src/allocator_internal.h

   1 /*
   2  * Copyright (c) 2012-2013 Apple Inc. All rights reserved.
   3  *
   4  * @APPLE_APACHE_LICENSE_HEADER_START@
   5  *
   6  * Licensed under the Apache License, Version 2.0 (the "License");
   7  * you may not use this file except in compliance with the License.
   8  * You may obtain a copy of the License at
   9  *
  10  *     http://www.apache.org/licenses/LICENSE-2.0
  11  *
  12  * Unless required by applicable law or agreed to in writing, software
  13  * distributed under the License is distributed on an "AS IS" BASIS,
  14  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  15  * See the License for the specific language governing permissions and
  16  * limitations under the License.
  17  *
  18  * @APPLE_APACHE_LICENSE_HEADER_END@
  19  */
  20
  21 /*
  22  * IMPORTANT: This header file describes INTERNAL interfaces to libdispatch
  23  * which are subject to change in future releases of Mac OS X. Any applications
  24  * relying on these interfaces WILL break.
  25  */
  26
  27 #ifndef __DISPATCH_ALLOCATOR_INTERNAL__
  28 #define __DISPATCH_ALLOCATOR_INTERNAL__
  29
  30 #ifndef DISPATCH_ALLOCATOR
  31 #if TARGET_OS_MAC && (defined(__LP64__) || TARGET_OS_EMBEDDED)
  32 #define DISPATCH_ALLOCATOR 1
  33 #endif
  34 #endif
  35
  36 #ifndef DISPATCH_USE_NANOZONE
  37 #if TARGET_OS_MAC && defined(__LP64__)
  38 #define DISPATCH_USE_NANOZONE 1
  39 #endif
  40 #endif
  41
  42 #ifndef DISPATCH_USE_MALLOCZONE
  43 #if (TARGET_OS_MAC && !DISPATCH_USE_NANOZONE) || \
  44                 (!TARGET_OS_MAC && HAVE_MALLOC_CREATE_ZONE)
  45 #define DISPATCH_USE_MALLOCZONE 1
  46 #endif
  47 #endif
  48
  49 #ifndef DISPATCH_CONTINUATION_MALLOC
  50 #if DISPATCH_USE_NANOZONE || !DISPATCH_ALLOCATOR
  51 #define DISPATCH_CONTINUATION_MALLOC 1
  52 #endif
  53 #endif
  54
  55 #if !DISPATCH_ALLOCATOR && !DISPATCH_CONTINUATION_MALLOC
  56 #error Invalid allocator configuration
  57 #endif
  58
  59 #if DISPATCH_ALLOCATOR && DISPATCH_CONTINUATION_MALLOC
  60 #define DISPATCH_ALLOC_NOINLINE DISPATCH_NOINLINE
  61 #else
  62 #define DISPATCH_ALLOC_NOINLINE
  63 #endif
  64
  65 #pragma mark -
  66 #pragma mark DISPATCH_ALLOCATOR
  67
  68 #if DISPATCH_ALLOCATOR
  69
  70 // Configuration here!
  71 #define NUM_CPU dispatch_hw_config(logical_cpus)
  72 #define MAGAZINES_PER_HEAP (NUM_CPU)
  73
  74 // Do you care about compaction or performance?
  75 #if TARGET_OS_EMBEDDED
  76 #define PACK_FIRST_PAGE_WITH_CONTINUATIONS 1
  77 #else
  78 #define PACK_FIRST_PAGE_WITH_CONTINUATIONS 0
  79 #endif
  80
  81 #ifndef PAGE_MAX_SIZE
  82 #define PAGE_MAX_SIZE PAGE_SIZE
  83 #endif
  84 #ifndef PAGE_MAX_MASK
  85 #define PAGE_MAX_MASK PAGE_MASK
  86 #endif
  87 #define DISPATCH_ALLOCATOR_PAGE_SIZE PAGE_MAX_SIZE
  88 #define DISPATCH_ALLOCATOR_PAGE_MASK PAGE_MAX_MASK
  89
  90
  91 #if TARGET_OS_EMBEDDED
  92 #define PAGES_PER_MAGAZINE 64
  93 #else
  94 #define PAGES_PER_MAGAZINE 512
  95 #endif
  96
  97 // Use the largest type your platform is comfortable doing atomic ops with.
