#define JEMALLOC_ARENA_C_ #include "jemalloc/internal/jemalloc_internal.h" /******************************************************************************/ /* Data. */ ssize_t opt_lg_dirty_mult = LG_DIRTY_MULT_DEFAULT; arena_bin_info_t arena_bin_info[NBINS]; JEMALLOC_ALIGNED(CACHELINE) const uint8_t small_size2bin[] = { #define S2B_8(i) i, #define S2B_16(i) S2B_8(i) S2B_8(i) #define S2B_32(i) S2B_16(i) S2B_16(i) #define S2B_64(i) S2B_32(i) S2B_32(i) #define S2B_128(i) S2B_64(i) S2B_64(i) #define S2B_256(i) S2B_128(i) S2B_128(i) #define S2B_512(i) S2B_256(i) S2B_256(i) #define S2B_1024(i) S2B_512(i) S2B_512(i) #define S2B_2048(i) S2B_1024(i) S2B_1024(i) #define S2B_4096(i) S2B_2048(i) S2B_2048(i) #define S2B_8192(i) S2B_4096(i) S2B_4096(i) #define SIZE_CLASS(bin, delta, size) \ S2B_##delta(bin) SIZE_CLASSES #undef S2B_8 #undef S2B_16 #undef S2B_32 #undef S2B_64 #undef S2B_128 #undef S2B_256 #undef S2B_512 #undef S2B_1024 #undef S2B_2048 #undef S2B_4096 #undef S2B_8192 #undef SIZE_CLASS }; /******************************************************************************/ /* Function prototypes for non-inline static functions. */ static void arena_avail_insert(arena_t *arena, arena_chunk_t *chunk, size_t pageind, size_t npages, bool maybe_adjac_pred, bool maybe_adjac_succ); static void arena_avail_remove(arena_t *arena, arena_chunk_t *chunk, size_t pageind, size_t npages, bool maybe_adjac_pred, bool maybe_adjac_succ); static void arena_run_split(arena_t *arena, arena_run_t *run, size_t size, bool large, size_t binind, bool zero); static arena_chunk_t *arena_chunk_alloc(arena_t *arena); static void arena_chunk_dealloc(arena_t *arena, arena_chunk_t *chunk); static arena_run_t *arena_run_alloc_helper(arena_t *arena, size_t size, bool large, size_t binind, bool zero); static arena_run_t *arena_run_alloc(arena_t *arena, size_t size, bool large, size_t binind, bool zero); static arena_chunk_t *chunks_dirty_iter_cb(arena_chunk_tree_t *tree, arena_chunk_t *chunk, void *arg); static void arena_purge(arena_t *arena, bool all); static void arena_run_dalloc(arena_t *arena, arena_run_t *run, bool dirty, bool cleaned); static void arena_run_trim_head(arena_t *arena, arena_chunk_t *chunk, arena_run_t *run, size_t oldsize, size_t newsize); static void arena_run_trim_tail(arena_t *arena, arena_chunk_t *chunk, arena_run_t *run, size_t oldsize, size_t newsize, bool dirty); static arena_run_t *arena_bin_runs_first(arena_bin_t *bin); static void arena_bin_runs_insert(arena_bin_t *bin, arena_run_t *run); static void arena_bin_runs_remove(arena_bin_t *bin, arena_run_t *run); static arena_run_t *arena_bin_nonfull_run_tryget(arena_bin_t *bin); static arena_run_t *arena_bin_nonfull_run_get(arena_t *arena, arena_bin_t *bin); static void *arena_bin_malloc_hard(arena_t *arena, arena_bin_t *bin); static void arena_dissociate_bin_run(arena_chunk_t *chunk, arena_run_t *run, arena_bin_t *bin); static void arena_dalloc_bin_run(arena_t *arena, arena_chunk_t *chunk, arena_run_t *run, arena_bin_t *bin); static void arena_bin_lower_run(arena_t *arena, arena_chunk_t *chunk, arena_run_t *run, arena_bin_t *bin); static void arena_ralloc_large_shrink(arena_t *arena, arena_chunk_t *chunk, void *ptr, size_t oldsize, size_t size); static bool arena_ralloc_large_grow(arena_t *arena, arena_chunk_t *chunk, void *ptr, size_t oldsize, size_t size, size_t extra, bool zero); static bool arena_ralloc_large(void *ptr, size_t oldsize, size_t size, size_t extra, bool zero); static size_t bin_info_run_size_calc(arena_bin_info_t *bin_info, size_t min_run_size); static void bin_info_init(void); /******************************************************************************/ static inline int arena_run_comp(arena_chunk_map_t *a, arena_chunk_map_t *b) { uintptr_t a_mapelm = (uintptr_t)a; uintptr_t b_mapelm = (uintptr_t)b; assert(a != NULL); assert(b != NULL); return ((a_mapelm > b_mapelm) - (a_mapelm < b_mapelm)); } /* Generate red-black tree functions. */ rb_gen(static UNUSED, arena_run_tree_, arena_run_tree_t, arena_chunk_map_t, u.rb_link, arena_run_comp) static inline int arena_avail_comp(arena_chunk_map_t *a, arena_chunk_map_t *b) { int ret; size_t a_size = a->bits & ~PAGE_MASK; size_t b_size = b->bits & ~PAGE_MASK; ret = (a_size > b_size) - (a_size < b_size); if (ret == 0) { uintptr_t a_mapelm, b_mapelm; if ((a->bits & CHUNK_MAP_KEY) != CHUNK_MAP_KEY) a_mapelm = (uintptr_t)a; else { /* * Treat keys as though they are lower than anything * else. */ a_mapelm = 0; } b_mapelm = (uintptr_t)b; ret = (a_mapelm > b_mapelm) - (a_mapelm < b_mapelm); } return (ret); } /* Generate red-black tree functions. */ rb_gen(static UNUSED, arena_avail_tree_, arena_avail_tree_t, arena_chunk_map_t, u.rb_link, arena_avail_comp) static inline int arena_chunk_dirty_comp(arena_chunk_t *a, arena_chunk_t *b) { size_t a_val, b_val; assert(a != NULL); assert(b != NULL); /* * Order such that chunks with higher fragmentation are "less than" * those with lower fragmentation. Fragmentation is measured as: * * mean current avail run size * -------------------------------- * mean defragmented avail run size * * navail * ----------- * nruns_avail nruns_avail-nruns_adjac * = ========================= = ----------------------- * navail nruns_avail * ----------------------- * nruns_avail-nruns_adjac * * The following code multiplies away the denominator prior to * comparison, in order to avoid division. * */ a_val = (a->nruns_avail - a->nruns_adjac) * b->nruns_avail; b_val = (b->nruns_avail - b->nruns_adjac) * a->nruns_avail; if (a_val < b_val) return (1); if (a_val > b_val) return (-1); /* Break ties by chunk address. */ { uintptr_t a_chunk = (uintptr_t)a; uintptr_t b_chunk = (uintptr_t)b; return ((a_chunk > b_chunk) - (a_chunk < b_chunk)); } } /* Generate red-black tree functions. */ rb_gen(static UNUSED, arena_chunk_dirty_, arena_chunk_tree_t, arena_chunk_t, dirty_link, arena_chunk_dirty_comp) static inline bool arena_avail_adjac_pred(arena_chunk_t *chunk, size_t pageind) { bool ret; if (pageind-1 < map_bias) ret = false; else { ret = (arena_mapbits_allocated_get(chunk, pageind-1) == 0); assert(ret == false || arena_mapbits_dirty_get(chunk, pageind-1) != arena_mapbits_dirty_get(chunk, pageind)); } return (ret); } static inline bool arena_avail_adjac_succ(arena_chunk_t *chunk, size_t pageind, size_t npages) { bool ret; if (pageind+npages == chunk_npages) ret = false; else { assert(pageind+npages < chunk_npages); ret = (arena_mapbits_allocated_get(chunk, pageind+npages) == 0); assert(ret == false || arena_mapbits_dirty_get(chunk, pageind) != arena_mapbits_dirty_get(chunk, pageind+npages)); } return (ret); } static inline bool arena_avail_adjac(arena_chunk_t *chunk, size_t pageind, size_t npages) { return (arena_avail_adjac_pred(chunk, pageind) || arena_avail_adjac_succ(chunk, pageind, npages)); } static void arena_avail_insert(arena_t *arena, arena_chunk_t *chunk, size_t pageind, size_t npages, bool maybe_adjac_pred, bool maybe_adjac_succ) { assert(npages == (arena_mapbits_unallocated_size_get(chunk, pageind) >> LG_PAGE)); /* * chunks_dirty is keyed by nruns_{avail,adjac}, so the chunk must be * removed and reinserted even if the run to be inserted is clean. */ if (chunk->ndirty != 0) arena_chunk_dirty_remove(&arena->chunks_dirty, chunk); if (maybe_adjac_pred && arena_avail_adjac_pred(chunk, pageind)) chunk->nruns_adjac++; if (maybe_adjac_succ && arena_avail_adjac_succ(chunk, pageind, npages)) chunk->nruns_adjac++; chunk->nruns_avail++; assert(chunk->nruns_avail > chunk->nruns_adjac); if (arena_mapbits_dirty_get(chunk, pageind) != 0) { arena->ndirty += npages; chunk->ndirty += npages; } if (chunk->ndirty != 0) arena_chunk_dirty_insert(&arena->chunks_dirty, chunk); arena_avail_tree_insert(&arena->runs_avail, arena_mapp_get(chunk, pageind)); } static void arena_avail_remove(arena_t *arena, arena_chunk_t *chunk, size_t pageind, size_t npages, bool maybe_adjac_pred, bool maybe_adjac_succ) { assert(npages == (arena_mapbits_unallocated_size_get(chunk, pageind) >> LG_PAGE)); /* * chunks_dirty is keyed by nruns_{avail,adjac}, so the chunk must be * removed and reinserted even if