Remove AppDomain unload (#20250)

* Remove AppDomain unload

This change removes all code in AppDomain that's related to AppDomain
unloading which is obsolete in CoreCLR. It also removes all calls to the
removed methods.
In few places, I have made the change simpler by taking into account the
fact that there is always just one AppDomain.

1 files changed, 2 insertions, 178 deletions

diff --git a/src/vm/threadsuspend.cpp b/src/vm/threadsuspend.cpp
index 6c761f3da1..abf9597074 100644
--- a/src/vm/threadsuspend.cpp
+++ b/src/vm/threadsuspend.cpp
@@ -639,13 +639,7 @@ void Thread::ClearAbortReason(BOOL pNoLock)
 
     // If there is an OBJECTHANDLE, try to clear it.
     if (oh != 0 && adid.m_dwId != 0)
-    {   // See if the domain is still valid; if so, destroy the ObjectHandle
-        AppDomainFromIDHolder ad(adid, TRUE);
-        if (!ad.IsUnloaded())
-        {   // Still a valid domain, so destroy the handle.
-            DestroyHandle(oh);
-        }
-    }
+        DestroyHandle(oh);
 }
 
 
@@ -1272,31 +1266,6 @@ BOOL Thread::IsRudeAbort()
     return (IsAbortRequested() && (m_AbortType == EEPolicy::TA_Rude));
 }
 
-BOOL Thread::IsRudeAbortOnlyForADUnload()
-{
-    CONTRACTL {
-        NOTHROW;
-        GC_NOTRIGGER;
-    }
-    CONTRACTL_END;
-
-    return (IsAbortRequested() &&
-            (m_AbortInfo & TAI_ADUnloadRudeAbort) &&
-            !(m_AbortInfo & (TAI_ThreadRudeAbort | TAI_FuncEvalRudeAbort))
-           );
-}
-
-BOOL Thread::IsRudeUnload()
-{
-    CONTRACTL {
-        NOTHROW;
-        GC_NOTRIGGER;
-    }
-    CONTRACTL_END;
-
-    return (IsAbortRequested() && (m_AbortInfo & TAI_ADUnloadRudeAbort));
-}
-
 BOOL Thread::IsFuncEvalAbort()
 {
     CONTRACTL {
@@ -1451,33 +1420,7 @@ Thread::UserAbort(ThreadAbortRequester requester,
             GetEEPolicy()->NotifyHostOnDefaultAction(operation,action);
             break;
         case eUnloadAppDomain:
-            {
-                AppDomain *pDomain = GetDomain();
-                if (!pDomain->IsDefaultDomain())
-                {
-                    GetEEPolicy()->NotifyHostOnDefaultAction(operation,action);
-                    pDomain->EnableADUnloadWorker(EEPolicy::ADU_Safe);
-                }
-            }
-            // AD unload does not abort finalizer thread.
-            if (this != FinalizerThread::GetFinalizerThread())
-            {
-                if (this == GetThread())
-                {
-                    Join(INFINITE,TRUE);
-                }
-                return S_OK;
-            }
-            break;
         case eRudeUnloadAppDomain:
-            {
-                AppDomain *pDomain = GetDomain();
-                if (!pDomain->IsDefaultDomain())
-                {
-                    GetEEPolicy()->NotifyHostOnDefaultAction(operation,action);
-                    pDomain->EnableADUnloadWorker(EEPolicy::ADU_Rude);
-                }
-            }
             // AD unload does not abort finalizer thread.
             if (this != FinalizerThread::GetFinalizerThread())
             {
@@ -1545,13 +1488,6 @@ Thread::UserAbort(ThreadAbortRequester requester,
         m_dwAbortPoint = 1;
 #endif
 
-        if (CLRHosted() && GetAbortEndTime() != MAXULONGLONG)
-        {
-            // ToDo: Skip debugger funcval
-            // Use our helper thread to watch abort.
-            AppDomain::EnableADUnloadWorkerForThreadAbort();
-        }
-
         GCX_COOP();
 
