Fix "out of buffers" crash (#3783)

Remove BufferManager implementation. Use MemoryManager allocation instead and re-use buffers where they are allocated (AudioPort.cpp & PlayHandle.cpp)

src/core/BufferManager.cpp

@@ -1,6 +1,7 @@
 /*
  * BufferManager.cpp - A buffer caching/memory management system
  *
+ * Copyright (c) 2017 Lukas W <lukaswhl/at/gmail.com>
  * Copyright (c) 2014 Vesa Kivimäki <contact/dot/diizy/at/nbl/dot/fi>
  * Copyright (c) 2006-2014 Tobias Doerffel <tobydox/at/users.sourceforge.net>
  *
@@ -25,56 +26,28 @@
 
 #include "BufferManager.h"
 
+#include "Engine.h"
+#include "Mixer.h"
 #include "MemoryManager.h"
 
-sampleFrame ** BufferManager::s_available;
-AtomicInt BufferManager::s_availableIndex = 0;
-sampleFrame ** BufferManager::s_released;
-AtomicInt BufferManager::s_releasedIndex = 0;
-//QReadWriteLock BufferManager::s_mutex;
-int BufferManager::s_size;
-
+static fpp_t framesPerPeriod;
 
 void BufferManager::init( fpp_t framesPerPeriod )
 {
-	s_available = MM_ALLOC( sampleFrame*, BM_INITIAL_BUFFERS );
-	s_released = MM_ALLOC( sampleFrame*, BM_INITIAL_BUFFERS );
-
-	int c = framesPerPeriod * BM_INITIAL_BUFFERS;
-	sampleFrame * b = MM_ALLOC( sampleFrame, c );
-
-	for( int i = 0; i < BM_INITIAL_BUFFERS; ++i )
-	{
-		s_available[ i ] = b;
-		b += framesPerPeriod;
-	}
-	s_availableIndex = BM_INITIAL_BUFFERS - 1;
-	s_size = BM_INITIAL_BUFFERS;
+	::framesPerPeriod = framesPerPeriod;
 }
 
 
 sampleFrame * BufferManager::acquire()
 {
-	if( s_availableIndex < 0 )
-	{
-		qFatal( "BufferManager: out of buffers" );
-	}
-
-	int i = s_availableIndex.fetchAndAddOrdered( -1 );
-	sampleFrame * b = s_available[ i ];
-
-	//qDebug( "acquired buffer: %p - index %d", b, i );
-	return b;
+	return MM_ALLOC( sampleFrame, ::framesPerPeriod );
 }
 
-
-void BufferManager::clear( sampleFrame * ab, const f_cnt_t frames,
-							const f_cnt_t offset )
+void BufferManager::clear( sampleFrame *ab, const f_cnt_t frames, const f_cnt_t offset )
 {
 	memset( ab + offset, 0, sizeof( *ab ) * frames );
 }
 
-
 #ifndef LMMS_DISABLE_SURROUND
 void BufferManager::clear( surroundSampleFrame * ab, const f_cnt_t frames,
 							const f_cnt_t offset )
@@ -86,43 +59,6 @@ void BufferManager::clear( surroundSampleFrame * ab, const f_cnt_t frames,
 
 void BufferManager::release( sampleFrame * buf )
 {
-	if (buf == nullptr) return;
-	int i = s_releasedIndex.fetchAndAddOrdered( 1 );
-	s_released[ i ] = buf;
-	//qDebug( "released buffer: %p - index %d", buf, i );
+	MM_FREE( buf );
 }
 
-
-void BufferManager::refresh() // non-threadsafe, hence it's called periodically from mixer at a time when no other threads can interfere
-{
-	if( s_releasedIndex == 0 ) return;
-	//qDebug( "refresh: %d buffers", int( s_releasedIndex ) );
-
-	int j = s_availableIndex;
-	for( int i = 0; i < s_releasedIndex; ++i )
-	{
-		++j;
-		s_available[ j ] = s_released[ i ];
-	}
-	s_availableIndex = j;
-	s_releasedIndex = 0;
-}
-
-
-/* // non-extensible for now
-void BufferManager::extend( int c )
-{
-	s_size += c;
-	sampleFrame ** tmp = MM_ALLOC( sampleFrame*, s_size );
-	MM_FREE( s_available );
-	s_available = tmp;
-
-	int cc = c * Engine::mixer()->framesPerPeriod();
-	sampleFrame * b = MM_ALLOC( sampleFrame, cc );
-
-	for( int i = 0; i < c; ++i )
-	{
-		s_available[ s_availableIndex.fetchAndAddOrdered( 1 ) + 1 ] = b;
-		b += Engine::mixer()->framesPerPeriod();
-	}
-}*/

