1 files changed, 83 insertions, 0 deletions
diff --git a/dbaccess/source/ui/browser/AsynchronousLink.cxx b/dbaccess/source/ui/browser/AsynchronousLink.cxx
new file mode 100644
index 000000000..c8a7e500f
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+++ b/dbaccess/source/ui/browser/AsynchronousLink.cxx
@@ -0,0 +1,83 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/*
+ * This file is part of the LibreOffice project.
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ *
+ * This file incorporates work covered by the following license notice:
+ *
+ *   Licensed to the Apache Software Foundation (ASF) under one or more
+ *   contributor license agreements. See the NOTICE file distributed
+ *   with this work for additional information regarding copyright
+ *   ownership. The ASF licenses this file to you under the Apache
+ *   License, Version 2.0 (the "License"); you may not use this file
+ *   except in compliance with the License. You may obtain a copy of
+ *   the License at http://www.apache.org/licenses/LICENSE-2.0 .
+ */
+
+#include <dbaccess/AsynchronousLink.hxx>
+#include <vcl/svapp.hxx>
+
+// OAsynchronousLink
+using namespace dbaui;
+OAsynchronousLink::OAsynchronousLink( const Link<void*,void>& _rHandler )
+    :m_aHandler(_rHandler)
+    ,m_aEventSafety()
+    ,m_aDestructionSafety()
+    ,m_nEventId(nullptr)
+{
+}
+
+OAsynchronousLink::~OAsynchronousLink()
+{
+    {
+        ::osl::MutexGuard aEventGuard( m_aEventSafety );
+        if ( m_nEventId )
+            Application::RemoveUserEvent(m_nEventId);
+        m_nEventId = nullptr;
+    }
+
+    {
+        ::osl::MutexGuard aDestructionGuard( m_aDestructionSafety );
+        // this is just for the case we're deleted while another thread just handled the event :
+        // if this other thread called our link while we were deleting the event here, the
+        // link handler blocked. With leaving the above block it continued, but now we are prevented
+        // to leave this destructor 'til the link handler recognizes that nEvent == 0 and leaves.
+    }
+}
+
+void OAsynchronousLink::Call( void* _pArgument )
+{
+    ::osl::MutexGuard aEventGuard( m_aEventSafety );
+    if (m_nEventId)
+        Application::RemoveUserEvent(m_nEventId);
+    m_nEventId = Application::PostUserEvent( LINK( this, OAsynchronousLink, OnAsyncCall ), _pArgument );
+}
+
+void OAsynchronousLink::CancelCall()
+{
+    ::osl::MutexGuard aEventGuard( m_aEventSafety );
+    if ( m_nEventId )
+        Application::RemoveUserEvent( m_nEventId );
+    m_nEventId = nullptr;
+}
+
+IMPL_LINK(OAsynchronousLink, OnAsyncCall, void*, _pArg, void)
+{
+    {
+        ::osl::MutexGuard aDestructionGuard( m_aDestructionSafety );
+        {
+            ::osl::MutexGuard aEventGuard( m_aEventSafety );
+            if (!m_nEventId)
+                // our destructor deleted the event just while we are waiting for m_aEventSafety
+                // -> get outta here
+                return;
+            m_nEventId = nullptr;
+        }
+    }
+    m_aHandler.Call(_pArg);
+}
+
+/* vim:set shiftwidth=4 softtabstop=4 expandtab: */