assert(dalloc_node || new_addr != NULL);
alloc_size = CHUNK_CEILING(s2u(size + alignment - chunksize));
/* Beware size_t wrap-around. */
if (alloc_size < size)
return (NULL);
malloc_mutex_lock(&arena->chunks_mtx);
if (new_addr != NULL) {
extent_node_t key;
extent_node_init(&key, arena, new_addr, alloc_size, false);
node = extent_tree_ad_search(chunks_ad, &key);
} else {
node = chunk_first_best_fit(arena, chunks_szad, chunks_ad,
alloc_size);
}
if (node == NULL || (new_addr != NULL && extent_node_size_get(node) <
size)) {
malloc_mutex_unlock(&arena->chunks_mtx);
return (NULL);
}
leadsize = ALIGNMENT_CEILING((uintptr_t)extent_node_addr_get(node),
alignment) - (uintptr_t)extent_node_addr_get(node);
assert(new_addr == NULL || leadsize == 0);
assert(extent_node_size_get(node) >= leadsize + size);
trailsize = extent_node_size_get(node) - leadsize - size;
ret = (void *)((uintptr_t)extent_node_addr_get(node) + leadsize);
zeroed = extent_node_zeroed_get(node);
if (zeroed)
*zero = true;
/* Remove node from the tree. */
extent_tree_szad_remove(chunks_szad, node);
extent_tree_ad_remove(chunks_ad, node);
arena_chunk_cache_maybe_remove(arena, node, cache);
if (leadsize != 0) {
/* Insert the leading space as a smaller chunk. */
extent_node_size_set(node, leadsize);
extent_tree_szad_insert(chunks_szad, node);
extent_tree_ad_insert(chunks_ad, node);
arena_chunk_cache_maybe_insert(arena, node, cache);
node = NULL;
}
if (trailsize != 0) {
/* Insert the trailing space as a smaller chunk. */
if (node == NULL) {
node = arena_node_alloc(arena);
if (node == NULL) {
malloc_mutex_unlock(&arena->chunks_mtx);
chunk_record(arena, chunks_szad, chunks_ad,
cache, ret, size, zeroed);
return (NULL);
}
}
extent_node_init(node, arena, (void *)((uintptr_t)(ret) + size),
trailsize, zeroed);
extent_tree_szad_insert(chunks_szad, node);
extent_tree_ad_insert(chunks_ad, node);
arena_chunk_cache_maybe_insert(arena, node, cache);
node = NULL;
}
malloc_mutex_unlock(&arena->chunks_mtx);
assert(dalloc_node || node != NULL);
if (dalloc_node && node != NULL)
arena_node_dalloc(arena, node);
if (*zero) {
if (!zeroed)
memset(ret, 0, size);
else if (config_debug) {
size_t i;
size_t *p = (size_t *)(uintptr_t)ret;
JEMALLOC_VALGRIND_MAKE_MEM_DEFINED(ret, size);
for (i = 0; i < size / sizeof(size_t); i++)
assert(p[i] == 0);
}
}
return (ret);
}
static void *
chunk_alloc_core_dss(arena_t *arena, void *new_addr, size_t size,
size_t alignment, bool *zero)
{
void *ret;
if ((ret = chunk_recycle(arena, &arena->chunks_szad_dss,
&arena->chunks_ad_dss, false, new_addr, size, alignment, zero,
true)) != NULL)
return (ret);
ret = chunk_alloc_dss(arena, new_addr, size, alignment, zero);
return (ret);
}
/*
* If the caller specifies (!*zero), it is still possible to receive zeroed
* memory, in which case *zero is toggled to true. arena_chunk_alloc() takes
* advantage of this to avoid demanding zeroed chunks, but taking advantage of
* them if they are returned.
*/
static void *
chunk_alloc_core(arena_t *arena, void *new_addr, size_t size, size_t alignment,
bool *zero, dss_prec_t dss_prec)
{
void *ret;
assert(size != 0);
assert((size & chunksize_mask) == 0);
assert(alignment != 0);
assert((alignment & chunksize_mask) == 0);
/* "primary" dss. */
if (have_dss && dss_prec == dss_prec_primary && (ret =
chunk_alloc_core_dss(arena, new_addr, size, alignment, zero)) !=
NULL)
return (ret);
/* mmap. */
if (!config_munmap && (ret = chunk_recycle(arena,
&arena->chunks_szad_mmap, &arena->chunks_ad_mmap, false, new_addr,
size, alignment, zero, true)) != NULL)
return (ret);
/*
* Requesting an address is not implemented for chunk_alloc_mmap(), so
* only call it if (new_addr == NULL).
*/
if (new_addr == NULL && (ret = chunk_alloc_mmap(size, alignment, zero))
!= NULL)
return (ret);
/* "secondary" dss. */
if (have_dss && dss_prec == dss_prec_secondary && (ret =
chunk_alloc_core_dss(arena, new_addr, size, alignment, zero)) !=
NULL)
return (ret);
/* All strategies for allocation failed. */
return (NULL);
}
void *
chunk_alloc_base(size_t size)
{
void *ret;
bool zero;
/*
* Directly call chunk_alloc_mmap() rather than chunk_alloc_core()
* because it's critical that chunk_alloc_base() return untouched
* demand-zeroed virtual memory.
