From 0d19e4579b2f4a16713da2f19c629ee02ba61f4b Mon Sep 17 00:00:00 2001
From: Aikar <aikar@aikar.co>
Date: Tue, 28 Jul 2020 22:19:01 -0400
Subject: [PATCH] Fix deadlock issue with watchdog stopping

Fixes #4008
---
 .../0447-Improved-Watchdog-Support.patch      | 54 +++++++++----------
 ...tance-map-to-optimise-entity-tracker.patch |  4 +-
 ...Wait-for-Async-Tasks-during-shutdown.patch |  4 +-
 ...ld-Difficulty-Remembering-Difficulty.patch |  6 +--
 4 files changed, 32 insertions(+), 36 deletions(-)

diff --git a/Spigot-Server-Patches/0447-Improved-Watchdog-Support.patch b/Spigot-Server-Patches/0447-Improved-Watchdog-Support.patch
index 142043bdb6..09bd2265e8 100644
--- a/Spigot-Server-Patches/0447-Improved-Watchdog-Support.patch
+++ b/Spigot-Server-Patches/0447-Improved-Watchdog-Support.patch
@@ -109,7 +109,7 @@ index 63fdae15ccbef0c39718b320dbd096794bcfa3b4..6beefff203ed6e448898eb5b2e95800d
          }
  
 diff --git a/src/main/java/net/minecraft/server/MinecraftServer.java b/src/main/java/net/minecraft/server/MinecraftServer.java
-index 04eb2af28f9843ef7641f5464d2a043c696de864..d9ed9df3021dab1f5ee0a51215a002253ac1e34c 100644
+index 04eb2af28f9843ef7641f5464d2a043c696de864..fb65978d783a91b341658e0ebe393ab77153a0d9 100644
 --- a/src/main/java/net/minecraft/server/MinecraftServer.java
 +++ b/src/main/java/net/minecraft/server/MinecraftServer.java
 @@ -159,7 +159,7 @@ public abstract class MinecraftServer extends IAsyncTaskHandlerReentrant<TickTas
@@ -138,31 +138,27 @@ index 04eb2af28f9843ef7641f5464d2a043c696de864..d9ed9df3021dab1f5ee0a51215a00225
      private final Object stopLock = new Object();
      public final boolean hasStopped() {
          synchronized (stopLock) {
-@@ -749,10 +752,22 @@ public abstract class MinecraftServer extends IAsyncTaskHandlerReentrant<TickTas
-         // CraftBukkit start - prevent double stopping on multiple threads
-         synchronized(stopLock) {
+@@ -751,6 +754,19 @@ public abstract class MinecraftServer extends IAsyncTaskHandlerReentrant<TickTas
              if (hasStopped) return;
-+            shutdownThread = Thread.currentThread();
              hasStopped = true;
-+            org.spigotmc.WatchdogThread.doStop(); // Paper
-+            // Paper start - kill main thread, and kill it hard
-+            if (!isMainThread()) {
-+                while (this.getThread().isAlive()) {
-+                    this.getThread().stop();
-+                    try {
-+                        Thread.sleep(1);
-+                    } catch (InterruptedException e) {}
-+                }
-+            }
-+            // Paper end
          }
++        // Paper start - kill main thread, and kill it hard
++        shutdownThread = Thread.currentThread();
++        org.spigotmc.WatchdogThread.doStop(); // Paper
++        if (!isMainThread()) {
++            MinecraftServer.LOGGER.info("Stopping main thread (Ignore any thread death message you see! - DO NOT REPORT THREAD DEATH TO PAPER)");
++            while (this.getThread().isAlive()) {
++                this.getThread().stop();
++                try {
++                    Thread.sleep(1);
++                } catch (InterruptedException e) {}
++            }
++        }
++        // Paper end
          // CraftBukkit end
--        MinecraftServer.LOGGER.info("Stopping server");
-+        MinecraftServer.LOGGER.info("Stopping server (Ignore any thread death message you see! - DO NOT REPORT THREAD DEATH TO PAPER)"); // Paper
+         MinecraftServer.LOGGER.info("Stopping server");
          MinecraftTimings.stopServer(); // Paper
-         // CraftBukkit start
-         if (this.server != null) {
-@@ -816,7 +831,18 @@ public abstract class MinecraftServer extends IAsyncTaskHandlerReentrant<TickTas
+@@ -816,7 +832,18 @@ public abstract class MinecraftServer extends IAsyncTaskHandlerReentrant<TickTas
              this.getUserCache().c(false); // Paper
          }
          // Spigot end
@@ -181,7 +177,7 @@ index 04eb2af28f9843ef7641f5464d2a043c696de864..d9ed9df3021dab1f5ee0a51215a00225
      }
  
