thread/Thread: use BoundMethod

src/IOThread.cxx

@@ -27,12 +27,17 @@
 
 #include <assert.h>
 
-static struct {
+static struct IOThread {
 	Mutex mutex;
 	Cond cond;
 
 	EventLoop *loop;
 	Thread thread;
+
+	IOThread():thread(BIND_THIS_METHOD(Run)) {}
+
+private:
+	void Run() noexcept;
 } io;
 
 void
@@ -44,15 +49,15 @@ io_thread_run(void)
 	io.loop->Run();
 }
 
-static void
+inline void
-io_thread_func(gcc_unused void *arg)
+IOThread::Run() noexcept
 {
 	SetThreadName("io");
 
 	/* lock+unlock to synchronize with io_thread_start(), to be
 	   sure that io.thread is set */
-	io.mutex.lock();
+	mutex.lock();
-	io.mutex.unlock();
+	mutex.unlock();
 
 	io_thread_run();
 }
@@ -73,7 +78,7 @@ io_thread_start()
 	assert(!io.thread.IsDefined());
 
 	const std::lock_guard<Mutex> protect(io.mutex);
-	io.thread.Start(io_thread_func, nullptr);
+	io.thread.Start();
 }
 
 void

src/db/update/Service.cxx

@@ -43,6 +43,7 @@ UpdateService::UpdateService(EventLoop &_loop, SimpleDatabase &_db,
 	:DeferredMonitor(_loop),
 	 db(_db), storage(_storage),
 	 listener(_listener),
+	 update_thread(BIND_THIS_METHOD(Task)),
 	 update_task_id(0),
 	 walk(nullptr)
 {
@@ -140,13 +141,6 @@ UpdateService::Task()
 	DeferredMonitor::Schedule();
 }
 
-void
-UpdateService::Task(void *ctx)
-{
-	UpdateService &service = *(UpdateService *)ctx;
-	return service.Task();
-}
-
 void
 UpdateService::StartThread(UpdateQueueItem &&i)
 {
@@ -158,7 +152,7 @@ UpdateService::StartThread(UpdateQueueItem &&i)
 	next = std::move(i);
 	walk = new UpdateWalk(GetEventLoop(), listener, *next.storage);
 
-	update_thread.Start(Task, this);
+	update_thread.Start();
 
 	FormatDebug(update_domain,
 		    "spawned thread for update job id %i", next.id);

src/db/update/Service.hxx

@@ -98,7 +98,6 @@ private:
 
 	/* the update thread */
 	void Task();
-	static void Task(void *ctx);
 
 	void StartThread(UpdateQueueItem &&i);
 

src/decoder/DecoderControl.cxx

@@ -30,7 +30,8 @@
 DecoderControl::DecoderControl(Mutex &_mutex, Cond &_client_cond,
 			       const AudioFormat _configured_audio_format,
 			       const ReplayGainConfig &_replay_gain_config)
-	:mutex(_mutex), client_cond(_client_cond),
+	:thread(BIND_THIS_METHOD(RunThread)),
+	 mutex(_mutex), client_cond(_client_cond),
 	 configured_audio_format(_configured_audio_format),
 	 replay_gain_config(_replay_gain_config) {}
 

src/decoder/DecoderControl.hxx

@@ -415,6 +415,9 @@ public:
 	 * mixramp_start/mixramp_end.
 	 */
 	void CycleMixRamp();
+
+private:
+	void RunThread();
 };
 
 #endif

src/decoder/DecoderThread.cxx

@@ -513,30 +513,28 @@ try {
 	dc.client_cond.signal();
 }
 
-static void
+void
-decoder_task(void *arg)
+DecoderControl::RunThread()
 {
-	DecoderControl &dc = *(DecoderControl *)arg;
-
 	SetThreadName("decoder");
 
-	const std::lock_guard<Mutex> protect(dc.mutex);
+	const std::lock_guard<Mutex> protect(mutex);
 
 	do {
-		assert(dc.state == DecoderState::STOP ||
+		assert(state == DecoderState::STOP ||
-		       dc.state == DecoderState::ERROR);
+		       state == DecoderState::ERROR);
 