*/
zero = true;
ret = chunk_alloc_mmap(size, chunksize, &zero);
if (ret == NULL)
return (NULL);
if (config_valgrind)
JEMALLOC_VALGRIND_MAKE_MEM_UNDEFINED(ret, size);
return (ret);
}
void *
chunk_alloc_cache(arena_t *arena, void *new_addr, size_t size, size_t alignment,
bool *zero, bool dalloc_node)
{
assert(size != 0);
assert((size & chunksize_mask) == 0);
assert(alignment != 0);
assert((alignment & chunksize_mask) == 0);
return (chunk_recycle(arena, &arena->chunks_szad_cache,
&arena->chunks_ad_cache, true, new_addr, size, alignment, zero,
dalloc_node));
}
static arena_t *
chunk_arena_get(unsigned arena_ind)
{
arena_t *arena;
/* Dodge tsd for a0 in order to avoid bootstrapping issues. */
arena = (arena_ind == 0) ? a0get() : arena_get(tsd_fetch(), arena_ind,
false, true);
/*
* The arena we're allocating on behalf of must have been initialized
* already.
*/
assert(arena != NULL);
return (arena);
}
static void *
chunk_alloc_arena(arena_t *arena, void *new_addr, size_t size, size_t alignment,
bool *zero)
{
void *ret;
ret = chunk_alloc_core(arena, new_addr, size, alignment, zero,
arena->dss_prec);
if (ret == NULL)
return (NULL);
if (config_valgrind)
JEMALLOC_VALGRIND_MAKE_MEM_UNDEFINED(ret, size);
return (ret);
}
/*
* Default arena chunk allocation routine in the absence of user override. This
* function isn't actually used by jemalloc, but it does the right thing if the
* application passes calls through to it during chunk allocation.
*/
void *
chunk_alloc_default(void *new_addr, size_t size, size_t alignment, bool *zero,
unsigned arena_ind)
{
arena_t *arena;
arena = chunk_arena_get(arena_ind);
return (chunk_alloc_arena(arena, new_addr, size, alignment, zero));
}
void *
chunk_alloc_wrapper(arena_t *arena, chunk_alloc_t *chunk_alloc, void *new_addr,
size_t size, size_t alignment, bool *zero)
{
void *ret;
ret = chunk_alloc(new_addr, size, alignment, zero, arena->ind);
if (ret == NULL)
return (NULL);
if (config_valgrind && chunk_alloc != chunk_alloc_default)
JEMALLOC_VALGRIND_MAKE_MEM_UNDEFINED(ret, chunksize);
return (ret);
}
void
chunk_record(arena_t *arena, extent_tree_t *chunks_szad,
extent_tree_t *chunks_ad, bool cache, void *chunk, size_t size, bool zeroed)
{
bool unzeroed;
extent_node_t *node, *prev;
extent_node_t key;
assert(!cache || !zeroed);
unzeroed = cache || !zeroed;
JEMALLOC_VALGRIND_MAKE_MEM_NOACCESS(chunk, size);
malloc_mutex_lock(&arena->chunks_mtx);
extent_node_init(&key, arena, (void *)((uintptr_t)chunk + size), 0,
false);
node = extent_tree_ad_nsearch(chunks_ad, &key);
/* Try to coalesce forward. */
if (node != NULL && extent_node_addr_get(node) ==
extent_node_addr_get(&key)) {
/*
* Coalesce chunk with the following address range. This does
* not change the position within chunks_ad, so only
* remove/insert from/into chunks_szad.
*/
extent_tree_szad_remove(chunks_szad, node);
arena_chunk_cache_maybe_remove(arena, node, cache);
extent_node_addr_set(node, chunk);
extent_node_size_set(node, size + extent_node_size_get(node));
extent_node_zeroed_set(node, extent_node_zeroed_get(node) &&
!unzeroed);
extent_tree_szad_insert(chunks_szad, node);
arena_chunk_cache_maybe_insert(arena, node, cache);
} else {
/* Coalescing forward failed, so insert a new node. */
node = arena_node_alloc(arena);
if (node == NULL) {
/*
* Node allocation failed, which is an exceedingly
* unlikely failure. Leak chunk after making sure its
* pages have already been purged, so that this is only
* a virtual memory leak.
*/
if (cache) {
chunk_purge_wrapper(arena, arena->chunk_purge,
chunk, 0, size);
}
goto label_return;
}
extent_node_init(node, arena, chunk, size, !unzeroed);
extent_tree_ad_insert(chunks_ad, node);
extent_tree_szad_insert(chunks_szad, node);
arena_chunk_cache_maybe_insert(arena, node, cache);
}
/* Try to coalesce backward. */
prev = extent_tree_ad_prev(chunks_ad, node);
if (prev != NULL && (void *)((uintptr_t)extent_node_addr_get(prev) +
extent_node_size_get(prev)) == chunk) {
/*
* Coalesce chunk with the previous address range. This does
* not change the position within chunks_ad, so only
* remove/insert node from/into chunks_szad.
