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 #if TARGET_IPHONE_SIMULATOR && IPHONE_SIMULATOR_HOST_MIN_VERSION_REQUIRED < 1090
  37 #undef DISPATCH_USE_NANOZONE
  38 #define DISPATCH_USE_NANOZONE 0
  39 #endif
  40 #ifndef DISPATCH_USE_NANOZONE
  41 #if TARGET_OS_MAC && defined(__LP64__) && \
  42                 (__MAC_OS_X_VERSION_MIN_REQUIRED >= 1090 || \
  43                 __IPHONE_OS_VERSION_MIN_REQUIRED >= 70000)
  44 #define DISPATCH_USE_NANOZONE 1
  45 #endif
  46 #endif
  47
  48 #ifndef DISPATCH_USE_MALLOCZONE
  49 #if (TARGET_OS_MAC && !DISPATCH_USE_NANOZONE) || \
  50                 (!TARGET_OS_MAC && HAVE_MALLOC_CREATE_ZONE)
  51 #define DISPATCH_USE_MALLOCZONE 1
  52 #endif
  53 #endif
  54
  55 #ifndef DISPATCH_CONTINUATION_MALLOC
  56 #if DISPATCH_USE_NANOZONE || !DISPATCH_ALLOCATOR
  57 #define DISPATCH_CONTINUATION_MALLOC 1
  58 #endif
  59 #endif
  60
  61 #if !DISPATCH_ALLOCATOR && !DISPATCH_CONTINUATION_MALLOC
  62 #error Invalid allocator configuration
  63 #endif
  64
  65 #if DISPATCH_ALLOCATOR && DISPATCH_CONTINUATION_MALLOC
  66 #define DISPATCH_ALLOC_NOINLINE DISPATCH_NOINLINE
  67 #else
  68 #define DISPATCH_ALLOC_NOINLINE
  69 #endif
  70
  71 #pragma mark -
  72 #pragma mark DISPATCH_ALLOCATOR
  73
  74 #if DISPATCH_ALLOCATOR
  75
  76 // Configuration here!
  77 #define NUM_CPU _dispatch_hw_config.cc_max_logical
  78 #define MAGAZINES_PER_HEAP (NUM_CPU)
  79
  80 // Do you care about compaction or performance?
  81 #if TARGET_OS_EMBEDDED
  82 #define PACK_FIRST_PAGE_WITH_CONTINUATIONS 1
  83 #else
  84 #define PACK_FIRST_PAGE_WITH_CONTINUATIONS 0
  85 #endif
  86
  87 #if TARGET_OS_EMBEDDED
  88 #define PAGES_PER_MAGAZINE 64
  89 #else
  90 #define PAGES_PER_MAGAZINE 512
  91 #endif
  92
  93 // Use the largest type your platform is comfortable doing atomic ops with.
  94 #if defined(__x86_64__) // TODO: rdar://11477843
  95 typedef unsigned long bitmap_t;
  96 #define BYTES_PER_BITMAP 8
  97 #else
  98 typedef uint32_t bitmap_t;
  99 #define BYTES_PER_BITMAP 4
 100 #endif
 101
 102 #define BITMAP_C(v) ((bitmap_t)(v))
 103 #define BITMAP_ALL_ONES (~BITMAP_C(0))
 104
 105 // Stop configuring.
 106
 107 #define CONTINUATIONS_PER_BITMAP (BYTES_PER_BITMAP * 8)
 108 #define BITMAPS_PER_SUPERMAP (BYTES_PER_SUPERMAP * 8)
 109
 110 #define BYTES_PER_MAGAZINE (PAGES_PER_MAGAZINE * PAGE_SIZE)
 111 #define CONSUMED_BYTES_PER_BITMAP (BYTES_PER_BITMAP + \
 112                 (DISPATCH_CONTINUATION_SIZE * CONTINUATIONS_PER_BITMAP))
 113
 114 #define BYTES_PER_SUPERMAP BYTES_PER_BITMAP
 115 #define CONSUMED_BYTES_PER_SUPERMAP (BYTES_PER_SUPERMAP + \
 116                 (BITMAPS_PER_SUPERMAP * CONSUMED_BYTES_PER_BITMAP))
 117
 118 #define BYTES_PER_HEAP (BYTES_PER_MAGAZINE * MAGAZINES_PER_HEAP)
 119
 120 #define BYTES_PER_PAGE PAGE_SIZE
 121 #define CONTINUATIONS_PER_PAGE (BYTES_PER_PAGE / DISPATCH_CONTINUATION_SIZE)
 122 #define BITMAPS_PER_PAGE (CONTINUATIONS_PER_PAGE / CONTINUATIONS_PER_BITMAP)
 123
 124 // Assumption: metadata will be only in the first page.