-		switch (dc.command) {
+		switch (command) {
 		case DecoderCommand::START:
-			dc.CycleMixRamp();
+			CycleMixRamp();
-			dc.replay_gain_prev_db = dc.replay_gain_db;
+			replay_gain_prev_db = replay_gain_db;
-			dc.replay_gain_db = 0;
+			replay_gain_db = 0;
 
-			decoder_run(dc);
+			decoder_run(*this);
 
-			if (dc.state == DecoderState::ERROR) {
+			if (state == DecoderState::ERROR) {
 				try {
-					std::rethrow_exception(dc.error);
+					std::rethrow_exception(error);
 				} catch (const std::exception &e) {
 					LogError(e);
 				} catch (...) {
@@ -552,20 +550,20 @@ decoder_task(void *arg)
 			/* we need to clear the pipe here; usually the
 			   PlayerThread is responsible, but it is not
 			   aware that the decoder has finished */
-			dc.pipe->Clear(*dc.buffer);
+			pipe->Clear(*buffer);
 
-			decoder_run(dc);
+			decoder_run(*this);
 			break;
 
 		case DecoderCommand::STOP:
-			dc.CommandFinishedLocked();
+			CommandFinishedLocked();
 			break;
 
 		case DecoderCommand::NONE:
-			dc.Wait();
+			Wait();
 			break;
 		}
-	} while (dc.command != DecoderCommand::NONE || !dc.quit);
+	} while (command != DecoderCommand::NONE || !quit);
 }
 
 void
@@ -574,5 +572,5 @@ decoder_thread_start(DecoderControl &dc)
 	assert(!dc.thread.IsDefined());
 
 	dc.quit = false;
-	dc.thread.Start(decoder_task, &dc);
+	dc.thread.Start();
 }

src/input/ThreadInputStream.cxx

@@ -54,10 +54,10 @@ ThreadInputStream::Start()
 	assert(p != nullptr);
 
 	buffer = new CircularBuffer<uint8_t>((uint8_t *)p, buffer_size);
-	thread.Start(ThreadFunc, this);
+	thread.Start();
 }
 
-inline void
+void
 ThreadInputStream::ThreadFunc()
 {
 	FormatThreadName("input:%s", plugin);
@@ -107,13 +107,6 @@ ThreadInputStream::ThreadFunc()
 	Close();
 }
 
-void
-ThreadInputStream::ThreadFunc(void *ctx)
-{
-	ThreadInputStream &tis = *(ThreadInputStream *)ctx;
-	tis.ThreadFunc();
-}
-
 void
 ThreadInputStream::Check()
 {

src/input/ThreadInputStream.hxx

@@ -73,6 +73,7 @@ public:
 			  size_t _buffer_size)
 		:InputStream(_uri, _mutex, _cond),
 		 plugin(_plugin),
+		 thread(BIND_THIS_METHOD(ThreadFunc)),
 		 buffer_size(_buffer_size) {}
 
 	virtual ~ThreadInputStream();
@@ -138,7 +139,6 @@ protected:
 
 private:
 	void ThreadFunc();
-	static void ThreadFunc(void *ctx);
 };
 
 #endif

src/neighbor/plugins/SmbclientNeighborPlugin.cxx

@@ -69,7 +69,8 @@ class SmbclientNeighborExplorer final : public NeighborExplorer {
 
 public:
 	SmbclientNeighborExplorer(NeighborListener &_listener)
-		:NeighborExplorer(_listener) {}
+		:NeighborExplorer(_listener),
+		 thread(BIND_THIS_METHOD(ThreadFunc)) {}
 
 	/* virtual methods from class NeighborExplorer */
 	void Open() override;
@@ -79,14 +80,13 @@ public:
 private:
 	void Run();
 	void ThreadFunc();
-	static void ThreadFunc(void *ctx);
 };
 
 void
 SmbclientNeighborExplorer::Open()
 {
 	quit = false;
-	thread.Start(ThreadFunc, this);
+	thread.Start();
 }
 
 void
@@ -239,6 +239,8 @@ SmbclientNeighborExplorer::Run()
 inline void
 SmbclientNeighborExplorer::ThreadFunc()
 {
+	SetThreadName("smbclient");
+
 	mutex.lock();
 
 	while (!quit) {
@@ -257,15 +259,6 @@ SmbclientNeighborExplorer::ThreadFunc()
 	mutex.unlock();
 }
 
