#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;
malloc_mutex_t chunks_mtx;
chunk_stats_t stats_chunks;
/*
* Trees of chunks that were previously allocated (trees differ only in node
* ordering). These are used when allocating chunks, in an attempt to re-use
* address space. Depending on function, different tree orderings are needed,
* which is why there are two trees with the same contents.
*/
static extent_tree_t chunks_szad_mmap;
static extent_tree_t chunks_ad_mmap;
static extent_tree_t chunks_szad_dss;
static extent_tree_t chunks_ad_dss;
rtree_t *chunks_rtree;
/* Various chunk-related settings. */
size_t chunksize;
size_t chunksize_mask; /* (chunksize - 1). */
size_t chunk_npages;
size_t map_bias;
size_t arena_maxclass; /* Max size class for arenas. */
/******************************************************************************/
/*
* Function prototypes for static functions that are referenced prior to
* definition.
*/
static void chunk_dalloc_core(void *chunk, size_t size);
/******************************************************************************/
static void *
chunk_recycle(extent_tree_t *chunks_szad, extent_tree_t *chunks_ad, size_t size,
size_t alignment, bool base, bool *zero)
{
void *ret;
extent_node_t *node;
extent_node_t key;
size_t alloc_size, leadsize, trailsize;
bool zeroed;
if (base) {
/*
* This function may need to call base_node_{,de}alloc(), but
* the current chunk allocation request is on behalf of the
* base allocator. Avoid deadlock (and if that weren't an
* issue, potential for infinite recursion) by returning NULL.
*/
return (NULL);
}
alloc_size = size + alignment - chunksize;
/* Beware size_t wrap-around. */
if (alloc_size < size)
return (NULL);
key.addr = NULL;
key.size = alloc_size;
malloc_mutex_lock(&chunks_mtx);
node = extent_tree_szad_nsearch(chunks_szad, &key);
if (node == NULL) {
malloc_mutex_unlock(&chunks_mtx);
return (NULL);
}
leadsize = ALIGNMENT_CEILING((uintptr_t)node->addr, alignment) -
(uintptr_t)node->addr;
assert(node->size >= leadsize + size);
trailsize = node->size - leadsize - size;
ret = (void *)((uintptr_t)node->addr + leadsize);
zeroed = node->zeroed;
if (zeroed)
*zero = true;
/* Remove node from the tree. */
extent_tree_szad_remove(chunks_szad, node);
extent_tree_ad_remove(chunks_ad, node);
if (leadsize != 0) {
/* Insert the leading space as a smaller chunk. */
node->size = leadsize;
extent_tree_szad_insert(chunks_szad, node);
extent_tree_ad_insert(chunks_ad, node);
node = NULL;
}
if (trailsize != 0) {
/* Insert the trailing space as a smaller chunk. */
if (node == NULL) {
/*
* An additional node is required, but
* base_node_alloc() can cause a new base chunk to be
* allocated. Drop chunks_mtx in order to avoid
* deadlock, and if node allocation fails, deallocate
* the result before returning an error.
