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--- libmalloc/libmalloc-166.220.1/src/thresholds.h
+++ /dev/null
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-/*
- * Copyright (c) 2015 Apple Inc. All rights reserved.
- *
- * @APPLE_LICENSE_HEADER_START@
- *
- * This file contains Original Code and/or Modifications of Original Code
- * as defined in and that are subject to the Apple Public Source License
- * Version 2.0 (the 'License'). You may not use this file except in
- * compliance with the License. Please obtain a copy of the License at
- * http://www.opensource.apple.com/apsl/ and read it before using this
- * file.
- *
- * The Original Code and all software distributed under the License are
- * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
- * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
- * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
- * Please see the License for the specific language governing rights and
- * limitations under the License.
- *
- * @APPLE_LICENSE_HEADER_END@
- */
-
-#ifndef __THRESHOLDS_H
-#define __THRESHOLDS_H
-
-/*
- * Tiny region size definitions; these are split into quanta of 16 bytes,
- * 64520 blocks is the magical value of how many quanta we can fit in a 1mb
- * region including the region trailer and metadata.
- */
-#define SHIFT_TINY_QUANTUM 4
-#define SHIFT_TINY_CEIL_BLOCKS 16 // ceil(log2(NUM_TINY_BLOCKS))
-#define TINY_QUANTUM (1 << SHIFT_TINY_QUANTUM)
-#define NUM_TINY_BLOCKS 64520
-#define NUM_TINY_CEIL_BLOCKS (1 << SHIFT_TINY_CEIL_BLOCKS)
-
-/*
- * Small region size definitions.
- *
- * We can only represent up to 1<<15 for msize; but we choose to stay
- * even below that to avoid the convention msize=0 => msize = (1<<15)
- */
-#define SHIFT_SMALL_QUANTUM (SHIFT_TINY_QUANTUM + 5) // 9
-#define SMALL_QUANTUM (1 << SHIFT_SMALL_QUANTUM) // 512 bytes
-#define SHIFT_SMALL_CEIL_BLOCKS 14 // ceil(log2(NUM_SMALL_BLOCKs))
-#define NUM_SMALL_BLOCKS 16319
-#define NUM_SMALL_CEIL_BLOCKS (1 << SHIFT_SMALL_CEIL_BLOCKS)
-#define SMALL_BLOCKS_ALIGN (SHIFT_SMALL_CEIL_BLOCKS + SHIFT_SMALL_QUANTUM) // 23
-
-#if MALLOC_TARGET_64BIT
-#define NUM_TINY_SLOTS 64 // number of slots for free-lists
-#else // MALLOC_TARGET_64BIT
-#define NUM_TINY_SLOTS 32 // number of slots for free-lists
-#endif // MALLOC_TARGET_64BIT
-
-/*
- * The threshold above which we start allocating from the small
- * magazines. Computed from the largest allocation we can make
- * in the tiny region (currently 1008 bytes on 64-bit, and
- * 496 bytes on 32-bit).
- */
-#define SMALL_THRESHOLD ((NUM_TINY_SLOTS - 1) * TINY_QUANTUM)
-
-/*
- * The threshold above which we start allocating from the large
- * "region" (ie. direct vm_allocates). The LARGEMEM size is used
- * on macOS and 64bit iOS with 16k pages, > 2gb and > 2 cores once
- * CONFIG_SMALL_CUTOFF_DYNAMIC is enabled (TODO: rdar://problem/35395572)
- * Must be a multiple of SMALL_QUANTUM (512 bytes)
- */
-#if MALLOC_TARGET_IOS
-#if MALLOC_TARGET_64BIT
-#define LARGE_THRESHOLD (15 * 1024) // <1 * 16k pages
-#define LARGE_THRESHOLD_LARGEMEM (64 * 1024) // 4 * 16k pages
-#else
-#define LARGE_THRESHOLD (15 * 1024) // <4 * 4k pages
-#define LARGE_THRESHOLD_LARGEMEM (64 * 1024) // 16 * 4k pages
-#endif
-#else
-#define LARGE_THRESHOLD (15 * 1024) // <4 * 4k pages
-#define LARGE_THRESHOLD_LARGEMEM (127 * 1024) // <32 * 4k pages
-#endif
-
-/*
- * The number of slots in the free-list for small blocks. To avoid going to
- * vm system as often on large memory machines, increase the number of free list
- * spots above some amount of RAM installed in the system.
- */
-#define NUM_SMALL_SLOTS (LARGE_THRESHOLD >> SHIFT_SMALL_QUANTUM)
-#define NUM_SMALL_SLOTS_LARGEMEM (LARGE_THRESHOLD_LARGEMEM >> SHIFT_SMALL_QUANTUM)
-
-/*
- * When all memory is touched after a copy, vm_copy() is always a lose
- * But if the memory is only read, vm_copy() wins over memmove() at 3 or 4 pages
- * (on a G3/300MHz)
- *
- * This must be >= LARGE_THRESHOLD
- */
-#if MALLOC_TARGET_IOS && MALLOC_TARGET_64BIT
-#define VM_COPY_THRESHOLD (48 * 1024) // 3 * 16k pages
-#define VM_COPY_THRESHOLD_LARGEMEM (96 * 1024) // 6 * 16k pages
-#else
-#define VM_COPY_THRESHOLD (40 * 1024) // 10 * 4k pages
-#define VM_COPY_THRESHOLD_LARGEMEM (128 * 1024) // 32 * 4k pages
-#endif
-
-/*
- * Large entry cache (death row) sizes. The large cache is bounded with
- * an overall top limit size, each entry is allowed a given slice of
- * that limit.
