hphp/runtime/vm/reverse-data-map.h

   1 /*
   2    +----------------------------------------------------------------------+
   3    | HipHop for PHP                                                       |
   4    +----------------------------------------------------------------------+
   5    | Copyright (c) 2010-present Facebook, Inc. (http://www.facebook.com)  |
   6    +----------------------------------------------------------------------+
   7    | This source file is subject to version 3.01 of the PHP license,      |
   8    | that is bundled with this package in the file LICENSE, and is        |
   9    | available through the world-wide-web at the following url:           |
  10    | http://www.php.net/license/3_01.txt                                  |
  11    | If you did not receive a copy of the PHP license and are unable to   |
  12    | obtain it through the world-wide-web, please send a note to          |
  13    | license@php.net so we can mail you a copy immediately.               |
  14    +----------------------------------------------------------------------+
  15 */
  16
  17 #pragma once
  18
  19 #include <folly/DiscriminatedPtr.h>
  20
  21 namespace HPHP {
  22
  23 struct ArrayData;
  24 struct Class;
  25 struct Func;
  26 struct NamedEntity;
  27 struct StringData;
  28 struct Unit;
  29
  30 namespace data_map {
  31 /*
  32  * Logical reverse mapping from memory address ranges to the VM objects
  33  * allocated at them.
  34  */
  35
  36 ///////////////////////////////////////////////////////////////////////////////
  37
  38 /*
  39  * Register the start address of an object.
  40  *
  41  * The object pointer must be 16-byte aligned.
  42  */
  43 void register_start(const ArrayData*);
  44 void register_start(const Class*);
  45 void register_start(const Func*);
  46 void register_start(const NamedEntity*);
  47 void register_start(const StringData*);
  48 void register_start(const Unit*);
  49
  50 /*
  51  * Deregister an object.
  52  *
  53  * Requires that register_start() was called on the object, and it has not yet
  54  * been deregistered.
  55  */
  56 void deregister(const ArrayData*);
  57 void deregister(const Class*);
  58 void deregister(const Func*);
  59 void deregister(const NamedEntity*);
  60 void deregister(const StringData*);
  61 void deregister(const Unit*);
  62
  63 /*
  64  * Look up the object containing `addr' as an internal pointer.
  65  *
  66  * This function is aware of the variable-length allocations of Func, Class,
  67  * and StringData, and takes them into consideration for determining
  68  * constituency.
  69  *
  70  * Returns an empty result if `addr' is not mapped.
  71  */
  72 using result = folly::DiscriminatedPtr<
  73   ArrayData,
  74   Class,
  75   Func,
  76   NamedEntity,
  77   StringData,
  78   Unit
  79 >;
  80 result find_containing(const void* addr);
  81
  82 ///////////////////////////////////////////////////////////////////////////////
  83
  84 }}
  85