mirror of
https://github.com/genodelabs/genode.git
synced 2024-12-28 01:28:53 +00:00
eba9c15746
The patch adjust the code of the base, base-<kernel>, and os repository.
To adapt existing components to fix violations of the best practices
suggested by "Effective C++" as reported by the -Weffc++ compiler
argument. The changes follow the patterns outlined below:
* A class with virtual functions can no longer publicly inherit base
classed without a vtable. The inherited object may either be moved
to a member variable, or inherited privately. The latter would be
used for classes that inherit 'List::Element' or 'Avl_node'. In order
to enable the 'List' and 'Avl_tree' to access the meta data, the
'List' must become a friend.
* Instead of adding a virtual destructor to abstract base classes,
we inherit the new 'Interface' class, which contains a virtual
destructor. This way, single-line abstract base classes can stay
as compact as they are now. The 'Interface' utility resides in
base/include/util/interface.h.
* With the new warnings enabled, all member variables must be explicitly
initialized. Basic types may be initialized with '='. All other types
are initialized with braces '{ ... }' or as class initializers. If
basic types and non-basic types appear in a row, it is nice to only
use the brace syntax (also for basic types) and align the braces.
* If a class contains pointers as members, it must now also provide a
copy constructor and assignment operator. In the most cases, one
would make them private, effectively disallowing the objects to be
copied. Unfortunately, this warning cannot be fixed be inheriting
our existing 'Noncopyable' class (the compiler fails to detect that
the inheriting class cannot be copied and still gives the error).
For now, we have to manually add declarations for both the copy
constructor and assignment operator as private class members. Those
declarations should be prepended with a comment like this:
/*
* Noncopyable
*/
Thread(Thread const &);
Thread &operator = (Thread const &);
In the future, we should revisit these places and try to replace
the pointers with references. In the presence of at least one
reference member, the compiler would no longer implicitly generate
a copy constructor. So we could remove the manual declaration.
Issue #465
113 lines
2.1 KiB
C++
113 lines
2.1 KiB
C++
/*
|
|
* \brief Representation of an open file
|
|
* \author Norman Feske
|
|
* \date 2011-02-17
|
|
*/
|
|
|
|
/*
|
|
* Copyright (C) 2011-2017 Genode Labs GmbH
|
|
*
|
|
* This file is part of the Genode OS framework, which is distributed
|
|
* under the terms of the GNU Affero General Public License version 3.
|
|
*/
|
|
|
|
#ifndef _INCLUDE__VFS__VFS_HANDLE_H_
|
|
#define _INCLUDE__VFS__VFS_HANDLE_H_
|
|
|
|
#include <vfs/directory_service.h>
|
|
|
|
namespace Vfs{
|
|
class Vfs_handle;
|
|
class File_io_service;
|
|
}
|
|
|
|
|
|
class Vfs::Vfs_handle
|
|
{
|
|
private:
|
|
|
|
Directory_service &_ds;
|
|
File_io_service &_fs;
|
|
Genode::Allocator &_alloc;
|
|
int _status_flags;
|
|
file_size _seek = 0;
|
|
|
|
/*
|
|
* Noncopyable
|
|
*/
|
|
Vfs_handle(Vfs_handle const &);
|
|
Vfs_handle &operator = (Vfs_handle const &);
|
|
|
|
public:
|
|
|
|
/**
|
|
* Opaque handle context
|
|
*/
|
|
struct Context : List<Context>::Element { };
|
|
|
|
Context *context = nullptr;
|
|
|
|
class Guard
|
|
{
|
|
private:
|
|
|
|
/*
|
|
* Noncopyable
|
|
*/
|
|
Guard(Guard const &);
|
|
Guard &operator = (Guard const &);
|
|
|
|
Vfs_handle * const _handle;
|
|
|
|
public:
|
|
|
|
Guard(Vfs_handle *handle) : _handle(handle) { }
|
|
|
|
~Guard()
|
|
{
|
|
if (_handle)
|
|
_handle->_ds.close(_handle);
|
|
}
|
|
};
|
|
|
|
enum { STATUS_RDONLY = 0, STATUS_WRONLY = 1, STATUS_RDWR = 2 };
|
|
|
|
Vfs_handle(Directory_service &ds,
|
|
File_io_service &fs,
|
|
Genode::Allocator &alloc,
|
|
int status_flags)
|
|
:
|
|
_ds(ds), _fs(fs),
|
|
_alloc(alloc),
|
|
_status_flags(status_flags)
|
|
{ }
|
|
|
|
virtual ~Vfs_handle() { }
|
|
|
|
Directory_service &ds() { return _ds; }
|
|
File_io_service &fs() { return _fs; }
|
|
Allocator &alloc() { return _alloc; }
|
|
|
|
int status_flags() const { return _status_flags; }
|
|
|
|
void status_flags(int flags) { _status_flags = flags; }
|
|
|
|
/**
|
|
* Return seek offset in bytes
|
|
*/
|
|
file_size seek() const { return _seek; }
|
|
|
|
/**
|
|
* Set seek offset in bytes
|
|
*/
|
|
void seek(file_offset seek) { _seek = seek; }
|
|
|
|
/**
|
|
* Advance seek offset by 'incr' bytes
|
|
*/
|
|
void advance_seek(file_size incr) { _seek += incr; }
|
|
};
|
|
|
|
|
|
#endif /* _INCLUDE__VFS__VFS_HANDLE_H_ */
|