genode/repos/os/include/vfs/env.h
Norman Feske 5ad98f2b7c vfs,libc: introduce Vfs::Env::User interface
The new interface is meant to replace the 'Vfs::Io_response_handler'.
In contrast to the 'Io_response_handler', which had to be called
on a 'Vfs_handle', the new interface does not require any specific
'Vfs_handle'. It is merely meant to prompt the VFS user (like the libc)
to re-attempt stalled I/O operations but it does not provide any
immediate hint, about which of the handles have become ready for
reading/writing.

Issue #4697
2023-01-24 12:07:28 +01:00

80 lines
1.7 KiB
C++

/*
* \brief Cross-plugin VFS environment
* \author Emery Hemingway
* \author Norman Feske
* \date 2018-04-02
*/
/*
* Copyright (C) 2018-2019 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__ENV_H_
#define _INCLUDE__VFS__ENV_H_
#include <vfs/file_system.h>
#include <vfs/remote_io.h>
#include <base/allocator.h>
#include <base/env.h>
namespace Vfs { struct Env; }
struct Vfs::Env : Interface
{
virtual Genode::Env &env() = 0;
/**
* Allocator for creating stuctures shared across open VFS handles
*/
virtual Genode::Allocator &alloc() = 0;
/**
* VFS root file system
*/
virtual File_system &root_dir() = 0;
/**
* Registry of deferred wakeups for plugins interacting with remote peers
*/
virtual Remote_io::Deferred_wakeups &deferred_wakeups() = 0;
/**
* Interface tailored for triggering and waiting for I/O
*/
struct Io : Interface, Genode::Noncopyable
{
/**
* Trigger the deferred wakeup of remote peers
*/
virtual void commit() = 0;
/**
* Wakeup remote peers and wait for I/O progress
*
* This method is intended for implementing synchronous I/O.
*/
virtual void commit_and_wait() = 0;
};
virtual Io &io() = 0;
/**
* Interface for notifying the VFS user about possible progress
*
* This interface allows VFS plugins to prompt the potential unblocking of
* the VFS user, e.g., continuing a write operation that was stalled
* because of a saturated I/O buffer.
*/
struct User : Interface, Genode::Noncopyable
{
virtual void wakeup_vfs_user() = 0;
};
virtual User &user() = 0;
};
#endif /* _INCLUDE__VFS__ENV_H_ */