removed RareEnablePreemptiveGC

Author: VSadov

src/coreclr/debug/ee/debugger.h

@@ -3807,7 +3807,7 @@ HANDLE OpenWin32EventOrThrow(
 // debugger may not be expecting it.  Instead, just leave the lock and retry.
 // When we leave, we'll enter coop mode first and get suspended if a suspension is in progress.
 // Afterwards, we'll transition back into preemptive mode, and we'll block because this thread
-// has been suspended by the debugger (see code:Thread::RareEnablePreemptiveGC).
+// has been suspended by the debugger (see code:Thread::RareDisablePreemptiveGC).
 #define SENDIPCEVENT_BEGIN_EX(pDebugger, thread, gcxStmt)                                 \
   {                                                                                       \
     FireEtwDebugIPCEventStart();                                                          \

src/coreclr/vm/eedbginterfaceimpl.cpp

@@ -652,7 +652,7 @@ void EEDbgInterfaceImpl::EnablePreemptiveGC(void)
     CONTRACTL
     {
         NOTHROW;
-        DISABLED(GC_TRIGGERS); // Disabled because disabled in RareEnablePreemptiveGC()
+        GC_NOTRIGGER;
     }
     CONTRACTL_END;
 

src/coreclr/vm/i386/asmhelpers.S

@@ -126,31 +126,6 @@ LEAF_ENTRY RestoreFPUContext, _TEXT
     ret     4
 LEAF_END RestoreFPUContext, _TEXT
 
-// -----------------------------------------------------------------------
-//  The out-of-line portion of the code to enable preemptive GC.
-//  After the work is done, the code jumps back to the "pRejoinPoint"
-//  which should be emitted right after the inline part is generated.
-//
-//  Assumptions:
-//       ebx = Thread
-//  Preserves
-//       all registers except ecx.
-//
-// -----------------------------------------------------------------------
-NESTED_ENTRY StubRareEnable, _TEXT, NoHandler
-    push    eax
-    push    edx
-
-    push    ebx
-
-    CHECK_STACK_ALIGNMENT
-    call    C_FUNC(StubRareEnableWorker)
-
-    pop     edx
-    pop     eax
-    ret
-NESTED_END StubRareEnable, _TEXT
-
 NESTED_ENTRY StubRareDisableTHROW, _TEXT, NoHandler
     push    eax
     push    edx

src/coreclr/vm/i386/asmhelpers.asm

@@ -24,7 +24,6 @@ EXTERN __imp__RtlUnwind@16:DWORD
 ifdef _DEBUG
 EXTERN _HelperMethodFrameConfirmState@20:PROC
 endif
-EXTERN _StubRareEnableWorker@4:PROC
 ifdef FEATURE_COMINTEROP
 EXTERN _StubRareDisableHRWorker@4:PROC
 endif ; FEATURE_COMINTEROP
@@ -394,29 +393,6 @@ endif
         retn    8
 _CallJitEHFinallyHelper@8 ENDP
 
-;-----------------------------------------------------------------------
-; The out-of-line portion of the code to enable preemptive GC.
-; After the work is done, the code jumps back to the "pRejoinPoint"
-; which should be emitted right after the inline part is generated.
-;
-; Assumptions:
-;      ebx = Thread
-; Preserves
-;      all registers except ecx.
-;
-;-----------------------------------------------------------------------
-_StubRareEnable proc public
-        push    eax
-        push    edx
-
-        push    ebx
-        call    _StubRareEnableWorker@4
-
-        pop     edx
-        pop     eax
-        retn
-_StubRareEnable ENDP
-
 ifdef FEATURE_COMINTEROP
 _StubRareDisableHR proc public
         push    edx

src/coreclr/vm/i386/cgenx86.cpp

@@ -911,18 +911,6 @@ Stub *GenerateInitPInvokeFrameHelper()
     RETURN psl->Link(SystemDomain::GetGlobalLoaderAllocator()->GetExecutableHeap());
 }
 
