#define JEMALLOC_CHUNK_C_
#include "jemalloc/internal/jemalloc_internal.h"
/******************************************************************************/
/* Data. */
const char *opt_dss = DSS_DEFAULT;
size_t opt_lg_chunk = 0;
/* 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;
static void *chunk_alloc_default(void *new_addr, size_t size,
size_t alignment, bool *zero, bool *commit, unsigned arena_ind);
static bool chunk_dalloc_default(void *chunk, size_t size, bool committed,
unsigned arena_ind);
static bool chunk_commit_default(void *chunk, size_t size, size_t offset,
size_t length, unsigned arena_ind);
static bool chunk_decommit_default(void *chunk, size_t size, size_t offset,
size_t length, unsigned arena_ind);
static bool chunk_purge_default(void *chunk, size_t size, size_t offset,
size_t length, unsigned arena_ind);
static bool chunk_split_default(void *chunk, size_t size, size_t size_a,
size_t size_b, bool committed, unsigned arena_ind);
static bool chunk_merge_default(void *chunk_a, size_t size_a, void *chunk_b,
size_t size_b, bool committed, unsigned arena_ind);
const chunk_hooks_t chunk_hooks_default = {
chunk_alloc_default,
chunk_dalloc_default,
chunk_commit_default,
chunk_decommit_default,
chunk_purge_default,
chunk_split_default,
chunk_merge_default
};
/******************************************************************************/
/*
* Function prototypes for static functions that are referenced prior to
* definition.
*/
static void chunk_record(arena_t *arena, chunk_hooks_t *chunk_hooks,
extent_tree_t *chunks_szad, extent_tree_t *chunks_ad, bool cache,
void *chunk, size_t size, bool zeroed, bool committed);
/******************************************************************************/
static chunk_hooks_t
chunk_hooks_get_locked(arena_t *arena)
{
return (arena->chunk_hooks);
}
chunk_hooks_t
chunk_hooks_get(arena_t *arena)
{
chunk_hooks_t chunk_hooks;
malloc_mutex_lock(&arena->chunks_mtx);
chunk_hooks = chunk_hooks_get_locked(arena);
malloc_mutex_unlock(&arena->chunks_mtx);
return (chunk_hooks);
}
chunk_hooks_t
chunk_hooks_set(arena_t *arena, const chunk_hooks_t *chunk_hooks)
{
chunk_hooks_t old_chunk_hooks;
malloc_mutex_lock(&arena->chunks_mtx);
old_chunk_hooks = arena->chunk_hooks;
/*
* Copy each field atomically so that it is impossible for readers to
* see partially updated pointers. There are places where readers only
* need one hook function pointer (therefore no need to copy the
* entirety of arena->chunk_hooks), and stale reads do not affect
* correctness, so they perform unlocked reads.
*/
#define ATOMIC_COPY_HOOK(n) do { \
union { \
chunk_##n##_t **n; \
void **v; \
} u; \
u.n = &arena->chunk_hooks.n; \
atomic_write_p(u.v, chunk_hooks->n); \
} while (0)
ATOMIC_COPY_HOOK(alloc);
ATOMIC_COPY_HOOK(dalloc);
ATOMIC_COPY_HOOK(commit);
ATOMIC_COPY_HOOK(decommit);
ATOMIC_COPY_HOOK(purge);
ATOMIC_COPY_HOOK(split);
ATOMIC_COPY_HOOK(merge);
#undef ATOMIC_COPY_HOOK
malloc_mutex_unlock(&arena->chunks_mtx);
return (old_chunk_hooks);
}
static void
chunk_hooks_assure_initialized_impl(arena_t *arena, chunk_hooks_t *chunk_hooks,
bool locked)
{
static const chunk_hooks_t uninitialized_hooks =
CHUNK_HOOKS_INITIALIZER;
if (memcmp(chunk_hooks, &uninitialized_hooks, sizeof(chunk_hooks_t)) ==
0) {
*chunk_hooks = locked ? chunk_hooks_get_locked(arena) :
chunk_hooks_get(arena);
}
}
static void
chunk_hooks_assure_initialized_locked(arena_t *arena,
chunk_hooks_t *chunk_hooks)
{
chunk_hooks_assure_initialized_impl(arena, chunk_hooks, true);
}
static void
chunk_hooks_assure_initialized(arena_t *arena, chunk_hooks_t *chunk_hooks)
{
chunk_hooks_assure_initialized_impl(arena, chunk_hooks, false);
}
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, false);
return (extent_tree_szad_nsearch(chunks_szad, &key));
}
static void *
chunk_recycle(arena_t *arena, chunk_hooks_t *chunk_hooks,
extent_tree_t *chunks_szad, extent_tree_t *chunks_ad, bool cache,
void *new_addr, size_t size, size_t alignment, bool *zero, bool *commit,
bool dalloc_node)
{
void *ret;
extent_node_t *node;
size_t alloc_size, leadsize, trailsize;
bool zeroed, committed;
assert(new_addr == NULL || alignment == chunksize);
/*
* Cached chunks use the node linkage embedded in their headers, in
* which case dalloc_node is true, and new_addr is non-NULL because
* we're operating on a specific chunk.