  98 // TODO: rdar://11477843
  99 typedef unsigned long bitmap_t;
 100 #if defined(__LP64__)
 101 #define BYTES_PER_BITMAP 8
 102 #else
 103 #define BYTES_PER_BITMAP 4
 104 #endif
 105
 106 #define BITMAP_C(v) ((bitmap_t)(v))
 107 #define BITMAP_ALL_ONES (~BITMAP_C(0))
 108
 109 // Stop configuring.
 110
 111 #define CONTINUATIONS_PER_BITMAP (BYTES_PER_BITMAP * 8)
 112 #define BITMAPS_PER_SUPERMAP (BYTES_PER_SUPERMAP * 8)
 113
 114 #define BYTES_PER_MAGAZINE (PAGES_PER_MAGAZINE * DISPATCH_ALLOCATOR_PAGE_SIZE)
 115 #define CONSUMED_BYTES_PER_BITMAP (BYTES_PER_BITMAP + \
 116                 (DISPATCH_CONTINUATION_SIZE * CONTINUATIONS_PER_BITMAP))
 117
 118 #define BYTES_PER_SUPERMAP BYTES_PER_BITMAP
 119 #define CONSUMED_BYTES_PER_SUPERMAP (BYTES_PER_SUPERMAP + \
 120                 (BITMAPS_PER_SUPERMAP * CONSUMED_BYTES_PER_BITMAP))
 121
 122 #define BYTES_PER_HEAP (BYTES_PER_MAGAZINE * MAGAZINES_PER_HEAP)
 123
 124 #define BYTES_PER_PAGE DISPATCH_ALLOCATOR_PAGE_SIZE
 125 #define CONTINUATIONS_PER_PAGE (BYTES_PER_PAGE / DISPATCH_CONTINUATION_SIZE)
 126 #define BITMAPS_PER_PAGE (CONTINUATIONS_PER_PAGE / CONTINUATIONS_PER_BITMAP)
 127
 128 // Assumption: metadata will be only in the first page.
 129 #define SUPERMAPS_PER_MAGAZINE ((BYTES_PER_MAGAZINE - BYTES_PER_PAGE) / \
 130                 CONSUMED_BYTES_PER_SUPERMAP)
 131 #define BITMAPS_PER_MAGAZINE (SUPERMAPS_PER_MAGAZINE * BITMAPS_PER_SUPERMAP)
 132 #define CONTINUATIONS_PER_MAGAZINE \
 133                 (BITMAPS_PER_MAGAZINE * CONTINUATIONS_PER_BITMAP)
 134
 135 #define HEAP_MASK (~(uintptr_t)(BYTES_PER_HEAP - 1))
 136 #define MAGAZINE_MASK (~(uintptr_t)(BYTES_PER_MAGAZINE - 1))
 137
 138 // this will round up such that first_bitmap_in_same_page() can mask the address
 139 // of a bitmap_t in the maps to obtain the first bitmap for that same page
 140 #define ROUND_UP_TO_BITMAP_ALIGNMENT(x) \
 141                 (((x) + ((BITMAPS_PER_PAGE * BYTES_PER_BITMAP) - 1u)) & \
 142                 ~((BITMAPS_PER_PAGE * BYTES_PER_BITMAP) - 1u))
 143 // Since these are both powers of two, we end up with not only the max alignment,
 144 // but happily the least common multiple, which will be the greater of the two.
