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109 lines
2.8 KiB
C++
109 lines
2.8 KiB
C++
//
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// SharedMemoryImpl.h
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//
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// Library: Foundation
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// Package: Processes
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// Module: SharedMemoryImpl
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//
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// Definition of the SharedMemoryImpl class.
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//
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// Copyright (c) 2007, Applied Informatics Software Engineering GmbH.
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// and Contributors.
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//
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// SPDX-License-Identifier: BSL-1.0
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//
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#ifndef Foundation_SharedMemoryImpl_INCLUDED
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#define Foundation_SharedMemoryImpl_INCLUDED
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#include "Poco/Foundation.h"
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#include "Poco/RefCountedObject.h"
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#include "Poco/SharedMemory.h"
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namespace Poco
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{
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class Foundation_API SharedMemoryImpl : public RefCountedObject
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/// Shared memory implementation for POSIX platforms.
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{
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public:
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SharedMemoryImpl(const std::string & name, std::size_t size, SharedMemory::AccessMode mode, const void * addrHint, bool server);
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/// Creates or connects to a shared memory object with the given name.
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///
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/// For maximum portability, name should be a valid Unix filename and not
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/// contain any slashes or backslashes.
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///
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/// An address hint can be passed to the system, specifying the desired
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/// start address of the shared memory area. Whether the hint
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/// is actually honored is, however, up to the system. Windows platform
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/// will generally ignore the hint.
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///
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/// If server is set to false, the shared memory region will be unlinked
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/// by calling shm_unlink when the SharedMemory object is destroyed.
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SharedMemoryImpl(const Poco::File & file, SharedMemory::AccessMode mode, const void * addrHint);
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/// Maps the entire contents of file into a shared memory segment.
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///
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/// An address hint can be passed to the system, specifying the desired
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/// start address of the shared memory area. Whether the hint
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/// is actually honored is, however, up to the system. Windows platform
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/// will generally ignore the hint.
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char * begin() const;
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/// Returns the start address of the shared memory segment.
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char * end() const;
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/// Returns the one-past-end end address of the shared memory segment.
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protected:
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void map(const void * addrHint);
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/// Maps the shared memory object.
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void unmap();
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/// Unmaps the shared memory object.
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void close();
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/// Releases the handle for the shared memory segment.
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~SharedMemoryImpl();
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/// Destroys the SharedMemoryImpl.
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private:
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SharedMemoryImpl();
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SharedMemoryImpl(const SharedMemoryImpl &);
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SharedMemoryImpl & operator=(const SharedMemoryImpl &);
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std::size_t _size;
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int _fd;
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char * _address;
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SharedMemory::AccessMode _access;
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std::string _name;
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bool _fileMapped;
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bool _server;
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};
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//
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// inlines
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//
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inline char * SharedMemoryImpl::begin() const
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{
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return _address;
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}
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inline char * SharedMemoryImpl::end() const
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{
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return _address + _size;
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}
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} // namespace Poco
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#endif // Foundation_SharedMemoryImpl_INCLUDED
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