-
-extern "C" VOID STDCALL StubRareEnableWorker(Thread *pThread)
-{
-    WRAPPER_NO_CONTRACT;
-
-    //printf("RareEnable\n");
-    pThread->RareEnablePreemptiveGC();
-}
-
-
-
-
 // Disable when calling into managed code from a place that fails via Exceptions
 extern "C" VOID STDCALL StubRareDisableTHROWWorker(Thread *pThread)
 {

src/coreclr/vm/i386/stublinkerx86.cpp

@@ -45,8 +45,6 @@
 
 
 #ifndef DACCESS_COMPILE
-
-extern "C" VOID __cdecl StubRareEnable(Thread *pThread);
 #ifdef FEATURE_COMINTEROP
 extern "C" HRESULT __cdecl StubRareDisableHR(Thread *pThread);
 #endif // FEATURE_COMINTEROP
@@ -2615,6 +2613,8 @@ void StubLinkerCPU::EmitComMethodStubEpilog(TADDR pFrameVptr,
         PRECONDITION(rgRareLabels[0] != NULL && rgRareLabels[1] != NULL && rgRareLabels[2] != NULL);
         PRECONDITION(rgRejoinLabels != NULL);
         PRECONDITION(rgRejoinLabels[0] != NULL && rgRejoinLabels[1] != NULL && rgRejoinLabels[2] != NULL);
+        PRECONDITION(4 == sizeof( ((Thread*)0)->m_State ));
+        PRECONDITION(4 == sizeof( ((Thread*)0)->m_fPreemptiveGCDisabled ));
     }
     CONTRACTL_END;
 
@@ -2623,11 +2623,9 @@ void StubLinkerCPU::EmitComMethodStubEpilog(TADDR pFrameVptr,
     // mov [ebx + Thread.GetFrame()], edi  ;; restore previous frame
     X86EmitIndexRegStore(kEBX, Thread::GetOffsetOfCurrentFrame(), kEDI);
 
-    //-----------------------------------------------------------------------
-    // Generate the inline part of disabling preemptive GC
-    //-----------------------------------------------------------------------
-    EmitEnable(rgRareLabels[2]); // rare gc
-    EmitLabel(rgRejoinLabels[2]);        // rejoin for rare gc
+    // move byte ptr [ebx + Thread.m_fPreemptiveGCDisabled],0
+    X86EmitOffsetModRM(0xc6, (X86Reg)0, kEBX, Thread::GetOffsetOfGCFlag());
+    Emit8(0);
 
     // add esp, popstack
     X86EmitAddEsp(sizeof(GSCookie) + UnmanagedToManagedFrame::GetOffsetOfCalleeSavedRegisters());
@@ -2651,12 +2649,6 @@ void StubLinkerCPU::EmitComMethodStubEpilog(TADDR pFrameVptr,
     // keeps on going past the previous "jmp eax".
     X86EmitReturn(0);
 
-    //-----------------------------------------------------------------------
-    // The out-of-line portion of enabling preemptive GC - rarely executed
-    //-----------------------------------------------------------------------
-    EmitLabel(rgRareLabels[2]);  // label for rare enable gc
-    EmitRareEnable(rgRejoinLabels[2]); // emit rare enable gc
-
     //-----------------------------------------------------------------------
     // The out-of-line portion of disabling preemptive GC - rarely executed
     //-----------------------------------------------------------------------
@@ -2736,6 +2728,8 @@ void StubLinkerCPU::EmitSharedComMethodStubEpilog(TADDR pFrameVptr,
         PRECONDITION(rgRareLabels[0] != NULL && rgRareLabels[1] != NULL && rgRareLabels[2] != NULL);
         PRECONDITION(rgRejoinLabels != NULL);
         PRECONDITION(rgRejoinLabels[0] != NULL && rgRejoinLabels[1] != NULL && rgRejoinLabels[2] != NULL);
+        PRECONDITION(4 == sizeof( ((Thread*)0)->m_State ));
+        PRECONDITION(4 == sizeof( ((Thread*)0)->m_fPreemptiveGCDisabled ));
     }
     CONTRACTL_END;
 
