genode/base/include/signal_session/signal_session.h
2013-01-10 21:44:47 +01:00

97 lines
2.8 KiB
C++

/*
* \brief Signal session interface
* \author Norman Feske
* \date 2009-08-05
*/
/*
* Copyright (C) 2009-2013 Genode Labs GmbH
*
* This file is part of the Genode OS framework, which is distributed
* under the terms of the GNU General Public License version 2.
*/
#ifndef _INCLUDE__SIGNAL_SESSION__SIGNAL_SESSION_H_
#define _INCLUDE__SIGNAL_SESSION__SIGNAL_SESSION_H_
#include <base/capability.h>
#include <base/exception.h>
#include <signal_session/source.h>
#include <session/session.h>
namespace Genode {
class Signal_context;
typedef Capability<Signal_context> Signal_context_capability;
typedef Capability<Signal_source> Signal_source_capability;
struct Signal_session : Session
{
static const char *service_name() { return "SIGNAL"; }
virtual ~Signal_session() { }
class Out_of_metadata : public Exception { };
/**
* Request capability for the signal-source interface
*/
virtual Signal_source_capability signal_source() = 0;
/**
* Allocate signal context
*
* \param imprint opaque value that gets delivered with signals
* originating from the allocated signal-context
* capability
* \return new signal-context capability
* \throw Out_of_metadata
*/
virtual Signal_context_capability alloc_context(long imprint) = 0;
/**
* Free signal-context
*
* \param cap capability of signal-context to release
*/
virtual void free_context(Signal_context_capability cap) = 0;
/**
* Submit signals to the specified signal context
*
* \param context signal destination
* \param cnt number of signals to submit at once
*
* Note that the 'context' argument does not necessarily belong to
* the signal session. Normally, it is a capability obtained from
* a potentially untrusted source. Because we cannot trust this
* capability, signals are not submitted by invoking 'cap' directly
* but by using it as argument to our trusted signal-session
* interface. Otherwise, a potential signal receiver could supply
* a capability with a blocking interface to compromise the
* nonblocking behaviour of the submit function.
*/
virtual void submit(Signal_context_capability context,
unsigned cnt = 1) = 0;
/*********************
** RPC declaration **
*********************/
GENODE_RPC(Rpc_signal_source, Signal_source_capability, signal_source);
GENODE_RPC_THROW(Rpc_alloc_context, Signal_context_capability, alloc_context,
GENODE_TYPE_LIST(Out_of_metadata), long);
GENODE_RPC(Rpc_free_context, void, free_context, Signal_context_capability);
GENODE_RPC(Rpc_submit, void, submit, Signal_context_capability, unsigned);
GENODE_RPC_INTERFACE(Rpc_submit, Rpc_signal_source, Rpc_alloc_context,
Rpc_free_context);
};
}
#endif /* _INCLUDE__CAP_SESSION__CAP_SESSION_H_ */