Jumpstub fixes (#15296)

- Reserve space for jump stubs for precodes and other code fragments at the end of each code heap segment. This is trying
to ensure that eventual allocation of jump stubs for precodes and other code fragments succeeds. Accounting is done
conservatively - reserves more than strictly required. It wastes a bit of address space, but no actual memory. Also,
this reserve is not used to allocate jump stubs for JITed code since the JITing can recover from failure to allocate
the jump stub now. Fixes #14996.

- Improve algorithm to reuse HostCodeHeap segments: Maintain estimated size of the largest free block in HostCodeHeap.
This estimate is updated when allocation request fails, and also when memory is returned to the HostCodeHeap. Fixes #14995.

- Retry JITing on failure to allocate jump stub. Failure to allocate jump during JITing is not fatal anymore. There is
extra memory reserved for jump stubs on retry to ensure that the retry succeeds allocating the jump stubs that it needs
with high probability.

- Respect CodeHeapRequestInfo::getRequestSize for HostCodeHeap. CodeHeapRequestInfo::getRequestSize is used to
throttle code heap segment size for large workloads. Not respecting it in HostCodeHeap lead to too many
too small code heap segments in large workloads.

- Switch HostCodeHeap nibble map to be allocated on regular heap as part. It simplied the math required to estimate
the nibble map size, and allocating on regular heap is overall goodness since it does not need to be executable.

1 files changed, 22 insertions, 26 deletions

diff --git a/src/vm/codeman.h b/src/vm/codeman.h
index afef682e2a..983e2ca555 100644
--- a/src/vm/codeman.h
+++ b/src/vm/codeman.h
@@ -365,9 +365,11 @@ struct CodeHeapRequestInfo
     const BYTE * m_hiAddr;          // hihest address to use to satisfy our request (0 -- don't care)
     size_t       m_requestSize;     // minimum size that must be made available
     size_t       m_reserveSize;     // Amount that VirtualAlloc will reserved
+    size_t       m_reserveForJumpStubs; // Amount to reserve for jump stubs (won't be allocated)
     bool         m_isDynamicDomain;
     bool         m_isCollectible;
-    
+    bool         m_throwOnOutOfMemoryWithinRange;
+
     bool   IsDynamicDomain()                    { return m_isDynamicDomain;    }
     void   SetDynamicDomain()                   { m_isDynamicDomain = true;    }
 
@@ -378,20 +380,26 @@ struct CodeHeapRequestInfo
     
     size_t getReserveSize()                     { return m_reserveSize;        }
     void   setReserveSize(size_t reserveSize)   { m_reserveSize = reserveSize; }
+
+    size_t getReserveForJumpStubs()             { return m_reserveForJumpStubs; }
+    void   setReserveForJumpStubs(size_t size)  { m_reserveForJumpStubs = size; }
+
+    bool   getThrowOnOutOfMemoryWithinRange()   { return m_throwOnOutOfMemoryWithinRange; }
+    void   setThrowOnOutOfMemoryWithinRange(bool value) { m_throwOnOutOfMemoryWithinRange = value; }
         
     void   Init();
     
     CodeHeapRequestInfo(MethodDesc *pMD)
         : m_pMD(pMD), m_pAllocator(0), 
           m_loAddr(0), m_hiAddr(0),
-          m_requestSize(0), m_reserveSize(0)
+          m_requestSize(0), m_reserveSize(0), m_reserveForJumpStubs(0)
     { WRAPPER_NO_CONTRACT;   Init(); }
     
     CodeHeapRequestInfo(MethodDesc *pMD, LoaderAllocator* pAllocator,
                         BYTE * loAddr, BYTE * hiAddr)
         : m_pMD(pMD), m_pAllocator(pAllocator), 
           m_loAddr(loAddr), m_hiAddr(hiAddr),
-          m_requestSize(0), m_reserveSize(0)
+          m_requestSize(0), m_reserveSize(0), m_reserveForJumpStubs(0)
     { WRAPPER_NO_CONTRACT;   Init(); }
 };
 
@@ -433,7 +441,7 @@ public:
 
     // Alloc the specified numbers of bytes for code. Returns NULL if the request does not fit
     // Space for header is reserved immediately before. It is not included in size.
-    virtual void* AllocMemForCode_NoThrow(size_t header, size_t size, DWORD alignment) = 0;
+    virtual void* AllocMemForCode_NoThrow(size_t header, size_t size, DWORD alignment, size_t reserveForJumpStubs) = 0;
 
 #ifdef DACCESS_COMPILE
     virtual void EnumMemoryRegions(CLRDataEnumMemoryFlags flags) = 0;
@@ -467,9 +475,7 @@ typedef struct _HeapList
     PTR_DWORD           pHdrMap;        // bit array used to find the start of methods
 
     size_t              maxCodeHeapSize;// Size of the entire contiguous block of memory
-    DWORD               cBlocks;        // Number of allocations
-    bool                bFull;          // Heap is considered full do not use for new allocations
-    bool                bFullForJumpStubs; // Heap is considered full do not use for new allocations of jump stubs
+    size_t              reserveForJumpStubs; // Amount of memory reserved for jump stubs in this block
 