 125 #define SUPERMAPS_PER_MAGAZINE ((BYTES_PER_MAGAZINE - BYTES_PER_PAGE) / \
 126                 CONSUMED_BYTES_PER_SUPERMAP)
 127 #define BITMAPS_PER_MAGAZINE (SUPERMAPS_PER_MAGAZINE * BITMAPS_PER_SUPERMAP)
 128 #define CONTINUATIONS_PER_MAGAZINE \
 129                 (BITMAPS_PER_MAGAZINE * CONTINUATIONS_PER_BITMAP)
 130
 131 #define HEAP_MASK (~(uintptr_t)(BYTES_PER_HEAP - 1))
 132 #define MAGAZINE_MASK (~(uintptr_t)(BYTES_PER_MAGAZINE - 1))
 133
 134 #define PADDING_TO_CONTINUATION_SIZE(x) (ROUND_UP_TO_CONTINUATION_SIZE(x) - (x))
 135
 136 #if defined(__LP64__)
 137 #define SIZEOF_HEADER 16
 138 #else
 139 #define SIZEOF_HEADER 8
 140 #endif
 141
 142 #define SIZEOF_SUPERMAPS (BYTES_PER_SUPERMAP * SUPERMAPS_PER_MAGAZINE)
 143 #define SIZEOF_MAPS (BYTES_PER_BITMAP * BITMAPS_PER_SUPERMAP * \
 144                 SUPERMAPS_PER_MAGAZINE)
 145
 146 // header is expected to end on supermap's required alignment
 147 #define HEADER_TO_SUPERMAPS_PADDING 0
 148 #define SUPERMAPS_TO_MAPS_PADDING (PADDING_TO_CONTINUATION_SIZE( \
 149                 SIZEOF_SUPERMAPS + HEADER_TO_SUPERMAPS_PADDING + SIZEOF_HEADER))
 150 #define MAPS_TO_FPMAPS_PADDING (PADDING_TO_CONTINUATION_SIZE(SIZEOF_MAPS))
 151
 152 #define BYTES_LEFT_IN_FIRST_PAGE (BYTES_PER_PAGE - \
 153                 (SIZEOF_HEADER + HEADER_TO_SUPERMAPS_PADDING + SIZEOF_SUPERMAPS + \
 154                 SUPERMAPS_TO_MAPS_PADDING + SIZEOF_MAPS + MAPS_TO_FPMAPS_PADDING))
 155
 156 #if PACK_FIRST_PAGE_WITH_CONTINUATIONS
 157
 158 #define FULL_BITMAPS_IN_FIRST_PAGE \
 159                 (BYTES_LEFT_IN_FIRST_PAGE / CONSUMED_BYTES_PER_BITMAP)
 160 #define REMAINDER_IN_FIRST_PAGE (BYTES_LEFT_IN_FIRST_PAGE - \
 161                 (FULL_BITMAPS_IN_FIRST_PAGE * CONSUMED_BYTES_PER_BITMAP) - \
 162                 (FULL_BITMAPS_IN_FIRST_PAGE ? 0 : ROUND_UP_TO_CONTINUATION_SIZE(BYTES_PER_BITMAP)))
 163
 164 #define REMAINDERED_CONTINUATIONS_IN_FIRST_PAGE \
 165                 (REMAINDER_IN_FIRST_PAGE / DISPATCH_CONTINUATION_SIZE)
 166 #define CONTINUATIONS_IN_FIRST_PAGE (FULL_BITMAPS_IN_FIRST_PAGE * \
 167                 CONTINUATIONS_PER_BITMAP) + REMAINDERED_CONTINUATIONS_IN_FIRST_PAGE
 168 #define BITMAPS_IN_FIRST_PAGE (FULL_BITMAPS_IN_FIRST_PAGE + \
 169                 (REMAINDERED_CONTINUATIONS_IN_FIRST_PAGE == 0 ? 0 : 1))
 170
 171 #define FPMAPS_TO_FPCONTS_PADDING (PADDING_TO_CONTINUATION_SIZE(\
 172                 BYTES_PER_BITMAP * BITMAPS_IN_FIRST_PAGE))
 173
 174 #else // PACK_FIRST_PAGE_WITH_CONTINUATIONS
 175
 176 #define MAPS_TO_CONTS_PADDING BYTES_LEFT_IN_FIRST_PAGE
 177
 178 #endif // PACK_FIRST_PAGE_WITH_CONTINUATIONS
 179
 180 #define AFTER_CONTS_PADDING (BYTES_PER_MAGAZINE - (BYTES_PER_PAGE + \
 181                 (DISPATCH_CONTINUATION_SIZE * CONTINUATIONS_PER_MAGAZINE)))
 182
 183 // This is the object our allocator allocates: a chunk of memory rounded up
 184 // from sizeof(struct dispatch_continuation_s) to the cacheline size, so
 185 // unrelated continuations don't share cachelines. It'd be nice if
 186 // dispatch_continuation_s included this rounding/padding, but it doesn't.