*/
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);
chunk_hooks_assure_initialized_locked(arena, chunk_hooks);
if (new_addr != NULL) {
extent_node_t key;
extent_node_init(&key, arena, new_addr, alloc_size, false,
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;
committed = extent_node_committed_get(node);
if (committed)
*commit = true;
/* Split the lead. */
if (leadsize != 0 &&
chunk_hooks->split(extent_node_addr_get(node),
extent_node_size_get(node), leadsize, size, false, arena->ind)) {
malloc_mutex_unlock(&arena->chunks_mtx);
return (NULL);
}
/* 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) {
/* Split the trail. */
if (chunk_hooks->split(ret, size + trailsize, size,
trailsize, false, arena->ind)) {
if (dalloc_node && node != NULL)
arena_node_dalloc(arena, node);
malloc_mutex_unlock(&arena->chunks_mtx);
chunk_record(arena, chunk_hooks, chunks_szad, chunks_ad,
cache, ret, size + trailsize, zeroed, committed);
return (NULL);
}
/* 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, chunk_hooks, chunks_szad,
chunks_ad, cache, ret, size + trailsize,
zeroed, committed);
return (NULL);
}
}
extent_node_init(node, arena, (void *)((uintptr_t)(ret) + size),
trailsize, zeroed, committed);
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 (!committed && chunk_hooks->commit(ret, size, 0, size, arena->ind)) {
malloc_mutex_unlock(&arena->chunks_mtx);
chunk_record(arena, chunk_hooks, chunks_szad, chunks_ad, cache,
ret, size, zeroed, committed);
return (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);
}
/*
* 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, bool *commit, 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_dss(arena, new_addr, size, alignment, zero, commit)) !=
NULL)
return (ret);
/* mmap. */
if ((ret = chunk_alloc_mmap(new_addr, size, alignment, zero, commit)) !=
NULL)
return (ret);
/* "secondary" dss. */
if (have_dss && dss_prec == dss_prec_secondary && (ret =
chunk_alloc_dss(arena, new_addr, size, alignment, zero, commit)) !=
NULL)
return (ret);
/* All strategies for allocation failed. */
return (NULL);
}
void *
chunk_alloc_base(size_t size)
{
void *ret;
bool zero, commit;
/*
* 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;
commit = true;
ret = chunk_alloc_mmap(NULL, size, chunksize, &zero, &commit);
if (ret == NULL)
return (NULL);
if (config_valgrind)
JEMALLOC_VALGRIND_MAKE_MEM_UNDEFINED(ret, size);
return (ret);
}
void *
chunk_alloc_cache(arena_t *arena, chunk_hooks_t *chunk_hooks, void *new_addr,
size_t size, size_t alignment, bool *zero, bool dalloc_node)
{
void *ret;
bool commit;
assert(size != 0);
assert((size & chunksize_mask) == 0);
assert(alignment != 0);
assert((alignment & chunksize_mask) == 0);
commit = true;
ret = chunk_recycle(arena, chunk_hooks, &arena->chunks_szad_cached,
&arena->chunks_ad_cached, true, new_addr, size, alignment, zero,
&commit, dalloc_node);
if (ret == NULL)
return (NULL);
assert(commit);
if (config_valgrind)
JEMALLOC_VALGRIND_MAKE_MEM_UNDEFINED(ret, size);
return (ret);
}
static arena_t *
chunk_arena_get(unsigned arena_ind)
{
arena_t *arena;
arena = arena_get(arena_ind, false);
/*
* The arena we're allocating on behalf of must have been initialized
* already.
