genode/repos/demo/include/launchpad/launchpad.h
Norman Feske 4d442bca30 Streamline exception types
This patch reduces the number of exception types by facilitating
globally defined exceptions for common usage patterns shared by most
services. In particular, RPC functions that demand a session-resource
upgrade not longer reflect this condition via a session-specific
exception but via the 'Out_of_ram' or 'Out_of_caps' types.

Furthermore, the 'Parent::Service_denied', 'Parent::Unavailable',
'Root::Invalid_args', 'Root::Unavailable', 'Service::Invalid_args',
'Service::Unavailable', and 'Local_service::Factory::Denied' types have
been replaced by the single 'Service_denied' exception type defined in
'session/session.h'.

This consolidation eases the error handling (there are fewer exceptions
to handle), alleviates the need to convert exceptions along the
session-creation call chain, and avoids possible aliasing problems
(catching the wrong type with the same name but living in a different
scope).
2017-05-31 13:16:07 +02:00

294 lines
8.8 KiB
C++

/*
* \brief Launchpad interface
* \author Norman Feske
* \date 2006-09-01
*
* This class is a convenience-wrapper for starting and killing
* child processes. To support the Launchpad application, is
* also provides an interface to glues the child handling and
* the GUI together.
*/
/*
* Copyright (C) 2006-2017 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__LAUNCHPAD__LAUNCHPAD_H_
#define _INCLUDE__LAUNCHPAD__LAUNCHPAD_H_
#include <util/xml_node.h>
#include <base/allocator.h>
#include <base/service.h>
#include <base/lock.h>
#include <base/child.h>
#include <timer_session/timer_session.h>
#include <pd_session/client.h>
#include <init/child_policy.h>
#include <os/session_requester.h>
class Launchpad;
class Launchpad_child : public Genode::Child_policy,
public Genode::List<Launchpad_child>::Element,
public Genode::Async_service::Wakeup
{
public:
typedef Genode::Child_policy::Name Name;
typedef Genode::Registered<Genode::Child_service> Child_service;
typedef Genode::Registered<Genode::Parent_service> Parent_service;
typedef Genode::Registry<Child_service> Child_services;
typedef Genode::Registry<Parent_service> Parent_services;
private:
Name const _name;
Binary_name const _elf_name;
Genode::Env &_env;
Genode::Allocator &_alloc;
Genode::Ram_session_capability _ref_ram_cap;
Genode::Ram_session_client _ref_ram { _ref_ram_cap };
Genode::Cap_quota const _cap_quota;
Genode::Ram_quota const _ram_quota;
Parent_services &_parent_services;
Child_services &_child_services;
Genode::Dataspace_capability _config_ds;
Genode::Session_requester _session_requester;
Init::Child_policy_provide_rom_file _config_policy;
Genode::Child _child;
/**
* Child_service::Wakeup callback
*/
void wakeup_async_service() override
{
_session_requester.trigger_update();
}
template <typename T>
static Genode::Service *_find_service(Genode::Registry<T> &services,
Genode::Service::Name const &name)
{
Genode::Service *service = nullptr;
services.for_each([&] (T &s) {
if (!service && (s.name() == name))
service = &s; });
return service;
}
public:
Launchpad_child(Genode::Env &env,
Genode::Allocator &alloc,
Genode::Session_label const &label,
Binary_name const &elf_name,
Genode::Cap_quota cap_quota,
Genode::Ram_quota ram_quota,
Parent_services &parent_services,
Child_services &child_services,
Genode::Dataspace_capability config_ds)
:
_name(label), _elf_name(elf_name),
_env(env), _alloc(alloc),
_ref_ram_cap(env.ram_session_cap()),
_cap_quota(Genode::Child::effective_quota(cap_quota)),
_ram_quota(Genode::Child::effective_quota(ram_quota)),
_parent_services(parent_services),
_child_services(child_services),
_session_requester(env.ep().rpc_ep(), _env.ram(), _env.rm()),
_config_policy("config", config_ds, &_env.ep().rpc_ep()),
_child(_env.rm(), _env.ep().rpc_ep(), *this)
{ }
~Launchpad_child()
{
using namespace Genode;
/* unregister services */
_child_services.for_each(
[&] (Child_service &service) {
if (service.has_id_space(_session_requester.id_space()))
Genode::destroy(_alloc, &service); });
}
/****************************
** Child_policy interface **
****************************/
Name name() const override { return _name; }
Binary_name binary_name() const override { return _elf_name; }
Genode::Pd_session &ref_pd() override { return _env.pd(); }