-void
-SmbclientNeighborExplorer::ThreadFunc(void *ctx)
-{
-	SetThreadName("smbclient");
-
-	SmbclientNeighborExplorer &e = *(SmbclientNeighborExplorer *)ctx;
-	e.ThreadFunc();
-}
-
 static NeighborExplorer *
 smbclient_neighbor_create(gcc_unused EventLoop &loop,
 			  NeighborListener &listener,

src/output/Init.cxx

@@ -51,7 +51,8 @@
 
 AudioOutput::AudioOutput(const AudioOutputPlugin &_plugin,
 			 const ConfigBlock &block)
-	:plugin(_plugin)
+	:plugin(_plugin),
+	 thread(BIND_THIS_METHOD(Task))
 {
 	assert(plugin.finish != nullptr);
 	assert(plugin.open != nullptr);

src/output/Internal.hxx

@@ -515,7 +515,6 @@ private:
 	 * The OutputThread.
 	 */
 	void Task();
-	static void Task(void *arg);
 };
 
 /**

src/output/OutputThread.cxx

@@ -396,7 +396,7 @@ AudioOutput::Pause()
 	pause = false;
 }
 
-inline void
+void
 AudioOutput::Task()
 {
 	FormatThreadName("output:%s", name);
@@ -512,17 +512,10 @@ AudioOutput::Task()
 	}
 }
 
-void
-AudioOutput::Task(void *arg)
-{
-	AudioOutput *ao = (AudioOutput *)arg;
-	ao->Task();
-}
-
 void
 AudioOutput::StartThread()
 {
 	assert(command == Command::NONE);
 
-	thread.Start(Task, this);
+	thread.Start();
 }

src/player/Control.cxx

@@ -37,6 +37,7 @@ PlayerControl::PlayerControl(PlayerListener &_listener,
 	 buffer_chunks(_buffer_chunks),
 	 buffered_before_play(_buffered_before_play),
 	 configured_audio_format(_configured_audio_format),
+	 thread(BIND_THIS_METHOD(RunThread)),
 	 replay_gain_config(_replay_gain_config)
 {
 }

src/player/Control.hxx

@@ -537,6 +537,9 @@ public:
 	void ApplyEnabled() override {
 		LockUpdateAudio();
 	}
+
+private:
+	void RunThread();
 };
 
 #endif

src/player/Thread.cxx

@@ -1147,91 +1147,89 @@ do_play(PlayerControl &pc, DecoderControl &dc,
 	player.Run();
 }
 
-static void
+void
-player_task(void *arg)
+PlayerControl::RunThread()
 {
-	PlayerControl &pc = *(PlayerControl *)arg;
-
 	SetThreadName("player");
 
-	DecoderControl dc(pc.mutex, pc.cond,
+	DecoderControl dc(mutex, cond,
-			  pc.configured_audio_format,
+			  configured_audio_format,
-			  pc.replay_gain_config);
+			  replay_gain_config);
 	decoder_thread_start(dc);
 
-	MusicBuffer buffer(pc.buffer_chunks);
+	MusicBuffer buffer(buffer_chunks);
 
-	pc.Lock();
+	Lock();
 
 	while (1) {
-		switch (pc.command) {
+		switch (command) {
 		case PlayerCommand::SEEK:
 		case PlayerCommand::QUEUE:
-			assert(pc.next_song != nullptr);
+			assert(next_song != nullptr);
 
-			pc.Unlock();
+			Unlock();
-			do_play(pc, dc, buffer);
+			do_play(*this, dc, buffer);
-			pc.listener.OnPlayerSync();
+			listener.OnPlayerSync();
-			pc.Lock();
+			Lock();
 			break;
 
 		case PlayerCommand::STOP:
-			pc.Unlock();
+			Unlock();
-			pc.outputs.Cancel();
+			outputs.Cancel();
-			pc.Lock();
+			Lock();
 