      public String getServerIp() {
-@@ -909,6 +935,7 @@ public abstract class MinecraftServer extends IAsyncTaskHandlerReentrant<TickTas
+@@ -909,6 +936,7 @@ public abstract class MinecraftServer extends IAsyncTaskHandlerReentrant<TickTas
  
      protected void v() {
          try {
@@ -189,7 +185,7 @@ index 04eb2af28f9843ef7641f5464d2a043c696de864..d9ed9df3021dab1f5ee0a51215a00225
              if (this.init()) {
                  this.nextTick = SystemUtils.getMonotonicMillis();
                  this.serverPing.setMOTD(new ChatComponentText(this.motd));
-@@ -916,6 +943,18 @@ public abstract class MinecraftServer extends IAsyncTaskHandlerReentrant<TickTas
+@@ -916,6 +944,18 @@ public abstract class MinecraftServer extends IAsyncTaskHandlerReentrant<TickTas
                  this.a(this.serverPing);
  
                  // Spigot start
@@ -208,7 +204,7 @@ index 04eb2af28f9843ef7641f5464d2a043c696de864..d9ed9df3021dab1f5ee0a51215a00225
                  org.spigotmc.WatchdogThread.hasStarted = true; // Paper
                  Arrays.fill( recentTps, 20 );
                  long start = System.nanoTime(), curTime, tickSection = start; // Paper - Further improve server tick loop
-@@ -971,6 +1010,12 @@ public abstract class MinecraftServer extends IAsyncTaskHandlerReentrant<TickTas
+@@ -971,6 +1011,12 @@ public abstract class MinecraftServer extends IAsyncTaskHandlerReentrant<TickTas
                  this.a((CrashReport) null);
              }
          } catch (Throwable throwable) {
@@ -221,7 +217,7 @@ index 04eb2af28f9843ef7641f5464d2a043c696de864..d9ed9df3021dab1f5ee0a51215a00225
              MinecraftServer.LOGGER.error("Encountered an unexpected exception", throwable);
              // Spigot Start
              if ( throwable.getCause() != null )
-@@ -1002,14 +1047,14 @@ public abstract class MinecraftServer extends IAsyncTaskHandlerReentrant<TickTas
+@@ -1002,14 +1048,14 @@ public abstract class MinecraftServer extends IAsyncTaskHandlerReentrant<TickTas
              } catch (Throwable throwable1) {
                  MinecraftServer.LOGGER.error("Exception stopping the server", throwable1);
              } finally {
@@ -239,7 +235,7 @@ index 04eb2af28f9843ef7641f5464d2a043c696de864..d9ed9df3021dab1f5ee0a51215a00225
              }
  
          }
-@@ -1065,6 +1110,12 @@ public abstract class MinecraftServer extends IAsyncTaskHandlerReentrant<TickTas
+@@ -1065,6 +1111,12 @@ public abstract class MinecraftServer extends IAsyncTaskHandlerReentrant<TickTas
  
      @Override
      protected TickTask postToMainThread(Runnable runnable) {
@@ -252,7 +248,7 @@ index 04eb2af28f9843ef7641f5464d2a043c696de864..d9ed9df3021dab1f5ee0a51215a00225
          return new TickTask(this.ticks, runnable);
      }
  