 187 typedef char padded_continuation[DISPATCH_CONTINUATION_SIZE];
 188
 189 // A dispatch_heap_t is the base address of an array of dispatch_magazine_s,
 190 // one magazine per CPU.
 191 typedef struct dispatch_magazine_s * dispatch_heap_t;
 192
 193 struct dispatch_magazine_header_s {
 194         // Link to the next heap in the chain. Only used in magazine 0's header
 195         dispatch_heap_t dh_next;
 196
 197         // Points to the first bitmap in the page where this CPU succesfully
 198         // allocated a continuation last time. Only used in the first heap.
 199         bitmap_t *last_found_page;
 200 };
 201
 202 // A magazine is a complex data structure. It must be exactly
 203 // PAGES_PER_MAGAZINE * PAGE_SIZE bytes long, and that value must be a
 204 // power of 2. (See magazine_for_continuation()).
 205 struct dispatch_magazine_s {
 206         // See above.
 207         struct dispatch_magazine_header_s header;
 208
 209         // Align supermaps as needed.
 210 #if HEADER_TO_SUPERMAPS_PADDING > 0
 211         char _pad0[HEADER_TO_SUPERMAPS_PADDING];
 212 #endif
 213
 214         // Second-level bitmap; each set bit means a bitmap_t in maps[][]
 215         // is completely full (and can be skipped while searching).
 216         bitmap_t supermaps[SUPERMAPS_PER_MAGAZINE];
 217
 218         // Align maps to a cacheline.
 219 #if SUPERMAPS_TO_MAPS_PADDING > 0
 220         char _pad1[SUPERMAPS_TO_MAPS_PADDING];
 221 #endif
 222
 223         // Each bit in maps[][] is the free/used state of a member of conts[][][].
 224         bitmap_t maps[SUPERMAPS_PER_MAGAZINE][BITMAPS_PER_SUPERMAP];
 225
 226         // Align fp_maps to a cacheline.
 227 #if MAPS_TO_FPMAPS_PADDING > 0
 228         char _pad2[MAPS_TO_FPMAPS_PADDING];
 229 #endif
 230
 231 #if PACK_FIRST_PAGE_WITH_CONTINUATIONS
 232         // Bitmaps for the continuations that live in the first page, which
 233         // are treated specially (they have faster search code).
 234         bitmap_t fp_maps[BITMAPS_IN_FIRST_PAGE];
 235
 236         // Align fp_conts to cacheline.
 237 #if FPMAPS_TO_FPCONTS_PADDING > 0
 238         char _pad3[FPMAPS_TO_FPCONTS_PADDING];
 239 #endif
 240
 241         // Continuations that live in the first page.
 242         padded_continuation fp_conts[CONTINUATIONS_IN_FIRST_PAGE];
 243
 244 #else // PACK_FIRST_PAGE_WITH_CONTINUATIONS
 245
 246 #if MAPS_TO_CONTS_PADDING > 0
 247         char _pad4[MAPS_TO_CONTS_PADDING];
 248 #endif
 249 #endif // PACK_FIRST_PAGE_WITH_CONTINUATIONS
 250
 251         // This is the big array of continuations.
 252         // This must start on a page boundary.
 253         padded_continuation conts[SUPERMAPS_PER_MAGAZINE][BITMAPS_PER_SUPERMAP]
 254                         [CONTINUATIONS_PER_BITMAP];
 255
 256         // Fill the unused space to exactly BYTES_PER_MAGAZINE
 257 #if AFTER_CONTS_PADDING > 0
 258         char _pad5[AFTER_CONTS_PADDING];
 259 #endif
 260 };
 261
 262 #if DISPATCH_DEBUG
 263 #define DISPATCH_ALLOCATOR_SCRIBBLE ((uintptr_t)0xAFAFAFAFAFAFAFAF)
 264 #endif
 265
 266 #endif // DISPATCH_ALLOCATOR
 267
 268 #endif // __DISPATCH_ALLOCATOR_INTERNAL__