Adding upstream version 6.0.4-dfsg.upstream/6.0.4-dfsgupstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 206 insertions, 0 deletions

diff --git a/include/iprt/cpp/autores.h b/include/iprt/cpp/autores.h
new file mode 100644
index 00000000..9879b887
--- /dev/null
+++ b/include/iprt/cpp/autores.h
@@ -0,0 +1,206 @@
+/** @file
+ * IPRT - C++ Resource Management.
+ */
+
+/*
+ * Copyright (C) 2008-2019 Oracle Corporation
+ *
+ * This file is part of VirtualBox Open Source Edition (OSE), as
+ * available from http://www.virtualbox.org. This file is free software;
+ * you can redistribute it and/or modify it under the terms of the GNU
+ * General Public License (GPL) as published by the Free Software
+ * Foundation, in version 2 as it comes in the "COPYING" file of the
+ * VirtualBox OSE distribution. VirtualBox OSE is distributed in the
+ * hope that it will be useful, but WITHOUT ANY WARRANTY of any kind.
+ *
+ * The contents of this file may alternatively be used under the terms
+ * of the Common Development and Distribution License Version 1.0
+ * (CDDL) only, as it comes in the "COPYING.CDDL" file of the
+ * VirtualBox OSE distribution, in which case the provisions of the
+ * CDDL are applicable instead of those of the GPL.
+ *
+ * You may elect to license modified versions of this file under the
+ * terms and conditions of either the GPL or the CDDL or both.
+ */
+
+#ifndef IPRT_INCLUDED_cpp_autores_h
+#define IPRT_INCLUDED_cpp_autores_h
+#ifndef RT_WITHOUT_PRAGMA_ONCE
+# pragma once
+#endif
+
+#include <iprt/types.h>
+#include <iprt/assert.h>
+#include <iprt/cpp/utils.h>
+
+
+
+/** @defgroup grp_rt_cpp_autores    C++ Resource Management
+ * @ingroup grp_rt_cpp
+ * @{
+ */
+
+/**
+ * A callable class template which returns the correct value against which an
+ * IPRT type must be compared to see if it is invalid.
+ *
+ * @warning This template *must* be specialised for the types it is to work with.
+ */
+template <class T>
+inline T RTAutoResNil(void)
+{
+    AssertFatalMsgFailed(("Unspecialized template!\n"));
+    return (T)0;
+}
+
+/** Specialisation of RTAutoResNil for RTFILE */
+template <>
+inline RTFILE RTAutoResNil(void)
+{
+    return NIL_RTFILE;
+}
+
+/**
+ * A function template which calls the correct destructor for an IPRT type.
+ *
+ * @warning This template *must* be specialised for the types it is to work with.
+ */
+template <class T>
+inline void RTAutoResDestruct(T a_h)
+{
+    AssertFatalMsgFailed(("Unspecialized template!\n"));
+    NOREF(a_h);
+}
+
+/**
+ * An auto pointer-type class for resources which take a C-style destructor
+ * (RTMemFree() or equivalent).
+ *
+ * The idea of this class is to manage resources which the current code is
+ * responsible for freeing.  By wrapping the resource in an RTCAutoRes, you
+ * ensure that the resource will be freed when you leave the scope in which
+ * the RTCAutoRes is defined, unless you explicitly release the resource.
+ *
+ * A typical use case is when a function is allocating a number of resources.
+ * If any single allocation fails then all other resources must be freed.  If
+ * all allocations succeed, then the resources should be returned to the
+ * caller.  By placing all allocated resources in RTCAutoRes containers, you
+ * ensure that they will be freed on failure, and only have to take care of
+ * releasing them when you return them.
+ *
+ * @param   T           The type of the resource.
+ * @param   Destruct    The function to be used to free the resource.
+ *                      This parameter must be supplied if there is no
+ *                      specialisation of RTAutoDestruct available for @a T.
+ * @param   NilRes      The function returning the NIL value for T. Required.
+ *                      This parameter must be supplied if there is no
+ *                      specialisation of RTAutoResNil available for @a T.
+ *
+ * @note    The class can not be initialised directly using assignment, due
+ *          to the lack of a copy constructor. This is intentional.
+ */
+template <class T, void Destruct(T) = RTAutoResDestruct<T>, T NilRes(void) = RTAutoResNil<T> >
+class RTCAutoRes
+    : public RTCNonCopyable
+{
+protected:
+    /** The resource handle. */
+    T m_hRes;
+
+public:
+    /**
+     * Constructor
+     *
+     * @param   a_hRes      The handle to resource to manage. Defaults to NIL.
+     */
+    RTCAutoRes(T a_hRes = NilRes())
+        : m_hRes(a_hRes)
+    {
+    }
+
+    /**
+     * Destructor.
+     *
+     * This destroys any resource currently managed by the object.
+     */
+    ~RTCAutoRes()
+    {
+        if (m_hRes != NilRes())
+            Destruct(m_hRes);
+    }
+
+    /**
+     * Assignment from a value.
+     *
+     * This destroys any resource currently managed by the object
+     * before taking on the new one.
+     *
+     * @param   a_hRes      The handle to the new resource.
+     */
+    RTCAutoRes &operator=(T a_hRes)
+    {
+        if (m_hRes != NilRes())
+            Destruct(m_hRes);
+        m_hRes = a_hRes;
+        return *this;
+    }
+
+    /**
+     * Checks if the resource handle is NIL or not.
+     */
+    bool operator!()
+    {
+        return m_hRes == NilRes();
+    }
+
+    /**
+     * Give up ownership the current resource, handing it to the caller.
+     *
+     * @returns The current resource handle.
+     *
+     * @note    Nothing happens to the resource when the object goes out of scope.
+     */
+    T release(void)
+    {
+        T Tmp = m_hRes;
+        m_hRes = NilRes();
+        return Tmp;
+    }
+
+    /**
+     * Deletes the current resources.
+     *
+     * @param   a_hRes      Handle to a new resource to manage. Defaults to NIL.
+     */
+    void reset(T a_hRes = NilRes())
+    {
+        if (a_hRes != m_hRes)
+        {
+            if (m_hRes != NilRes())
+                Destruct(m_hRes);
+            m_hRes = a_hRes;
+        }
+    }
+
+    /**
+     * Get the raw resource handle.
+     *
+     * Typically used passing the handle to some IPRT function while
+     * the object remains in scope.
+     *
+     * @returns The raw resource handle.
+     */
+    T get(void)
+    {
+        return m_hRes;
+    }
+};
+
+/** @} */
+
+
+/* include after template definition */
+#include <iprt/mem.h>
+
+#endif /* !IPRT_INCLUDED_cpp_autores_h */
+