Attempt to cut out a lot of synchronized calls

A lot of these don't actually have any effect as they'll only be called
on the main thread or they are getters where the state is guaranteed to
be consistent whenever it is accessed.

Hopefully this'll reduce the chance of world updates being blocked by
waiting for peripheral locks to be released.

src/main/java/dan200/computercraft/shared/peripheral/common/TilePeripheralBase.java

@@ -112,12 +112,12 @@ public void setDirection( EnumFacing dir )
         }
     }
 
-    public synchronized int getAnim()
+    public int getAnim()
     {
         return m_anim;
     }
     
-    public synchronized void setAnim( int anim )
+    public void setAnim( int anim )
     {
         if( anim != m_anim )
         {
@@ -127,12 +127,12 @@ public synchronized void setAnim( int anim )
     }
 
     @Override    
-    public synchronized void update()
+    public void update()
     {
         if( m_changed )
         {
-            updateBlock();
             m_changed = false;
+            updateBlock();
         }
     }
             

src/main/java/dan200/computercraft/shared/peripheral/diskdrive/TileDiskDrive.java

@@ -80,12 +80,9 @@ public TileDiskDrive()
     public void destroy()
     {
         ejectContents( true );
-        synchronized( this )
+        if( m_recordPlaying )
         {
-            if( m_recordPlaying )
-            {
-                stopRecord();
-            }
+            stopRecord();
         }
     }
 
@@ -170,13 +167,10 @@ public void update()
         super.update();
 
         // Ejection
-        synchronized( this )
+        if( m_ejectQueued )
         {
-            if( m_ejectQueued )
-            {
-                ejectContents( false );
-                m_ejectQueued = false;
-            }
+            ejectContents( false );
+            m_ejectQueued = false;
         }
         
         // Music
@@ -391,10 +385,7 @@ public boolean isUsableByPlayer( @Nonnull EntityPlayer player )
     @Override
     public void clear()
     {
-        synchronized( this )
-        {
-            setInventorySlotContents( 0, ItemStack.EMPTY );
-        }
+        setInventorySlotContents( 0, ItemStack.EMPTY );
     }
 
     @Override
@@ -425,18 +416,12 @@ public IPeripheral getPeripheral( EnumFacing side )
     @Nonnull
     public ItemStack getDiskStack()
     {
-        synchronized( this )
-        {
-            return getStackInSlot( 0 );
-        }
+        return getStackInSlot( 0 );
     }
 
     public void setDiskStack( @Nonnull ItemStack stack )
     {
-        synchronized( this )
-        {
-            setInventorySlotContents( 0, stack );
-        }
+        setInventorySlotContents( 0, stack );
     }
 
     public IMedia getDiskMedia()
@@ -569,7 +554,7 @@ private synchronized void unmountDisk( IComputerAccess computer )
         }
     }
 
-    private synchronized void updateAnim()
+    private void updateAnim()
     {            
         if( !m_diskStack.isEmpty() )
         {

src/main/java/dan200/computercraft/shared/peripheral/modem/ModemPeripheral.java

@@ -75,7 +75,7 @@ public synchronized void destroy()
         m_open = false;
     }
     
-    public synchronized boolean pollChanged()
+    public boolean pollChanged()
     {
         if( m_changed )
         {
@@ -85,9 +85,9 @@ public synchronized boolean pollChanged()
         return false;
     }
 
-    public synchronized boolean isActive()
+    public boolean isActive()
     {
-        return (m_computer != null) && m_open;
+        return m_computer != null && m_open;
     }
 
     @Override

src/main/java/dan200/computercraft/shared/peripheral/modem/TileModemBase.java

@@ -37,7 +37,7 @@ protected TileModemBase()
     protected abstract ModemPeripheral createPeripheral();
             
     @Override
-    public synchronized void destroy()
+    public void destroy()
     {
         if( m_modem != null )
         {

src/main/java/dan200/computercraft/shared/peripheral/printer/TilePrinter.java

@@ -190,10 +190,7 @@ public boolean isEmpty()
     @Override    
     public ItemStack getStackInSlot(int i)
     {
-        synchronized( m_inventory )
-        {
-            return m_inventory.get( i );
-        }
+        return m_inventory.get( i );
     }
 
     @Nonnull

src/main/java/dan200/computercraft/shared/peripheral/speaker/SpeakerPeripheral.java

@@ -20,6 +20,7 @@
 
 import javax.annotation.Nonnull;
 import javax.annotation.Nullable;
+import java.util.concurrent.atomic.AtomicInteger;
 
 import static dan200.computercraft.core.apis.ArgumentHelper.getString;
 import static dan200.computercraft.core.apis.ArgumentHelper.optReal;
@@ -28,13 +29,13 @@ public class SpeakerPeripheral implements IPeripheral {
     private TileSpeaker m_speaker;
     private long m_clock;
     private long m_lastPlayTime;
-    private int m_notesThisTick;
+    private final AtomicInteger m_notesThisTick;
 
     public SpeakerPeripheral()
     {
         m_clock = 0;
         m_lastPlayTime = 0;
-        m_notesThisTick = 0;
+        m_notesThisTick = new AtomicInteger(  );
     }
 
     SpeakerPeripheral(TileSpeaker speaker)
@@ -43,10 +44,10 @@ public SpeakerPeripheral()
         m_speaker = speaker;
     }
 
-    public synchronized void update()
+    public void update()
     {
         m_clock++;
-        m_notesThisTick = 0;
+        m_notesThisTick.set( 0 );
     }
 
     public World getWorld()
@@ -59,9 +60,9 @@ public BlockPos getPos()
         return m_speaker.getPos();
     }
 
-    public synchronized boolean madeSound(long ticks)
+    public boolean madeSound(long ticks)
     {
-        return (m_clock - m_lastPlayTime <= ticks) ;
+        return m_clock - m_lastPlayTime <= ticks;
     }
 
     /* IPeripheral implementation */
@@ -146,7 +147,7 @@ private synchronized Object[] playNote( Object[] arguments, ILuaContext context
 
         if( returnValue[0] instanceof Boolean && (Boolean) returnValue[0] )
         {
-            m_notesThisTick++;
+            m_notesThisTick.incrementAndGet();
         }
 
         return returnValue;
@@ -161,7 +162,7 @@ private synchronized Object[] playSound( Object[] arguments, ILuaContext context
 
         ResourceLocation resourceName = new ResourceLocation( name );
 
-        if( m_clock - m_lastPlayTime >= TileSpeaker.MIN_TICKS_BETWEEN_SOUNDS || ( ( m_clock - m_lastPlayTime == 0 ) && ( m_notesThisTick < ComputerCraft.maxNotesPerTick ) && isNote ) )
+        if( m_clock - m_lastPlayTime >= TileSpeaker.MIN_TICKS_BETWEEN_SOUNDS || (isNote && m_clock - m_lastPlayTime == 0 && m_notesThisTick.get() < ComputerCraft.maxNotesPerTick) )
         {
             if( SoundEvent.REGISTRY.containsKey(resourceName) )
             {

src/main/java/dan200/computercraft/shared/peripheral/speaker/TileSpeaker.java

@@ -25,7 +25,7 @@ public TileSpeaker()
     }
 
     @Override
-    public synchronized void update()
+    public void update()
     {
         m_peripheral.update();
     }