genode/repos/base/include/trace_session/client.h

/*
 * \brief  Client-side TRACE session interface
 * \author Norman Feske
 * \date   2013-08-12
 */

/*
 * Copyright (C) 2013-2017 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__TRACE_SESSION__CLIENT_H_
#define _INCLUDE__TRACE_SESSION__CLIENT_H_

#include <trace_session/trace_session.h>
#include <base/rpc_client.h>
#include <base/env.h>

namespace Genode { namespace Trace { struct Session_client; } }


struct Genode::Trace::Session_client : Genode::Rpc_client<Genode::Trace::Session>
{
	private:

		/**
		 * Shared-memory buffer used for carrying the payload of the
		 * 'subjects()' RPC function.
		 */
		class Argument_buffer
		{
			private:

				/*
				 * Noncopyable
				 */
				Argument_buffer(Argument_buffer const &);
				Argument_buffer &operator = (Argument_buffer const &);

			public:

				Region_map &rm;
				char       *base;
				size_t      size;

				Argument_buffer(Region_map &rm, Dataspace_capability ds)
				:
					rm(rm),
					base(rm.attach(ds)),
					size(ds.call<Dataspace::Rpc_size>())
				{ }

				~Argument_buffer()
				{
					rm.detach(base);
				}
		};

		Argument_buffer _argument_buffer;

	public:

		/**
		 * Constructor
		 */
		explicit Session_client(Region_map &rm, Capability<Trace::Session> session)
		:
			Rpc_client<Trace::Session>(session),
			_argument_buffer(rm, call<Rpc_dataspace>())
		{ }

		/**
		 * Retrieve subject directory
		 *
		 * \throw Out_of_ram
		 * \throw Out_of_caps
		 */
		virtual size_t subjects(Subject_id *dst, size_t dst_len)
		{
			size_t const num_subjects = min(call<Rpc_subjects>(), dst_len);

			memcpy(dst, _argument_buffer.base, num_subjects*sizeof(Subject_id));

			return num_subjects;
		}

		struct For_each_subject_info_result { size_t count; size_t limit; };

		template <typename FN>
		For_each_subject_info_result for_each_subject_info(FN const &fn)
		{
			size_t const num_subjects = call<Rpc_subject_infos>();
			size_t const max_subjects = _argument_buffer.size / (sizeof(Subject_info) + sizeof(Subject_id));

			Subject_info * const infos = reinterpret_cast<Subject_info *>(_argument_buffer.base);
			Subject_id   * const ids   = reinterpret_cast<Subject_id *>(infos + max_subjects);

			for (unsigned i = 0; i < num_subjects; i++) {
				fn(ids[i], infos[i]);
			}

			return { .count = num_subjects, .limit = max_subjects };
		}

		Policy_id alloc_policy(size_t size) override {
			return call<Rpc_alloc_policy>(size); }

		Dataspace_capability policy(Policy_id policy_id) override {
			return call<Rpc_policy>(policy_id); }

		void unload_policy(Policy_id policy_id) override {
			call<Rpc_unload_policy>(policy_id); }

		void trace(Subject_id s, Policy_id p, size_t buffer_size) override {
			call<Rpc_trace>(s, p, buffer_size); }

		void rule(Session_label const &label, Thread_name const &thread,
		          Policy_id policy, size_t buffer_size) override {
			call<Rpc_rule>(label, thread, policy, buffer_size); }

		void pause(Subject_id subject) override {
			call<Rpc_pause>(subject); }

		void resume(Subject_id subject) override {
			call<Rpc_resume>(subject); }

		Subject_info subject_info(Subject_id subject) override {
			return call<Rpc_subject_info>(subject); }

		Dataspace_capability buffer(Subject_id subject) override {
			return call<Rpc_buffer>(subject); }

		void free(Subject_id subject) override {
			call<Rpc_free>(subject); }
};

#endif /* _INCLUDE__TRACE_SESSION__CLIENT_H_ */