         OBJECTREF exceptObj;
@@ -1583,7 +1519,6 @@ Thread::UserAbort(ThreadAbortRequester requester,
     {
         // A host may call ICLRTask::Abort on a critical thread.  We don't want to
         // block this thread.
-        AppDomain::EnableADUnloadWorkerForThreadAbort();
         return S_OK;
     }
 
@@ -2120,14 +2055,6 @@ LPrepareRetry:
                 SetRudeAbortEndTimeFromEEPolicy();
                 goto LRetry;
             case eUnloadAppDomain:
-                {
-                    AppDomain *pDomain = GetDomain();
-                    if (!pDomain->IsDefaultDomain())
-                    {
-                        GetEEPolicy()->NotifyHostOnTimeout(operation1, action1);
-                        pDomain->EnableADUnloadWorker(EEPolicy::ADU_Safe);
-                    }
-                }
                 // AD unload does not abort finalizer thread.
                 if (this == FinalizerThread::GetFinalizerThread())
                 {
@@ -2146,14 +2073,6 @@ LPrepareRetry:
                 }
                 break;
             case eRudeUnloadAppDomain:
-                {
-                    AppDomain *pDomain = GetDomain();
-                    if (!pDomain->IsDefaultDomain())
-                    {
-                        GetEEPolicy()->NotifyHostOnTimeout(operation1, action1);
-                        pDomain->EnableADUnloadWorker(EEPolicy::ADU_Rude);
-                    }
-                }
                 // AD unload does not abort finalizer thread.
                 if (this == FinalizerThread::GetFinalizerThread())
                 {
@@ -2285,26 +2204,6 @@ void Thread::ThreadAbortWatchDogEscalate(Thread *pThread)
             GetEEPolicy()->NotifyHostOnTimeout(operation,action);
             pThread->UserAbort(Thread::TAR_Thread, EEPolicy::TA_Rude, INFINITE, Thread::UAC_WatchDog);
             break;
-        case eUnloadAppDomain:
-            {
-                AppDomain *pDomain = pThread->GetDomain();
-                if (!pDomain->IsDefaultDomain())
-                {
-                    GetEEPolicy()->NotifyHostOnTimeout(operation,action);
-                    pDomain->EnableADUnloadWorker(EEPolicy::ADU_Safe);
-                }
-            }
-            break;
-        case eRudeUnloadAppDomain:
-            {
-                AppDomain *pDomain = pThread->GetDomain();
-                if (!pDomain->IsDefaultDomain())
-                {
-                    GetEEPolicy()->NotifyHostOnTimeout(operation,action);
-                    pDomain->EnableADUnloadWorker(EEPolicy::ADU_Rude);
-                }
-            }
-            break;
         case eExitProcess:
         case eFastExitProcess:
         case eRudeExitProcess:
@@ -2463,26 +2362,6 @@ void Thread::MarkThreadForAbort(ThreadAbortRequester requester, EEPolicy::Thread
         }
     }
 
-    if (requester & TAR_ADUnload)
-    {
-        if (abortType == EEPolicy::TA_Safe)
-        {
-            abortInfo |= TAI_ADUnloadAbort;
-        }
-        else if (abortType == EEPolicy::TA_Rude)
-        {
-            abortInfo |= TAI_ADUnloadRudeAbort;
-        }
-        else if (abortType == EEPolicy::TA_V1Compatible)
-        {
-            abortInfo |= TAI_ADUnloadV1Abort;
-        }
-        if (IsADUnloadHelperThread())
-        {
-            abortInfo |= TAI_ForADUnloadThread;
-        }
-    }
-
     if (requester & TAR_FuncEval)
     {
         if (abortType == EEPolicy::TA_Safe)
@@ -2534,14 +2413,8 @@ void Thread::MarkThreadForAbort(ThreadAbortRequester requester, EEPolicy::Thread
             {
                 m_RudeAbortEndTime = endTime;
             }
-            // We can not call into host if we are in the middle of stack overflow.
-            // And we don't need to wake up our watchdog if there is no timeout.
-            if (GetThread() == this && (requester & TAR_StackOverflow) == 0)
-        {
-            AppDomain::EnableADUnloadWorkerForThreadAbort();
         }
     }
-    }
 
     if (abortInfo == (m_AbortInfo & abortInfo))
     {
@@ -2658,13 +2531,6 @@ void Thread::UnmarkThreadForAbort(ThreadAbortRequester requester, BOOL fForce)
         }
     }
 