@@ -2748,12 +2742,13 @@ void StubLinkerCPU::EmitSharedComMethodStubEpilog(TADDR pFrameVptr,
     X86EmitIndexRegStore(kEBX, Thread::GetOffsetOfCurrentFrame(), kEDI);
 
     //-----------------------------------------------------------------------
-    // Generate the inline part of enabling preemptive GC
+    // Generate enabling preemptive GC
     //-----------------------------------------------------------------------
     EmitLabel(NoEntryLabel);    // need to enable preemp mode even when we fail the disable as rare disable will return in coop mode
 
-    EmitEnable(rgRareLabels[2]);     // rare enable gc
-    EmitLabel(rgRejoinLabels[2]);        // rejoin for rare enable gc
+    // move byte ptr [ebx + Thread.m_fPreemptiveGCDisabled],0
+    X86EmitOffsetModRM(0xc6, (X86Reg)0, kEBX, Thread::GetOffsetOfGCFlag());
+    Emit8(0);
 
 #ifdef PROFILING_SUPPORTED
     // If profiling is active, emit code to notify profiler of transition
@@ -2800,12 +2795,6 @@ void StubLinkerCPU::EmitSharedComMethodStubEpilog(TADDR pFrameVptr,
     // keeps on going past the previous "jmp ecx".
     X86EmitReturn(0);
 
-    //-----------------------------------------------------------------------
-    // The out-of-line portion of enabling preemptive GC - rarely executed
-    //-----------------------------------------------------------------------
-    EmitLabel(rgRareLabels[2]);  // label for rare enable gc
-    EmitRareEnable(rgRejoinLabels[2]); // emit rare enable gc
-
     //-----------------------------------------------------------------------
     // The out-of-line portion of disabling preemptive GC - rarely executed
     //-----------------------------------------------------------------------
@@ -3335,77 +3324,6 @@ VOID StubLinkerCPU::EmitUnwindInfoCheckSubfunction()
 
 #if defined(FEATURE_COMINTEROP) && defined(TARGET_X86)
 
-//-----------------------------------------------------------------------
-// Generates the inline portion of the code to enable preemptive GC. Hopefully,
-// the inline code is all that will execute most of the time. If this code
-// path is entered at certain times, however, it will need to jump out to
-// a separate out-of-line path which is more expensive. The "pForwardRef"
-// label indicates the start of the out-of-line path.
-//
-// Assumptions:
-//      ebx = Thread
-// Preserves
-//      all registers except ecx.
-//
-//-----------------------------------------------------------------------
-VOID StubLinkerCPU::EmitEnable(CodeLabel *pForwardRef)
-{
-    CONTRACTL
-    {
-        STANDARD_VM_CHECK;
-
-        PRECONDITION(4 == sizeof( ((Thread*)0)->m_State ));
-        PRECONDITION(4 == sizeof( ((Thread*)0)->m_fPreemptiveGCDisabled ));
-    }
-    CONTRACTL_END;
-
-    // move byte ptr [ebx + Thread.m_fPreemptiveGCDisabled],0
-    X86EmitOffsetModRM(0xc6, (X86Reg)0, kEBX, Thread::GetOffsetOfGCFlag());
-    Emit8(0);
-
-    _ASSERTE(FitsInI1(Thread::TS_CatchAtSafePoint));
-
-    // test byte ptr [ebx + Thread.m_State], TS_CatchAtSafePoint
-    X86EmitOffsetModRM(0xf6, (X86Reg)0, kEBX, Thread::GetOffsetOfState());
-    Emit8(Thread::TS_CatchAtSafePoint);
-
-    // jnz RarePath
-    X86EmitCondJump(pForwardRef, X86CondCode::kJNZ);
-
-#ifdef _DEBUG
-    X86EmitDebugTrashReg(kECX);
-#endif
-
-}
-
-
-//-----------------------------------------------------------------------
-// Generates the out-of-line portion of the code to enable preemptive GC.
-// After the work is done, the code jumps back to the "pRejoinPoint"
-// which should be emitted right after the inline part is generated.
-//
-// Assumptions:
-//      ebx = Thread
-// Preserves
-//      all registers except ecx.
-//
-//-----------------------------------------------------------------------
-VOID StubLinkerCPU::EmitRareEnable(CodeLabel *pRejoinPoint)
-{
-    STANDARD_VM_CONTRACT;
-
-    X86EmitCall(NewExternalCodeLabel((LPVOID) StubRareEnable), 0);
-#ifdef _DEBUG
-    X86EmitDebugTrashReg(kECX);
-#endif
-    if (pRejoinPoint)
-    {
-        X86EmitNearJump(pRejoinPoint);
-    }
-
-}
-
-
 //-----------------------------------------------------------------------
 // Generates the inline portion of the code to disable preemptive GC. Hopefully,
 // the inline code is all that will execute most of the time. If this code

