black_hole: add Play and Record session

This commit introduces support for the Play and Record session to
the black hole component in the most minimal way possible.

Fixes #5157.

repos/os/recipes/pkg/black_hole/runtime

@@ -11,6 +11,8 @@
 		<report/>
 		<gpu/>
 		<usb/>
+		<play/>
+		<record/>
 	</provides>
 
 	<config>
@@ -23,6 +25,8 @@
 		<rom/>
 		<gpu/>
 		<usb/>
+		<play/>
+		<record/>
 	</config>
 
 	<content>

repos/os/recipes/src/black_hole/used_apis

@@ -8,4 +8,6 @@ report_session
 uplink_session
 gpu_session
 usb_session
+play_session
+record_session
 os

repos/os/src/server/black_hole/README

@@ -13,6 +13,8 @@ in the configuration of the component.
 * ROM
 * Gpu
 * Usb
+* Play
+* Record
 
 <config>
 	<audio_in/>
@@ -24,6 +26,8 @@ in the configuration of the component.
 	<rom/>
 	<gpu/>
 	<usb/>
+	<play/>
+	<record/>
 </config>
 
 Black hole optionally requests the following sessions as client.

repos/os/src/server/black_hole/config.xsd

@@ -4,6 +4,8 @@
 	<xs:element name="config">
 		<xs:complexType>
 			<xs:choice minOccurs="0" maxOccurs="unbounded">
+				<xs:element name="record"/>
+				<xs:element name="play"/>
 				<xs:element name="usb"/>
 				<xs:element name="gpu"/>
 				<xs:element name="rom"/>

repos/os/src/server/black_hole/main.cc

@@ -32,6 +32,8 @@
 #include "rom.h"
 #include "gpu.h"
 #include "usb.h"
+#include "play.h"
+#include "record.h"
 
 
 /***************
@@ -57,6 +59,8 @@ struct Black_hole::Main
 	Genode::Constructible<Gpu_root>        gpu_root       { };
 	Genode::Constructible<Usb_root>        usb_root       { };
 	Genode::Constructible<Uplink_client>   uplink_client  { };
+	Genode::Constructible<Play_root>       play_root      { };
+	Genode::Constructible<Record_root>     record_root    { };
 
 	Main(Genode::Env &env) : env(env)
 	{
@@ -102,6 +106,14 @@ struct Black_hole::Main
 			usb_root.construct(env, heap);
 			env.parent().announce(env.ep().manage(*usb_root));
 		}
+		if (_config_rom.xml().has_sub_node("play")) {
+			play_root.construct(env, heap);
+			env.parent().announce(env.ep().manage(*play_root));
+		}
+		if (_config_rom.xml().has_sub_node("record")) {
+			record_root.construct(env, heap);
+			env.parent().announce(env.ep().manage(*record_root));
+		}
 
 		if (_config_rom.xml().has_sub_node("uplink_client")) {
 			uplink_client.construct(env, heap);

repos/os/src/server/black_hole/play.h

@@ -0,0 +1,95 @@
+/*
+ * \brief  Play service of the black hole component
+ * \author Josef Soentgen
+ * \date   2024-04-02
+ */
+
+/*
+ * Copyright (C) 2024 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 _PLAY_SESSION_H_
+#define _PLAY_SESSION_H_
+
+#include <base/attached_ram_dataspace.h>
+#include <play_session/play_session.h>
+#include <root/component.h>
+
+namespace Black_hole {
+
+	using namespace Genode;
+
+	class  Play_session;
+	class  Play_root;
+}
+
+
+class Black_hole::Play_session : public Session_object<Play::Session, Play_session>
+{
+	private:
+
+		Env                     &_env;
+		Attached_ram_dataspace   _ram_ds;
+
+	public:
+
+		Play_session(Env             &env,
+		             Resources const &resources,
+		             Label     const &label,
+		             Diag      const &diag)
+		:
+			Session_object(env.ep(), resources, label, diag),
+			_env(env),
+			_ram_ds(_env.ram(), _env.rm(), Play::Session::DATASPACE_SIZE)
+		{ }
+
+		/****************************
+		 ** Play session interface **
+		 ****************************/
+
+		Dataspace_capability dataspace() { return _ram_ds.cap(); }
+
+		Play::Time_window schedule(Play::Time_window,
+		                           Play::Duration,
+		                           Play::Num_samples)
+		{
+			return { };
+		}
+
+		void stop() { }
+};
+
+
+class Black_hole::Play_root : public Root_component<Play_session>
+{
+	private:
+
+		Env &_env;
+
+	protected:
+
+		Play_session *_create_session(const char *args) override
+		{
+			if (session_resources_from_args(args).ram_quota.value < Play::Session::DATASPACE_SIZE)
+				throw Insufficient_ram_quota();
+
+			return new (md_alloc())
+				Play_session(_env,
+				             session_resources_from_args(args),
+				             session_label_from_args(args),
+				             session_diag_from_args(args));
+		}
+
+	public:
+
+		Play_root(Env &env, Allocator &md_alloc)
+		:
+			Root_component<Play_session>(&env.ep().rpc_ep(), &md_alloc),
+			_env(env)
+		{ }
+};
+
+#endif /* _PLAY_SESSION_H_ */

repos/os/src/server/black_hole/record.h

@@ -0,0 +1,109 @@
+/*
+ * \brief  Record service of the black hole component
+ * \author Josef Soentgen
+ * \date   2024-04-02
+ */
+
+/*
+ * Copyright (C) 2024 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 _RECORD_SESSION_H_
+#define _RECORD_SESSION_H_
+
+#include <base/attached_ram_dataspace.h>
+#include <record_session/record_session.h>
+#include <root/component.h>
+
+namespace Black_hole {
+
+	using namespace Genode;
+
+	class  Record_session;
+	class  Record_root;
+}
+
+
+class Black_hole::Record_session : public Session_object<Record::Session, Record_session>
+{
+	private:
+
+		Env                       &_env;
+		Attached_ram_dataspace     _ram_ds;
+		Signal_context_capability  _wakeup_sigh;
+
+	public:
+
+		Record_session(Env             &env,
+		             Resources const &resources,
+		             Label     const &label,
+		             Diag      const &diag)
+		:
+			Session_object(env.ep(), resources, label, diag),
+			_env(env),
+			_ram_ds(_env.ram(), _env.rm(), Record::Session::DATASPACE_SIZE),
+			_wakeup_sigh()
+		{ }
+
+		void wakeup()
+		{
+			if (_wakeup_sigh.valid())
+				Signal_transmitter(_wakeup_sigh).submit();
+		}
+
+		/****************************
+		 ** Record session interface **
+		 ****************************/
+
+		Dataspace_capability dataspace() { return _ram_ds.cap(); }
+
+		void wakeup_sigh(Signal_context_capability sigh)
+		{
+			_wakeup_sigh = sigh;
+			wakeup(); /* initial wakeup */
+		}
+
+		Record::Session::Record_result record(Record::Num_samples)
+		{
+			return Record::Time_window { 0, 0 };
+		}
+
+		void record_at(Record::Time_window,
+		               Record::Num_samples)
+		{ }
+};
+
+
+class Black_hole::Record_root : public Root_component<Record_session>
+{
+	private:
+
+		Env &_env;
+
+	protected:
+
+		Record_session *_create_session(const char *args) override
+		{
+			if (session_resources_from_args(args).ram_quota.value < Record::Session::DATASPACE_SIZE)
+				throw Insufficient_ram_quota();
+
+			return new (md_alloc())
+				Record_session(_env,
+				             session_resources_from_args(args),
+				             session_label_from_args(args),
+				             session_diag_from_args(args));
+		}
+
+	public:
+
+		Record_root(Env &env, Allocator &md_alloc)
+		:
+			Root_component<Record_session>(&env.ep().rpc_ep(), &md_alloc),
+			_env(env)
+		{ }
+};
+
+#endif /* _RECORD_SESSION_H_ */