the run to be removed is clean. */ if (chunk->ndirty != 0) arena_chunk_dirty_remove(&arena->chunks_dirty, chunk); if (maybe_adjac_pred && arena_avail_adjac_pred(chunk, pageind)) chunk->nruns_adjac--; if (maybe_adjac_succ && arena_avail_adjac_succ(chunk, pageind, npages)) chunk->nruns_adjac--; chunk->nruns_avail--; assert(chunk->nruns_avail > chunk->nruns_adjac || (chunk->nruns_avail == 0 && chunk->nruns_adjac == 0)); if (arena_mapbits_dirty_get(chunk, pageind) != 0) { arena->ndirty -= npages; chunk->ndirty -= npages; } if (chunk->ndirty != 0) arena_chunk_dirty_insert(&arena->chunks_dirty, chunk); arena_avail_tree_remove(&arena->runs_avail, arena_mapp_get(chunk, pageind)); } static inline void * arena_run_reg_alloc(arena_run_t *run, arena_bin_info_t *bin_info) { void *ret; unsigned regind; bitmap_t *bitmap = (bitmap_t *)((uintptr_t)run + (uintptr_t)bin_info->bitmap_offset); assert(run->nfree > 0); assert(bitmap_full(bitmap, &bin_info->bitmap_info) == false); regind = bitmap_sfu(bitmap, &bin_info->bitmap_info); ret = (void *)((uintptr_t)run + (uintptr_t)bin_info->reg0_offset + (uintptr_t)(bin_info->reg_interval * regind)); run->nfree--; if (regind == run->nextind) run->nextind++; assert(regind < run->nextind); return (ret); } static inline void arena_run_reg_dalloc(arena_run_t *run, void *ptr) { arena_chunk_t *chunk = (arena_chunk_t *)CHUNK_ADDR2BASE(run); size_t pageind = ((uintptr_t)ptr - (uintptr_t)chunk) >> LG_PAGE; size_t mapbits = arena_mapbits_get(chunk, pageind); size_t binind = arena_ptr_small_binind_get(ptr, mapbits); arena_bin_info_t *bin_info = &arena_bin_info[binind]; unsigned regind = arena_run_regind(run, bin_info, ptr); bitmap_t *bitmap = (bitmap_t *)((uintptr_t)run + (uintptr_t)bin_info->bitmap_offset); assert(run->nfree < bin_info->nregs); /* Freeing an interior pointer can cause assertion failure. */ assert(((uintptr_t)ptr - ((uintptr_t)run + (uintptr_t)bin_info->reg0_offset)) % (uintptr_t)bin_info->reg_interval == 0); assert((uintptr_t)ptr >= (uintptr_t)run + (uintptr_t)bin_info->reg0_offset); /* Freeing an unallocated pointer can cause assertion failure. */ assert(bitmap_get(bitmap, &bin_info->bitmap_info, regind)); bitmap_unset(bitmap, &bin_info->bitmap_info, regind); run->nfree++; } static inline void arena_chunk_validate_zeroed(arena_chunk_t *chunk, size_t run_ind) { size_t i; UNUSED size_t *p = (size_t *)((uintptr_t)chunk + (run_ind << LG_PAGE)); for (i = 0; i < PAGE / sizeof(size_t); i++) assert(p[i] == 0); } static void arena_run_split(arena_t *arena, arena_run_t *run, size_t size, bool large, size_t binind, bool zero) { arena_chunk_t *chunk; size_t run_ind, total_pages, need_pages, rem_pages, i; size_t flag_dirty; assert((large && binind == BININD_INVALID) || (large == false && binind != BININD_INVALID)); chunk = (arena_chunk_t *)CHUNK_ADDR2BASE(run); run_ind = (unsigned)(((uintptr_t)run - (uintptr_t)chunk) >> LG_PAGE); flag_dirty = arena_mapbits_dirty_get(chunk, run_ind); total_pages = arena_mapbits_unallocated_size_get(chunk, run_ind) >> LG_PAGE; assert(arena_mapbits_dirty_get(chunk, run_ind+total_pages-1) == flag_dirty); need_pages = (size >> LG_PAGE); assert(need_pages > 0); assert(need_pages <= total_pages); rem_pages = total_pages - need_pages; arena_avail_remove(arena, chunk, run_ind, total_pages, true, true); if (config_stats) { /* * Update stats_cactive if nactive is crossing a chunk * multiple. */ size_t cactive_diff = CHUNK_CEILING((arena->nactive + need_pages) << LG_PAGE) - CHUNK_CEILING(arena->nactive << LG_PAGE); if (cactive_diff != 0) stats_cactive_add(cactive_diff); } arena->nactive += need_pages; /* Keep track of trailing unused pages for later use. */ if (rem_pages > 0) { if (flag_dirty != 0) { arena_mapbits_unallocated_set(chunk, run_ind+need_pages, (rem_pages << LG_PAGE), CHUNK_MAP_DIRTY); arena_mapbits_unallocated_set(chunk, run_ind+total_pages-1, (rem_pages << LG_PAGE), CHUNK_MAP_DIRTY); } else { arena_mapbits_unallocated_set(chunk, run_ind+need_pages, (rem_pages << LG_PAGE), arena_mapbits_unzeroed_get(chunk, run_ind+need_pages)); arena_mapbits_unallocated_set(chunk, run_ind+total_pages-1, (rem_pages << LG_PAGE), arena_mapbits_unzeroed_get(chunk, run_ind+total_pages-1)); } arena_avail_insert(arena, chunk, run_ind+need_pages, rem_pages, false, true); } /* * Update the page map separately for large vs. small runs, since it is * possible to avoid iteration for large mallocs. */ if (large) { if (zero) { if (flag_dirty == 0) { /* * The run is clean, so some pages may be * zeroed (i.e. never before touched). */ for (i = 0; i < need_pages; i++) { if (arena_mapbits_unzeroed_get(chunk, run_ind+i) != 0) { VALGRIND_MAKE_MEM_UNDEFINED( (void *)((uintptr_t) chunk + ((run_ind+i) << LG_PAGE)), PAGE); memset((void *)((uintptr_t) chunk + ((run_ind+i) << LG_PAGE)), 0, PAGE); } else if (config_debug) { VALGRIND_MAKE_MEM_DEFINED( (void *)((uintptr_t) chunk + ((run_ind+i) << LG_PAGE)), PAGE); arena_chunk_validate_zeroed( chunk, run_ind+i); } } } else { /* * The run is dirty, so all pages must be * zeroed. */ VALGRIND_MAKE_MEM_UNDEFINED((void *)((uintptr_t)chunk + (run_ind << LG_PAGE)), (need_pages << LG_PAGE)); memset((void *)((uintptr_t)chunk + (run_ind << LG_PAGE)), 0, (need_pages << LG_PAGE)); } } /* * Set the last element first, in case the run only contains one * page (i.e. both statements set the same element). */ arena_mapbits_large_set(chunk, run_ind+need_pages-1, 0, flag_dirty); arena_mapbits_large_set(chunk, run_ind, size, flag_dirty); } else { assert(zero == false); /* * Propagate the dirty and unzeroed flags to the allocated * small run, so that arena_dalloc_bin_run() has the ability to * conditionally trim clean pages. */ arena_mapbits_small_set(chunk, run_ind, 0, binind, flag_dirty); /* * The first page will always be dirtied during small run * initialization, so a validation failure here would not * actually cause an observable failure. */ if (config_debug && flag_dirty == 0 && arena_mapbits_unzeroed_get(chunk, run_ind) == 0) arena_chunk_validate_zeroed(chunk, run_ind); for (i = 1; i < need_pages - 1; i++) { arena_mapbits_small_set(chunk, run_ind+i, i, binind, 0); if (config_debug && flag_dirty == 0 && arena_mapbits_unzeroed_get(chunk, run_ind+i) == 0) arena_chunk_validate_zeroed(chunk, run_ind+i); } arena_mapbits_small_set(chunk, run_ind+need_pages-1, need_pages-1, binind, flag_dirty); if (config_debug && flag_dirty == 0 && arena_mapbits_unzeroed_get(chunk, run_ind+need_pages-1) == 0) { arena_chunk_validate_zeroed(chunk, run_ind+need_pages-1); } } } static arena_chunk_t * arena_chunk_alloc(arena_t *arena) { arena_chunk_t *chunk; size_t i; if (arena->spare != NULL) { chunk = arena->spare; arena->spare = NULL; assert(arena_mapbits_allocated_get(chunk, map_bias) == 0); assert(arena_mapbits_allocated_get(chunk, chunk_npages-1) == 0); assert(arena_mapbits_unallocated_size_get(chunk, map_bias) == arena_maxclass); assert(arena_mapbits_unallocated_size_get(chunk, chunk_npages-1) == arena_maxclass); assert(arena_mapbits_dirty_get(chunk, map_bias) == arena_mapbits_dirty_get(chunk, chunk_npages-1)); } else { bool zero; size_t unzeroed; zero = false; malloc_mutex_unlock(&arena->lock); chunk = (arena_chunk_t *)chunk_alloc(chunksize, chunksize, false, &zero, arena->dss_prec); malloc_mutex_lock(&arena->lock); if (chunk == NULL) return (NULL); if (config_stats) arena->stats.mapped += chunksize; chunk->arena = arena; /* * Claim that no pages are in use, since the header is merely * overhead. */ chunk->ndirty = 0; chunk->nruns_avail = 0; chunk->nruns_adjac = 0; /* * Initialize the map to contain one maximal free untouched run. * Mark the pages as zeroed iff chunk_alloc() returned a zeroed * chunk. */ unzeroed = zero ? 