src/coreclr/vm/i386/stublinkerx86.h

@@ -323,9 +323,6 @@ class StubLinkerCPU : public StubLinker
         }
 
 #if defined(FEATURE_COMINTEROP) && defined(TARGET_X86)
-        VOID EmitEnable(CodeLabel *pForwardRef);
-        VOID EmitRareEnable(CodeLabel *pRejoinPoint);
-
         VOID EmitDisable(CodeLabel *pForwardRef, BOOL fCallIn, X86Reg ThreadReg);
         VOID EmitRareDisable(CodeLabel *pRejoinPoint);
         VOID EmitRareDisableHRESULT(CodeLabel *pRejoinPoint, CodeLabel *pExitPoint);

src/coreclr/vm/threads.cpp

@@ -1399,13 +1399,6 @@ Thread::Thread()
 #ifdef _DEBUG
     m_ulForbidTypeLoad      = 0;
     m_GCOnTransitionsOK     = TRUE;
-#endif
-
-#ifdef ENABLE_CONTRACTS
-    m_ulEnablePreemptiveGCCount  = 0;
-#endif
-
-#ifdef _DEBUG
     dbg_m_cSuspendedThreads = 0;
     dbg_m_cSuspendedThreadsWithoutOSLock = 0;
     m_Creator.Clear();

src/coreclr/vm/threads.h

@@ -1397,11 +1397,6 @@ class Thread
         // holding a spin lock in coop mode and transit to preemp mode will cause deadlock on GC
         _ASSERTE ((m_StateNC & Thread::TSNC_OwnsSpinLock) == 0);
 
-#ifdef ENABLE_CONTRACTS_IMPL
-        _ASSERTE(!GCForbidden());
-        TriggersGC(this);
-#endif
-
         // ------------------------------------------------------------------------
         //   ** WARNING ** WARNING ** WARNING ** WARNING ** WARNING ** WARNING **  |
         // ------------------------------------------------------------------------
@@ -1414,21 +1409,12 @@ class Thread
         // ------------------------------------------------------------------------
 
         m_fPreemptiveGCDisabled.StoreWithoutBarrier(0);
-#ifdef ENABLE_CONTRACTS
-        m_ulEnablePreemptiveGCCount ++;
-#endif  // _DEBUG
-
-        // TODO: VS remove this. no polling on going to preemptive
-        //       Delete RareEnablePreemptiveGC as well.
-        if (CatchAtSafePointOpportunistic())
-            RareEnablePreemptiveGC();
 #endif
     }
 
 #if defined(STRESS_HEAP) && defined(_DEBUG)
     void PerformPreemptiveGC();
 #endif
-    void RareEnablePreemptiveGC();
     void PulseGCMode();
 
     //--------------------------------------------------------------
@@ -2804,11 +2790,6 @@ class Thread
 
 #endif // TRACK_SYNC
 
-private:
-#ifdef ENABLE_CONTRACTS_DATA
-    ULONG  m_ulEnablePreemptiveGCCount;
-#endif  // _DEBUG
-
 private:
     // For suspends:
     CLREvent        m_DebugSuspendEvent;