src/vm/methoddescbackpatchinfo.h

   1 // Licensed to the .NET Foundation under one or more agreements.
   2 // The .NET Foundation licenses this file to you under the MIT license.
   3 // See the LICENSE file in the project root for more information.
   4
   5 #pragma once
   6
   7 #include "debugmacrosext.h"
   8 #include "crossloaderallocatorhash.h"
   9
  10 #ifndef CROSSGEN_COMPILE
  11
  12 #define DISABLE_COPY(T) \
  13     T(const T &) = delete; \
  14     T &operator =(const T &) = delete
  15
  16 ////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
  17 // EntryPointSlots
  18
  19 class EntryPointSlots
  20 {
  21 public:
  22     enum SlotType : UINT8
  23     {
  24         SlotType_Normal, // pointer-sized value not in executable code
  25         SlotType_Vtable, // pointer-sized value not in executable code, may be relative based on MethodTable::VTableIndir2_t
  26         SlotType_Executable, // pointer-sized value in executable code
  27         SlotType_ExecutableRel32, // 32-bit value relative to the end of the slot, in executable code
  28
  29         SlotType_Count,
  30         SlotType_Mask = SlotType_Vtable | SlotType_Executable | SlotType_ExecutableRel32
  31     };
  32
  33 #ifndef DACCESS_COMPILE
  34 private:
  35     static SIZE_T GetRequiredSlotAlignment(SlotType slotType)
  36     {
  37         LIMITED_METHOD_CONTRACT;
  38         _ASSERTE(slotType >= SlotType_Normal);
  39         _ASSERTE(slotType < SlotType_Count);
  40
  41         return slotType == SlotType_ExecutableRel32 ? sizeof(INT32) : sizeof(void *);
  42     }
  43
  44 public:
  45     static UINT_PTR ConvertSlotAndTypePairToUINT_PTR(TADDR slot, SlotType slotType)
  46     {
  47         slot |= (TADDR)slotType;
  48         return (UINT_PTR)slot;
  49     }
  50
  51     static void ConvertUINT_PTRToSlotAndTypePair(UINT_PTR storedData, TADDR *pSlot, SlotType *pSlotType)
  52     {
  53         *pSlot = storedData;
  54         *pSlotType = (SlotType)(*pSlot & SlotType_Mask);
  55         *pSlot ^= *pSlotType;
  56     }
  57
  58     static void Backpatch_Locked(TADDR slot, SlotType slotType, PCODE entryPoint);
  59 #endif
  60 };
  61
  62 ////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
  63 // MethodDescBackpatchInfoTracker
  64
  65 class MethodDescBackpatchInfoTracker
  66 {
  67 private:
  68     static CrstStatic s_lock;
  69     static bool s_isLocked;
  70
  71     class BackpatchInfoTrackerHashTraits : public NoRemoveDefaultCrossLoaderAllocatorHashTraits<MethodDesc *, UINT_PTR>
  72     {
  73     };
  74
  75     typedef CrossLoaderAllocatorHash<BackpatchInfoTrackerHashTraits> BackpatchInfoTrackerHash;
  76
  77     // Contains information about slots associated with the MethodDesc that were recorded for backpatching. This field and its
  78     // data is protected by s_lock.
  79     BackpatchInfoTrackerHash m_backpatchInfoHash;
  80
  81 #ifndef DACCESS_COMPILE
  82 public:
  83     static void StaticInitialize();
  84 #endif
  85
  86     void Initialize(LoaderAllocator *pLoaderAllocator)
  87     {
  88         WRAPPER_NO_CONTRACT;
  89         m_backpatchInfoHash.Init(pLoaderAllocator);
  90     }
  91
  92 #ifdef _DEBUG
  93 public:
  94     static bool IsLockedByCurrentThread();
  95 #endif
  96
  97 #ifndef DACCESS_COMPILE
  98 public:
  99     static bool IsLockedByAnyThread()
 100     {
 101         LIMITED_METHOD_CONTRACT;
 102         return VolatileLoadWithoutBarrier(&s_isLocked);
 103     }
 104
 105     static void PollForDebuggerSuspension();
 106 #endif
 107
 108 public:
 109     class ConditionalLockHolder : CrstHolderWithState
 110     {
 111     private:
 112         bool m_isLocked;
 113
 114     public:
 115         ConditionalLockHolder(bool acquireLock = true)
 116             : CrstHolderWithState(
 117 #ifndef DACCESS_COMPILE
 118                 acquireLock ? &MethodDescBackpatchInfoTracker::s_lock : nullptr
 119 #else
 120                 nullptr
 121 #endif
 122                 ),
 123             m_isLocked(false)
 124         {
 125             WRAPPER_NO_CONTRACT;
 126
 127         #ifndef DACCESS_COMPILE
 128             if (acquireLock)
 129             {
 130                 _ASSERTE(IsLockedByCurrentThread());
 131                 _ASSERTE(!s_isLocked);
 132                 m_isLocked = true;
 133                 s_isLocked = true;
 134             }
 135         #endif
 136         }
 137
 138         ~ConditionalLockHolder()
 139         {
 140             WRAPPER_NO_CONTRACT;
 141
 142         #ifndef DACCESS_COMPILE
 143             if (m_isLocked)
 144             {
 145                 _ASSERTE(IsLockedByCurrentThread());
 146                 _ASSERTE(s_isLocked);
 147                 s_isLocked = false;
 148             }
 149         #endif
 150         }
 151     };
 152
 153 public:
 154     MethodDescBackpatchInfoTracker()
 155     {
 156         LIMITED_METHOD_CONTRACT;
 157     }
 158
 159 #ifdef _DEBUG
 160 public:
 161     static bool MayHaveEntryPointSlotsToBackpatch(PTR_MethodDesc methodDesc);
 162 #endif
 163
 164 #ifndef DACCESS_COMPILE
 165 public:
 166     void Backpatch_Locked(MethodDesc *pMethodDesc, PCODE entryPoint);
 167     void AddSlotAndPatch_Locked(MethodDesc *pMethodDesc, LoaderAllocator *pLoaderAllocatorOfSlot, TADDR slot, EntryPointSlots::SlotType slotType, PCODE currentEntryPoint);
 168 public:
 169 #endif
 170
 171     friend class ConditionalLockHolder;
 172
 173     DISABLE_COPY(MethodDescBackpatchInfoTracker);
 174 };
 175
 176 #undef DISABLE_COPY
 177
 178 #endif // !CROSSGEN_COMPILE