0 : CHUNK_MAP_UNZEROED; arena_mapbits_unallocated_set(chunk, map_bias, arena_maxclass, unzeroed); /* * There is no need to initialize the internal page map entries * unless the chunk is not zeroed. */ if (zero == false) { for (i = map_bias+1; i < chunk_npages-1; i++) arena_mapbits_unzeroed_set(chunk, i, unzeroed); } else if (config_debug) { for (i = map_bias+1; i < chunk_npages-1; i++) { assert(arena_mapbits_unzeroed_get(chunk, i) == unzeroed); } } arena_mapbits_unallocated_set(chunk, chunk_npages-1, arena_maxclass, unzeroed); } /* Insert the run into the runs_avail tree. */ arena_avail_insert(arena, chunk, map_bias, chunk_npages-map_bias, false, false); return (chunk); } static void arena_chunk_dealloc(arena_t *arena, arena_chunk_t *chunk) { assert(arena_mapbits_allocated_get(chunk, map_bias) == 0); assert(arena_mapbits_allocated_get(chunk, chunk_npages-1) == 0); assert(arena_mapbits_unallocated_size_get(chunk, map_bias) == arena_maxclass); assert(arena_mapbits_unallocated_size_get(chunk, chunk_npages-1) == arena_maxclass); assert(arena_mapbits_dirty_get(chunk, map_bias) == arena_mapbits_dirty_get(chunk, chunk_npages-1)); /* * Remove run from the runs_avail tree, so that the arena does not use * it. */ arena_avail_remove(arena, chunk, map_bias, chunk_npages-map_bias, false, false); if (arena->spare != NULL) { arena_chunk_t *spare = arena->spare; arena->spare = chunk; malloc_mutex_unlock(&arena->lock); chunk_dealloc((void *)spare, chunksize, true); malloc_mutex_lock(&arena->lock); if (config_stats) arena->stats.mapped -= chunksize; } else arena->spare = chunk; } static arena_run_t * arena_run_alloc_helper(arena_t *arena, size_t size, bool large, size_t binind, bool zero) { arena_run_t *run; arena_chunk_map_t *mapelm, key; key.bits = size | CHUNK_MAP_KEY; mapelm = arena_avail_tree_nsearch(&arena->runs_avail, &key); if (mapelm != NULL) { arena_chunk_t *run_chunk = CHUNK_ADDR2BASE(mapelm); size_t pageind = (((uintptr_t)mapelm - (uintptr_t)run_chunk->map) / sizeof(arena_chunk_map_t)) + map_bias; run = (arena_run_t *)((uintptr_t)run_chunk + (pageind << LG_PAGE)); arena_run_split(arena, run, size, large, binind, zero); return (run); } return (NULL); } static arena_run_t * arena_run_alloc(arena_t *arena, size_t size, bool large, size_t binind, bool zero) { arena_chunk_t *chunk; arena_run_t *run; assert(size <= arena_maxclass); assert((size & PAGE_MASK) == 0); assert((large && binind == BININD_INVALID) || (large == false && binind != BININD_INVALID)); /* Search the arena's chunks for the lowest best fit. */ run = arena_run_alloc_helper(arena, size, large, binind, zero); if (run != NULL) return (run); /* * No usable runs. Create a new chunk from which to allocate the run. */ chunk = arena_chunk_alloc(arena); if (chunk != NULL) { run = (arena_run_t *)((uintptr_t)chunk + (map_bias << LG_PAGE)); arena_run_split(arena, run, size, large, binind, zero); return (run); } /* * arena_chunk_alloc() failed, but another thread may have made * sufficient memory available while this one dropped arena->lock in * arena_chunk_alloc(), so search one more time. */ return (arena_run_alloc_helper(arena, size, large, binind, zero)); } static inline void arena_maybe_purge(arena_t *arena) { size_t npurgeable, threshold; /* Don't purge if the option is disabled. */ if (opt_lg_dirty_mult < 0) return; /* Don't purge if all dirty pages are already being purged. */ if (arena->ndirty <= arena->npurgatory) return; npurgeable = arena->ndirty - arena->npurgatory; threshold = (arena->nactive >> opt_lg_dirty_mult); /* * Don't purge unless the number of purgeable pages exceeds the * threshold. */ if (npurgeable <= threshold) return; arena_purge(arena, false); } static inline size_t arena_chunk_purge(arena_t *arena, arena_chunk_t *chunk, bool all) { size_t npurged; ql_head(arena_chunk_map_t) mapelms; arena_chunk_map_t *mapelm; size_t pageind, npages; size_t nmadvise; ql_new(&mapelms); /* * If chunk is the spare, temporarily re-allocate it, 1) so that its * run is reinserted into runs_avail, and 2) so that it cannot be * completely discarded by another thread while arena->lock is dropped * by this thread. Note that the arena_run_dalloc() call will * implicitly deallocate the chunk, so no explicit action is required * in this function to deallocate the chunk. * * Note that once a chunk contains dirty pages, it cannot again contain * a single run unless 1) it is a dirty run, or 2) this function purges * dirty pages and causes the transition to a single clean run. Thus * (chunk == arena->spare) is possible, but it is not possible for * this function to be called on the spare unless it contains a dirty * run. */ if (chunk == arena->spare) { assert(arena_mapbits_dirty_get(chunk, map_bias) != 0); assert(arena_mapbits_dirty_get(chunk, chunk_npages-1) != 0); arena_chunk_alloc(arena); } if (config_stats) arena->stats.purged += chunk->ndirty; /* * Operate on all dirty runs if there is no clean/dirty run * fragmentation. */ if (chunk->nruns_adjac == 0) all = true; /* * Temporarily allocate free dirty runs within chunk. If all is false, * only operate on dirty runs that are fragments; otherwise operate on * all dirty runs. */ for (pageind = map_bias; pageind < chunk_npages; pageind += npages) { mapelm = arena_mapp_get(chunk, pageind); if (arena_mapbits_allocated_get(chunk, pageind) == 0) { size_t run_size = arena_mapbits_unallocated_size_get(chunk, pageind); npages = run_size >> LG_PAGE; assert(pageind + npages <= chunk_npages); assert(arena_mapbits_dirty_get(chunk, pageind) == arena_mapbits_dirty_get(chunk, pageind+npages-1)); if (arena_mapbits_dirty_get(chunk, pageind) != 0 && (all || arena_avail_adjac(chunk, pageind, npages))) { arena_run_t *run = (arena_run_t *)((uintptr_t) chunk + (uintptr_t)(pageind << LG_PAGE)); arena_run_split(arena, run, run_size, true, BININD_INVALID, false); /* Append to list for later processing. */ ql_elm_new(mapelm, u.ql_link); ql_tail_insert(&mapelms, mapelm, u.ql_link); } } else { /* Skip run. */ if (arena_mapbits_large_get(chunk, pageind) != 0) { npages = arena_mapbits_large_size_get(chunk, pageind) >> LG_PAGE; } else { size_t binind; arena_bin_info_t *bin_info; arena_run_t *run = (arena_run_t *)((uintptr_t) chunk + (uintptr_t)(pageind << LG_PAGE)); assert(arena_mapbits_small_runind_get(chunk, pageind) == 0); binind = arena_bin_index(arena, run->bin); bin_info = &arena_bin_info[binind]; npages = bin_info->run_size >> LG_PAGE; } } } assert(pageind == chunk_npages); assert(chunk->ndirty == 0 || all == false); assert(chunk->nruns_adjac == 0); malloc_mutex_unlock(&arena->lock); if (config_stats) nmadvise = 0; npurged = 0; ql_foreach(mapelm, &mapelms, u.ql_link) { bool unzeroed; size_t flag_unzeroed, i; pageind = (((uintptr_t)mapelm - (uintptr_t)chunk->map) / sizeof(arena_chunk_map_t)) + map_bias; npages = arena_mapbits_large_size_get(chunk, pageind) >> LG_PAGE; assert(pageind + npages <= chunk_npages); unzeroed = pages_purge((void *)((uintptr_t)chunk + (pageind << LG_PAGE)), (npages << LG_PAGE)); flag_unzeroed = unzeroed ? CHUNK_MAP_UNZEROED : 0; /* * Set the unzeroed flag for all pages, now that pages_purge() * has returned whether the pages were zeroed as a side effect * of purging. This chunk map modification is safe even though * the arena mutex isn't currently owned by this thread, * because the run is marked as allocated, thus protecting it * from being modified by any other thread. As long as these * writes don't perturb the first and last elements' * CHUNK_MAP_ALLOCATED bits, behavior is well defined. */ for (i = 0; i < npages; i++) { arena_mapbits_unzeroed_set(chunk, pageind+i, flag_unzeroed); } npurged += npages; if (config_stats) nmadvise++; } malloc_mutex_lock(&arena->lock); if (config_stats) arena->stats.nmadvise += nmadvise; /* Deallocate runs. */ for (mapelm = ql_first(&mapelms); mapelm != NULL; mapelm = ql_first(&mapelms)) { arena_run_t *run; pageind = (((uintptr_t)mapelm - (uintptr_t)chunk->map) / sizeof(arena_chunk_map_t)) + map_bias; run = (arena_run_t *)((uintptr_t)chunk + (uintptr_t)(pageind << LG_PAGE)); ql_remove(&mapelms, mapelm, u.ql_link); arena_run_dalloc(arena, run, false, true); } return (npurged); } static arena_chunk_t * chunks_dirty_iter_cb(arena_chunk_tree_t *tree, arena_chunk_t *chunk, void *arg) { size_t *ndirty = (size_t *)arg; assert(chunk->ndirty != 0); *ndirty += chunk->ndirty; return (NULL); } static void arena_purge(arena_t *arena, bool all) { arena_chunk_t *chunk; size_t npurgatory; if (config_debug) { size_t ndirty = 0; arena_chunk_dirty_iter(&arena->chunks_dirty, NULL, chunks_dirty_iter_cb, (void *)&ndirty); assert(ndirty == arena->ndirty); } assert(arena->ndirty > arena->npurgatory || all); assert((arena->nactive >> opt_lg_dirty_mult) < (arena->ndirty - arena->npurgatory) || all); if (config_stats) arena->stats.npurge++; /* * Compute the minimum number of pages that this thread should try to * purge, and add the result to arena->npurgatory. This will keep * multiple threads from racing to reduce ndirty below the threshold. */ { size_t npurgeable = arena->ndirty - arena->npurgatory; if (all == false) { size_t threshold = (arena->nactive >> opt_lg_dirty_mult); npurgatory = npurgeable - threshold; } else npurgatory = npurgeable; } arena->npurgatory += npurgatory; while (npurgatory > 0) { size_t npurgeable, npurged, nunpurged; /* Get next chunk with dirty pages. */ chunk = arena_chunk_dirty_first(&arena->chunks_dirty); if (chunk == NULL) { /* * This thread was unable to purge as many pages as * originally intended, due to races with other threads * that either did some of the purging work, or re-used * dirty pages. */ arena->npurgatory -= npurgatory; return; } npurgeable = chunk->ndirty; assert(npurgeable != 0); if (npurgeable > npurgatory && chunk->nruns_adjac == 0) { /* * This thread will purge all the dirty pages in chunk, * so set npurgatory to reflect this thread's intent to * purge the pages. This tends to reduce the chances * of the following scenario: * * 1) This thread sets arena->npurgatory such that * (arena->ndirty - arena->npurgatory) is at the * threshold. * 2) This thread drops arena->lock. * 3) Another thread causes one or more pages to be * dirtied, and immediately determines that it must * purge dirty pages. * * If this scenario *does* play out, that's okay, * because all of the purging work being done really * needs to happen. */ arena->npurgatory += npurgeable - npurgatory; npurgatory = npurgeable; } /* * Keep track of how many pages are purgeable, versus how many * actually get purged, and adjust counters accordingly. */ arena->npurgatory -= npurgeable; npurgatory -= npurgeable; npurged = arena_chunk_purge(arena, chunk, all); nunpurged = npurgeable - npurged; arena->npurgatory += nunpurged; npurgatory += nunpurged; } } void arena_purge_all(arena_t *arena) { malloc_mutex_lock(&arena->lock); arena_purge(arena, true); malloc_mutex_unlock(&arena->lock); } static void arena_run_dalloc(arena_t *arena, arena_run_t *run, bool dirty, bool cleaned) { arena_chunk_t *chunk; size_t size, run_ind, run_pages, flag_dirty; chunk = (arena_chunk_t *)CHUNK_ADDR2BASE(run); run_ind = (size_t)(((uintptr_t)run - (uintptr_t)chunk) >> LG_PAGE); assert(run_ind >= map_bias); assert(run_ind < chunk_npages); if (arena_mapbits_large_get(chunk, run_ind) != 0) { size = arena_mapbits_large_size_get(chunk, run_ind); assert(size == PAGE || arena_mapbits_large_size_get(chunk, run_ind+(size>>LG_PAGE)-1) == 0); } else { size_t binind = arena_bin_index(arena, run->bin); arena_bin_info_t *bin_info = &arena_bin_info[binind]; size = bin_info->run_size; } run_pages = (size >> LG_PAGE); if (config_stats) { /* * Update stats_cactive if nactive is crossing a chunk * multiple. */ size_t cactive_diff = CHUNK_CEILING(arena->nactive << LG_PAGE) - CHUNK_CEILING((arena->nactive - run_pages) << LG_PAGE); if (cactive_diff != 0) stats_cactive_sub(cactive_diff); } arena->nactive -= run_pages; /* * The run is dirty if the caller claims to have dirtied it, as well as * if it was already dirty before being allocated and the caller * doesn't claim to have cleaned it. */ assert(arena_mapbits_dirty_get(chunk, run_ind) == arena_mapbits_dirty_get(chunk, run_ind+run_pages-1)); if (cleaned == false && arena_mapbits_dirty_get(chunk, run_ind) != 0) dirty = true; flag_dirty = dirty ? CHUNK_MAP_DIRTY : 0; /* Mark pages as unallocated in the chunk map. */ if (dirty) { arena_mapbits_unallocated_set(chunk, run_ind, size, CHUNK_MAP_DIRTY); arena_mapbits_unallocated_set(chunk, run_ind+run_pages-1, size, CHUNK_MAP_DIRTY); } else { arena_mapbits_unallocated_set(chunk, run_ind, size, arena_mapbits_unzeroed_get(chunk, run_ind)); arena_mapbits_unallocated_set(chunk, run_ind+run_pages-1, size, arena_mapbits_unzeroed_get(chunk, run_ind+run_pages-1)); } /* Try to coalesce forward. */ if (run_ind + run_pages < chunk_npages && arena_mapbits_allocated_get(chunk, run_ind+run_pages) == 0 && arena_mapbits_dirty_get(chunk, run_ind+run_pages) == flag_dirty) { size_t nrun_size = arena_mapbits_unallocated_size_get(chunk, run_ind+run_pages); size_t nrun_pages = nrun_size >> LG_PAGE; /* * Remove successor from runs_avail; the coalesced run is * inserted later. */ assert(arena_mapbits_unallocated_size_get(chunk, run_ind+run_pages+nrun_pages-1) == nrun_size); assert(arena_mapbits_dirty_get(chunk, run_ind+run_pages+nrun_pages-1) == flag_dirty); arena_avail_remove(arena, chunk, run_ind+run_pages, nrun_pages, false, true); size += nrun_size; run_pages += nrun_pages; arena_mapbits_unallocated_size_set(chunk, run_ind, size); arena_mapbits_unallocated_size_set(chunk, run_ind+run_pages-1, size); } /* Try to coalesce backward. */ if (run_ind > map_bias && arena_mapbits_allocated_get(chunk, run_ind-1) == 0 && arena_mapbits_dirty_get(chunk, run_ind-1) == flag_dirty) { size_t prun_size = arena_mapbits_unallocated_size_get(chunk, run_ind-1); size_t prun_pages = prun_size >> LG_PAGE; run_ind -= prun_pages; /* * Remove predecessor from runs_avail; the coalesced run is * inserted later. */ assert(arena_mapbits_unallocated_size_get(chunk, run_ind) == prun_size); assert(arena_mapbits_dirty_get(chunk, run_ind) == flag_dirty); arena_avail_remove(arena, chunk, run_ind, prun_pages, true, false); size += prun_size; run_pages += prun_pages; arena_mapbits_unallocated_size_set(chunk, run_ind, size); arena_mapbits_unallocated_size_set(chunk, run_ind+run_pages-1, size); } /* Insert into runs_avail, now that coalescing is complete. */ assert(arena_mapbits_unallocated_size_get(chunk, run_ind) == arena_mapbits_unallocated_size_get(chunk, run_ind+run_pages-1)); assert(arena_mapbits_dirty_get(chunk, run_ind) == arena_mapbits_dirty_get(chunk, run_ind+run_pages-1)); arena_avail_insert(arena, chunk, run_ind, run_pages, true, true); /* Deallocate chunk if it is now completely unused. */ if (size == arena_maxclass) { assert(run_ind == map_bias); assert(run_pages == (arena_maxclass >> LG_PAGE)); arena_chunk_dealloc(arena, chunk); } /* * It is okay to do dirty page processing here even if the chunk was * deallocated above, since in that case it is the spare. Waiting * until after possible chunk deallocation to do dirty processing * allows for an old spare to be fully deallocated, thus decreasing the * chances of spuriously crossing the dirty page purging threshold. */ if (dirty) arena_maybe_purge(arena); } static void arena_run_trim_head(arena_t *arena, arena_chunk_t *chunk, arena_run_t *run, size_t oldsize, size_t newsize) { size_t pageind = ((uintptr_t)run - (uintptr_t)chunk) >> LG_PAGE; size_t head_npages = (oldsize - newsize) >> LG_PAGE; size_t flag_dirty = arena_mapbits_dirty_get(chunk, pageind); assert(oldsize > newsize); /* * Update the chunk map so that arena_run_dalloc() can treat the * leading run as separately allocated. Set the last element of each * run first, in case of single-page runs. */ assert(arena_mapbits_large_size_get(chunk, pageind) == oldsize); arena_mapbits_large_set(chunk, pageind+head_npages-1, 0, flag_dirty); arena_mapbits_large_set(chunk, pageind, oldsize-newsize, flag_dirty); if (config_debug) { UNUSED size_t tail_npages = newsize >> LG_PAGE; assert(arena_mapbits_large_size_get(chunk, pageind+head_npages+tail_npages-1) == 0); assert(arena_mapbits_dirty_get(chunk, pageind+head_npages+tail_npages-1) == flag_dirty); } arena_mapbits_large_set(chunk, pageind+head_npages, newsize, flag_dirty); arena_run_dalloc(arena, run, false, false); } static void arena_run_trim_tail(arena_t *arena, arena_chunk_t *chunk, arena_run_t *run, size_t oldsize, size_t newsize, bool dirty) { size_t pageind = ((uintptr_t)run - (uintptr_t)chunk) >> LG_PAGE; size_t head_npages = newsize >> LG_PAGE; size_t flag_dirty = arena_mapbits_dirty_get(chunk, pageind); assert(oldsize > newsize); /* * Update the chunk map so that arena_run_dalloc() can treat the * trailing run as separately allocated. Set the last element of each * run first, in case of single-page runs. */ assert(arena_mapbits_large_size_get(chunk, pageind) == oldsize); arena_mapbits_large_set(chunk, pageind+head_npages-1, 0, flag_dirty); arena_mapbits_large_set(chunk, pageind, newsize, flag_dirty); if (config_debug) { UNUSED size_t tail_npages = (oldsize - newsize) >> LG_PAGE; assert(arena_mapbits_large_size_get(chunk, pageind+head_npages+tail_npages-1) == 0); assert(arena_mapbits_dirty_get(chunk, pageind+head_npages+tail_npages-1) == flag_dirty); } arena_mapbits_large_set(chunk, pageind+head_npages, oldsize-newsize, flag_dirty); arena_run_dalloc(arena, (arena_run_t *)((uintptr_t)run + newsize), dirty, false); } static arena_run_t * arena_bin_runs_first(arena_bin_t *bin) { arena_chunk_map_t *mapelm = arena_run_tree_first(&bin->runs); if (mapelm != NULL) { arena_chunk_t *chunk; size_t pageind; arena_run_t *run; chunk = (arena_chunk_t *)CHUNK_ADDR2BASE(mapelm); pageind = ((((uintptr_t)mapelm - (uintptr_t)chunk->map) / sizeof(arena_chunk_map_t))) + map_bias; run = (arena_run_t *)((uintptr_t)chunk + (uintptr_t)((pageind - arena_mapbits_small_runind_get(chunk, pageind)) << LG_PAGE)); return (run); } return (NULL); } static void arena_bin_runs_insert(arena_bin_t *bin, arena_run_t *run) { arena_chunk_t *chunk = CHUNK_ADDR2BASE(run); size_t pageind = ((uintptr_t)run - (uintptr_t)chunk) >> LG_PAGE; arena_chunk_map_t *mapelm = arena_mapp_get(chunk, pageind); assert(arena_run_tree_search(&bin->runs, mapelm) == NULL); arena_run_tree_insert(&bin->runs, mapelm); } static void arena_bin_runs_remove(arena_bin_t *bin, arena_run_t *run) { arena_chunk_t *chunk = (arena_chunk_t *)CHUNK_ADDR2BASE(run); size_t pageind = ((uintptr_t)run - (uintptr_t)chunk) >> LG_PAGE; arena_chunk_map_t *mapelm = arena_mapp_get(chunk, pageind); assert(arena_run_tree_search(&bin->runs, mapelm) != NULL); arena_run_tree_remove(&bin->runs, mapelm); } static arena_run_t * arena_bin_nonfull_run_tryget(arena_bin_t *bin) { arena_run_t *run = arena_bin_runs_first(bin); if (run != NULL) { arena_bin_runs_remove(bin, run); if (config_stats) bin->stats.reruns++; } return (run); } static arena_run_t * arena_bin_nonfull_run_get(arena_t *arena, arena_bin_t *bin) { arena_run_t *run; size_t binind; arena_bin_info_t *bin_info; /* Look for a usable run. */ run = arena_bin_nonfull_run_tryget(bin); if (run != NULL) return (run); /* No existing runs have any space available. */ binind = arena_bin_index(arena, bin); bin_info = &arena_bin_info[binind]; /* Allocate a new run. */ malloc_mutex_unlock(&bin->lock); /******************************/ malloc_mutex_lock(&arena->lock); run = arena_run_alloc(arena, bin_info->run_size, false, binind, false); if (run != NULL) { bitmap_t *bitmap = (bitmap_t *)((uintptr_t)run + (uintptr_t)bin_info->bitmap_offset); /* Initialize run internals. */ VALGRIND_MAKE_MEM_UNDEFINED(run, bin_info->reg0_offset - bin_info->redzone_size); run->bin = bin; run->nextind = 0; run->nfree = bin_info->nregs; bitmap_init(bitmap, &bin_info->bitmap_info); } malloc_mutex_unlock(&arena->lock); /********************************/ malloc_mutex_lock(&bin->lock); if (run != NULL) { if (config_stats) { bin->stats.nruns++; bin->stats.curruns++; } return (run); } /* * arena_run_alloc() failed, but another thread may have made * sufficient memory available while this one dropped bin->lock above, * so search one more time. */ run = arena_bin_nonfull_run_tryget(bin); if (run != NULL) return (run); return (NULL); } /* Re-fill bin->runcur, then call arena_run_reg_alloc(). */ static void * arena_bin_malloc_hard(arena_t *arena, arena_bin_t *bin) { void *ret; size_t binind; arena_bin_info_t *bin_info; arena_run_t *run; binind = arena_bin_index(arena, bin); bin_info = &arena_bin_info[binind]; bin->runcur = NULL; run = arena_bin_nonfull_run_get(arena, bin); if (bin->runcur != NULL && bin->runcur->nfree > 0) { /* * Another thread updated runcur while this one ran without the * bin lock in arena_bin_nonfull_run_get(). */ assert(bin->runcur->nfree > 0); ret = arena_run_reg_alloc(bin->runcur, bin_info); if (run != NULL) { arena_chunk_t *chunk; /* * arena_run_alloc() may have allocated run, or it may * have pulled run from the bin's run tree. Therefore * it is unsafe to make any assumptions about how run * has previously been used, and arena_bin_lower_run() * must be called, as if a region were just deallocated * from the run. */ chunk = (arena_chunk_t *)CHUNK_ADDR2BASE(run); if (run->nfree == bin_info->nregs) arena_dalloc_bin_run(arena, chunk, run, bin); else arena_bin_lower_run(arena, chunk, run, bin); } return (ret); } if (run == NULL) return (NULL); bin->runcur = run; assert(bin->runcur->nfree > 0); return (arena_run_reg_alloc(bin->runcur, bin_info)); } void arena_prof_accum(arena_t *arena, uint64_t accumbytes) { cassert(config_prof); if (config_prof && prof_interval != 0) { arena->prof_accumbytes += accumbytes; if (arena->prof_accumbytes >= prof_interval) { prof_idump(); arena->prof_accumbytes -= prof_interval; } } } void arena_tcache_fill_small(arena_t *arena, tcache_bin_t *tbin, size_t binind, uint64_t prof_accumbytes) { unsigned i, nfill; arena_bin_t *bin; arena_run_t *run; void *ptr; assert(tbin->ncached == 0); if (config_prof) { malloc_mutex_lock(&arena->lock); arena_prof_accum(arena, prof_accumbytes); malloc_mutex_unlock(&arena->lock); } bin = &arena->bins[binind]; malloc_mutex_lock(&bin->lock); for (i = 0, nfill = (tcache_bin_info[binind].ncached_max >> tbin->lg_fill_div); i < nfill; i++) { if ((run = bin->runcur) != NULL && run->nfree > 0) ptr = arena_run_reg_alloc(run, &arena_bin_info[binind]); else ptr = arena_bin_malloc_hard(arena, bin); if (ptr == NULL) break; if (config_fill && opt_junk) { arena_alloc_junk_small(ptr, &arena_bin_info[binind], true); } /* Insert such that low regions get used first. */ tbin->avail[nfill - 1 - i] = ptr; } if (config_stats) { bin->stats.allocated += i * arena_bin_info[binind].reg_size; bin->stats.nmalloc += i; bin->stats.nrequests += tbin->tstats.nrequests; bin->stats.nfills++; tbin->tstats.nrequests = 0; } malloc_mutex_unlock(&bin->lock); tbin->ncached = i; } void arena_alloc_junk_small(void *ptr, arena_bin_info_t *bin_info, bool zero) { if (zero) { size_t redzone_size = bin_info->redzone_size; memset((void *)((uintptr_t)ptr - redzone_size), 0xa5, redzone_size); memset((void *)((uintptr_t)ptr + bin_info->reg_size), 0xa5, redzone_size); } else { memset((void *)((uintptr_t)ptr - bin_info->redzone_size), 0xa5, bin_info->reg_interval); } } void arena_dalloc_junk_small(void *ptr, arena_bin_info_t *bin_info) { size_t size = bin_info->reg_size; size_t redzone_size = bin_info->redzone_size; size_t i; bool error = false; for (i = 1; i <= redzone_size; i++) { unsigned byte; if ((byte = *(uint8_t *)((uintptr_t)ptr - i)) != 0xa5) { error = true; malloc_printf(": Corrupt redzone " "%zu byte%s before %p (size %zu), byte=%#x\n", i, (i == 1) ? "" : "s", ptr, size, byte); } } for (i = 0; i < redzone_size; i++) { unsigned byte; if ((byte = *(uint8_t *)((uintptr_t)ptr + size + i)) != 0xa5) { error = true; malloc_printf(": Corrupt redzone " "%zu byte%s after end of %p (size %zu), byte=%#x\n", i, (i == 1) ? "" : "s", ptr, size, byte); } } if (opt_abort && error) abort(); memset((void *)((uintptr_t)ptr - redzone_size), 0x5a, bin_info->reg_interval); } void * arena_malloc_small(arena_t *arena, size_t size, bool zero) { void *ret; arena_bin_t *bin; arena_run_t *run; size_t binind; binind = SMALL_SIZE2BIN(size); assert(binind < NBINS); bin = &arena->bins[binind]; size = arena_bin_info[binind].reg_size; malloc_mutex_lock(&bin->lock); if ((run = bin->runcur) != NULL && run->nfree > 0) ret = arena_run_reg_alloc(run, &arena_bin_info[binind]); else ret = arena_bin_malloc_hard(arena, bin); if (ret == NULL) { malloc_mutex_unlock(&bin->lock); return (NULL); } if (config_stats) { bin->stats.allocated += size; bin->stats.nmalloc++; bin->stats.nrequests++; } malloc_mutex_unlock(&bin->lock); if (config_prof && isthreaded == false) { malloc_mutex_lock(&arena->lock); arena_prof_accum(arena, size); malloc_mutex_unlock(&arena->lock); } if (zero == false) { if (config_fill) { if (opt_junk) { arena_alloc_junk_small(ret, &arena_bin_info[binind], false); } else if (opt_zero) memset(ret, 0, size); } } else { if (config_fill && opt_junk) { arena_alloc_junk_small(ret, &arena_bin_info[binind], true); } VALGRIND_MAKE_MEM_UNDEFINED(ret, size); memset(ret, 0, size); } return (ret); } void * arena_malloc_large(arena_t *arena, size_t size, bool zero) { void *ret; /* Large allocation. */ size = PAGE_CEILING(size); malloc_mutex_lock(&arena->lock); ret = (void *)arena_run_alloc(arena, size, true, BININD_INVALID, zero); if (ret == NULL) { malloc_mutex_unlock(&arena->lock); return (NULL); } if (config_stats) { arena->stats.nmalloc_large++; arena->stats.nrequests_large++; arena->stats.allocated_large += size; arena->stats.lstats[(size >> LG_PAGE) - 1].nmalloc++; arena->stats.lstats[(size >> LG_PAGE) - 1].nrequests++; arena->stats.lstats[(size >> LG_PAGE) - 1].curruns++; } if (config_prof) arena_prof_accum(arena, size); malloc_mutex_unlock(&arena->lock); if (zero == false) { if (config_fill) { if (opt_junk) memset(ret, 0xa5, size); else if (opt_zero) memset(ret, 0, size); } } return (ret); } /* Only handles large allocations that require more than page alignment. */ void * arena_palloc(arena_t *arena, size_t size, size_t alignment, bool zero) { void *ret; size_t alloc_size, leadsize, trailsize; arena_run_t *run; arena_chunk_t *chunk; assert((size & PAGE_MASK) == 0); alignment = PAGE_CEILING(alignment); alloc_size = size + alignment - PAGE; malloc_mutex_lock(&arena->lock); run = arena_run_alloc(arena, alloc_size, true, BININD_INVALID, zero); if (run == NULL) { malloc_mutex_unlock(&arena->lock); return (NULL); } chunk = (arena_chunk_t *)CHUNK_ADDR2BASE(run); leadsize = ALIGNMENT_CEILING((uintptr_t)run, alignment) - (uintptr_t)run; assert(alloc_size >= leadsize + size); trailsize = alloc_size - leadsize - size; ret = (void *)((uintptr_t)run + leadsize); if (leadsize != 0) { arena_run_trim_head(arena, chunk, run, alloc_size, alloc_size - leadsize); } if (trailsize != 0) { arena_run_trim_tail(arena, chunk, ret, size + trailsize, size, false); } if (config_stats) { arena->stats.nmalloc_large++; arena->stats.nrequests_large++; arena->stats.allocated_large += size; arena->stats.lstats[(size >> LG_PAGE) - 1].nmalloc++; arena->stats.lstats[(size >> LG_PAGE) - 1].nrequests++; arena->stats.lstats[(size >> LG_PAGE) - 1].curruns++; } malloc_mutex_unlock(&arena->lock); if (config_fill && zero == false) { if (opt_junk) memset(ret, 0xa5, size); else if (opt_zero) memset(ret, 0, size); } return (ret); } void arena_prof_promoted(const void *ptr, size_t size) { arena_chunk_t *chunk; size_t pageind, binind; cassert(config_prof); assert(ptr != NULL); assert(CHUNK_ADDR2BASE(ptr) != ptr); assert(isalloc(ptr, false) == PAGE); assert(isalloc(ptr, true) == PAGE); assert(size <= SMALL_MAXCLASS); chunk = (arena_chunk_t *)CHUNK_ADDR2BASE(ptr); pageind = ((uintptr_t)ptr - (uintptr_t)chunk) >> LG_PAGE; binind = SMALL_SIZE2BIN(size); assert(binind < NBINS); arena_mapbits_large_binind_set(chunk, pageind, binind); assert(isalloc(ptr, false) == PAGE); assert(isalloc(ptr, true) == size); } static void arena_dissociate_bin_run(arena_chunk_t *chunk, arena_run_t *run, arena_bin_t *bin) { /* Dissociate run from bin. */ if (run == bin->runcur) bin->runcur = NULL; else { size_t binind = arena_bin_index(chunk->arena, bin); arena_bin_info_t *bin_info = &arena_bin_info[binind]; if (bin_info->nregs != 1) { /* * This block's conditional is necessary because if the * run only contains one region, then it never gets * inserted into the non-full runs tree. */ arena_bin_runs_remove(bin, run); } } } static void arena_dalloc_bin_run(arena_t *arena, arena_chunk_t *chunk, arena_run_t *run, arena_bin_t *bin) { size_t binind; arena_bin_info_t *bin_info; size_t npages, run_ind, past; assert(run != bin->runcur); assert(arena_run_tree_search(&bin->runs, arena_mapp_get(chunk, ((uintptr_t)run-(uintptr_t)chunk)>>LG_PAGE)) == NULL); binind = arena_bin_index(chunk->arena, run->bin); bin_info = &arena_bin_info[binind]; malloc_mutex_unlock(&bin->lock); /******************************/ npages = bin_info->run_size >> LG_PAGE; run_ind = (size_t)(((uintptr_t)run - (uintptr_t)chunk) >> LG_PAGE); past = (size_t)(PAGE_CEILING((uintptr_t)run + (uintptr_t)bin_info->reg0_offset + (uintptr_t)(run->nextind * bin_info->reg_interval - bin_info->redzone_size) - (uintptr_t)chunk) >> LG_PAGE); malloc_mutex_lock(&arena->lock); /* * If the run was originally clean, and some pages were never touched, * trim the clean pages before deallocating the dirty portion of the * run. */ assert(arena_mapbits_dirty_get(chunk, run_ind) == arena_mapbits_dirty_get(chunk, run_ind+npages-1)); if (arena_mapbits_dirty_get(chunk, run_ind) == 0 && past - run_ind < npages) { /* Trim clean pages. Convert to large run beforehand. */ assert(npages > 0); arena_mapbits_large_set(chunk, run_ind, bin_info->run_size, 0); arena_mapbits_large_set(chunk, run_ind+npages-1, 0, 0); arena_run_trim_tail(arena, chunk, run, (npages << LG_PAGE), ((past - run_ind) << LG_PAGE), false); /* npages = past - run_ind; */ } arena_run_dalloc(arena, run, true, false); malloc_mutex_unlock(&arena->lock); /****************************/ malloc_mutex_lock(&bin->lock); if (config_stats) bin->stats.curruns--; } static void arena_bin_lower_run(arena_t *arena, arena_chunk_t *chunk, arena_run_t *run, arena_bin_t *bin) { /* * Make sure that if bin->runcur is non-NULL, it refers to the lowest * non-full run. It is okay to NULL runcur out rather than proactively * keeping it pointing at the lowest non-full run. */ if ((uintptr_t)run < (uintptr_t)bin->runcur) { /* Switch runcur. */ if (bin->runcur->nfree > 0) arena_bin_runs_insert(bin, bin->runcur); bin->runcur = run; if (config_stats) bin->stats.reruns++; } else arena_bin_runs_insert(bin, run); } void arena_dalloc_bin_locked(arena_t *arena, arena_chunk_t *chunk, void *ptr, arena_chunk_map_t *mapelm) { size_t pageind; arena_run_t *run; arena_bin_t *bin; arena_bin_info_t *bin_info; size_t size, binind; pageind = ((uintptr_t)ptr - (uintptr_t)chunk) >> LG_PAGE; run = (arena_run_t *)((uintptr_t)chunk + (uintptr_t)((pageind - arena_mapbits_small_runind_get(chunk, pageind)) << LG_PAGE)); bin = run->bin; binind = arena_ptr_small_binind_get(ptr, mapelm->bits); bin_info = &arena_bin_info[binind]; if (config_fill || config_stats) size = bin_info->reg_size; if (config_fill && opt_junk) arena_dalloc_junk_small(ptr, bin_info); arena_run_reg_dalloc(run, ptr); if (run->nfree == bin_info->nregs) { arena_dissociate_bin_run(chunk, run, bin); arena_dalloc_bin_run(arena, chunk, run, bin); } else if (run->nfree == 1 && run != bin->runcur) arena_bin_lower_run(arena, chunk, run, bin); if (config_stats) { bin->stats.allocated -= size; bin->stats.ndalloc++; } } void arena_dalloc_bin(arena_t *arena, arena_chunk_t *chunk, void *ptr, size_t pageind, arena_chunk_map_t *mapelm) { arena_run_t *run; arena_bin_t *bin; run = (arena_run_t *)((uintptr_t)chunk + (uintptr_t)((pageind - arena_mapbits_small_runind_get(chunk, pageind)) << LG_PAGE)); bin = run->bin; malloc_mutex_lock(&bin->lock); arena_dalloc_bin_locked(arena, chunk, ptr, mapelm); malloc_mutex_unlock(&bin->lock); } void arena_dalloc_small(arena_t *arena, arena_chunk_t *chunk, void *ptr, size_t pageind) { arena_chunk_map_t *mapelm; if (config_debug) { /* arena_ptr_small_binind_get() does extra sanity checking. */ assert(arena_ptr_small_binind_get(ptr, arena_mapbits_get(chunk, pageind)) != BININD_INVALID); } mapelm = arena_mapp_get(chunk, pageind); arena_dalloc_bin(arena, chunk, ptr, pageind, mapelm); } void arena_dalloc_large_locked(arena_t *arena, arena_chunk_t *chunk, void *ptr) { if (config_fill || config_stats) { size_t pageind = ((uintptr_t)ptr - (uintptr_t)chunk) >> LG_PAGE; size_t size = arena_mapbits_large_size_get(chunk, pageind); if (config_fill && config_stats && opt_junk) memset(ptr, 0x5a, size); if (config_stats) { arena->stats.ndalloc_large++; arena->stats.allocated_large -= size; arena->stats.lstats[(size >> LG_PAGE) - 1].ndalloc++; arena->stats.lstats[(size >> LG_PAGE) - 1].curruns--; } } arena_run_dalloc(arena, (arena_run_t *)ptr, true, false); } void arena_dalloc_large(arena_t *arena, arena_chunk_t *chunk, void *ptr) { malloc_mutex_lock(&arena->lock); arena_dalloc_large_locked(arena, chunk, ptr); malloc_mutex_unlock(&arena->lock); } static void arena_ralloc_large_shrink(arena_t *arena, arena_chunk_t *chunk, void *ptr, size_t oldsize, size_t size) { assert(size < oldsize); /* * Shrink the run, and make trailing pages available for other * allocations. */ malloc_mutex_lock(&arena->lock); arena_run_trim_tail(arena, chunk, (arena_run_t *)ptr, oldsize, size, true); if (config_stats) { arena->stats.ndalloc_large++; arena->stats.allocated_large -= oldsize; arena->stats.lstats[(oldsize >> LG_PAGE) - 1].ndalloc++; arena->stats.lstats[(oldsize >> LG_PAGE) - 1].curruns--; arena->stats.nmalloc_large++; arena->stats.nrequests_large++; arena->stats.allocated_large += size; arena->stats.lstats[(size >> LG_PAGE) - 1].nmalloc++; arena->stats.lstats[(size >> LG_PAGE) - 1].nrequests++; arena->stats.lstats[(size >> LG_PAGE) - 1].curruns++; } malloc_mutex_unlock(&arena->lock); } static bool arena_ralloc_large_grow(arena_t *arena, arena_chunk_t *chunk, void *ptr, size_t oldsize, size_t size, size_t extra, bool zero) { size_t pageind = ((uintptr_t)ptr - (uintptr_t)chunk) >> LG_PAGE; size_t npages = oldsize >> LG_PAGE; size_t followsize; assert(oldsize == arena_mapbits_large_size_get(chunk, pageind)); /* Try to extend the run. */ assert(size + extra > oldsize); malloc_mutex_lock(&arena->lock); if (pageind + npages < chunk_npages && arena_mapbits_allocated_get(chunk, pageind+npages) == 0 && (followsize = arena_mapbits_unallocated_size_get(chunk, pageind+npages)) >= size - oldsize) { /* * The next run is available and sufficiently large. Split the * following run, then merge the first part with the existing * allocation. */ size_t flag_dirty; size_t splitsize = (oldsize + followsize <= size + extra) ? followsize : size + extra - oldsize; arena_run_split(arena, (arena_run_t *)((uintptr_t)chunk + ((pageind+npages) << LG_PAGE)), splitsize, true, BININD_INVALID, zero); size = oldsize + splitsize; npages = size >> LG_PAGE; /* * Mark the extended run as dirty if either portion of the run * was dirty before allocation. This is rather pedantic, * because there's not actually any sequence of events that * could cause the resulting run to be passed to * arena_run_dalloc() with the dirty argument set to false * (which is when dirty flag consistency would really matter). */ flag_dirty = arena_mapbits_dirty_get(chunk, pageind) | arena_mapbits_dirty_get(chunk, pageind+npages-1); arena_mapbits_large_set(chunk, pageind, size, flag_dirty); arena_mapbits_large_set(chunk, pageind+npages-1, 0, flag_dirty); if (config_stats) { arena->stats.ndalloc_large++; arena->stats.allocated_large -= oldsize; arena->stats.lstats[(oldsize >> LG_PAGE) - 1].ndalloc++; arena->stats.lstats[(oldsize >> LG_PAGE) - 1].curruns--; arena->stats.nmalloc_large++; arena->stats.nrequests_large++; arena->stats.allocated_large += size; arena->stats.lstats[(size >> LG_PAGE) - 1].nmalloc++; arena->stats.lstats[(size >> LG_PAGE) - 1].nrequests++; arena->stats.lstats[(size >> LG_PAGE) - 1].curruns++; } malloc_mutex_unlock(&arena->lock); return (false); } malloc_mutex_unlock(&arena->lock); return (true); } /* * Try to resize a large allocation, in order to avoid copying. This will * always fail if growing an object, and the following run is already in use. */ static bool arena_ralloc_large(void *ptr, size_t oldsize, size_t size, size_t extra, bool zero) { size_t psize; psize = PAGE_CEILING(size + extra); if (psize == oldsize) { /* Same size class. */ if (config_fill && opt_junk && size < oldsize) { memset((void *)((uintptr_t)ptr + size), 0x5a, oldsize - size); } return (false); } else { arena_chunk_t *chunk; arena_t *arena; chunk = (arena_chunk_t *)CHUNK_ADDR2BASE(ptr); arena = chunk->arena; if (psize < oldsize) { /* Fill before shrinking in order avoid a race. */ if (config_fill && opt_junk) { memset((void *)((uintptr_t)ptr + size), 0x5a, oldsize - size); } arena_ralloc_large_shrink(arena, chunk, ptr, oldsize, psize); return (false); } else { bool ret = arena_ralloc_large_grow(arena, chunk, ptr, oldsize, PAGE_CEILING(size), psize - PAGE_CEILING(size), zero); if (config_fill && ret == false && zero == false && opt_zero) { memset((void *)((uintptr_t)ptr + oldsize), 0, size - oldsize); } return (ret); } } } void * arena_ralloc_no_move(void *ptr, size_t oldsize, size_t size, size_t extra, bool zero) { /* * Avoid moving the allocation if the size class can be left the same. */ if (oldsize <= arena_maxclass) { if (oldsize <= SMALL_MAXCLASS) { assert(arena_bin_info[SMALL_SIZE2BIN(oldsize)].reg_size == oldsize); if ((size + extra <= SMALL_MAXCLASS && SMALL_SIZE2BIN(size + extra) == SMALL_SIZE2BIN(oldsize)) || (size <= oldsize && size + extra >= oldsize)) { if (config_fill && opt_junk && size < oldsize) { memset((void *)((uintptr_t)ptr + size), 0x5a, oldsize - size); } return (ptr); } } else { assert(size <= arena_maxclass); if (size + extra > SMALL_MAXCLASS) { if (arena_ralloc_large(ptr, oldsize, size, extra, zero) == false) return (ptr); } } } /* Reallocation would require a move. */ return (NULL); } void * arena_ralloc(arena_t *arena, void *ptr, size_t oldsize, size_t size, size_t extra, size_t alignment, bool zero, bool try_tcache_alloc, bool try_tcache_dalloc) { void *ret; size_t copysize; /* Try to avoid moving the allocation. */ ret = arena_ralloc_no_move(ptr, oldsize, size, extra, zero); if (ret != NULL) return (ret); /* * size and oldsize are different enough that we need to move the * object. In that case, fall back to allocating new space and * copying. */ if (alignment != 0) { size_t usize = sa2u(size + extra, alignment); if (usize == 0) return (NULL); ret = ipallocx(usize, alignment, zero, try_tcache_alloc, arena); } else ret = arena_malloc(arena, size + extra, zero, try_tcache_alloc); if (ret == NULL) { if (extra == 0) return (NULL); /* Try again, this time without extra. */ if (alignment != 0) { size_t usize = sa2u(size, alignment); if (usize == 0) return (NULL); ret = ipallocx(usize, alignment, zero, try_tcache_alloc, arena); } else ret = arena_malloc(arena, size, zero, try_tcache_alloc); if (ret == NULL) return (NULL); } /* Junk/zero-filling were already done by ipalloc()/arena_malloc(). */ /* * Copy at most size bytes (not size+extra), since the caller has no * expectation that the extra bytes will be reliably preserved. */ copysize = (size < oldsize) ? size : oldsize; VALGRIND_MAKE_MEM_UNDEFINED(ret, copysize); memcpy(ret, ptr, copysize); iqallocx(ptr, try_tcache_dalloc); return (ret); } dss_prec_t arena_dss_prec_get(arena_t *arena) { dss_prec_t ret; malloc_mutex_lock(&arena->lock); ret = arena->dss_prec; malloc_mutex_unlock(&arena->lock); return (ret); } void arena_dss_prec_set(arena_t *arena, dss_prec_t dss_prec) { malloc_mutex_lock(&arena->lock); arena->dss_prec = dss_prec; malloc_mutex_unlock(&arena->lock); } void arena_stats_merge(arena_t *arena, const char **dss, size_t *nactive, size_t *ndirty, arena_stats_t *astats, malloc_bin_stats_t *bstats, malloc_large_stats_t *lstats) { unsigned i; malloc_mutex_lock(&arena->lock); *dss = dss_prec_names[arena->dss_prec]; *nactive += arena->nactive; *ndirty += arena->ndirty; astats->mapped += arena->stats.mapped; astats->npurge += arena->stats.npurge; astats->nmadvise += arena->stats.nmadvise; astats->purged += arena->stats.purged; astats->allocated_large += arena->stats.allocated_large; astats->nmalloc_large += arena->stats.nmalloc_large; astats->ndalloc_large += arena->stats.ndalloc_large; astats->nrequests_large += arena->stats.nrequests_large; for (i = 0; i < nlclasses; i++) { lstats[i].nmalloc += arena->stats.lstats[i].nmalloc; lstats[i].ndalloc += arena->stats.lstats[i].ndalloc; lstats[i].nrequests += arena->stats.lstats[i].nrequests; lstats[i].curruns += arena->stats.lstats[i].curruns; } malloc_mutex_unlock(&arena->lock); for (i = 0; i < NBINS; i++) { arena_bin_t *bin = &arena->bins[i]; malloc_mutex_lock(&bin->lock); bstats[i].allocated += bin->stats.allocated; bstats[i].nmalloc += bin->stats.nmalloc; bstats[i].ndalloc += bin->stats.ndalloc; bstats[i].nrequests += bin->stats.nrequests; if (config_tcache) { bstats[i].nfills += bin->stats.nfills; bstats[i].nflushes += bin->stats.nflushes; } bstats[i].nruns += bin->stats.nruns; bstats[i].reruns += bin->stats.reruns; bstats[i].curruns += bin->stats.curruns; malloc_mutex_unlock(&bin->lock); } } bool arena_new(arena_t *arena, unsigned ind) { unsigned i; arena_bin_t *bin; arena->ind = ind; arena->nthreads = 0; if (malloc_mutex_init(&arena->lock)) return (true); if (config_stats) { memset(&arena->stats, 0, sizeof(arena_stats_t)); arena->stats.lstats = (malloc_large_stats_t *)base_alloc(nlclasses * sizeof(malloc_large_stats_t)); if (arena->stats.lstats == NULL) return (true); memset(arena->stats.lstats, 0, nlclasses * sizeof(malloc_large_stats_t)); if (config_tcache) ql_new(&arena->tcache_ql); } if (config_prof) arena->prof_accumbytes = 0; arena->dss_prec = chunk_dss_prec_get(); /* Initialize chunks. */ arena_chunk_dirty_new(&arena->chunks_dirty); arena->spare = NULL; arena->nactive = 0; arena->ndirty = 0; arena->npurgatory = 0; arena_avail_tree_new(&arena->runs_avail); /* Initialize bins. */ for (i = 0; i < NBINS; i++) { bin = &arena->bins[i]; if (malloc_mutex_init(&bin->lock)) return (true); bin->runcur = NULL; arena_run_tree_new(&bin->runs); if (config_stats) memset(&bin->stats, 0, sizeof(malloc_bin_stats_t)); } return (false); } /* * Calculate bin_info->run_size such that it meets the following constraints: * * *) bin_info->run_size >= min_run_size * *) bin_info->run_size <= arena_maxclass * *) run header overhead <= RUN_MAX_OVRHD (or header overhead relaxed). * *) bin_info->nregs <= RUN_MAXREGS * * bin_info->nregs, bin_info->bitmap_offset, and bin_info->reg0_offset are also * calculated here, since these settings are all interdependent. */ static size_t bin_info_run_size_calc(arena_bin_info_t *bin_info, size_t min_run_size) { size_t pad_size; size_t try_run_size, good_run_size; uint32_t try_nregs, good_nregs; uint32_t try_hdr_size, good_hdr_size; uint32_t try_bitmap_offset, good_bitmap_offset; uint32_t try_ctx0_offset, good_ctx0_offset; uint32_t try_redzone0_offset, good_redzone0_offset; assert(min_run_size >= PAGE); assert(min_run_size <= arena_maxclass); /* * Determine redzone size based on minimum alignment and minimum * redzone size. Add padding to the end of the run if it is needed to * align the regions. The padding allows each redzone to be half the * minimum alignment; without the padding, each redzone would have to * be twice as large in order to maintain alignment. */ if (config_fill && opt_redzone) { size_t align_min = ZU(1) << (ffs(bin_info->reg_size) - 1); if (align_min <= REDZONE_MINSIZE) { bin_info->redzone_size = REDZONE_MINSIZE; pad_size = 0; } else { bin_info->redzone_size = align_min >> 1; pad_size = bin_info->redzone_size; } } else { bin_info->redzone_size = 0; pad_size = 0; } bin_info->reg_interval = bin_info->reg_size + (bin_info->redzone_size << 1); /* * Calculate known-valid settings before entering the run_size * expansion loop, so that the first part of the loop always copies * valid settings. * * The do..while loop iteratively reduces the number of regions until * the run header and the regions no longer overlap. A closed formula * would be quite messy, since there is an interdependency between the * header's mask length and the number of regions. */ try_run_size = min_run_size; try_nregs = ((try_run_size - sizeof(arena_run_t)) / bin_info->reg_interval) + 1; /* Counter-act try_nregs-- in loop. */ if (try_nregs > RUN_MAXREGS) { try_nregs = RUN_MAXREGS + 1; /* Counter-act try_nregs-- in loop. */ } do { try_nregs--; try_hdr_size = sizeof(arena_run_t); /* Pad to a long boundary. */ try_hdr_size = LONG_CEILING(try_hdr_size); try_bitmap_offset = try_hdr_size; /* Add space for bitmap. */ try_hdr_size += bitmap_size(try_nregs); if (config_prof && opt_prof && prof_promote == false) { /* Pad to a quantum boundary. */ try_hdr_size = QUANTUM_CEILING(try_hdr_size); try_ctx0_offset = try_hdr_size; /* Add space for one (prof_ctx_t *) per region. */ try_hdr_size += try_nregs * sizeof(prof_ctx_t *); } else try_ctx0_offset = 0; try_redzone0_offset = try_run_size - (try_nregs * bin_info->reg_interval) - pad_size; } while (try_hdr_size > try_redzone0_offset); /* run_size expansion loop. */ do { /* * Copy valid settings before trying more aggressive settings. */ good_run_size = try_run_size; good_nregs = try_nregs; good_hdr_size = try_hdr_size; good_bitmap_offset = try_bitmap_offset; good_ctx0_offset = try_ctx0_offset; good_redzone0_offset = try_redzone0_offset; /* Try more aggressive settings. */ try_run_size += PAGE; try_nregs = ((try_run_size - sizeof(arena_run_t) - pad_size) / bin_info->reg_interval) + 1; /* Counter-act try_nregs-- in loop. */ if (try_nregs > RUN_MAXREGS) { try_nregs = RUN_MAXREGS + 1; /* Counter-act try_nregs-- in loop. */ } do { try_nregs--; try_hdr_size = sizeof(arena_run_t); /* Pad to a long boundary. */ try_hdr_size = LONG_CEILING(try_hdr_size); try_bitmap_offset = try_hdr_size; /* Add space for bitmap. */ try_hdr_size += bitmap_size(try_nregs); if (config_prof && opt_prof && prof_promote == false) { /* Pad to a quantum boundary. */ try_hdr_size = QUANTUM_CEILING(try_hdr_size); try_ctx0_offset = try_hdr_size; /* * Add space for one (prof_ctx_t *) per region. */ try_hdr_size += try_nregs * sizeof(prof_ctx_t *); } try_redzone0_offset = try_run_size - (try_nregs * bin_info->reg_interval) - pad_size; } while (try_hdr_size > try_redzone0_offset); } while (try_run_size <= arena_maxclass && try_run_size <= arena_maxclass && RUN_MAX_OVRHD * (bin_info->reg_interval << 3) > RUN_MAX_OVRHD_RELAX && (try_redzone0_offset << RUN_BFP) > RUN_MAX_OVRHD * try_run_size && try_nregs < RUN_MAXREGS); assert(good_hdr_size <= good_redzone0_offset); /* Copy final settings. */ bin_info->run_size = good_run_size; bin_info->nregs = good_nregs; bin_info->bitmap_offset = good_bitmap_offset; bin_info->ctx0_offset = good_ctx0_offset; bin_info->reg0_offset = good_redzone0_offset + bin_info->redzone_size; assert(bin_info->reg0_offset - bin_info->redzone_size + (bin_info->nregs * bin_info->reg_interval) + pad_size == bin_info->run_size); return (good_run_size); } static void bin_info_init(void) { arena_bin_info_t *bin_info; size_t prev_run_size = PAGE; #define SIZE_CLASS(bin, delta, size) \ bin_info = &arena_bin_info[bin]; \ bin_info->reg_size = size; \ prev_run_size = bin_info_run_size_calc(bin_info, prev_run_size);\ bitmap_info_init(&bin_info->bitmap_info, bin_info->nregs); SIZE_CLASSES #undef SIZE_CLASS } void arena_boot(void) { size_t header_size; unsigned i; /* * Compute the header size such that it is large enough to contain the * page map. The page map is biased to omit entries for the header * itself, so some iteration is necessary to compute the map bias. * * 1) Compute safe header_size and map_bias values that include enough * space for an unbiased page map. * 2) Refine map_bias based on (1) to omit the header pages in the page * map. The resulting map_bias may be one too small. * 3) Refine map_bias based on (2). The result will be >= the result * from (2), and will always be correct. */ map_bias = 0; for (i = 0; i < 3; i++) { header_size = offsetof(arena_chunk_t, map) + (sizeof(arena_chunk_map_t) * (chunk_npages-map_bias)); map_bias = (header_size >> LG_PAGE) + ((header_size & PAGE_MASK) != 0); } assert(map_bias > 0); arena_maxclass = chunksize - (map_bias << LG_PAGE); bin_info_init(); } void arena_prefork(arena_t *arena) { unsigned i; malloc_mutex_prefork(&arena->lock); for (i = 0; i < NBINS; i++) malloc_mutex_prefork(&arena->bins[i].lock); } void arena_postfork_parent(arena_t *arena) { unsigned i; for (i = 0; i < NBINS; i++) malloc_mutex_postfork_parent(&arena->bins[i].lock); malloc_mutex_postfork_parent(&arena->lock); } void arena_postfork_child(arena_t *arena) { unsigned i; for (i = 0; i < NBINS; i++) malloc_mutex_postfork_child(&arena->bins[i].lock); malloc_mutex_postfork_child(&arena->lock); }