From f3bc708389fb8ce40fde4788e747c62ab394a10d Mon Sep 17 00:00:00 2001
From: Shane Freeder <theboyetronic@gmail.com>
Date: Sun, 14 May 2017 14:49:56 +0100
Subject: [PATCH] Allow the watchdog to try sanely stopping the server

---
 .../Access-items-by-EquipmentSlot.patch       |   2 +-
 .../Add-exception-reporting-event.patch       |  24 +-
 .../Ensure-commands-are-not-ran-async.patch   |   2 +-
 ...le-async-calls-to-restart-the-server.patch | 220 ++++++++++++++++--
 4 files changed, 212 insertions(+), 36 deletions(-)

diff --git a/Spigot-API-Patches/Access-items-by-EquipmentSlot.patch b/Spigot-API-Patches/Access-items-by-EquipmentSlot.patch
index 89b54ed8a7..b65cf2a657 100644
--- a/Spigot-API-Patches/Access-items-by-EquipmentSlot.patch
+++ b/Spigot-API-Patches/Access-items-by-EquipmentSlot.patch
@@ -5,7 +5,7 @@ Subject: [PATCH] Access items by EquipmentSlot
 
 
 diff --git a/src/main/java/org/bukkit/inventory/PlayerInventory.java b/src/main/java/org/bukkit/inventory/PlayerInventory.java
-index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
+index 557cc04d..799f1506 100644
 --- a/src/main/java/org/bukkit/inventory/PlayerInventory.java
 +++ b/src/main/java/org/bukkit/inventory/PlayerInventory.java
 @@ -0,0 +0,0 @@ public interface PlayerInventory extends Inventory {
diff --git a/Spigot-API-Patches/Add-exception-reporting-event.patch b/Spigot-API-Patches/Add-exception-reporting-event.patch
index 28fa9646d6..e6f0ab5a87 100644
--- a/Spigot-API-Patches/Add-exception-reporting-event.patch
+++ b/Spigot-API-Patches/Add-exception-reporting-event.patch
@@ -6,7 +6,7 @@ Subject: [PATCH] Add exception reporting event
 
