Refactor Utilcode's IAllocators.

- `DefaultAllocator` has been replaced with `HostAllocator` in RyuJIT, which
  uses the JIT hosting interface to allocate and free memory.
- The definition of `DefaultAllocator` has been moved into its own file, as it
  remains in use by the interpreter and the binder.
- `ProcessHeapAllocator` has been moved into JIT32, as that was its only
  remaining user.
- `AllowZeroAllocator`'s static field has been changed to an instance field
  to avoid the need to define storage for the static field in Utilcode.

[tfs-changeset: 1581242]

12 files changed, 93 insertions, 120 deletions

diff --git a/src/inc/iallocator.h b/src/inc/iallocator.h
index fea024171e..b4c1b71120 100644
--- a/src/inc/iallocator.h
+++ b/src/inc/iallocator.h
@@ -30,55 +30,12 @@ class IAllocator
     virtual void  Free(void* p) = 0;
 };
 
-// The "DefaultAllocator" class may be used by classes that wish to
-// provide the flexibility of using an "IAllocator" may avoid writing
-// conditionals at allocation sites about whether a non-default
-// "IAllocator" has been provided: if none is, they can simply set the
-// allocator to DefaultAllocator::Singleton().
-
-class DefaultAllocator: public IAllocator
-{
-    static DefaultAllocator s_singleton;
-
-  public:
-    void* Alloc(size_t sz)
-    {
-        return ::operator new(sz);
-    }
-
-    void* ArrayAlloc(size_t elemSize, size_t numElems)
-    {
-        ClrSafeInt<size_t> safeElemSize(elemSize);
-        ClrSafeInt<size_t> safeNumElems(numElems);
-        ClrSafeInt<size_t> sz = safeElemSize * safeNumElems;
-        if (sz.IsOverflow())
-        {
-            return NULL;
-        }
-        else
-        {
-            return ::operator new(sz.Value());
-        }
-    }
-
-    virtual void Free(void * p)
-    {
-        ::operator delete(p);
-    }
-
-    static DefaultAllocator* Singleton()
-    {
-        return &s_singleton;
-    }
-};
-
 // This class wraps an allocator that does not allow zero-length allocations,
-// producing one that does (every zero-length allocation produces a pointer to the same 
+// producing one that does (every zero-length allocation produces a pointer to the same
 // statically-allocated memory, and freeing that pointer is a no-op).
 class AllowZeroAllocator: public IAllocator
 {
-    static int s_zeroLenAllocTarg;
-
+    int m_zeroLenAllocTarg;
     IAllocator* m_alloc;
 
 public:
@@ -87,8 +44,8 @@ public:
     void* Alloc(size_t sz)
     {
         if (sz == 0)
-        { 
-            return (void*)(&s_zeroLenAllocTarg);
+        {
+            return (void*)(&m_zeroLenAllocTarg);
         }
         else
         {
@@ -99,8 +56,8 @@ public:
     void* ArrayAlloc(size_t elemSize, size_t numElems)
     {
         if (elemSize == 0 || numElems == 0)
-        { 
-            return (void*)(&s_zeroLenAllocTarg);
+        {
+            return (void*)(&m_zeroLenAllocTarg);
         }
         else
         {
@@ -110,58 +67,11 @@ public:
 
     virtual void Free(void * p)
     {
-        if (p != (void*)(&s_zeroLenAllocTarg))
+        if (p != (void*)(&m_zeroLenAllocTarg))
         {
             m_alloc->Free(p);
         }
     }
 };
 
