Fix two AVs with InProcess (#656)

src/AspNetCore/Src/applicationinfo.cpp

@@ -183,42 +183,12 @@ APPLICATION_INFO::EnsureApplicationCreated()
     APPLICATION*        pApplication = NULL;
     STACK_STRU(struFileName, 300);  // >MAX_PATH
     STRU                struHostFxrDllLocation;
-    PWSTR*              pwzArgv;
-    DWORD               dwArgCount;
 
     if (m_pApplication != NULL)
     {
         goto Finished;
     }
 
-    if (m_pConfiguration->QueryHostingModel() == APP_HOSTING_MODEL::HOSTING_IN_PROCESS)
-    {
-        if (FAILED(hr = HOSTFXR_UTILITY::GetHostFxrParameters(
-            g_hEventLog,
-            m_pConfiguration->QueryProcessPath()->QueryStr(),
-            m_pConfiguration->QueryApplicationPhysicalPath()->QueryStr(),
-            m_pConfiguration->QueryArguments()->QueryStr(),
-            &struHostFxrDllLocation,
-            &dwArgCount,
-            &pwzArgv)))
-        {
-            goto Finished;
-        }
-
-        if (FAILED(hr = m_pConfiguration->SetHostFxrFullPath(struHostFxrDllLocation.QueryStr())))
-        {
-            goto Finished;
-        }
-
-        m_pConfiguration->SetHostFxrArguments(dwArgCount, pwzArgv);
-    }
-
-    hr = FindRequestHandlerAssembly();
-    if (FAILED(hr))
-    {
-        goto Finished;
-    }
-
     if (m_pApplication == NULL)
     {
         AcquireSRWLockExclusive(&m_srwLock);
@@ -233,6 +203,18 @@ APPLICATION_INFO::EnsureApplicationCreated()
         //
         if (!m_fAppOfflineFound)
         {
+
+            // Move the request handler check inside of the lock
+            // such that only one request finds and loads it.
+            // FindRequestHandlerAssembly obtains a global lock, but after releasing the lock,
+            // there is a period where we could call
+
+            hr = FindRequestHandlerAssembly();
+            if (FAILED(hr))
+            {
+                goto Finished;
+            }
+
             if (m_pfnAspNetCoreCreateApplication == NULL)
             {
                 hr = HRESULT_FROM_WIN32(ERROR_INVALID_FUNCTION);

src/AspNetCore/Src/dllmain.cpp

@@ -48,7 +48,7 @@ BOOL WINAPI DllMain(HMODULE hModule,
         DisableThreadLibraryCalls(hModule);
         break;
     case DLL_PROCESS_DETACH:
-        // IIS can cause dll detatch to occur before we receive global notifications
+        // IIS can cause dll detach to occur before we receive global notifications
         // For example, when we switch the bitness of the worker process, 
         // this is a bug in IIS. To try to avoid AVs, we will set a global flag
         g_fInShutdown = TRUE;

src/RequestHandler/dllmain.cxx

@@ -10,6 +10,7 @@ BOOL                g_fGlobalInitialize = FALSE;
 BOOL                g_fOutOfProcessInitialize = FALSE;
 BOOL                g_fOutOfProcessInitializeError = FALSE;
 BOOL                g_fWinHttpNonBlockingCallbackAvailable = FALSE;
+BOOL                g_fProcessDetach = FALSE;
 DWORD               g_OptionalWinHttpFlags = 0;
 DWORD               g_dwAspNetCoreDebugFlags = 0;
 DWORD               g_dwDebugFlags = 0;
@@ -263,6 +264,8 @@ BOOL APIENTRY DllMain(HMODULE hModule,
         DisableThreadLibraryCalls(hModule);
         InitializeSRWLock(&g_srwLockRH);
         break;
+    case DLL_PROCESS_DETACH:
+        g_fProcessDetach = TRUE;
     default:
         break;
     }

src/RequestHandler/inprocess/inprocessapplication.cpp

@@ -77,10 +77,14 @@ IN_PROCESS_APPLICATION::ShutDown()
 
     if (!m_fShutdownCalledFromManaged)
     {
-        // Initiate a recycle such that another worker process is created to replace this one.
+        // We cannot call into managed if the dll is detaching from the process.
-
+        // Calling into managed code when the dll is detaching is strictly a bad idea,
-        m_ShutdownHandler(m_ShutdownHandlerContext);
+        // and usually results in an AV saying "The string binding is invalid"
-        m_ShutdownHandler = NULL;
+        if (!g_fProcessDetach)
+        {
+            m_ShutdownHandler(m_ShutdownHandlerContext);
+            m_ShutdownHandler = NULL;
+        }
 
         ReleaseSRWLockExclusive(&m_srwLock);
         fLocked = FALSE;
@@ -608,7 +612,6 @@ IN_PROCESS_APPLICATION::LoadManagedApplication
 
         goto Finished;
     }
-
     m_hThread = CreateThread(
         NULL,       // default security attributes
         0,          // default stack size
@@ -759,8 +762,8 @@ IN_PROCESS_APPLICATION::ExecuteApplication(
     HMODULE             hModule;
     hostfxr_main_fn     pProc;
 
-    // should be a redudant call here, but we will be safe and call it twice.
+    DBG_ASSERT(m_status == APPLICATION_STATUS::STARTING);
-    // TODO AV here on m_pHostFxrParameters being null
+
     hModule = LoadLibraryW(m_pConfig->QueryHostFxrFullPath());
 
     if (hModule == NULL)

src/RequestHandler/precomp.hxx

@@ -111,6 +111,7 @@ extern BOOL       g_fWinHttpNonBlockingCallbackAvailable;
 extern BOOL       g_fWebSocketSupported;
 extern BOOL       g_fNsiApiNotSupported;
 extern BOOL       g_fEnableReferenceCountTracing;
+extern BOOL       g_fProcessDetach;
 extern DWORD      g_dwActiveServerProcesses;
 extern DWORD      g_OptionalWinHttpFlags;
 extern SRWLOCK    g_srwLockRH;