fix the AV in recycle process, issue #192. (#201)

* fix the AV in recycle process. this is due to we call Recycle again when the background thread exists

* more fixes

* reset hosting mode when all applications got removed

build/Version.props

@@ -3,7 +3,7 @@
    <PropertyGroup> 
      <AspNetCoreModuleVersionMajor>7</AspNetCoreModuleVersionMajor> 
      <AspNetCoreModuleVersionMinor>1</AspNetCoreModuleVersionMinor> 
-     <AspNetCoreModuleVersionPatch>1968</AspNetCoreModuleVersionPatch> 
+     <AspNetCoreModuleVersionPatch>1987</AspNetCoreModuleVersionPatch> 
      <AspNetCoreModuleVersionSuffix>-RTM</AspNetCoreModuleVersionSuffix> 
    </PropertyGroup> 
  </Project> 

src/AspNetCore/Inc/inprocessapplication.h

@@ -95,6 +95,7 @@ private:
 
     BOOL                            m_fManagedAppLoaded;
     BOOL                            m_fLoadManagedAppError;
+    BOOL                            m_fInitialized;
     BOOL                            m_fIsWebSocketsConnection;
 
     static IN_PROCESS_APPLICATION*   s_Application;

src/AspNetCore/Inc/resource.h

@@ -11,7 +11,7 @@
 #define ASPNETCORE_EVENT_RAPID_FAIL_COUNT_EXCEEDED_MSG       L"Maximum rapid fail count per minute of '%d' exceeded."
 #define ASPNETCORE_EVENT_PROCESS_START_INTERNAL_ERROR_MSG    L"Application '%s' failed to parse processPath and arguments due to internal error, ErrorCode = '0x%x'."
 #define ASPNETCORE_EVENT_PROCESS_START_POSTCREATE_ERROR_MSG  L"Application '%s' with physical root '%s' created process with commandline '%s'but failed to get its status, ErrorCode = '0x%x'."
-#define ASPNETCORE_EVENT_PROCESS_START_ERROR_MSG             L"Application '%s' with physical root '%s' failed to start process with commandline '%s', ErrorCode = '0x%x : %x."
+#define ASPNETCORE_EVENT_PROCESS_START_ERROR_MSG             L"Application '%s' with physical root '%s' failed to start process with commandline '%s', ErrorCode = '0x%x'  processStatus code '%x'."
 #define ASPNETCORE_EVENT_PROCESS_START_WRONGPORT_ERROR_MSG   L"Application '%s' with physical root '%s' created process with commandline '%s' but failed to listen on the given port '%d'"
 #define ASPNETCORE_EVENT_PROCESS_START_NOTREADY_ERROR_MSG    L"Application '%s' with physical root '%s' created process with commandline '%s' but either crashed or did not reponse or did not listen on the given port '%d', ErrorCode = '0x%x'"
 #define ASPNETCORE_EVENT_INVALID_STDOUT_LOG_FILE_MSG         L"Warning: Could not create stdoutLogFile %s, ErrorCode = %d."

src/AspNetCore/Src/applicationmanager.cxx

@@ -221,6 +221,10 @@ APPLICATION_MANAGER::RecycleApplication(
     }
     AcquireSRWLockExclusive(&m_srwLock);
     m_pApplicationHash->DeleteKey(&key);
+    if (m_pApplicationHash->Count() == 0)
+    {
+        m_hostingModel = HOSTING_UNKNOWN;
+    }
     ReleaseSRWLockExclusive(&m_srwLock);
 
 Finished:

src/AspNetCore/Src/aspnetcoreconfig.cxx

@@ -5,17 +5,26 @@
 
 ASPNETCORE_CONFIG::~ASPNETCORE_CONFIG()
 {
-    if (QueryHostingModel() == HOSTING_IN_PROCESS && 
+    if (QueryHostingModel() == HOSTING_IN_PROCESS &&
-        !g_fRecycleProcessCalled && 
+        !g_fRecycleProcessCalled &&
-        !g_pHttpServer->IsCommandLineLaunch())
+        (g_pHttpServer->GetAdminManager() != NULL))
     {
+        // There is a bug in IHttpServer::RecycleProcess. It will hit AV when worker process
+        // has already been in recycling state.
+        // To workaround, do null check on GetAdminManager(). If it is NULL, worker process is in recycling
+        // Do not call RecycleProcess again
+
         // RecycleProcess can olny be called once
         // In case of configuration change for in-process app
         // We want notify IIS first to let new request routed to new worker process
-        g_fRecycleProcessCalled = TRUE;
+
         g_pHttpServer->RecycleProcess(L"AspNetCore Recycle Process on Configuration Change");
     }
 