 #if defined(_TARGET_AMD64_)
     BYTE        CLRPersonalityRoutine[JUMP_ALLOCATE_SIZE];                 // jump thunk to personality routine
@@ -483,18 +489,6 @@ typedef struct _HeapList
     void SetNext(PTR_HeapList next)
     { hpNext = next; }
 
-    void SetHeapFull() 
-    { VolatileStore(&bFull, true); }
-
-    bool IsHeapFull() 
-    { return VolatileLoad(&bFull); }
-
-    void SetHeapFullForJumpStubs() 
-    { VolatileStore(&bFullForJumpStubs, true); }
-
-    bool IsHeapFullForJumpStubs() 
-    { return VolatileLoad(&bFullForJumpStubs); }
-
 } HeapList;
 
 //-----------------------------------------------------------------------------
@@ -527,7 +521,7 @@ public:
         WRAPPER_NO_CONTRACT;
     }
 
-    virtual void* AllocMemForCode_NoThrow(size_t header, size_t size, DWORD alignment) DAC_EMPTY_RET(NULL);
+    virtual void* AllocMemForCode_NoThrow(size_t header, size_t size, DWORD alignment, size_t reserveForJumpStubs) DAC_EMPTY_RET(NULL);
 
 #ifdef DACCESS_COMPILE
     virtual void EnumMemoryRegions(CLRDataEnumMemoryFlags flags)
@@ -1015,7 +1009,7 @@ public:
 
     BOOL                LoadJIT();
 
-    CodeHeader*         allocCode(MethodDesc* pFD, size_t blockSize, CorJitAllocMemFlag flag
+    CodeHeader*         allocCode(MethodDesc* pFD, size_t blockSize, size_t reserveForJumpStubs, CorJitAllocMemFlag flag
 #ifdef WIN64EXCEPTIONS
                                   , UINT nUnwindInfos
                                   , TADDR * pModuleBase
@@ -1025,7 +1019,8 @@ public:
     EE_ILEXCEPTION*     allocEHInfo(CodeHeader* pCodeHeader, unsigned numClauses, size_t * pAllocationSize);
     JumpStubBlockHeader* allocJumpStubBlock(MethodDesc* pMD, DWORD numJumps, 
                                             BYTE * loAddr, BYTE * hiAddr,
-                                            LoaderAllocator *pLoaderAllocator);
+                                            LoaderAllocator *pLoaderAllocator,
+                                            bool throwOnOutOfMemoryWithinRange);
 
     void *              allocCodeFragmentBlock(size_t blockSize, unsigned alignment, LoaderAllocator *pLoaderAllocator, StubCodeBlockKind kind);
 #endif // !DACCESS_COMPILE && !CROSSGEN_COMPILE
@@ -1091,11 +1086,10 @@ private :
 #ifndef DACCESS_COMPILE
 #ifndef CROSSGEN_COMPILE
     HeapList*   NewCodeHeap(CodeHeapRequestInfo *pInfo, DomainCodeHeapList *pADHeapList);
-    HeapList*   GetCodeHeap(CodeHeapRequestInfo *pInfo);
     bool        CanUseCodeHeap(CodeHeapRequestInfo *pInfo, HeapList *pCodeHeap);
     void*       allocCodeRaw(CodeHeapRequestInfo *pInfo, 
                              size_t header, size_t blockSize, unsigned align,
-                             HeapList ** ppCodeHeap /* Writeback, Can be null */ );
+                             HeapList ** ppCodeHeap);
 
     DomainCodeHeapList *GetCodeHeapList(CodeHeapRequestInfo *pInfo, LoaderAllocator *pAllocator, BOOL fDynamicOnly = FALSE);
     DomainCodeHeapList *CreateCodeHeapList(CodeHeapRequestInfo *pInfo);
@@ -1357,7 +1351,8 @@ public:
                           PCODE target,
                           BYTE * loAddr,
                           BYTE * hiAddr,
-                          LoaderAllocator *pLoaderAllocator = NULL);
+                          LoaderAllocator *pLoaderAllocator = NULL,
+                          bool throwOnOutOfMemoryWithinRange = true);
 #endif
 
 private:
@@ -1430,7 +1425,8 @@ private:
     static PCODE getNextJumpStub(MethodDesc* pMD,
                                  PCODE target,
                                  BYTE * loAddr,  BYTE * hiAddr,
-                                 LoaderAllocator *pLoaderAllocator);
+                                 LoaderAllocator *pLoaderAllocator,
+                                 bool throwOnOutOfMemoryWithinRange);
 #endif    
 
 private: