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| -rw-r--r-- | bridges/inc/vtablefactory.hxx | 221 |
1 files changed, 221 insertions, 0 deletions
diff --git a/bridges/inc/vtablefactory.hxx b/bridges/inc/vtablefactory.hxx new file mode 100644 index 0000000000..9afcb83709 --- /dev/null +++ b/bridges/inc/vtablefactory.hxx @@ -0,0 +1,221 @@ +/* -*- 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 . + */ + +#pragma once + +#include <rtl/alloc.h> +#include <rtl/ustring.hxx> +#include <sal/types.h> +#include <typelib/typedescription.hxx> + +#include <memory> +#include <mutex> +#include <unordered_map> + +/*See: http://people.redhat.com/drepper/selinux-mem.html*/ +#if defined(LINUX) || defined(OPENBSD) || defined(FREEBSD) \ + || defined(NETBSD) || defined(DRAGONFLY) || defined (ANDROID) \ + || defined(HAIKU) +#define USE_DOUBLE_MMAP +#endif + +namespace bridges::cpp_uno::shared { + +/** Hand out vtable structures for interface type descriptions. + */ +class VtableFactory { +public: + // This structure is not defined in the generic part, but instead has to be + // defined individually for each CPP--UNO bridge: + /** A vtable slot. + */ + struct Slot; + + /** A raw vtable block. + */ + struct Block { + /** The start of the raw vtable block. + + It points to the start of the allocated memory block, whereas the + vtable pointer typically points some bytes into the block (e.g., + skipping an RTTI pointer, see mapBlockToVtable). Also, the block + contains any generated code snippets, after the vtable itself. + */ + void * start; + +#ifdef USE_DOUBLE_MMAP + /** When separately mmapping the block for writing and executing + exec points to the same memory as start, except start is used + exclusively for writing and exec for executing + */ + void * exec; + + /** File handle for the underlying anonymous file + */ + int fd; +#endif + + /** The size of the raw vtable block, in bytes. + */ + sal_Size size; + }; + + /** The vtable structure corresponding to an interface type. + */ + struct Vtables { + /** The number of blocks/vtables. + */ + sal_Int32 count; + + /** An array of blocks, representing the multiple vtables of a + (multiple-inheritance) type. + + <p>A block is a raw vtable. It points to the start of the allocated + memory block, whereas the vtable pointer typically points some bytes + into the block (e.g., skipping an RTTI pointer, see + mapBlockToVtable). Also, the block contains any generated code + snippets, after the vtable itself.</p> + */ + std::unique_ptr<Block[]> blocks; + + Vtables() + : count(0) + { + } + }; + + VtableFactory(); + + ~VtableFactory(); + + /** Given an interface type description, return its corresponding vtable + structure. + */ + const Vtables& getVtables(typelib_InterfaceTypeDescription * type); + + // This function is not defined in the generic part, but instead has to be + // defined individually for each CPP--UNO bridge: + /** Given a pointer to a block, turn it into a vtable pointer. + */ + static Slot * mapBlockToVtable(void * block); + +private: + class GuardedBlocks; + friend class GuardedBlocks; + + class BaseOffset; + + VtableFactory(VtableFactory const &) = delete; + VtableFactory& operator =(const VtableFactory&) = delete; + + bool createBlock(Block &block, sal_Int32 slotCount) const; + + void freeBlock(Block const & block) const; + + sal_Int32 createVtables( + GuardedBlocks & blocks, BaseOffset const & baseOffset, + typelib_InterfaceTypeDescription * type, sal_Int32 vtableNumber, + typelib_InterfaceTypeDescription * mostDerived, bool includePrimary) + const; + + // This function is not defined in the generic part, but instead has to be + // defined individually for each CPP--UNO bridge: + /** Calculate the size of a raw vtable block. + + @param slotCount the number of virtual function slots the returned + vtable block shall support (if there are any platform-specific slots, + like an RTTI pointer, or a pointer to a destructor, they are not covered + by slotCount) + @return the size of the raw vtable block, in bytes + */ + static std::size_t getBlockSize(sal_Int32 slotCount); + + // This function is not defined in the generic part, but instead has to be + // defined individually for each CPP--UNO bridge: + /** Initialize a raw vtable block. + + @param block the start address of the raw vtable block + @param slotCount the number of slots + @param vtableNumber zero-based count across all the most derived type's + vtables (for vtable's "offset to top" slot) + @param type non-null most derived type (for vtable's "typeinfo pointer" + slot) + @return a pointer past the last vtable slot + */ + static Slot * initializeBlock( + void * block, sal_Int32 slotCount, sal_Int32 vtableNumber, + typelib_InterfaceTypeDescription * type); + + // This function is not defined in the generic part, but instead has to be + // defined individually for each CPP--UNO bridge: + /** Fill the vtable slots corresponding to all local (i.e., not inherited) + functions of a given interface type (and generate any necessary code + snippets for them). + + @param slots on input, points past the vtable slot to be filled with + the last virtual function local to the given type; on output, points to + the vtable slot filled with the first virtual function local to the + given type + @param code points to the start of the area where code snippets can be + generated + @param writetoexecdiff when the same code area is mapped twice, once for + writing for code-generation, and once for code-execution, then this + records the offset from a writable address to its executable address + @param type the interface type description for which to generate vtable + slots + @param functionOffset the function offset of the first vtable slot + (typically coded into the code snippet for that vtable slot) + @param functionCount the number of vtable slots to fill (the number of + local functions of the given type, passed in so that it doesn't need to + be recomputed) + @param vtableOffset the offset of this vtable (needed to adjust the + this pointer, typically coded into the code snippets for all the filled + vtable slots) + @return a pointer to the remaining code snippet area + */ + static unsigned char * addLocalFunctions( + Slot ** slots, unsigned char * code, +#ifdef USE_DOUBLE_MMAP + sal_PtrDiff writetoexecdiff, +#endif + typelib_InterfaceTypeDescription const * type, sal_Int32 functionOffset, + sal_Int32 functionCount, sal_Int32 vtableOffset); + + // This function is not defined in the generic part, but instead has to be + // defined individually for each CPP--UNO bridge: + /** Flush all the generated code snippets of a vtable, on platforms that + require it. + + @param begin points to the start of the code snippet area + @param end points behind the end of the code snippet area + */ + static void flushCode( + unsigned char const * begin, unsigned char const * end); + + typedef std::unordered_map< OUString, Vtables > Map; + + std::mutex m_mutex; + Map m_map; + + rtl_arena_type * m_arena; +}; + +} + +/* vim:set shiftwidth=4 softtabstop=4 expandtab: */ |