1 files changed, 174 insertions, 0 deletions
diff --git a/include/vcl/threadex.hxx b/include/vcl/threadex.hxx
new file mode 100644
index 000000000..af2978ce3
--- /dev/null
+++ b/include/vcl/threadex.hxx
@@ -0,0 +1,174 @@
+/* -*- 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 .
+ */
+
+#ifndef INCLUDED_VCL_THREADEX_HXX
+#define INCLUDED_VCL_THREADEX_HXX
+
+#include <osl/conditn.hxx>
+#include <tools/link.hxx>
+#include <vcl/dllapi.h>
+
+#include <optional>
+#include <memory>
+
+namespace vcl
+{
+    class VCL_DLLPUBLIC SolarThreadExecutor
+    {
+        osl::Condition          m_aStart;
+        osl::Condition          m_aFinish;
+        bool                    m_bTimeout;
+
+        DECL_DLLPRIVATE_LINK( worker, void*, void );
+
+    public:
+        SolarThreadExecutor();
+        virtual ~SolarThreadExecutor();
+
+        virtual void doIt() = 0;
+        void execute();
+    };
+
+namespace solarthread {
+
+/// @internal
+namespace detail {
+
+template <typename FuncT, typename ResultT>
+class GenericSolarThreadExecutor final : public SolarThreadExecutor
+{
+public:
+    static ResultT exec( FuncT const& func )
+    {
+        typedef GenericSolarThreadExecutor<FuncT, ResultT> ExecutorT;
+        ::std::unique_ptr<ExecutorT> const pExecutor( new ExecutorT(func) );
+        pExecutor->execute();
+        if (pExecutor->m_exc)
+            std::rethrow_exception(pExecutor->m_exc);
+        return *pExecutor->m_result;
+    }
+
+private:
+    explicit GenericSolarThreadExecutor( FuncT const& func )
+        : m_func(func), m_result() {}
+
+    virtual void doIt() override
+    {
+        try {
+            m_result = m_func();
+        }
+        catch (...) {
+            m_exc = std::current_exception();
+        }
+    }
+
+    std::exception_ptr m_exc;
+#ifdef _MSC_VER
+    FuncT m_func; // "const" and std::bind() results in Error C3848 expression would lose const-volatile qualifiers
+#else
+    FuncT const m_func;
+#endif
+    // using std::optional here omits the need that ResultT is default
+    // constructable:
+    ::std::optional<ResultT> m_result;
+};
+
+template <typename FuncT>
+class GenericSolarThreadExecutor<FuncT, void> final : public SolarThreadExecutor
+{
+public:
+    static void exec( FuncT const& func )
+    {
+        typedef GenericSolarThreadExecutor<FuncT, void> ExecutorT;
+        ::std::unique_ptr<ExecutorT> const pExecutor( new ExecutorT(func) );
+        pExecutor->execute();
+        if (pExecutor->m_exc)
+            std::rethrow_exception(pExecutor->m_exc);
+    }
+
+private:
+    explicit GenericSolarThreadExecutor( FuncT const& func )
+        : m_func(func) {}
+
+    virtual void doIt() override
+    {
+        try {
+            m_func();
+        }
+        catch (...) {
+            m_exc = std::current_exception();
+        }
+    }
+
+    std::exception_ptr m_exc;
+    FuncT const m_func;
+};
+
+} // namespace detail
+
+
+/** This function will execute the passed functor synchronously in the
+    solar thread, thus the calling thread will (eventually) be blocked until
+    the functor has been called.
+    Any exception that came up calling the functor in the solar thread
+    will be caught and rethrown in the calling thread.
+    The result type of this function needs to be default constructable.
+    Please keep in mind not to pass addresses to stack variables
+    (e.g. for out parameters) to foreign threads, use inout_by_ref()
+    for this purpose.  For in parameters, this may not affect you, because
+    the functor object is copy constructed into free store.  This way
+    you must not use \verbatim std::cref()/std::ref() \endverbatim or similar
+    for objects on your thread's stack.
+    Use inout_by_ref() or inout_by_ptr() for this purpose, e.g.
+
+    \code{.cpp}
+        using namespace vcl::solarthread;
+
+        long n = 3;
+        // calling foo( long & r ):
+        syncExecute( std::bind( &foo, inout_by_ref(n) ) );
+        // calling foo( long * p ):
+        syncExecute( std::bind( &foo, inout_by_ptr(&n) ) );
+
+        char const* pc = "default";
+        // calling foo( char const** ppc ):
+        syncExecute( std::bind( &foo, inout_by_ptr(&pc) ) );
+        // calling foo( char const*& rpc ):
+        syncExecute( std::bind( &foo, inout_by_ref(pc) ) );
+    \endcode
+
+    @tpl ResultT result type, defaults to FuncT::result_type to seamlessly
+                 support mem_fn and bind
+    @tpl FuncT functor type, let your compiler deduce this type
+    @param func functor object to be executed in solar thread
+    @return return value of functor
+*/
+template <typename FuncT>
+inline auto syncExecute(FuncT const& func) -> decltype(func())
+{
+    return detail::GenericSolarThreadExecutor<
+        FuncT, decltype(func())>::exec(func);
+}
+
+} // namespace solarthread
+} // namespace vcl
+
+#endif // INCLUDED_VCL_THREADEX_HXX
+
+/* vim:set shiftwidth=4 softtabstop=4 expandtab: */