 			/* fall through */
 
 		case PlayerCommand::PAUSE:
-			delete pc.next_song;
+			delete next_song;
-			pc.next_song = nullptr;
+			next_song = nullptr;
 
-			pc.CommandFinished();
+			CommandFinished();
 			break;
 
 		case PlayerCommand::CLOSE_AUDIO:
-			pc.Unlock();
+			Unlock();
 
-			pc.outputs.Release();
+			outputs.Release();
 
-			pc.Lock();
+			Lock();
-			pc.CommandFinished();
+			CommandFinished();
 
 			assert(buffer.IsEmptyUnsafe());
 
 			break;
 
 		case PlayerCommand::UPDATE_AUDIO:
-			pc.Unlock();
+			Unlock();
-			pc.outputs.EnableDisable();
+			outputs.EnableDisable();
-			pc.Lock();
+			Lock();
-			pc.CommandFinished();
+			CommandFinished();
 			break;
 
 		case PlayerCommand::EXIT:
-			pc.Unlock();
+			Unlock();
 
 			dc.Quit();
 
-			pc.outputs.Close();
+			outputs.Close();
 
-			pc.LockCommandFinished();
+			LockCommandFinished();
 			return;
 
 		case PlayerCommand::CANCEL:
-			delete pc.next_song;
+			delete next_song;
-			pc.next_song = nullptr;
+			next_song = nullptr;
 
-			pc.CommandFinished();
+			CommandFinished();
 			break;
 
 		case PlayerCommand::REFRESH:
 			/* no-op when not playing */
-			pc.CommandFinished();
+			CommandFinished();
 			break;
 
 		case PlayerCommand::NONE:
-			pc.Wait();
+			Wait();
 			break;
 		}
 	}
@@ -1242,5 +1240,5 @@ StartPlayerThread(PlayerControl &pc)
 {
 	assert(!pc.thread.IsDefined());
 
-	pc.thread.Start(player_task, &pc);
+	pc.thread.Start();
 }

src/thread/Thread.cxx

@@ -25,14 +25,11 @@
 #include "java/Global.hxx"
 #endif
 
-bool
+void
-Thread::Start(void (*_f)(void *ctx), void *_ctx)
+Thread::Start()
 {
 	assert(!IsDefined());
 
-	f = _f;
-	ctx = _ctx;
-
 #ifdef _WIN32
 	handle = ::CreateThread(nullptr, 0, ThreadProc, this, 0, &id);
 	if (handle == nullptr)
@@ -56,8 +53,6 @@ Thread::Start(void (*_f)(void *ctx), void *_ctx)
 	creating = false;
 #endif
 #endif
-
-	return true;
 }
 
 void
@@ -89,7 +84,7 @@ Thread::Run()
 #endif
 #endif
 
-	f(ctx);
+	f();
 
 #ifdef ANDROID
 	Java::DetachCurrentThread();

src/thread/Thread.hxx

@@ -21,6 +21,7 @@
 #define MPD_THREAD_HXX
 
 #include "check.h"
+#include "util/BindMethod.hxx"
 #include "Compiler.h"
 
 #ifdef _WIN32
@@ -32,6 +33,9 @@
 #include <assert.h>
 
 class Thread {
+	typedef BoundMethod<void()> Function;
+	const Function f;
+
 #ifdef _WIN32
 	HANDLE handle = nullptr;
 	DWORD id;
@@ -49,11 +53,8 @@ class Thread {
 #endif
 #endif
 
-	void (*f)(void *ctx);
-	void *ctx;
-
 public:
-	Thread() = default;
+	explicit Thread(Function _f):f(_f) {}
 
 	Thread(const Thread &) = delete;
 
@@ -89,7 +90,7 @@ public:
 #endif
 	}
 
-	bool Start(void (*f)(void *ctx), void *ctx);
+	void Start();
 	void Join();
 
 private:

test/run_output.cxx

@@ -44,6 +44,8 @@
 #include <stdlib.h>
 #include <stdio.h>
 
+void AudioOutput::Task() {}
+
 class DummyAudioOutputClient final : public AudioOutputClient {
 public:
 	/* virtual methods from AudioOutputClient */