 145 #define ROUND_UP_TO_BITMAP_ALIGNMENT_AND_CONTINUATION_SIZE(x) (ROUND_UP_TO_CONTINUATION_SIZE(ROUND_UP_TO_BITMAP_ALIGNMENT(x)))
 146 #define PADDING_TO_BITMAP_ALIGNMENT_AND_CONTINUATION_SIZE(x) (ROUND_UP_TO_BITMAP_ALIGNMENT_AND_CONTINUATION_SIZE(x) - (x))
 147
 148 #define PADDING_TO_CONTINUATION_SIZE(x) (ROUND_UP_TO_CONTINUATION_SIZE(x) - (x))
 149
 150 #if defined(__LP64__)
 151 #define SIZEOF_HEADER 16
 152 #else
 153 #define SIZEOF_HEADER 8
 154 #endif
 155
 156 #define SIZEOF_SUPERMAPS (BYTES_PER_SUPERMAP * SUPERMAPS_PER_MAGAZINE)
 157 #define SIZEOF_MAPS (BYTES_PER_BITMAP * BITMAPS_PER_SUPERMAP * \
 158                 SUPERMAPS_PER_MAGAZINE)
 159
 160 // header is expected to end on supermap's required alignment
 161 #define HEADER_TO_SUPERMAPS_PADDING 0
 162 // we want to align the maps to a continuation size, but we must also have proper padding
 163 // so that we can perform first_bitmap_in_same_page()
 164 #define SUPERMAPS_TO_MAPS_PADDING (PADDING_TO_BITMAP_ALIGNMENT_AND_CONTINUATION_SIZE( \
 165                 SIZEOF_SUPERMAPS + HEADER_TO_SUPERMAPS_PADDING + SIZEOF_HEADER))
 166
 167 #define MAPS_TO_FPMAPS_PADDING (PADDING_TO_CONTINUATION_SIZE(SIZEOF_MAPS))
 168
 169 #define BYTES_LEFT_IN_FIRST_PAGE (BYTES_PER_PAGE - \
 170                 (SIZEOF_HEADER + HEADER_TO_SUPERMAPS_PADDING + SIZEOF_SUPERMAPS + \
 171                 SUPERMAPS_TO_MAPS_PADDING + SIZEOF_MAPS + MAPS_TO_FPMAPS_PADDING))
 172
 173 #if PACK_FIRST_PAGE_WITH_CONTINUATIONS
 174
 175 #define FULL_BITMAPS_IN_FIRST_PAGE \
 176                 (BYTES_LEFT_IN_FIRST_PAGE / CONSUMED_BYTES_PER_BITMAP)
 177 #define REMAINDER_IN_FIRST_PAGE (BYTES_LEFT_IN_FIRST_PAGE - \
 178                 (FULL_BITMAPS_IN_FIRST_PAGE * CONSUMED_BYTES_PER_BITMAP) - \
 179                 (FULL_BITMAPS_IN_FIRST_PAGE ? 0 : \
 180                 ROUND_UP_TO_CONTINUATION_SIZE(BYTES_PER_BITMAP)))
 181
 182 #define REMAINDERED_CONTINUATIONS_IN_FIRST_PAGE \
 183                 (REMAINDER_IN_FIRST_PAGE / DISPATCH_CONTINUATION_SIZE)
 184 #define CONTINUATIONS_IN_FIRST_PAGE (FULL_BITMAPS_IN_FIRST_PAGE * \
 185                 CONTINUATIONS_PER_BITMAP) + REMAINDERED_CONTINUATIONS_IN_FIRST_PAGE
 186 #define BITMAPS_IN_FIRST_PAGE (FULL_BITMAPS_IN_FIRST_PAGE + \
 187                 (REMAINDERED_CONTINUATIONS_IN_FIRST_PAGE == 0 ? 0 : 1))
 188
 189 #define FPMAPS_TO_FPCONTS_PADDING (PADDING_TO_CONTINUATION_SIZE(\
 190                 BYTES_PER_BITMAP * BITMAPS_IN_FIRST_PAGE))
 191
 192 #else // PACK_FIRST_PAGE_WITH_CONTINUATIONS
 193
 194 #define MAPS_TO_CONTS_PADDING BYTES_LEFT_IN_FIRST_PAGE
 195
 196 #endif // PACK_FIRST_PAGE_WITH_CONTINUATIONS
 197
 198 #define AFTER_CONTS_PADDING (BYTES_PER_MAGAZINE - (BYTES_PER_PAGE + \
 199                 (DISPATCH_CONTINUATION_SIZE * CONTINUATIONS_PER_MAGAZINE)))
 200
 201 // This is the object our allocator allocates: a chunk of memory rounded up
 202 // from sizeof(struct dispatch_continuation_s) to the cacheline size, so
 203 // unrelated continuations don't share cachelines. It'd be nice if
 204 // dispatch_continuation_s included this rounding/padding, but it doesn't.