- */
-#if MALLOC_TARGET_64BIT
-#define LARGE_ENTRY_CACHE_SIZE 16
-#define LARGE_CACHE_SIZE_LIMIT ((vm_size_t)0x80000000) /* 2Gb */
-#define LARGE_CACHE_SIZE_ENTRY_LIMIT (LARGE_CACHE_SIZE_LIMIT / LARGE_ENTRY_CACHE_SIZE)
-#else // MALLOC_TARGET_64BIT
-#define LARGE_ENTRY_CACHE_SIZE 8
-#define LARGE_CACHE_SIZE_LIMIT ((vm_size_t)0x02000000) /* 32Mb */
-#define LARGE_CACHE_SIZE_ENTRY_LIMIT (LARGE_CACHE_SIZE_LIMIT / LARGE_ENTRY_CACHE_SIZE)
-#endif // MALLOC_TARGET_64BIT
-
-/*
- * Large entry cache (death row) "flotsam" limits. Until the large cache
- * contains at least "high" bytes, the cache is not cleaned under memory
- * pressure. After that, memory pressure notifications cause cache cleaning
- * until the large cache drops below the "low" limit.
- */
-#define SZONE_FLOTSAM_THRESHOLD_LOW (1024 * 512)
-#define SZONE_FLOTSAM_THRESHOLD_HIGH (1024 * 1024)
-
-/*
- * The magazine freelist array must be large enough to accomdate the allocation
- * granularity of both the tiny and small allocators. In addition, the last
- * slot in the list is special and reserved for coalesced regions bigger than
- * the overall max allocation size of the allocator.
- */
-#define MAGAZINE_FREELIST_SLOTS (NUM_SMALL_SLOTS_LARGEMEM + 1)
-#define MAGAZINE_FREELIST_BITMAP_WORDS ((MAGAZINE_FREELIST_SLOTS + 31) >> 5)
-
-/*
- * Density threshold used in determining the level of emptiness before
- * moving regions to the recirc depot.
- */
-#define DENSITY_THRESHOLD(a) \
- ((a) - ((a) >> 2)) // "Emptiness" f = 0.25, so "Density" is (1 - f)*a. Generally: ((a) - ((a) >> -log2(f)))
-
-/*
- * Minimum number of regions to retain in a recirc depot.
- */
-#define DEFAULT_RECIRC_RETAINED_REGIONS 2
-
-/* Sanity checks. */
-
-MALLOC_STATIC_ASSERT(NUM_SMALL_SLOTS_LARGEMEM == LARGE_THRESHOLD_LARGEMEM >> SHIFT_SMALL_QUANTUM,
- "NUM_SMALL_SLOTS_LARGEMEM must match LARGE_THRESHOLD_LARGEMEM >> SHIFT_SMALL_QUANTUM");
-
-MALLOC_STATIC_ASSERT(NUM_TINY_SLOTS <= NUM_SMALL_SLOTS_LARGEMEM,
- "NUM_TINY_SLOTS must be less than or equal to NUM_SMALL_SLOTS_LARGEMEM");
-
-MALLOC_STATIC_ASSERT((LARGE_THRESHOLD % SMALL_QUANTUM) == 0,
- "LARGE_THRESHOLD must be a multiple of SMALL_QUANTUM");
-MALLOC_STATIC_ASSERT((LARGE_THRESHOLD_LARGEMEM % SMALL_QUANTUM) == 0,
- "LARGE_THRESHOLD_LARGEMEM must be a multiple of SMALL_QUANTUM");
-
-MALLOC_STATIC_ASSERT((LARGE_THRESHOLD / SMALL_QUANTUM) <= NUM_SMALL_SLOTS,
- "LARGE_THRESHOLD must be less than NUM_SMALL_SLOTS * SMALL_QUANTUM");
-MALLOC_STATIC_ASSERT((LARGE_THRESHOLD_LARGEMEM / SMALL_QUANTUM) <= NUM_SMALL_SLOTS_LARGEMEM,
- "LARGE_THRESHOLD_LARGEMEM must be less than NUM_SMALL_SLOTS * SMALL_QUANTUM");
-
-MALLOC_STATIC_ASSERT(VM_COPY_THRESHOLD >= LARGE_THRESHOLD,
- "VM_COPY_THRESHOLD must be larger than LARGE_THRESHOLD");
-MALLOC_STATIC_ASSERT(VM_COPY_THRESHOLD_LARGEMEM >= LARGE_THRESHOLD_LARGEMEM,
- "VM_COPY_THRESHOLD_LARGEMEM must be larger than LARGE_THRESHOLD_LARGEMEM");
-
-#endif // __THRESHOLDS_H