*/
extent_tree_szad_remove(chunks_szad, prev);
extent_tree_ad_remove(chunks_ad, prev);
arena_chunk_cache_maybe_remove(arena, prev, cache);
extent_tree_szad_remove(chunks_szad, node);
arena_chunk_cache_maybe_remove(arena, node, cache);
extent_node_addr_set(node, extent_node_addr_get(prev));
extent_node_size_set(node, extent_node_size_get(prev) +
extent_node_size_get(node));
extent_node_zeroed_set(node, extent_node_zeroed_get(prev) &&
extent_node_zeroed_get(node));
extent_tree_szad_insert(chunks_szad, node);
arena_chunk_cache_maybe_insert(arena, node, cache);
arena_node_dalloc(arena, prev);
}
label_return:
malloc_mutex_unlock(&arena->chunks_mtx);
}
void
chunk_dalloc_cache(arena_t *arena, void *chunk, size_t size)
{
assert(chunk != NULL);
assert(CHUNK_ADDR2BASE(chunk) == chunk);
assert(size != 0);
assert((size & chunksize_mask) == 0);
chunk_record(arena, &arena->chunks_szad_cache, &arena->chunks_ad_cache,
true, chunk, size, false);
arena_maybe_purge(arena);
}
void
chunk_dalloc_arena(arena_t *arena, void *chunk, size_t size, bool zeroed)
{
assert(chunk != NULL);
assert(CHUNK_ADDR2BASE(chunk) == chunk);
assert(size != 0);
assert((size & chunksize_mask) == 0);
if (have_dss && chunk_in_dss(chunk)) {
chunk_record(arena, &arena->chunks_szad_dss,
&arena->chunks_ad_dss, false, chunk, size, zeroed);
} else if (chunk_dalloc_mmap(chunk, size)) {
chunk_record(arena, &arena->chunks_szad_mmap,
&arena->chunks_ad_mmap, false, chunk, size, zeroed);
}
}
/*
* Default arena chunk deallocation routine in the absence of user override.
* This function isn't actually used by jemalloc, but it does the right thing if
* the application passes calls through to it during chunk deallocation.
*/
bool
chunk_dalloc_default(void *chunk, size_t size, unsigned arena_ind)
{
chunk_dalloc_arena(chunk_arena_get(arena_ind), chunk, size, false);
return (false);
}
void
chunk_dalloc_wrapper(arena_t *arena, chunk_dalloc_t *chunk_dalloc, void *chunk,
size_t size)
{
chunk_dalloc(chunk, size, arena->ind);
if (config_valgrind && chunk_dalloc != chunk_dalloc_default)
JEMALLOC_VALGRIND_MAKE_MEM_NOACCESS(chunk, size);
}
bool
chunk_purge_arena(arena_t *arena, void *chunk, size_t offset, size_t length)
{
assert(chunk != NULL);
assert(CHUNK_ADDR2BASE(chunk) == chunk);
assert((offset & PAGE_MASK) == 0);
assert(length != 0);
assert((length & PAGE_MASK) == 0);
return (pages_purge((void *)((uintptr_t)chunk + (uintptr_t)offset),
length));
}
bool
chunk_purge_default(void *chunk, size_t offset, size_t length,
unsigned arena_ind)
{
return (chunk_purge_arena(chunk_arena_get(arena_ind), chunk, offset,
length));
}
bool
chunk_purge_wrapper(arena_t *arena, chunk_purge_t *chunk_purge, void *chunk,
size_t offset, size_t length)
{
return (chunk_purge(chunk, offset, length, arena->ind));
}
static rtree_node_elm_t *
chunks_rtree_node_alloc(size_t nelms)
{
return ((rtree_node_elm_t *)base_alloc(nelms *
sizeof(rtree_node_elm_t)));
}
bool
chunk_boot(void)
{
/* Set variables according to the value of opt_lg_chunk. */
chunksize = (ZU(1) << opt_lg_chunk);
assert(chunksize >= PAGE);
chunksize_mask = chunksize - 1;
chunk_npages = (chunksize >> LG_PAGE);
if (have_dss && chunk_dss_boot())
return (true);
if (rtree_new(&chunks_rtree, (ZU(1) << (LG_SIZEOF_PTR+3)) -
opt_lg_chunk, chunks_rtree_node_alloc, NULL))
return (true);
return (false);
}
void
chunk_prefork(void)
{
chunk_dss_prefork();
}
void
chunk_postfork_parent(void)
{
chunk_dss_postfork_parent();
}
void
chunk_postfork_child(void)
{
chunk_dss_postfork_child();
}