-
-// ProcessHeapAllocator: This class implements an IAllocator that allocates and frees memory
-// from the process heap. This is similar to DefaultAllocator, but it can be used by the JIT
-// which doesn't allow the use of operator new/delete.
-
-class ProcessHeapAllocator: public IAllocator
-{
-    static ProcessHeapAllocator s_singleton;
-
-public:
-
-    virtual void* Alloc(size_t sz)
-    {
-        return ClrAllocInProcessHeap(0, S_SIZE_T(sz));
-    }
-
-    virtual void* ArrayAlloc(size_t elemSize, size_t numElems)
-    {
-        ClrSafeInt<size_t> safeElemSize(elemSize);
-        ClrSafeInt<size_t> safeNumElems(numElems);
-        ClrSafeInt<size_t> sz = safeElemSize * safeNumElems;
-        if (sz.IsOverflow())
-        {
-            return nullptr;
-        }
-        else
-        {
-            return ClrAllocInProcessHeap(0, S_SIZE_T(sz));
-        }
-    }
-
-    virtual void Free(void* p)
-    {
-        if (p != nullptr)
-        {
-            (void)ClrFreeInProcessHeap(0, p);
-        }
-    }
-
-    static ProcessHeapAllocator* Singleton()
-    {
-        return &s_singleton;
-    }
-};
-
 #endif // _IALLOCATOR_DEFINED_
-        
-
diff --git a/src/inc/simplerhash.inl b/src/inc/simplerhash.inl
index 1a7d004b26..091f047311 100644
--- a/src/inc/simplerhash.inl
+++ b/src/inc/simplerhash.inl
@@ -51,7 +51,7 @@ SimplerHashTable<Key,KeyFuncs,Value,Behavior>::SimplerHashTable(IAllocator* allo
 {
     LIMITED_METHOD_CONTRACT;
 
-    if (m_alloc == NULL) m_alloc = DefaultAllocator::Singleton();
+    assert(m_alloc != nullptr);
 
 #ifndef __GNUC__ // these crash GCC
     static_assert_no_msg(Behavior::s_growth_factor_numerator > Behavior::s_growth_factor_denominator);
diff --git a/src/jit/CMakeLists.txt b/src/jit/CMakeLists.txt
index b18b8cf3be..b492cf7a9c 100644
--- a/src/jit/CMakeLists.txt
+++ b/src/jit/CMakeLists.txt
@@ -32,6 +32,7 @@ set( JIT_SOURCES
   gentree.cpp
   gschecks.cpp
   hashbv.cpp
+  hostallocator.cpp
   importer.cpp
   inline.cpp
   inlinepolicy.cpp
diff --git a/src/jit/compiler.cpp b/src/jit/compiler.cpp
index 264286679a..ca9726f04f 100644
--- a/src/jit/compiler.cpp
+++ b/src/jit/compiler.cpp
@@ -14,6 +14,7 @@ XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
 #ifdef _MSC_VER
 #pragma hdrstop
 #endif // _MSC_VER
+#include "hostallocator.h"
 #include "emit.h"
 #include "ssabuilder.h"
 #include "valuenum.h"
@@ -246,10 +247,10 @@ NodeSizeStats genNodeSizeStats;
 NodeSizeStats genNodeSizeStatsPerFunc;
 
 unsigned    genTreeNcntHistBuckets[] = { 10, 20, 30, 40, 50, 100, 200, 300, 400, 500, 1000, 5000, 10000, 0 };
-histo       genTreeNcntHist(DefaultAllocator::Singleton(), genTreeNcntHistBuckets);
+histo       genTreeNcntHist(HostAllocator::getHostAllocator(), genTreeNcntHistBuckets);
 
 unsigned    genTreeNsizHistBuckets[] = { 1000, 5000, 10000, 50000, 100000, 500000, 1000000, 0 };
-histo       genTreeNsizHist(DefaultAllocator::Singleton(), genTreeNsizHistBuckets);
+histo       genTreeNsizHist(HostAllocator::getHostAllocator(), genTreeNsizHistBuckets);
 #endif // MEASURE_NODE_SIZE
 
