Changed inheritance of IceUtil::GCShared from IceUtil::Shared to virtual

    inheritance, so we don't have two IceUtil::Shared instances in a class
    that uses multiple inheritance and ends up deriving from
    IceUtil::Shared more than once.
Added a test case to the thread tests for a class that inherits from both
    GCShared and Thread to proved that there is indeed only one shared
    instance of IceUtil::Shared in such a class.

1 files changed, 50 insertions, 0 deletions

diff --git a/cpp/test/IceUtil/thread/GCSharedTest.cpp b/cpp/test/IceUtil/thread/GCSharedTest.cpp
new file mode 100644
index 00000000000..73b7cc3c355
--- /dev/null
+++ b/cpp/test/IceUtil/thread/GCSharedTest.cpp
@@ -0,0 +1,50 @@
+// **********************************************************************
+//
+// Copyright (c) 2003-2004 ZeroC, Inc. All rights reserved.
+//
+// This copy of Ice is licensed to you under the terms described in the
+// ICE_LICENSE file included in this distribution.
+//
+// **********************************************************************
+
+#include <IceUtil/IceUtil.h>
+
+#include <GCSharedTest.h>
+#include <IceUtil/Thread.h>
+#include <IceUtil/GCShared.h>
+#include <TestCommon.h>
+
+using namespace std;
+using namespace IceUtil;
+
+static const string GCSharedTestName("GCShared");
+
+struct TestClass : public Thread, GCShared
+{
+    virtual void run() {}
+    virtual void __gcReachable(GCObjectMultiSet&) const {}
+    virtual void __gcClear() {}
+
+    bool basesAreVirtual()
+    {
+	GCShared::_noDelete = true;
+	Thread::_noDelete = false;
+	//
+	// If we have virtual bases, there will be only one instance of the IceUtil::Shared base class,
+	// so GCShared::_noDelete will be false after the second assignment.
+	//
+	return !GCShared::_noDelete;
+    }
+};
+
+GCSharedTest::GCSharedTest() :
+    TestBase(GCSharedTestName)
+{
+}
+
+void
+GCSharedTest::run()
+{
+    TestClass tc;
+    test(tc.basesAreVirtual());
+}