From a7b14c66607ae9b54b25ae4386a50f0e8f04eb9c Mon Sep 17 00:00:00 2001
From: Tobias Doerffel <tobias.doerffel@gmail.com>
Date: Wed, 27 Feb 2008 17:49:35 +0000
Subject: [PATCH] lock audioPort-buffers before writing them

git-svn-id: https://lmms.svn.sf.net/svnroot/lmms/branches/lmms-mv@725 0778d3d1-df1d-0410-868b-ea421aaaa00d
---
 include/audio_port.h     | 30 +++++++++++++++++++++++++++++-
 src/audio/audio_port.cpp |  9 ++++++---
 src/core/mixer.cpp       | 15 +++++++++------
 3 files changed, 44 insertions(+), 10 deletions(-)

diff --git a/include/audio_port.h b/include/audio_port.h
index a7177772d..357c7ae8a 100644
--- a/include/audio_port.h
+++ b/include/audio_port.h
@@ -27,6 +27,8 @@
 #define _AUDIO_PORT_H
 
 #include <QtCore/QString>
+#include <QtCore/QMutex>
+#include <QtCore/QMutexLocker>
 
 #include "effect_chain.h"
 
@@ -46,6 +48,26 @@ public:
 		return( m_secondBuffer );
 	}
 
+	inline void lockFirstBuffer( void )
+	{
+		m_firstBufferLock.lock();
+	}
+
+	inline void lockSecondBuffer( void )
+	{
+		m_secondBufferLock.lock();
+	}
+
+	inline void unlockFirstBuffer( void )
+	{
+		m_firstBufferLock.unlock();
+	}
+
+	inline void unlockSecondBuffer( void )
+	{
+		m_secondBufferLock.unlock();
+	}
+
 	void nextPeriod( void );
 
 
@@ -85,11 +107,14 @@ public:
 
 	enum bufferUsages
 	{
-		NONE, FIRST, BOTH
+		NoUsage,
+		FirstBuffer,
+		BothBuffers
 	} m_bufferUsage;
 	
 	inline bool processEffects( void )
 	{
+		QMutexLocker m( &m_firstBufferLock );
 		return( m_effects.processAudioBuffer( m_firstBuffer,
 								m_frames ) );
 	}
@@ -97,6 +122,9 @@ public:
 private:
 	surroundSampleFrame * m_firstBuffer;
 	surroundSampleFrame * m_secondBuffer;
+	QMutex m_firstBufferLock;
+	QMutex m_secondBufferLock;
+
 	bool m_extOutputEnabled;
 	fx_ch_t m_nextFxChannel;
 
diff --git a/src/audio/audio_port.cpp b/src/audio/audio_port.cpp
index 7b9bafd1a..00510aa13 100644
--- a/src/audio/audio_port.cpp
+++ b/src/audio/audio_port.cpp
@@ -35,7 +35,7 @@
 
 
 audioPort::audioPort( const QString & _name, track * _track ) :
-	m_bufferUsage( NONE ),
+	m_bufferUsage( NoUsage ),
 	m_firstBuffer( new surroundSampleFrame[
 				engine::getMixer()->framesPerPeriod()] ),
 	m_secondBuffer( new surroundSampleFrame[
@@ -70,12 +70,15 @@ audioPort::~audioPort()
 
 void audioPort::nextPeriod( void )
 {
+	m_firstBufferLock.lock();
 	engine::getMixer()->clearAudioBuffer( m_firstBuffer,
 				engine::getMixer()->framesPerPeriod() );
 	qSwap( m_firstBuffer, m_secondBuffer );
+	m_firstBufferLock.unlock();
 	// this is how we decrease state of buffer-usage ;-)
-	m_bufferUsage = ( m_bufferUsage != NONE ) ?
-		( ( m_bufferUsage == FIRST ) ? NONE : FIRST ) : NONE;
+	m_bufferUsage = ( m_bufferUsage != NoUsage ) ?
+		( ( m_bufferUsage == FirstBuffer ) ?
+					NoUsage : FirstBuffer ) : NoUsage;
 }
 
 
diff --git a/src/core/mixer.cpp b/src/core/mixer.cpp
index b9ad6229d..40dab8160 100644
--- a/src/core/mixer.cpp
+++ b/src/core/mixer.cpp
@@ -170,7 +170,7 @@ private:
 		{
 		audioPort * a = (audioPort *) it->job;
 		bool me = a->processEffects();
-		if( a->m_bufferUsage != audioPort::NONE || me )
+		if( a->m_bufferUsage != audioPort::NoUsage || me )
 		{
 			m_mixer->processBuffer(
 					a->firstBuffer(),
@@ -567,7 +567,7 @@ const surroundSampleFrame * mixer::renderNextBuffer( void )
 						it != m_audioPorts.end(); ++it )
 			{
 				more_effects = ( *it )->processEffects();
-				if( ( *it )->m_bufferUsage != audioPort::NONE ||
+				if( ( *it )->m_bufferUsage != audioPort::NoUsage ||
 								more_effects )
 				{
 					processBuffer( ( *it )->firstBuffer(),
@@ -648,6 +648,7 @@ void FASTCALL mixer::bufferToPort( const sampleFrame * _buf,
 	fpp_t end_frame = start_frame + _frames;
 	const fpp_t loop1_frame = tMin( end_frame, m_framesPerPeriod );
 
+	_port->lockFirstBuffer();
 	for( fpp_t frame = start_frame; frame < loop1_frame; ++frame )
 	{
 		for( ch_cnt_t chnl = 0; chnl < m_audioDev->channels(); ++chnl )
@@ -658,7 +659,9 @@ void FASTCALL mixer::bufferToPort( const sampleFrame * _buf,
 						_volume_vector.vol[chnl];
 		}
 	}
+	_port->unlockFirstBuffer();
 
+	_port->lockSecondBuffer();
 	if( end_frame > m_framesPerPeriod )
 	{
 		fpp_t frames_done = m_framesPerPeriod - start_frame;
@@ -676,14 +679,14 @@ void FASTCALL mixer::bufferToPort( const sampleFrame * _buf,
 			}
 		}
 		// we used both buffers so set flags
-		_port->m_bufferUsage = audioPort::BOTH;
+		_port->m_bufferUsage = audioPort::BothBuffers;
 	}
-	else if( _port->m_bufferUsage == audioPort::NONE )
+	else if( _port->m_bufferUsage == audioPort::NoUsage )
 	{
 		// only first buffer touched
-		_port->m_bufferUsage = audioPort::FIRST;
+		_port->m_bufferUsage = audioPort::FirstBuffer;
 	}
-
+	_port->unlockSecondBuffer();
 }