 /*****************************************************************************
@@ -300,16 +301,16 @@ unsigned    argTotalGTF_ASGinArgs;
 unsigned    argMaxTempsPerMethod;
 
 unsigned    argCntBuckets[] = { 0, 1, 2, 3, 4, 5, 6, 10, 0 };
-histo       argCntTable(DefaultAllocator::Singleton(), argCntBuckets);
+histo       argCntTable(HostAllocator::getHostAllocator(), argCntBuckets);
 
 unsigned    argDWordCntBuckets[] = { 0, 1, 2, 3, 4, 5, 6, 10, 0 };
-histo       argDWordCntTable(DefaultAllocator::Singleton(), argDWordCntBuckets);
+histo       argDWordCntTable(HostAllocator::getHostAllocator(), argDWordCntBuckets);
 
 unsigned    argDWordLngCntBuckets[] = { 0, 1, 2, 3, 4, 5, 6, 10, 0 };
-histo       argDWordLngCntTable(DefaultAllocator::Singleton(), argDWordLngCntBuckets);
+histo       argDWordLngCntTable(HostAllocator::getHostAllocator(), argDWordLngCntBuckets);
 
 unsigned    argTempsCntBuckets[] = { 0, 1, 2, 3, 4, 5, 6, 10, 0 };
-histo       argTempsCntTable(DefaultAllocator::Singleton(), argTempsCntBuckets);
+histo       argTempsCntTable(HostAllocator::getHostAllocator(), argTempsCntBuckets);
 
 #endif // CALL_ARG_STATS
 
@@ -336,12 +337,12 @@ histo       argTempsCntTable(DefaultAllocator::Singleton(), argTempsCntBuckets);
 //          --------------------------------------------------
 
 unsigned    bbCntBuckets[] = { 1, 2, 3, 5, 10, 20, 50, 100, 1000, 10000, 0 };
-histo       bbCntTable(DefaultAllocator::Singleton(), bbCntBuckets);
+histo       bbCntTable(HostAllocator::getHostAllocator(), bbCntBuckets);
 
 /* Histogram for the IL opcode size of methods with a single basic block */
 
 unsigned    bbSizeBuckets[] = { 1, 4, 8, 16, 32, 64, 128, 256, 512, 1024, 2048, 0 };
-histo       bbOneBBSizeTable(DefaultAllocator::Singleton(), bbSizeBuckets);
+histo       bbOneBBSizeTable(HostAllocator::getHostAllocator(), bbSizeBuckets);
 
 #endif // COUNT_BASIC_BLOCKS
 
@@ -373,12 +374,12 @@ bool        loopOverflowThisMethod;     // True if we exceeded the max # of loop
 /* Histogram for number of loops in a method */
 
 unsigned    loopCountBuckets[] = { 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 0 };
-histo       loopCountTable(DefaultAllocator::Singleton(), loopCountBuckets);
+histo       loopCountTable(HostAllocator::getHostAllocator(), loopCountBuckets);
 
 /* Histogram for number of loop exits */
 
 unsigned    loopExitCountBuckets[] = { 0, 1, 2, 3, 4, 5, 6, 0 };
-histo       loopExitCountTable(DefaultAllocator::Singleton(), loopExitCountBuckets);
+histo       loopExitCountTable(HostAllocator::getHostAllocator(), loopExitCountBuckets);
 
 #endif // COUNT_LOOPS
 
@@ -2113,7 +2114,7 @@ void                Compiler::compInitOptions(CORJIT_FLAGS* jitFlags)
             {
                 // NOTE: The Assembly name list is allocated in the process heap, not in the no-release heap, which is reclaimed
                 // for every compilation. This is ok because we only allocate once, due to the static.
-                s_pAltJitExcludeAssembliesList = new (ProcessHeapAllocator::Singleton()) AssemblyNamesList2(wszAltJitExcludeAssemblyList, ProcessHeapAllocator::Singleton());
+                s_pAltJitExcludeAssembliesList = new (HostAllocator::getHostAllocator()) AssemblyNamesList2(wszAltJitExcludeAssemblyList, HostAllocator::getHostAllocator());
             }
         }
 
diff --git a/src/jit/ee_il_dll.cpp b/src/jit/ee_il_dll.cpp
index dc069fe0e6..da0ae901fe 100644
--- a/src/jit/ee_il_dll.cpp
+++ b/src/jit/ee_il_dll.cpp
@@ -22,7 +22,7 @@ XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
 