*/
malloc_mutex_unlock(&chunks_mtx);
node = base_node_alloc();
if (node == NULL) {
chunk_dalloc_core(ret, size);
return (NULL);
}
malloc_mutex_lock(&chunks_mtx);
}
node->addr = (void *)((uintptr_t)(ret) + size);
node->size = trailsize;
node->zeroed = zeroed;
extent_tree_szad_insert(chunks_szad, node);
extent_tree_ad_insert(chunks_ad, node);
node = NULL;
}
malloc_mutex_unlock(&chunks_mtx);
if (node != NULL)
base_node_dalloc(node);
if (*zero) {
if (zeroed == false)
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 == false), 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(size_t size, size_t alignment, bool base, 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) {
if ((ret = chunk_recycle(&chunks_szad_dss, &chunks_ad_dss, size,
alignment, base, zero)) != NULL)
return (ret);
if ((ret = chunk_alloc_dss(size, alignment, zero)) != NULL)
return (ret);
}
/* mmap. */
if ((ret = chunk_recycle(&chunks_szad_mmap, &chunks_ad_mmap, size,
alignment, base, zero)) != NULL)
return (ret);
if ((ret = chunk_alloc_mmap(size, alignment, zero)) != NULL)
return (ret);
/* "secondary" dss. */
if (have_dss && dss_prec == dss_prec_secondary) {
if ((ret = chunk_recycle(&chunks_szad_dss, &chunks_ad_dss, size,
alignment, base, zero)) != NULL)
return (ret);
if ((ret = chunk_alloc_dss(size, alignment, zero)) != NULL)
return (ret);
}
/* All strategies for allocation failed. */
return (NULL);
}
static bool
chunk_register(void *chunk, size_t size, bool base)
{
assert(chunk != NULL);
assert(CHUNK_ADDR2BASE(chunk) == chunk);
if (config_ivsalloc && base == false) {
if (rtree_set(chunks_rtree, (uintptr_t)chunk, 1))
return (true);
}
if (config_stats || config_prof) {
bool gdump;
malloc_mutex_lock(&chunks_mtx);
if (config_stats)
stats_chunks.nchunks += (size / chunksize);
stats_chunks.curchunks += (size / chunksize);
if (stats_chunks.curchunks > stats_chunks.highchunks) {
stats_chunks.highchunks =
stats_chunks.curchunks;
if (config_prof)
gdump = true;
} else if (config_prof)
gdump = false;
malloc_mutex_unlock(&chunks_mtx);
if (config_prof && opt_prof && opt_prof_gdump && gdump)
prof_gdump();
}
if (config_valgrind)
JEMALLOC_VALGRIND_MAKE_MEM_UNDEFINED(chunk, size);
return (false);
}
void *
chunk_alloc_base(size_t size)
{
void *ret;
bool zero;
zero = false;
ret = chunk_alloc_core(size, chunksize, true, &zero,
chunk_dss_prec_get());
if (ret == NULL)
return (NULL);
if (chunk_register(ret, size, true)) {
chunk_dalloc_core(ret, size);
return (NULL);
}
return (ret);
}
void *
chunk_alloc_arena(chunk_alloc_t *chunk_alloc, chunk_dalloc_t *chunk_dalloc,
unsigned arena_ind, size_t size, size_t alignment, bool *zero)
{
void *ret;
ret = chunk_alloc(size, alignment, zero, arena_ind);
if (ret != NULL && chunk_register(ret, size, false)) {
chunk_dalloc(ret, size, arena_ind);
ret = NULL;
}
return (ret);
}
/* Default arena chunk allocation routine in the absence of user override. */
void *
chunk_alloc_default(size_t size, size_t alignment, bool *zero,
unsigned arena_ind)
{
return (chunk_alloc_core(size, alignment, false, zero,
arenas[arena_ind]->dss_prec));
}
static void
chunk_record(extent_tree_t *chunks_szad, extent_tree_t *chunks_ad, void *chunk,
size_t size)
{
bool unzeroed;
extent_node_t *xnode, *node, *prev, *xprev, key;
unzeroed = pages_purge(chunk, size);
JEMALLOC_VALGRIND_MAKE_MEM_NOACCESS(chunk, size);
/*
* Allocate a node before acquiring chunks_mtx even though it might not
* be needed, because base_node_alloc() may cause a new base chunk to
* be allocated, which could cause deadlock if chunks_mtx were already
* held.
*/
xnode = base_node_alloc();
/* Use xprev to implement conditional deferred deallocation of prev. */
xprev = NULL;
malloc_mutex_lock(&chunks_mtx);
key.addr = (void *)((uintptr_t)chunk + size);
node = extent_tree_ad_nsearch(chunks_ad, &key);
/* Try to coalesce forward. */
if (node != NULL && node->addr == key.addr) {
/*
* 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);
node->addr = chunk;
node->size += size;
node->zeroed = (node->zeroed && (unzeroed == false));
extent_tree_szad_insert(chunks_szad, node);
} else {
/* Coalescing forward failed, so insert a new node. */
if (xnode == NULL) {
/*
* base_node_alloc() failed, which is an exceedingly
* unlikely failure. Leak chunk; its pages have
* already been purged, so this is only a virtual
* memory leak.
