mirror of
https://github.com/ClickHouse/ClickHouse.git
synced 2024-11-28 18:42:26 +00:00
109 lines
2.8 KiB
C++
109 lines
2.8 KiB
C++
//
|
|
// SharedMemoryImpl.h
|
|
//
|
|
// Library: Foundation
|
|
// Package: Processes
|
|
// Module: SharedMemoryImpl
|
|
//
|
|
// Definition of the SharedMemoryImpl class.
|
|
//
|
|
// Copyright (c) 2007, Applied Informatics Software Engineering GmbH.
|
|
// and Contributors.
|
|
//
|
|
// SPDX-License-Identifier: BSL-1.0
|
|
//
|
|
|
|
|
|
#ifndef Foundation_SharedMemoryImpl_INCLUDED
|
|
#define Foundation_SharedMemoryImpl_INCLUDED
|
|
|
|
|
|
#include "Poco/Foundation.h"
|
|
#include "Poco/RefCountedObject.h"
|
|
#include "Poco/SharedMemory.h"
|
|
|
|
|
|
namespace Poco
|
|
{
|
|
|
|
|
|
class Foundation_API SharedMemoryImpl : public RefCountedObject
|
|
/// Shared memory implementation for POSIX platforms.
|
|
{
|
|
public:
|
|
SharedMemoryImpl(const std::string & name, std::size_t size, SharedMemory::AccessMode mode, const void * addrHint, bool server);
|
|
/// Creates or connects to a shared memory object with the given name.
|
|
///
|
|
/// For maximum portability, name should be a valid Unix filename and not
|
|
/// contain any slashes or backslashes.
|
|
///
|
|
/// An address hint can be passed to the system, specifying the desired
|
|
/// start address of the shared memory area. Whether the hint
|
|
/// is actually honored is, however, up to the system. Windows platform
|
|
/// will generally ignore the hint.
|
|
///
|
|
/// If server is set to false, the shared memory region will be unlinked
|
|
/// by calling shm_unlink when the SharedMemory object is destroyed.
|
|
|
|
SharedMemoryImpl(const Poco::File & file, SharedMemory::AccessMode mode, const void * addrHint);
|
|
/// Maps the entire contents of file into a shared memory segment.
|
|
///
|
|
/// An address hint can be passed to the system, specifying the desired
|
|
/// start address of the shared memory area. Whether the hint
|
|
/// is actually honored is, however, up to the system. Windows platform
|
|
/// will generally ignore the hint.
|
|
|
|
char * begin() const;
|
|
/// Returns the start address of the shared memory segment.
|
|
|
|
char * end() const;
|
|
/// Returns the one-past-end end address of the shared memory segment.
|
|
|
|
protected:
|
|
void map(const void * addrHint);
|
|
/// Maps the shared memory object.
|
|
|
|
void unmap();
|
|
/// Unmaps the shared memory object.
|
|
|
|
void close();
|
|
/// Releases the handle for the shared memory segment.
|
|
|
|
~SharedMemoryImpl();
|
|
/// Destroys the SharedMemoryImpl.
|
|
|
|
private:
|
|
SharedMemoryImpl();
|
|
SharedMemoryImpl(const SharedMemoryImpl &);
|
|
SharedMemoryImpl & operator=(const SharedMemoryImpl &);
|
|
|
|
std::size_t _size;
|
|
int _fd;
|
|
char * _address;
|
|
SharedMemory::AccessMode _access;
|
|
std::string _name;
|
|
bool _fileMapped;
|
|
bool _server;
|
|
};
|
|
|
|
|
|
//
|
|
// inlines
|
|
//
|
|
inline char * SharedMemoryImpl::begin() const
|
|
{
|
|
return _address;
|
|
}
|
|
|
|
|
|
inline char * SharedMemoryImpl::end() const
|
|
{
|
|
return _address + _size;
|
|
}
|
|
|
|
|
|
} // namespace Poco
|
|
|
|
|
|
#endif // Foundation_SharedMemoryImpl_INCLUDED
|