 /*****************************************************************************/
 
-static ICorJitHost* g_jitHost = nullptr;
+ICorJitHost* g_jitHost = nullptr;
 static CILJit* ILJitter = 0;        // The one and only JITTER I return
 #ifndef FEATURE_MERGE_JIT_AND_ENGINE
 HINSTANCE g_hInst = NULL;
diff --git a/src/jit/ee_il_dll.hpp b/src/jit/ee_il_dll.hpp
index c61deb57a1..b1e0327d6b 100644
--- a/src/jit/ee_il_dll.hpp
+++ b/src/jit/ee_il_dll.hpp
@@ -2,6 +2,8 @@
 // The .NET Foundation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
+extern ICorJitHost* g_jitHost;
+
 class CILJit: public ICorJitCompiler
 {
     CorJitResult __stdcall compileMethod (
diff --git a/src/jit/emit.cpp b/src/jit/emit.cpp
index 493d13cde0..e5b6842b14 100644
--- a/src/jit/emit.cpp
+++ b/src/jit/emit.cpp
@@ -16,6 +16,7 @@ XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
 #pragma hdrstop
 #endif
 
+#include "hostallocator.h"
 #include "instr.h"
 #include "emit.h"
 #include "codegen.h"
@@ -264,13 +265,13 @@ static  unsigned    totActualSize;
         unsigned    emitter::emitIFcounts[emitter::IF_COUNT];
 
 static  unsigned    emitSizeBuckets[] = { 100, 1024*1, 1024*2, 1024*3, 1024*4, 1024*5, 1024*10, 0 };
-static  histo       emitSizeTable(DefaultAllocator::Singleton(), emitSizeBuckets);
+static  histo       emitSizeTable(HostAllocator::getHostAllocator(), emitSizeBuckets);
 
 static  unsigned    GCrefsBuckets[] = { 0, 1, 2, 5, 10, 20, 50, 128, 256, 512, 1024, 0 };
-static  histo       GCrefsTable(DefaultAllocator::Singleton(), GCrefsBuckets);
+static  histo       GCrefsTable(HostAllocator::getHostAllocator(), GCrefsBuckets);
 
 static  unsigned    stkDepthBuckets[] = { 0, 1, 2, 5, 10, 16, 32, 128, 1024, 0 };
-static  histo       stkDepthTable(DefaultAllocator::Singleton(), stkDepthBuckets);
+static  histo       stkDepthTable(HostAllocator::getHostAllocator(), stkDepthBuckets);
 
 size_t              emitter::emitSizeMethod;
 