+    // It's safe for us to set this g_fRecycleProcessCalled
+    // as in_process scenario will always recycle the worker process for configuration change
+    g_fRecycleProcessCalled = TRUE;
+
     m_struApplicationFullPath.Reset();
     if (m_pEnvironmentVariables != NULL)
     {

src/AspNetCore/Src/forwardinghandler.cxx

@@ -1043,7 +1043,6 @@ FORWARDING_HANDLER::OnExecuteRequestHandler(
     IHttpRequest               *pRequest = m_pW3Context->GetRequest();
     IHttpResponse              *pResponse = m_pW3Context->GetResponse();
     PROTOCOL_CONFIG            *pProtocol = &sm_ProtocolConfig;
-    APPLICATION_MANAGER        *pApplicationManager = NULL;
     SERVER_PROCESS             *pServerProcess = NULL;
     USHORT                      cchHostName = 0;
     BOOL                        fSecure = FALSE;
@@ -1427,7 +1426,7 @@ Failure:
         }
         else
         {
-            if (SUCCEEDED(pApplicationManager->Get502ErrorPage(&pDataChunk)))
+            if (SUCCEEDED(APPLICATION_MANAGER::GetInstance()->Get502ErrorPage(&pDataChunk)))
             {
                 if (FAILED(hr = pResponse->WriteEntityChunkByReference(pDataChunk)))
                 {

src/AspNetCore/Src/inprocessapplication.cxx

@@ -335,7 +335,8 @@ IN_PROCESS_APPLICATION*  IN_PROCESS_APPLICATION::s_Application = NULL;
 IN_PROCESS_APPLICATION::IN_PROCESS_APPLICATION() :
     m_ProcessExitCode ( 0 ),
     m_fManagedAppLoaded ( FALSE ),
-    m_fLoadManagedAppError ( FALSE )
+    m_fLoadManagedAppError ( FALSE ),
+    m_fInitialized ( FALSE )
 {
 }
 
@@ -510,6 +511,7 @@ IN_PROCESS_APPLICATION::Initialize(
        hr =  HRESULT_FROM_WIN32(GetLastError());
        goto Finished;
     }
+    m_fInitialized = TRUE;
 
 Finished:
     return hr;
@@ -636,50 +638,57 @@ IN_PROCESS_APPLICATION::Recycle(
     VOID
 )
 {
-    DWORD    dwThreadStatus = 0;
+    if (m_fInitialized)
-    DWORD    dwTimeout = m_pConfiguration->QueryShutdownTimeLimitInMS();
-
-    AcquireSRWLockExclusive(&m_srwLock);
-
-    if (!g_pHttpServer->IsCommandLineLaunch() && !g_fRecycleProcessCalled)
     {
-        // IIS scenario.
+        DWORD    dwThreadStatus = 0;
-        // notify IIS first so that new request will be routed to new worker process
+        DWORD    dwTimeout = m_pConfiguration->QueryShutdownTimeLimitInMS();
-        g_fRecycleProcessCalled = TRUE;
-        g_pHttpServer->RecycleProcess(L"AspNetCore Recycle Process on Demand");
-    }
-    // First call into the managed server and shutdown
-    if (m_ShutdownHandler != NULL)
-    {
-        m_ShutdownHandler(m_ShutdownHandlerContext);
-        m_ShutdownHandler = NULL;
-    }
 
-    if (m_hThread != NULL &&
+        AcquireSRWLockExclusive(&m_srwLock);
-        GetExitCodeThread(m_hThread, &dwThreadStatus) != 0 &&
+
-        dwThreadStatus == STILL_ACTIVE)
+        if (!g_pHttpServer->IsCommandLineLaunch() &&
-    {
+            !g_fRecycleProcessCalled &&
-        // wait for gracefullshut down, i.e., the exit of the background thread or timeout
+            (g_pHttpServer->GetAdminManager() != NULL))
-        if (WaitForSingleObject(m_hThread, dwTimeout) != WAIT_OBJECT_0)
         {
-            // if the thread is still running, we need kill it first before exit to avoid AV
+            // IIS scenario.
-            if (GetExitCodeThread(m_hThread, &dwThreadStatus) != 0 && dwThreadStatus == STILL_ACTIVE)
+            // notify IIS first so that new request will be routed to new worker process
+            g_pHttpServer->RecycleProcess(L"AspNetCore Recycle Process on Demand");
+        }
+
+        g_fRecycleProcessCalled = TRUE;
+
+        // First call into the managed server and shutdown
+        if (m_ShutdownHandler != NULL)
+        {
+            m_ShutdownHandler(m_ShutdownHandlerContext);
+            m_ShutdownHandler = NULL;
+        }
+
+        if (m_hThread != NULL &&
+            GetExitCodeThread(m_hThread, &dwThreadStatus) != 0 &&
+            dwThreadStatus == STILL_ACTIVE)
+        {
+            // wait for gracefullshut down, i.e., the exit of the background thread or timeout
+            if (WaitForSingleObject(m_hThread, dwTimeout) != WAIT_OBJECT_0)
             {
-                TerminateThread(m_hThread, STATUS_CONTROL_C_EXIT);
+                // if the thread is still running, we need kill it first before exit to avoid AV
+                if (GetExitCodeThread(m_hThread, &dwThreadStatus) != 0 && dwThreadStatus == STILL_ACTIVE)
+                {
+                    TerminateThread(m_hThread, STATUS_CONTROL_C_EXIT);
+                }
             }
         }
-    }
 
-    CloseHandle(m_hThread);
+        CloseHandle(m_hThread);
-    m_hThread = NULL;
+        m_hThread = NULL;
-    s_Application = NULL;
+        s_Application = NULL;
-    ReleaseSRWLockExclusive(&m_srwLock);
 
-    if (g_pHttpServer->IsCommandLineLaunch())
+        ReleaseSRWLockExclusive(&m_srwLock);
-    {
+        if (g_pHttpServer && g_pHttpServer->IsCommandLineLaunch())
-        // IISExpress scenario
+        {
-        // Can only call exit to terminate current process
+            // IISExpress scenario
-        exit(0);
+            // Can only call exit to terminate current process
+            exit(0);
+        }
     }
 }