Changeset 50945 in vbox

Timestamp:

Apr 1, 2014 3:16:22 PM (11 years ago)

Author:

vboxsync

Message:

ConsoleImpl: fix a race at SafeVMPtr.

File:

• trunk/src/VBox/Main/include/ConsoleImpl.h (modified) (4 diffs)

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

@@ -338 +338 @@
         ~AutoVMCallerBase()
         {
-            if (SUCCEEDED(mRC))
-                mThat->releaseVMCaller();
+            doRelease();
         }
         /** Decreases the number of callers before the instance is destroyed. */
         void releaseCaller()
         {
-            AssertReturnVoid(SUCCEEDED(mRC));
-            mThat->releaseVMCaller();
-            mRC = E_FAIL;
+            Assert(SUCCEEDED(mRC));
+            doRelease();
         }
         /** Restores the number of callers after by #release(). #rc() must be
@@ -361 +359 @@
     protected:
         Console *mThat;
-        HRESULT mRC;
+        void doRelease()
+        {
+            if (SUCCEEDED(mRC))
+            {
+                mThat->releaseVMCaller();
+                mRC = E_FAIL;
+            }
+        }
     private:
+        HRESULT mRC; /* Whether the caller was added. */
         DECLARE_CLS_COPY_CTOR_ASSIGN_NOOP(AutoVMCallerBase)
     };
@@ -422 +428 @@
         typedef AutoVMCallerBase<taQuiet, true> Base;
     public:
-        SafeVMPtrBase(Console *aThat) : Base(aThat), mpUVM(NULL)
-        {
-            if (SUCCEEDED(Base::mRC))
-                Base::mRC = aThat->safeVMPtrRetainer(&mpUVM, taQuiet);
+        SafeVMPtrBase(Console *aThat) : Base(aThat), mRC(S_OK), mpUVM(NULL)
+        {
+            if (Base::isOk())
+                mRC = aThat->safeVMPtrRetainer(&mpUVM, taQuiet);
         }
         ~SafeVMPtrBase()
         {
-            if (SUCCEEDED(Base::mRC))
-                release();
+            doRelease();
         }
         /** Direct PUVM access. */
@@ -437 +442 @@
         void release()
         {
-            AssertReturnVoid(SUCCEEDED(Base::mRC));
-            Base::mThat->safeVMPtrReleaser(&mpUVM);
-            Base::releaseCaller();
+            Assert(SUCCEEDED(mRC));
+            doRelease();
         }
 
+        /** The combined result of Console::addVMCaller() and Console::safeVMPtrRetainer */
+        HRESULT rc() const { return SUCCEEDED(mRC)? Base::rc(): mRC; }
+        /** Shortcut to SUCCEEDED(rc()) */
+        bool isOk() const { return SUCCEEDED(mRC) && Base::isOk(); }
+
     private:
+        void doRelease()
+        {
+            if (SUCCEEDED(mRC))
+            {
+                Base::mThat->safeVMPtrReleaser(&mpUVM);
+                mRC = E_FAIL;
+            }
+            Base::doRelease();
+        }
+        HRESULT mRC; /* Whether the VM ptr was retained. */
         PUVM    mpUVM;
         DECLARE_CLS_COPY_CTOR_ASSIGN_NOOP(SafeVMPtrBase)