-@@ -1307,6 +1358,7 @@ public abstract class MinecraftServer extends IAsyncTaskHandlerReentrant<TickTas
+@@ -1307,6 +1359,7 @@ public abstract class MinecraftServer extends IAsyncTaskHandlerReentrant<TickTas
                  try {
                      crashreport = CrashReport.a(throwable, "Exception ticking world");
                  } catch (Throwable t) {
@@ -260,7 +256,7 @@ index 04eb2af28f9843ef7641f5464d2a043c696de864..d9ed9df3021dab1f5ee0a51215a00225
                      throw new RuntimeException("Error generating crash report", t);
                  }
                  // Spigot End
-@@ -1757,7 +1809,8 @@ public abstract class MinecraftServer extends IAsyncTaskHandlerReentrant<TickTas
+@@ -1757,7 +1810,8 @@ public abstract class MinecraftServer extends IAsyncTaskHandlerReentrant<TickTas
              this.resourcePackRepository.a(collection);
              this.saveData.a(a(this.resourcePackRepository));
              datapackresources.i();
@@ -271,7 +267,7 @@ index 04eb2af28f9843ef7641f5464d2a043c696de864..d9ed9df3021dab1f5ee0a51215a00225
              this.customFunctionData.a(this.dataPackResources.a());
              this.ak.a(this.dataPackResources.h());
 diff --git a/src/main/java/net/minecraft/server/PlayerChunkMap.java b/src/main/java/net/minecraft/server/PlayerChunkMap.java
-index c31e7c977194c953a47f5f04d9f90442a88e2db3..6e7754588960a1e6ceacc8b4cfd8237a10e210bb 100644
+index d95ef14f5a4babc8c8fff349baf6a9aa44edcc82..1fcf75b2ed3c8c1ca2e31f679fc7d507f963caf2 100644
 --- a/src/main/java/net/minecraft/server/PlayerChunkMap.java
 +++ b/src/main/java/net/minecraft/server/PlayerChunkMap.java
 @@ -486,6 +486,7 @@ public class PlayerChunkMap extends IChunkLoader implements PlayerChunk.d {
diff --git a/Spigot-Server-Patches/0478-Use-distance-map-to-optimise-entity-tracker.patch b/Spigot-Server-Patches/0478-Use-distance-map-to-optimise-entity-tracker.patch
index 843379b430..96251a29bd 100644
--- a/Spigot-Server-Patches/0478-Use-distance-map-to-optimise-entity-tracker.patch
+++ b/Spigot-Server-Patches/0478-Use-distance-map-to-optimise-entity-tracker.patch
@@ -44,10 +44,10 @@ index 9b89c0c8a3f1dada4e9b2aaeed0b92e56229b7ca..0c46297e6ff229538d77b2f481e4ab13
          List<Entity> list = this.tracker.getPassengers();
  
 diff --git a/src/main/java/net/minecraft/server/MinecraftServer.java b/src/main/java/net/minecraft/server/MinecraftServer.java
-index d9ed9df3021dab1f5ee0a51215a002253ac1e34c..b32d41fac5f855e302469209f368c3674b849fe3 100644
+index fb65978d783a91b341658e0ebe393ab77153a0d9..752ef8c1f99c6ef224e4df0c544f7894c2b3d3ab 100644
 --- a/src/main/java/net/minecraft/server/MinecraftServer.java
 +++ b/src/main/java/net/minecraft/server/MinecraftServer.java
-@@ -1526,6 +1526,7 @@ public abstract class MinecraftServer extends IAsyncTaskHandlerReentrant<TickTas
+@@ -1527,6 +1527,7 @@ public abstract class MinecraftServer extends IAsyncTaskHandlerReentrant<TickTas
          }
      }
  
diff --git a/Spigot-Server-Patches/0488-Wait-for-Async-Tasks-during-shutdown.patch b/Spigot-Server-Patches/0488-Wait-for-Async-Tasks-during-shutdown.patch
index 2810cdbc53..d37ec7f0f7 100644
--- a/Spigot-Server-Patches/0488-Wait-for-Async-Tasks-during-shutdown.patch
+++ b/Spigot-Server-Patches/0488-Wait-for-Async-Tasks-during-shutdown.patch
@@ -10,10 +10,10 @@ Adds a 5 second grace period for any async tasks to finish and warns
 if any are still running after that delay just as reload does.
 