*/
goto label_return;
}
node = xnode;
xnode = NULL; /* Prevent deallocation below. */
node->addr = chunk;
node->size = size;
node->zeroed = (unzeroed == false);
extent_tree_ad_insert(chunks_ad, node);
extent_tree_szad_insert(chunks_szad, node);
}
/* Try to coalesce backward. */
prev = extent_tree_ad_prev(chunks_ad, node);
if (prev != NULL && (void *)((uintptr_t)prev->addr + prev->size) ==
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);
extent_tree_szad_remove(chunks_szad, node);
node->addr = prev->addr;
node->size += prev->size;
node->zeroed = (node->zeroed && prev->zeroed);
extent_tree_szad_insert(chunks_szad, node);
xprev = prev;
}
label_return:
malloc_mutex_unlock(&chunks_mtx);
/*
* Deallocate xnode and/or xprev after unlocking chunks_mtx in order to
* avoid potential deadlock.
*/
if (xnode != NULL)
base_node_dalloc(xnode);
if (xprev != NULL)
base_node_dalloc(xprev);
}
void
chunk_unmap(void *chunk, size_t size)
{
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(&chunks_szad_dss, &chunks_ad_dss, chunk, size);
else if (chunk_dalloc_mmap(chunk, size))
chunk_record(&chunks_szad_mmap, &chunks_ad_mmap, chunk, size);
}
static void
chunk_dalloc_core(void *chunk, size_t size)
{
assert(chunk != NULL);
assert(CHUNK_ADDR2BASE(chunk) == chunk);
assert(size != 0);
assert((size & chunksize_mask) == 0);
if (config_ivsalloc)
rtree_set(chunks_rtree, (uintptr_t)chunk, 0);
if (config_stats || config_prof) {
malloc_mutex_lock(&chunks_mtx);
assert(stats_chunks.curchunks >= (size / chunksize));
stats_chunks.curchunks -= (size / chunksize);
malloc_mutex_unlock(&chunks_mtx);
}
chunk_unmap(chunk, size);
}
/* Default arena chunk deallocation routine in the absence of user override. */
bool
chunk_dalloc_default(void *chunk, size_t size, unsigned arena_ind)
{
chunk_dalloc_core(chunk, size);
return (false);
}
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 (config_stats || config_prof) {
if (malloc_mutex_init(&chunks_mtx))
return (true);
memset(&stats_chunks, 0, sizeof(chunk_stats_t));
}
if (have_dss && chunk_dss_boot())
return (true);
extent_tree_szad_new(&chunks_szad_mmap);
extent_tree_ad_new(&chunks_ad_mmap);
extent_tree_szad_new(&chunks_szad_dss);
extent_tree_ad_new(&chunks_ad_dss);
if (config_ivsalloc) {
chunks_rtree = rtree_new((ZU(1) << (LG_SIZEOF_PTR+3)) -
opt_lg_chunk, base_alloc, NULL);
if (chunks_rtree == NULL)
return (true);
}
return (false);
}
void
chunk_prefork(void)
{
malloc_mutex_prefork(&chunks_mtx);
if (config_ivsalloc)
rtree_prefork(chunks_rtree);
chunk_dss_prefork();
}
void
chunk_postfork_parent(void)
{
chunk_dss_postfork_parent();
if (config_ivsalloc)
rtree_postfork_parent(chunks_rtree);
malloc_mutex_postfork_parent(&chunks_mtx);
}
void
chunk_postfork_child(void)
{
chunk_dss_postfork_child();
if (config_ivsalloc)
rtree_postfork_child(chunks_rtree);
malloc_mutex_postfork_child(&chunks_mtx);
}