genode/repos/base/include/rom_session/rom_session.h
Norman Feske cfdbccc5c2 Remove blocking calls from root and parent RPCs
This is a redesign of the root and parent interfaces to eliminate
blocking RPC calls.

- New session representation at the parent (base/session_state.h)
- base-internal root proxy mechanism as migration path
- Redesign of base/service.h
- Removes ancient 'Connection::KEEP_OPEN' feature
- Interface change of 'Child', 'Child_policy', 'Slave', 'Slave_policy'
- New 'Slave::Connection'
- Changed child-construction procedure to be compatible with the
  non-blocking parent interface and to be easier to use
- The child's initial LOG session, its binary ROM session, and the
  linker ROM session have become part of the child's envirenment.
- Session upgrading must now be performed via 'env.upgrade' instead
  of performing a sole RPC call the parent. To make RAM upgrades
  easier, the 'Connection' provides a new 'upgrade_ram' method.

Issue #2120
2016-11-25 16:06:42 +01:00

112 lines
3.5 KiB
C++

/*
* \brief ROM session interface
* \author Norman Feske
* \date 2006-07-06
*
* A ROM session corresponds to a ROM module. The module name is specified as
* an argument on session creation.
*/
/*
* Copyright (C) 2006-2014 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__ROM_SESSION__ROM_SESSION_H_
#define _INCLUDE__ROM_SESSION__ROM_SESSION_H_
#include <dataspace/capability.h>
#include <session/session.h>
#include <base/signal.h>
namespace Genode {
struct Rom_dataspace;
struct Rom_session;
struct Rom_session_client;
typedef Capability<Rom_dataspace> Rom_dataspace_capability;
}
struct Genode::Rom_dataspace : Dataspace { };
struct Genode::Rom_session : Session
{
static const char *service_name() { return "ROM"; }
typedef Rom_session_client Client;
virtual ~Rom_session() { }
/**
* Request dataspace containing the ROM session data
*
* \return capability to ROM dataspace
*
* The capability may be invalid.
*
* Consecutive calls of this method are not guaranteed to return the
* same dataspace as dynamic ROM sessions may update the ROM data
* during the lifetime of the session. When calling the method, the
* server may destroy the old dataspace and replace it with a new one
* containing the updated data. Hence, prior calling this method, the
* client should make sure to detach the previously requested dataspace
* from its local address space.
*/
virtual Rom_dataspace_capability dataspace() = 0;
/**
* Update ROM dataspace content
*
* This method is an optimization for use cases where ROM dataspaces
* are updated at a high rate. In such cases, requesting a new
* dataspace for each update induces a large overhead because
* memory mappings must be revoked and updated (e.g., handling the
* page faults referring to the dataspace). If the updated content
* fits in the existing dataspace, those costly operations can be
* omitted.
*
* When this method is called, the server may replace the dataspace
* content with new data.
*
* \return true if the existing dataspace contains up-to-date content,
* or false if a new dataspace must be requested via the
* 'dataspace' method
*/
virtual bool update() { return false; }
/**
* Register signal handler to be notified of ROM data changes
*
* The ROM session interface allows for the implementation of ROM
* services that dynamically update the data exported as ROM dataspace
* during the lifetime of the session. This is useful in scenarios
* where this data is generated rather than originating from a static
* file, for example to update a program's configuration at runtime.
*
* By installing a signal handler using the 'sigh()' method, the
* client will receive a notification each time the data changes at the
* server. From the client's perspective, the original data contained
* in the currently used dataspace remains unchanged until the client
* calls 'dataspace()' the next time.
*/
virtual void sigh(Signal_context_capability sigh) = 0;
/*********************
** RPC declaration **
*********************/
GENODE_RPC(Rpc_dataspace, Rom_dataspace_capability, dataspace);
GENODE_RPC(Rpc_sigh, void, sigh, Signal_context_capability);
GENODE_RPC(Rpc_update, bool, update);
GENODE_RPC_INTERFACE(Rpc_dataspace, Rpc_update, Rpc_sigh);
};
#endif /* _INCLUDE__ROM_SESSION__ROM_SESSION_H_ */