 205 typedef char padded_continuation[DISPATCH_CONTINUATION_SIZE];
 206
 207 // A dispatch_heap_t is the base address of an array of dispatch_magazine_s,
 208 // one magazine per CPU.
 209 typedef struct dispatch_magazine_s * dispatch_heap_t;
 210
 211 struct dispatch_magazine_header_s {
 212         // Link to the next heap in the chain. Only used in magazine 0's header
 213         dispatch_heap_t dh_next;
 214
 215         // Points to the first bitmap in the page where this CPU successfully
 216         // allocated a continuation last time. Only used in the first heap.
 217         bitmap_t *last_found_page;
 218 };
 219
 220 // A magazine is a complex data structure. It must be exactly
 221 // PAGES_PER_MAGAZINE * PAGE_SIZE bytes long, and that value must be a
 222 // power of 2. (See magazine_for_continuation()).
 223 struct dispatch_magazine_s {
 224         // See above.
 225         struct dispatch_magazine_header_s header;
 226
 227         // Align supermaps as needed.
 228 #if HEADER_TO_SUPERMAPS_PADDING > 0
 229         char _pad0[HEADER_TO_SUPERMAPS_PADDING];
 230 #endif
 231
 232         // Second-level bitmap; each set bit means a bitmap_t in maps[][]
 233         // is completely full (and can be skipped while searching).
 234         bitmap_t supermaps[SUPERMAPS_PER_MAGAZINE];
 235
 236         // Align maps to a cacheline.
 237 #if SUPERMAPS_TO_MAPS_PADDING > 0
 238         char _pad1[SUPERMAPS_TO_MAPS_PADDING];
 239 #endif
 240
 241         // Each bit in maps[][] is the free/used state of a member of conts[][][].
 242         bitmap_t maps[SUPERMAPS_PER_MAGAZINE][BITMAPS_PER_SUPERMAP];
 243
 244         // Align fp_maps to a cacheline.
 245 #if MAPS_TO_FPMAPS_PADDING > 0
 246         char _pad2[MAPS_TO_FPMAPS_PADDING];
 247 #endif
 248
 249 #if PACK_FIRST_PAGE_WITH_CONTINUATIONS
 250         // Bitmaps for the continuations that live in the first page, which
 251         // are treated specially (they have faster search code).
 252         bitmap_t fp_maps[BITMAPS_IN_FIRST_PAGE];
 253
 254         // Align fp_conts to cacheline.
 255 #if FPMAPS_TO_FPCONTS_PADDING > 0
 256         char _pad3[FPMAPS_TO_FPCONTS_PADDING];
 257 #endif
 258
 259         // Continuations that live in the first page.
 260         padded_continuation fp_conts[CONTINUATIONS_IN_FIRST_PAGE];
 261
 262 #else // PACK_FIRST_PAGE_WITH_CONTINUATIONS
 263
 264 #if MAPS_TO_CONTS_PADDING > 0
 265         char _pad4[MAPS_TO_CONTS_PADDING];
 266 #endif
 267 #endif // PACK_FIRST_PAGE_WITH_CONTINUATIONS
 268
 269         // This is the big array of continuations.
 270         // This must start on a page boundary.
 271         padded_continuation conts[SUPERMAPS_PER_MAGAZINE][BITMAPS_PER_SUPERMAP]
 272                         [CONTINUATIONS_PER_BITMAP];
 273
 274         // Fill the unused space to exactly BYTES_PER_MAGAZINE
 275 #if AFTER_CONTS_PADDING > 0
 276         char _pad5[AFTER_CONTS_PADDING];
 277 #endif
 278 };
 279
 280 #if DISPATCH_DEBUG
 281 #define DISPATCH_ALLOCATOR_SCRIBBLE ((uintptr_t)0xAFAFAFAFAFAFAFAF)
 282 #endif
 283
 284 #endif // DISPATCH_ALLOCATOR
 285
 286 #endif // __DISPATCH_ALLOCATOR_INTERNAL__