Changeset 63639 in vbox

Timestamp:

Aug 25, 2016 2:31:10 PM (8 years ago)

Author:

vboxsync

Message:

VBoxC: Looks like VirtualBoxClient::Data::m_pEventSource is holding in extra reference on the ATL module, causing VBoxC to be unloaded too late because DllCanUnloadNow() returns S_FALSE due to GetLockCount() being 1 instead of 0. Created a hack for discounting the module lock held by the EventSource in the VirtualBoxClient singelton.

Location:

trunk/src/VBox/Main

Files:

• include/VirtualBoxClientImpl.h (modified) (2 diffs)
• src-client/VirtualBoxClientImpl.cpp (modified) (2 diffs)
• src-client/win/dllmain.cpp (modified) (2 diffs)

trunk/src/VBox/Main/include/VirtualBoxClientImpl.h

@@ -66 +66 @@
     struct Data
     {
-        Data()
+        Data() : m_ThreadWatcher(NIL_RTTHREAD), m_SemEvWatcher(NIL_RTSEMEVENT)
         {}
+
+        ~Data()
+        {
+            /* HACK ALERT! This is for DllCanUnloadNow(). */
+            if (m_pEventSource.isNotNull())
+            {
+                s_cUnnecessaryAtlModuleLocks--;
+                AssertMsg(s_cUnnecessaryAtlModuleLocks == 0, ("%d\n", s_cUnnecessaryAtlModuleLocks));
+            }
+        }
 
         ComPtr<IVirtualBox> m_pVirtualBox;
@@ -77 +87 @@
 
     Data mData;
+
+public:
+    /** Hack for discounting the AtlModule lock held by Data::m_pEventSource during
+     * DllCanUnloadNow().  This is incremented to 1 when init() initialized
+     * m_pEventSource and is decremented by the Data destructor (above). */
+    static LONG s_cUnnecessaryAtlModuleLocks;
 };
 
-#endif // ____H_VIRTUALBOXCLIENTIMPL
+#endif
 /* vi: set tabstop=4 shiftwidth=4 expandtab: */

trunk/src/VBox/Main/src-client/VirtualBoxClientImpl.cpp

@@ -37 +37 @@
 uint32_t VirtualBoxClient::g_cInstances = 0;
 
+LONG VirtualBoxClient::s_cUnnecessaryAtlModuleLocks = 0;
 
 // constructor / destructor
@@ -104 +105 @@
         AssertComRCThrow(rc, setError(rc,
                                       tr("Could not initialize EventSource for VirtualBoxClient")));
+
+        /* HACK ALERT! This is for DllCanUnloadNow(). */
+        s_cUnnecessaryAtlModuleLocks++;
+        AssertMsg(s_cUnnecessaryAtlModuleLocks == 1, ("%d\n", s_cUnnecessaryAtlModuleLocks));
 
         /* Setting up the VBoxSVC watcher thread. If anything goes wrong here it

trunk/src/VBox/Main/src-client/win/dllmain.cpp

@@ -75 +75 @@
 {
     AssertReturn(g_pAtlComModule, S_OK);
-    return g_pAtlComModule->GetLockCount() == 0 ? S_OK : S_FALSE;
+    LONG const cLocks = g_pAtlComModule->GetLockCount();
+    Assert(cLocks >= VirtualBoxClient::s_cUnnecessaryAtlModuleLocks);
+    return cLocks <= VirtualBoxClient::s_cUnnecessaryAtlModuleLocks ? S_OK : S_FALSE;
 }
 
@@ -83 +85 @@
 STDAPI DllGetClassObject(REFCLSID rclsid, REFIID riid, LPVOID *ppv)
 {
+    HRESULT hrc;
     AssertReturn(g_pAtlComModule, E_UNEXPECTED);
     return g_pAtlComModule->GetClassObject(rclsid, riid, ppv);