[Performous-commit] Tapio Vierros : No more accessing NoteLabels list from two threads ( synth fix).

[Tapio V. <aa...@us...>]

Author: Tapio Vierros <tap...@gm...>
Date:   Mon Feb 21 21:20:42 2011 +0200

No more accessing NoteLabels list from two threads (synth fix).

---

 editorapp.cc |   21 +++++++++++++++++----
 synth.hh     |   37 +++++++++++++++++++++++++++----------
 2 files changed, 44 insertions(+), 14 deletions(-)

diff --git a/editorapp.cc b/editorapp.cc
index d4f72c1..162ca82 100644
--- a/editorapp.cc
+++ b/editorapp.cc
@@ -741,8 +741,7 @@ void EditorApp::playButton()
 void EditorApp::on_chkSynth_clicked(bool checked)
 {
 	if (checked && player && player->state() == Phonon::PlayingState) {
-		synth.reset(new Synth(noteGraph->noteLabels()));
-		synth->tick(player->currentTime());
+		synth.reset(new Synth);
 	} else if (!checked) {
 		synth.reset();
 	}
@@ -765,8 +764,22 @@ void EditorApp::audioTick(qint64 time)
 {
 	if (noteGraph && player)
 		noteGraph->updateMusicPos(time, (player->state() == Phonon::PlayingState ? true : false));
-	if (synth)
-		synth->tick(time);
+
+	if (noteGraph && synth) {
+		// Here we create some notes for the synthesizer to use.
+		// We don't simply pass the whole list because then there
+		// would be two threads working on the same list.
+		SynthNotes notes;
+		const NoteLabels &nls = noteGraph->noteLabels();
+		int numberOfNotesToPass = 12;
+		for (NoteLabels::const_iterator it = nls.begin(); it != nls.end() && numberOfNotesToPass > 0; ++it) {
+			if ((*it)->note().begin >= time / 1000.0) {
+				notes.push_back(SynthNote((*it)->note()));
+				--numberOfNotesToPass;
+			}
+		}
+		synth->tick(time, notes);
+	}
 }
 
 void EditorApp::playerStateChanged(Phonon::State newstate, Phonon::State oldstate)
diff --git a/synth.hh b/synth.hh
index dc9c959..ea568ca 100644
--- a/synth.hh
+++ b/synth.hh
@@ -19,12 +19,23 @@
 	#define M_PI 3.141592653589793
 #endif
 
+struct SynthNote {
+	SynthNote(): note(24), begin(), length() {}
+	SynthNote(const Note& n): note(n.note), begin(n.begin), length(n.length()) {}
+	bool operator<(const SynthNote& rhs) { return begin < rhs.begin; }
+	int note;
+	double begin;
+	double length;
+};
+
+typedef QList<SynthNote> SynthNotes;
+
+
 class Synth: public QThread
 {
 	Q_OBJECT
 public:
-	//FIXME: Giving notes this way and not guarding access will fail miserably some day
-	Synth(NoteLabels& notes, QObject *parent = NULL) : QThread(parent), m_notes(notes), m_delay(), m_pos(), m_noteBegin(), m_curBuffer(), m_quit()
+	Synth(QObject *parent = NULL) : QThread(parent), m_delay(), m_pos(), m_noteBegin(), m_curBuffer(), m_quit()
 	{
 		// Apparantly we need to register some types
 		qRegisterMetaType<Phonon::MediaSource>("MediaSource");
@@ -34,9 +45,11 @@ public:
 	~Synth() { stop(); wait(); }
 
 	/// Updates the synth
-	void tick(qint64 pos) {
+	void tick(qint64 pos, const SynthNotes& notes) {
 		QMutexLocker locker(&m_mutex);
 		m_pos = pos / 1000.0;
+		m_notes = notes;
+
 		if (isRunning()) m_condition.wakeOne();
 		else start();
 	}
@@ -95,17 +108,21 @@ private:
 	/// Calculates the next values
 	void calcNext() {
 		QElapsedTimer timer; timer.start();
-		NoteLabels::const_iterator it = m_notes.begin();
-		while (it != m_notes.end() && (*it)->note().begin < m_pos) ++it;
-		if (it == m_notes.end()) { m_delay = ULONG_MAX / 1000.0; return; }
-		Note n = (*it)->note();
-		m_delay = n.begin - m_pos;
+		SynthNote n;
+		{
+			QMutexLocker locker(&m_mutex);
+			SynthNotes::const_iterator it = m_notes.begin();
+			while (it != m_notes.end() && it->begin < m_pos) ++it;
+			if (it == m_notes.end()) { m_delay = ULONG_MAX / 1000.0; return; }
+			n = *it;
+		}
 
+		m_delay = n.begin - m_pos;
 		if (n.begin != m_noteBegin) {
 			// Need to create a new buffer
 			m_noteBegin = n.begin;
 			m_player[m_curBuffer]->clear();
-			createBuffer(n.note, n.length());
+			createBuffer(n.note, n.length);
 			m_player[m_curBuffer]->setCurrentSource(m_soundData[m_curBuffer]);
 		}
 		// Compensate for the time spent in this function
@@ -162,7 +179,7 @@ private:
 
 	static const int sampleRate = 8000; ///< Sample rate
 
-	NoteLabels m_notes; ///< Notes
+	SynthNotes m_notes; ///< Notes to synthesize
 	double m_delay; ///< How many seconds until the next sound must be played
 	double m_pos; ///< Position where we are now
 	double m_noteBegin; ///< Position of the next note