Genode::Pd_session_capability ref_pd_cap() const override { return _env.pd_session_cap(); }
Genode::Ram_session &ref_ram() override { return _ref_ram; }
Genode::Ram_session_capability ref_ram_cap() const override { return _ref_ram_cap; }
void init(Genode::Pd_session &session,
Genode::Pd_session_capability cap) override
{
session.ref_account(_env.pd_session_cap());
_env.pd().transfer_quota(cap, _cap_quota);
}
void init(Genode::Ram_session &session,
Genode::Ram_session_capability cap) override
{
session.ref_account(_ref_ram_cap);
_ref_ram.transfer_quota(cap, _ram_quota);
}
Genode::Id_space<Genode::Parent::Server> &server_id_space() override {
return _session_requester.id_space(); }
Genode::Service &resolve_session_request(Genode::Service::Name const &service_name,
Genode::Session_state::Args const &args) override
{
Genode::Service *service = nullptr;
/* check for config file request */
if ((service = _config_policy
.resolve_session_request(service_name.string(), args.string())))
return *service;
/* check for "session_requests" ROM request */
Genode::Session_label const label(Genode::label_from_args(args.string()));
if (service_name == Genode::Rom_session::service_name()
&& label.last_element() == Genode::Session_requester::rom_name())
return _session_requester.service();
/* if service is provided by one of our children, use it */
if ((service = _find_service(_child_services, service_name)))
return *service;
/*
* Handle special case of the demo scenario when the user uses
* a nested Launchad for starting another Nitpicker instance
* before starting Liquid_fb. In this case, we do not want to
* delegate Nitpicker's session requests to the parent. The
* parent may be a launchpad again trying to apply the same
* policy. This instance will recognise that the session is not
* available at init (because the actual input and framebuffer
* drivers are singletons, and would therefore block for
* Framebuffer or Input to become available at one of its own
* children. The launchpad with which the user originally
* interacted, however, would block at the parent interface
* until this condition gets satisfied.
*/
if (service_name != "Input"
&& service_name != "Framebuffer"
&& ((service = _find_service(_parent_services, service_name))))
return *service;
Genode::warning(name(), ": service ", service_name, " not available");
throw Genode::Service_denied();
}
void announce_service(Genode::Service::Name const &service_name) override
{
if (_find_service(_child_services, service_name)) {
Genode::warning(name(), ": service ", service_name, " is already registered");
return;
}
new (_alloc)
Child_service(_child_services, service_name,
_session_requester.id_space(),
_child.session_factory(), *this,
_child.ram_session_cap(),
_child.pd_session_cap());
}
};
class Launchpad
{
private:
Genode::Env &_env;
Genode::Heap _heap { _env.ram(), _env.rm() };
unsigned long _initial_quota;
Launchpad_child::Parent_services _parent_services;
Launchpad_child::Child_services _child_services;
Genode::Lock _children_lock;
Genode::List<Launchpad_child> _children;
bool _child_name_exists(Launchpad_child::Name const &);
Launchpad_child::Name _get_unique_child_name(Launchpad_child::Name const &);
Genode::Sliced_heap _sliced_heap;
protected:
int _ypos;
public:
typedef Genode::Cap_quota Cap_quota;
typedef Genode::Ram_quota Ram_quota;
Launchpad(Genode::Env &env, unsigned long initial_quota);
unsigned long initial_quota() { return _initial_quota; }
virtual ~Launchpad() { }
/**
* Process launchpad XML configuration
*/
void process_config(Genode::Xml_node);
/*************************
** Configuring the GUI **
*************************/
virtual void quota(unsigned long quota) { }
virtual void add_launcher(Launchpad_child::Name const &binary_name,
Cap_quota caps, unsigned long default_quota,
Genode::Dataspace_capability config_ds) { }
virtual void add_child(Launchpad_child::Name const &,
unsigned long quota,
Launchpad_child &,
Genode::Allocator &) { }
virtual void remove_child(Launchpad_child::Name const &,
Genode::Allocator &) { }
Launchpad_child *start_child(Launchpad_child::Name const &binary_name,
Cap_quota cap_quota, Ram_quota ram_quota,
Genode::Dataspace_capability config_ds);
/**
* Exit child and close all its sessions
*/
void exit_child(Launchpad_child &child);
};
#endif /* _INCLUDE__LAUNCHPAD__LAUNCHPAD_H_ */