Player activity logger fixes (#1842)

- Fix potential race condition when adding entries to the list
 - Make the thread a daemon thread and give it a name for thread dumps

Grepped for usages of mBufferedPlayerActivity, no gt addon seems to use it so the type change should be fine.

2 files changed, 18 insertions, 11 deletions

diff --git a/src/main/java/gregtech/common/GT_PlayerActivityLogger.java b/src/main/java/gregtech/common/GT_PlayerActivityLogger.java
index 686c066c2c..7a113bdfb3 100644
--- a/src/main/java/gregtech/common/GT_PlayerActivityLogger.java
+++ b/src/main/java/gregtech/common/GT_PlayerActivityLogger.java
@@ -10,20 +10,22 @@ public class GT_PlayerActivityLogger implements Runnable {
     @Override
     public void run() {
         try {
+            ArrayList<String> buffer = new ArrayList<>();
             for (;;) {
                 if (GT_Log.pal == null) {
                     return;
                 }
-                ArrayList<String> tList = GT_Mod.gregtechproxy.mBufferedPlayerActivity;
-                GT_Mod.gregtechproxy.mBufferedPlayerActivity = new ArrayList<>();
                 String tLastOutput = "";
-                int i = 0;
-                for (int j = tList.size(); i < j; i++) {
-                    if (!tLastOutput.equals(tList.get(i))) {
-                        GT_Log.pal.println(tList.get(i));
+                // Block on first element for efficiency
+                buffer.add(GT_Mod.gregtechproxy.mBufferedPlayerActivity.take());
+                GT_Mod.gregtechproxy.mBufferedPlayerActivity.drainTo(buffer);
+                for (String output : buffer) {
+                    if (!output.equals(tLastOutput)) {
+                        GT_Log.pal.println(output);
+                        tLastOutput = output;
                     }
-                    tLastOutput = tList.get(i);
                 }
+                buffer.clear();
                 Thread.sleep(10000L);
             }
         } catch (Throwable e) {}
diff --git a/src/main/java/gregtech/common/GT_Proxy.java b/src/main/java/gregtech/common/GT_Proxy.java
index 749dea08fe..2678d01cef 100644
--- a/src/main/java/gregtech/common/GT_Proxy.java
+++ b/src/main/java/gregtech/common/GT_Proxy.java
@@ -25,8 +25,10 @@ import java.util.List;
 import java.util.Locale;
 import java.util.Map;
 import java.util.UUID;
+import java.util.concurrent.BlockingQueue;
 import java.util.concurrent.ConcurrentHashMap;
 import java.util.concurrent.ConcurrentMap;
+import java.util.concurrent.LinkedBlockingQueue;
 import java.util.concurrent.locks.ReentrantLock;
 import java.util.stream.Collectors;
 
@@ -497,7 +499,7 @@ public abstract class GT_Proxy implements IGT_Mod, IGuiHandler, IFuelHandler, IG
                     "redalloyInsulated",
                     "infusedteslatiteBundled"));
     private final DateFormat mDateFormat = DateFormat.getInstance();
-    public ArrayList<String> mBufferedPlayerActivity = new ArrayList<>();
+    public final BlockingQueue<String> mBufferedPlayerActivity = new LinkedBlockingQueue<>();
     public final GT_BlockMap<Boolean> mCTMBlockCache = new GT_BlockMap<>();
     public boolean mHardcoreCables = false;
     public boolean mDisableVanillaOres = true;
@@ -1188,7 +1190,10 @@ public abstract class GT_Proxy implements IGT_Mod, IGuiHandler, IFuelHandler, IG
         GT_Log.out.println("GT_Mod: Beginning PostLoad-Phase.");
         GT_Log.ore.println("GT_Mod: Beginning PostLoad-Phase.");
         if (GT_Log.pal != null) {
-            new Thread(new GT_PlayerActivityLogger()).start();
+            final Thread playerActivityLogger = new Thread(new GT_PlayerActivityLogger());
+            playerActivityLogger.setDaemon(true);
+            playerActivityLogger.setName("GT5U Player activity logger");
+            playerActivityLogger.start();
         }
         GregTech_API.sPostloadStarted = true;
 
@@ -1487,7 +1492,7 @@ public abstract class GT_Proxy implements IGT_Mod, IGuiHandler, IFuelHandler, IG
         }
         if ((!aEvent.entityPlayer.worldObj.isRemote) && (aEvent.action != PlayerInteractEvent.Action.RIGHT_CLICK_AIR)
                 && (GT_Log.pal != null)) {
-            this.mBufferedPlayerActivity.add(
+            this.mBufferedPlayerActivity.offer(
                     getDataAndTime() + ";"
                             + aEvent.action.name()
                             + ";"
@@ -1529,7 +1534,7 @@ public abstract class GT_Proxy implements IGT_Mod, IGuiHandler, IFuelHandler, IG
     public void onBlockHarvestingEvent(BlockEvent.HarvestDropsEvent aEvent) {
         if (aEvent.harvester != null) {
             if ((!aEvent.world.isRemote) && (GT_Log.pal != null)) {
-                this.mBufferedPlayerActivity.add(
+                this.mBufferedPlayerActivity.offer(
                         getDataAndTime() + ";HARVEST_BLOCK;"
                                 + aEvent.harvester.getDisplayName()
                                 + ";DIM:"