diff --git a/src/jit/hostallocator.cpp b/src/jit/hostallocator.cpp
new file mode 100644
index 0000000000..b737424ee8
--- /dev/null
+++ b/src/jit/hostallocator.cpp
@@ -0,0 +1,40 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+#include "jitpch.h"
+#include "hostallocator.h"
+
+HostAllocator HostAllocator::s_hostAllocator;
+
+void* HostAllocator::Alloc(size_t size)
+{
+    assert(g_jitHost != nullptr);
+    return g_jitHost->allocateMemory(size, false);
+}
+
+void* HostAllocator::ArrayAlloc(size_t elemSize, size_t numElems)
+{
+    assert(g_jitHost != nullptr);
+
+    ClrSafeInt<size_t> safeElemSize(elemSize);
+    ClrSafeInt<size_t> safeNumElems(numElems);
+    ClrSafeInt<size_t> size = safeElemSize * safeNumElems;
+    if (size.IsOverflow())
+    {
+        return nullptr;
+    }
+
+    return g_jitHost->allocateMemory(size.Value(), false);
+}
+
+void HostAllocator::Free(void* p)
+{
+    assert(g_jitHost != nullptr);
+    g_jitHost->freeMemory(p, false);
+}
+
+HostAllocator* HostAllocator::getHostAllocator()
+{
+    return &s_hostAllocator;
+}
diff --git a/src/jit/hostallocator.h b/src/jit/hostallocator.h
new file mode 100644
index 0000000000..c51eccc75e
--- /dev/null
+++ b/src/jit/hostallocator.h
@@ -0,0 +1,20 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+class HostAllocator : public IAllocator
+{
+private:
+    static HostAllocator s_hostAllocator;
+
+    HostAllocator() {}
+
+public:
+    void* Alloc(size_t size) override;
+
+    void* ArrayAlloc(size_t elemSize, size_t numElems) override;
+
+    void Free(void* p) override;
+
+    static HostAllocator* getHostAllocator();
+};
diff --git a/src/jit/jit.settings.targets b/src/jit/jit.settings.targets
index dfbe8f85f9..b95852f63c 100644
--- a/src/jit/jit.settings.targets
+++ b/src/jit/jit.settings.targets
@@ -82,6 +82,7 @@
         <CppCompile Include="..\LoopCloning.cpp" />
         <CppCompile Include="..\inline.cpp" />
         <CppCompile Include="..\inlinepolicy.cpp" />
+        <CppCompile Include="..\hostallocator.cpp" />
         <CppCompile Condition="'$(ClDefines.Contains(`LEGACY_BACKEND`))'=='True'" Include="..\CodeGenLegacy.cpp" />
         <CppCompile Condition="'$(ClDefines.Contains(`LEGACY_BACKEND`))'=='False'"  Include="..\Lower.cpp" />
         <CppCompile Condition="'$(ClDefines.Contains(`LEGACY_BACKEND`))'=='False'"  Include="..\LSRA.cpp" />
diff --git a/src/utilcode/iallocator.cpp b/src/utilcode/iallocator.cpp
index d6dabc7f2e..8c5fc838e5 100644
--- a/src/utilcode/iallocator.cpp
+++ b/src/utilcode/iallocator.cpp
@@ -4,11 +4,7 @@
 
 #include "stdafx.h"                     // Precompiled header key.
 #include "iallocator.h"
+#include "defaultallocator.h"
 
 // static
 DefaultAllocator DefaultAllocator::s_singleton;
-
-// static
-ProcessHeapAllocator ProcessHeapAllocator::s_singleton;
-
-int AllowZeroAllocator::s_zeroLenAllocTarg;
diff --git a/src/vm/interpreter.cpp b/src/vm/interpreter.cpp
index a846e424df..bdfa9622f9 100644
--- a/src/vm/interpreter.cpp
+++ b/src/vm/interpreter.cpp
@@ -23,6 +23,7 @@
 #include "runtimehandles.h"
 #include "vars.hpp"
 #include "cycletimer.h"
+#include "defaultallocator.h"
 #ifdef FEATURE_REMOTING
 #include "remoting.h"
 #endif
@@ -10837,7 +10838,7 @@ Interpreter::AddrToMDMap* Interpreter::GetAddrToMdMap()
 
     if (s_addrToMDMap == NULL)
     {
-        s_addrToMDMap = new AddrToMDMap(/* use default allocator */ NULL);
+        s_addrToMDMap = new AddrToMDMap(DefaultAllocator::Singleton());
     }
     return s_addrToMDMap;
 }
@@ -10899,7 +10900,7 @@ Interpreter::MethodHandleToInterpMethInfoPtrMap* Interpreter::GetMethodHandleToI
 
     if (s_methodHandleToInterpMethInfoPtrMap == NULL)
     {
-        s_methodHandleToInterpMethInfoPtrMap = new MethodHandleToInterpMethInfoPtrMap(/* use default allocator */ NULL);
+        s_methodHandleToInterpMethInfoPtrMap = new MethodHandleToInterpMethInfoPtrMap(DefaultAllocator::Singleton());
     }
     return s_methodHandleToInterpMethInfoPtrMap;
 }