-    if (requester & TAR_ADUnload)
-    {
-        m_AbortInfo &= ~(TAI_ADUnloadAbort   |
-                         TAI_ADUnloadV1Abort |
-                         TAI_ADUnloadRudeAbort);
-    }
-
     if (requester & TAR_FuncEval)
     {
         m_AbortInfo &= ~(TAI_FuncEvalAbort   |
@@ -2718,21 +2584,6 @@ void Thread::UnmarkThreadForAbort(ThreadAbortRequester requester, BOOL fForce)
     STRESS_LOG3(LF_APPDOMAIN, LL_ALWAYS, "Unmark Thread %p Thread Id = %x for abort from requester %d\n", this, GetThreadId(), requester);
 }
 
-// Make sure that when AbortRequest bit is cleared, we also dec TrapReturningThreads count.
-void Thread::ResetBeginAbortedForADUnload()
-{
-    CONTRACTL
-    {
-        NOTHROW;
-        GC_NOTRIGGER;
-    }
-    CONTRACTL_END;
-
-    AbortRequestLockHolder lh(this);
-
-    m_AbortInfo &= ~TAI_ForADUnloadThread;
-}
-
 void Thread::InternalResetAbort(ThreadAbortRequester requester, BOOL fResetRudeAbort)
 {
     CONTRACTL {
@@ -2762,7 +2613,7 @@ void Thread::SetAbortRequest(EEPolicy::ThreadAbortTypes abortType)
     }
     CONTRACTL_END;
 
-    MarkThreadForAbort(TAR_ADUnload, abortType);
+    MarkThreadForAbort(TAR_Thread, abortType);
 
     if (m_State & TS_Interruptible)
     {
@@ -3212,26 +3063,6 @@ void Thread::HandleThreadAbortTimeout()
             GetEEPolicy()->NotifyHostOnTimeout(operation,action);
             MarkThreadForAbort(TAR_Thread, EEPolicy::TA_Rude);
             break;
-        case eUnloadAppDomain:
-            {
-                AppDomain *pDomain = GetDomain();
-                if (!pDomain->IsDefaultDomain())
-                {
-                    GetEEPolicy()->NotifyHostOnTimeout(operation,action);
-                    pDomain->EnableADUnloadWorker(EEPolicy::ADU_Safe);
-                }
-            }
-            break;
-        case eRudeUnloadAppDomain:
-            {
-                AppDomain *pDomain = GetDomain();
-                if (!pDomain->IsDefaultDomain())
-                {
-                    GetEEPolicy()->NotifyHostOnTimeout(operation,action);
-                    pDomain->EnableADUnloadWorker(EEPolicy::ADU_Rude);
-                }
-            }
-            break;
         case eExitProcess:
         case eFastExitProcess:
         case eRudeExitProcess:
@@ -3345,13 +3176,6 @@ void Thread::PreWorkForThreadAbort()
             EPolicyAction action = GetEEPolicy()->GetDefaultAction(OPR_ThreadRudeAbortInCriticalRegion, this);
             switch (action)
             {
-            case eRudeUnloadAppDomain:
-                if (!pDomain->IsDefaultDomain())
-                {
-                    GetEEPolicy()->NotifyHostOnDefaultAction(OPR_ThreadRudeAbortInCriticalRegion,action);
-                    pDomain->EnableADUnloadWorker(EEPolicy::ADU_Rude);
-                }
-                break;
             case eExitProcess:
             case eFastExitProcess:
             case eRudeExitProcess: