#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(); }