src/core/MemoryHelper.cpp

@@ -30,7 +30,7 @@
  * Allocate a number of bytes and return them.
  * @param byteNum is the number of bytes
  */
-void* MemoryHelper::alignedMalloc( int byteNum )
+void* MemoryHelper::alignedMalloc( size_t byteNum )
 {
 	char *ptr, *ptr2, *aligned_ptr;
 	int align_mask = ALIGN_SIZE - 1;

src/core/Mixer.cpp

@@ -482,9 +482,6 @@ const surroundSampleFrame * Mixer::renderNextBuffer()
 	Controller::triggerFrameCounter();
 	AutomatableModel::incrementPeriodCounter();
 
-	// refresh buffer pool
-	BufferManager::refresh();
-
 	s_renderingThread = false;
 
 	m_profiler.finishPeriod( processingSampleRate(), m_framesPerPeriod );

src/core/PlayHandle.cpp

@@ -24,16 +24,21 @@
  
 #include "PlayHandle.h"
 #include "BufferManager.h"
+#include "Engine.h"
+#include "Mixer.h"
 
 #include <QtCore/QThread>
+#include <QDebug>
 
+#include <iterator>
 
-PlayHandle::PlayHandle( const Type type, f_cnt_t offset ) :
-		m_type( type ),
-		m_offset( offset ),
-		m_affinity( QThread::currentThread() ),
-		m_playHandleBuffer( NULL ),
-		m_usesBuffer( true )
+PlayHandle::PlayHandle(const Type type, f_cnt_t offset) :
+		m_type(type),
+		m_offset(offset),
+		m_affinity(QThread::currentThread()),
+		m_playHandleBuffer(BufferManager::acquire()),
+		m_bufferReleased(true),
+		m_usesBuffer(true)
 {
 }
 
@@ -48,8 +53,8 @@ void PlayHandle::doProcessing()
 {
 	if( m_usesBuffer )
 	{
-		if( ! m_playHandleBuffer ) m_playHandleBuffer = BufferManager::acquire();
-		play( m_playHandleBuffer );
+		m_bufferReleased = false;
+		play( buffer() );
 	}
 	else
 	{
@@ -60,6 +65,10 @@ void PlayHandle::doProcessing()
 
 void PlayHandle::releaseBuffer()
 {
-	BufferManager::release( m_playHandleBuffer );
-	m_playHandleBuffer = NULL;
+	m_bufferReleased = true;
 }
+
+sampleFrame* PlayHandle::buffer()
+{
+	return m_bufferReleased ? nullptr : reinterpret_cast<sampleFrame*>(m_playHandleBuffer);
+};

src/core/audio/AudioPort.cpp

@@ -36,7 +36,7 @@ AudioPort::AudioPort( const QString & _name, bool _has_effect_chain,
 		FloatModel * volumeModel, FloatModel * panningModel,
 		BoolModel * mutedModel ) :
 	m_bufferUsage( false ),
-	m_portBuffer( NULL ),
+	m_portBuffer( BufferManager::acquire() ),
 	m_extOutputEnabled( false ),
 	m_nextFxChannel( 0 ),
 	m_name( "unnamed port" ),
@@ -57,6 +57,7 @@ AudioPort::~AudioPort()
 	setExtOutputEnabled( false );
 	Engine::mixer()->removeAudioPort( this );
 	delete m_effects;
+	BufferManager::release( m_portBuffer );
 }
 
 
@@ -110,8 +111,7 @@ void AudioPort::doProcessing()
 
 	const fpp_t fpp = Engine::mixer()->framesPerPeriod();
 
-	// get a buffer for processing and clear it
-	m_portBuffer = BufferManager::acquire();
+	// clear the buffer
 	BufferManager::clear( m_portBuffer, fpp );
 
 	//qDebug( "Playhandles: %d", m_playHandles.size() );
@@ -225,8 +225,6 @@ void AudioPort::doProcessing()
 																			// TODO: improve the flow here - convert to pull model
 		m_bufferUsage = false;
 	}
-
-	BufferManager::release( m_portBuffer ); // release buffer, we don't need it anymore
 }