*/
assert(arena != NULL);
return (arena);
}
static void *
chunk_alloc_default(void *new_addr, size_t size, size_t alignment, bool *zero,
bool *commit, unsigned arena_ind)
{
void *ret;
arena_t *arena;
arena = chunk_arena_get(arena_ind);
ret = chunk_alloc_core(arena, new_addr, size, alignment, zero, commit,
arena->dss_prec);
if (ret == NULL)
return (NULL);
if (config_valgrind)
JEMALLOC_VALGRIND_MAKE_MEM_UNDEFINED(ret, size);
return (ret);
}
static void *
chunk_alloc_retained(arena_t *arena, chunk_hooks_t *chunk_hooks, void *new_addr,
size_t size, size_t alignment, bool *zero, bool *commit)
{
assert(size != 0);
assert((size & chunksize_mask) == 0);
assert(alignment != 0);
assert((alignment & chunksize_mask) == 0);
return (chunk_recycle(arena, chunk_hooks, &arena->chunks_szad_retained,
&arena->chunks_ad_retained, false, new_addr, size, alignment, zero,
commit, true));
}
void *
chunk_alloc_wrapper(arena_t *arena, chunk_hooks_t *chunk_hooks, void *new_addr,
size_t size, size_t alignment, bool *zero, bool *commit)
{
void *ret;
chunk_hooks_assure_initialized(arena, chunk_hooks);
ret = chunk_alloc_retained(arena, chunk_hooks, new_addr, size,
alignment, zero, commit);
if (ret == NULL) {
ret = chunk_hooks->alloc(new_addr, size, alignment, zero,
commit, arena->ind);
if (ret == NULL)
return (NULL);
}
if (config_valgrind && chunk_hooks->alloc != chunk_alloc_default)
JEMALLOC_VALGRIND_MAKE_MEM_UNDEFINED(ret, chunksize);
return (ret);
}
static void
chunk_record(arena_t *arena, chunk_hooks_t *chunk_hooks,
extent_tree_t *chunks_szad, extent_tree_t *chunks_ad, bool cache,
void *chunk, size_t size, bool zeroed, bool committed)
{
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);
chunk_hooks_assure_initialized_locked(arena, chunk_hooks);
extent_node_init(&key, arena, (void *)((uintptr_t)chunk + size), 0,
false, 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) && extent_node_committed_get(node) ==
committed && !chunk_hooks->merge(chunk, size,
extent_node_addr_get(node), extent_node_size_get(node), false,
arena->ind)) {
/*
* 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, chunk_hooks, chunk,
size, 0, size);
}
goto label_return;
}
extent_node_init(node, arena, chunk, size, !unzeroed,
committed);
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 &&
extent_node_committed_get(prev) == committed &&
!chunk_hooks->merge(extent_node_addr_get(prev),
extent_node_size_get(prev), chunk, size, false, arena->ind)) {
/*
* 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, chunk_hooks_t *chunk_hooks, void *chunk,
size_t size, bool committed)
{
assert(chunk != NULL);
assert(CHUNK_ADDR2BASE(chunk) == chunk);
assert(size != 0);
assert((size & chunksize_mask) == 0);
chunk_record(arena, chunk_hooks, &arena->chunks_szad_cached,
&arena->chunks_ad_cached, true, chunk, size, false, committed);
arena_maybe_purge(arena);
}
static bool
chunk_dalloc_default(void *chunk, size_t size, bool committed,
unsigned arena_ind)
{
if (!have_dss || !chunk_in_dss(chunk))
return (chunk_dalloc_mmap(chunk, size));
return (true);
}
void
chunk_dalloc_wrapper(arena_t *arena, chunk_hooks_t *chunk_hooks, void *chunk,
size_t size, bool zeroed, bool committed)
{
assert(chunk != NULL);
assert(CHUNK_ADDR2BASE(chunk) == chunk);
assert(size != 0);
assert((size & chunksize_mask) == 0);
chunk_hooks_assure_initialized(arena, chunk_hooks);
/* Try to deallocate. */
if (!chunk_hooks->dalloc(chunk, size, committed, arena->ind))
return;
/* Try to decommit; purge if that fails. */
if (committed) {
committed = chunk_hooks->decommit(chunk, size, 0, size,
arena->ind);
}
zeroed = !committed || !chunk_hooks->purge(chunk, size, 0, size,
arena->ind);
chunk_record(arena, chunk_hooks, &arena->chunks_szad_retained,
&arena->chunks_ad_retained, false, chunk, size, zeroed, committed);
}
static bool
chunk_commit_default(void *chunk, size_t size, size_t offset, size_t length,
unsigned arena_ind)
{
return (pages_commit((void *)((uintptr_t)chunk + (uintptr_t)offset),
length));
}
static bool
chunk_decommit_default(void *chunk, size_t size, size_t offset, size_t length,
unsigned arena_ind)
{
return (pages_decommit((void *)((uintptr_t)chunk + (uintptr_t)offset),
length));
}
static bool
chunk_purge_default(void *chunk, size_t size, size_t offset, size_t length,
unsigned arena_ind)
{
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_wrapper(arena_t *arena, chunk_hooks_t *chunk_hooks, void *chunk,
size_t size, size_t offset, size_t length)
{
chunk_hooks_assure_initialized(arena, chunk_hooks);
return (chunk_hooks->purge(chunk, size, offset, length, arena->ind));
}
static bool
chunk_split_default(void *chunk, size_t size, size_t size_a, size_t size_b,
bool committed, unsigned arena_ind)
{
if (!maps_coalesce)
return (true);
return (false);
}
static bool
chunk_merge_default(void *chunk_a, size_t size_a, void *chunk_b, size_t size_b,
bool committed, unsigned arena_ind)
{
if (!maps_coalesce)
return (true);
if (have_dss && chunk_in_dss(chunk_a) != chunk_in_dss(chunk_b))
return (true);
return (false);
}
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)
{
#ifdef _WIN32
SYSTEM_INFO info;
GetSystemInfo(&info);
/*
* Verify actual page size is equal to or an integral multiple of
* configured page size.
*/
if (info.dwPageSize & ((1U << LG_PAGE) - 1))
return (true);
/*
* Configure chunksize (if not set) to match granularity (usually 64K),
* so pages_map will always take fast path.
*/
if (!opt_lg_chunk) {
opt_lg_chunk = ffs_u((unsigned)info.dwAllocationGranularity)
- 1;
}
#else
if (!opt_lg_chunk)
opt_lg_chunk = LG_CHUNK_DEFAULT;
#endif
/* 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, (unsigned)((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();
}