 diff --git a/src/main/java/net/minecraft/server/MinecraftServer.java b/src/main/java/net/minecraft/server/MinecraftServer.java
-index b32d41fac5f855e302469209f368c3674b849fe3..7c1c929819c450f853c91618b2853fcb424caa22 100644
+index 752ef8c1f99c6ef224e4df0c544f7894c2b3d3ab..aaea027a3c3f6797e2c763f0ae7159e2d431049e 100644
 --- a/src/main/java/net/minecraft/server/MinecraftServer.java
 +++ b/src/main/java/net/minecraft/server/MinecraftServer.java
-@@ -772,6 +772,7 @@ public abstract class MinecraftServer extends IAsyncTaskHandlerReentrant<TickTas
+@@ -773,6 +773,7 @@ public abstract class MinecraftServer extends IAsyncTaskHandlerReentrant<TickTas
          // CraftBukkit start
          if (this.server != null) {
              this.server.disablePlugins();
diff --git a/Spigot-Server-Patches/0522-Fix-Per-World-Difficulty-Remembering-Difficulty.patch b/Spigot-Server-Patches/0522-Fix-Per-World-Difficulty-Remembering-Difficulty.patch
index c53afcca97..26aa3daa08 100644
--- a/Spigot-Server-Patches/0522-Fix-Per-World-Difficulty-Remembering-Difficulty.patch
+++ b/Spigot-Server-Patches/0522-Fix-Per-World-Difficulty-Remembering-Difficulty.patch
@@ -39,10 +39,10 @@ index 4c561181a977fd0244325880bb6a8cd6a54dcacc..8b2755a3b95e472e884976195d1d3551
  
      @Override
 diff --git a/src/main/java/net/minecraft/server/MinecraftServer.java b/src/main/java/net/minecraft/server/MinecraftServer.java
-index 7c1c929819c450f853c91618b2853fcb424caa22..26f230a801bd8efa5f8b61dee53fe7b1435f906b 100644
+index aaea027a3c3f6797e2c763f0ae7159e2d431049e..67a6fc68c6611dab2a3617d5605d7a9e7d9bee2a 100644
 --- a/src/main/java/net/minecraft/server/MinecraftServer.java
 +++ b/src/main/java/net/minecraft/server/MinecraftServer.java
-@@ -1519,11 +1519,14 @@ public abstract class MinecraftServer extends IAsyncTaskHandlerReentrant<TickTas
+@@ -1520,11 +1520,14 @@ public abstract class MinecraftServer extends IAsyncTaskHandlerReentrant<TickTas
          this.H = keypair;
      }
  
@@ -63,7 +63,7 @@ index 7c1c929819c450f853c91618b2853fcb424caa22..26f230a801bd8efa5f8b61dee53fe7b1
      }
  
 diff --git a/src/main/java/net/minecraft/server/PlayerConnection.java b/src/main/java/net/minecraft/server/PlayerConnection.java
-index 4a99a05ef2d01383553e59833a8723f5364168ed..cf83059fec9f11df992827f0c0249243caa9ac33 100644
+index 999ab59d1efc095029baea4d4101eb9b2f80347f..1cc16c20ca03902c3e871a7ec19fab442253da27 100644
 --- a/src/main/java/net/minecraft/server/PlayerConnection.java
 +++ b/src/main/java/net/minecraft/server/PlayerConnection.java
 @@ -2780,7 +2780,7 @@ public class PlayerConnection implements PacketListenerPlayIn {