 diff --git a/src/main/java/com/destroystokyo/paper/event/server/ServerExceptionEvent.java b/src/main/java/com/destroystokyo/paper/event/server/ServerExceptionEvent.java
 new file mode 100644
-index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000
+index 00000000..4109454a
 --- /dev/null
 +++ b/src/main/java/com/destroystokyo/paper/event/server/ServerExceptionEvent.java
 @@ -0,0 +0,0 @@
@@ -49,7 +49,7 @@ index 0000000000000000000000000000000000000000..00000000000000000000000000000000
 +}
 diff --git a/src/main/java/com/destroystokyo/paper/exception/ServerCommandException.java b/src/main/java/com/destroystokyo/paper/exception/ServerCommandException.java
 new file mode 100644
-index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000
+index 00000000..6fb39af0
 --- /dev/null
 +++ b/src/main/java/com/destroystokyo/paper/exception/ServerCommandException.java
 @@ -0,0 +0,0 @@
@@ -119,7 +119,7 @@ index 0000000000000000000000000000000000000000..00000000000000000000000000000000
 +}
 diff --git a/src/main/java/com/destroystokyo/paper/exception/ServerEventException.java b/src/main/java/com/destroystokyo/paper/exception/ServerEventException.java
 new file mode 100644
-index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000
+index 00000000..410b2413
 --- /dev/null
 +++ b/src/main/java/com/destroystokyo/paper/exception/ServerEventException.java
 @@ -0,0 +0,0 @@
@@ -177,7 +177,7 @@ index 0000000000000000000000000000000000000000..00000000000000000000000000000000
 +}
 diff --git a/src/main/java/com/destroystokyo/paper/exception/ServerException.java b/src/main/java/com/destroystokyo/paper/exception/ServerException.java
 new file mode 100644
-index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000
+index 00000000..c06ea394
 --- /dev/null
 +++ b/src/main/java/com/destroystokyo/paper/exception/ServerException.java
 @@ -0,0 +0,0 @@
@@ -206,7 +206,7 @@ index 0000000000000000000000000000000000000000..00000000000000000000000000000000
 +}
 diff --git a/src/main/java/com/destroystokyo/paper/exception/ServerInternalException.java b/src/main/java/com/destroystokyo/paper/exception/ServerInternalException.java
 new file mode 100644
-index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000
+index 00000000..e762ed0d
 --- /dev/null
 +++ b/src/main/java/com/destroystokyo/paper/exception/ServerInternalException.java
 @@ -0,0 +0,0 @@
@@ -247,7 +247,7 @@ index 0000000000000000000000000000000000000000..00000000000000000000000000000000
 +}
 diff --git a/src/main/java/com/destroystokyo/paper/exception/ServerPluginEnableDisableException.java b/src/main/java/com/destroystokyo/paper/exception/ServerPluginEnableDisableException.java
 new file mode 100644
-index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000
+index 00000000..f016ba3b
 --- /dev/null
 +++ b/src/main/java/com/destroystokyo/paper/exception/ServerPluginEnableDisableException.java
 @@ -0,0 +0,0 @@
@@ -274,7 +274,7 @@ index 0000000000000000000000000000000000000000..00000000000000000000000000000000
 \ No newline at end of file
 diff --git a/src/main/java/com/destroystokyo/paper/exception/ServerPluginException.java b/src/main/java/com/destroystokyo/paper/exception/ServerPluginException.java
 new file mode 100644
-index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000
+index 00000000..6defac28
 --- /dev/null
 +++ b/src/main/java/com/destroystokyo/paper/exception/ServerPluginException.java
 @@ -0,0 +0,0 @@
@@ -318,7 +318,7 @@ index 0000000000000000000000000000000000000000..00000000000000000000000000000000
 +}
 diff --git a/src/main/java/com/destroystokyo/paper/exception/ServerPluginMessageException.java b/src/main/java/com/destroystokyo/paper/exception/ServerPluginMessageException.java
 new file mode 100644
-index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000
+index 00000000..89e13252
 --- /dev/null
 +++ b/src/main/java/com/destroystokyo/paper/exception/ServerPluginMessageException.java
 @@ -0,0 +0,0 @@
@@ -388,7 +388,7 @@ index 0000000000000000000000000000000000000000..00000000000000000000000000000000
 +}
 diff --git a/src/main/java/com/destroystokyo/paper/exception/ServerSchedulerException.java b/src/main/java/com/destroystokyo/paper/exception/ServerSchedulerException.java
 new file mode 100644
-index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000
+index 00000000..2d0b2d4a
 --- /dev/null
 +++ b/src/main/java/com/destroystokyo/paper/exception/ServerSchedulerException.java
 @@ -0,0 +0,0 @@
@@ -431,7 +431,7 @@ index 0000000000000000000000000000000000000000..00000000000000000000000000000000
 +}
 diff --git a/src/main/java/com/destroystokyo/paper/exception/ServerTabCompleteException.java b/src/main/java/com/destroystokyo/paper/exception/ServerTabCompleteException.java
 new file mode 100644
-index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000
+index 00000000..5582999f
 --- /dev/null
 +++ b/src/main/java/com/destroystokyo/paper/exception/ServerTabCompleteException.java
 @@ -0,0 +0,0 @@
@@ -458,7 +458,7 @@ index 0000000000000000000000000000000000000000..00000000000000000000000000000000
 +    }
 +}
 diff --git a/src/main/java/org/bukkit/command/SimpleCommandMap.java b/src/main/java/org/bukkit/command/SimpleCommandMap.java
-index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
+index 466757b9..08976cd4 100644
 --- a/src/main/java/org/bukkit/command/SimpleCommandMap.java
 +++ b/src/main/java/org/bukkit/command/SimpleCommandMap.java
 @@ -0,0 +0,0 @@ import java.util.List;
@@ -494,7 +494,7 @@ index 0000000000000000000000000000000000000000..00000000000000000000000000000000
      }
  
 diff --git a/src/main/java/org/bukkit/plugin/SimplePluginManager.java b/src/main/java/org/bukkit/plugin/SimplePluginManager.java
-index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
+index ffb68704..d1f7cdde 100644
 --- a/src/main/java/org/bukkit/plugin/SimplePluginManager.java
 +++ b/src/main/java/org/bukkit/plugin/SimplePluginManager.java
 @@ -0,0 +0,0 @@ import java.util.logging.Level;
diff --git a/Spigot-Server-Patches/Ensure-commands-are-not-ran-async.patch b/Spigot-Server-Patches/Ensure-commands-are-not-ran-async.patch
index cd20bdc141..efb593f4c5 100644
--- a/Spigot-Server-Patches/Ensure-commands-are-not-ran-async.patch
+++ b/Spigot-Server-Patches/Ensure-commands-are-not-ran-async.patch
@@ -14,7 +14,7 @@ big slowdown in execution but throwing an exception at same time to raise awaren
 that it is happening so that plugin authors can fix their code to stop executing commands async.
 
 diff --git a/src/main/java/net/minecraft/server/PlayerConnection.java b/src/main/java/net/minecraft/server/PlayerConnection.java
-index 27283efad..57879c76d 100644
+index 0fe8525dc..d983ca5cd 100644
 --- a/src/main/java/net/minecraft/server/PlayerConnection.java
 +++ b/src/main/java/net/minecraft/server/PlayerConnection.java
 @@ -0,0 +0,0 @@ public class PlayerConnection implements PacketListenerPlayIn, ITickable {
diff --git a/Spigot-Server-Patches/Properly-handle-async-calls-to-restart-the-server.patch b/Spigot-Server-Patches/Properly-handle-async-calls-to-restart-the-server.patch
index d6bb697698..45c85ebc30 100644
--- a/Spigot-Server-Patches/Properly-handle-async-calls-to-restart-the-server.patch
+++ b/Spigot-Server-Patches/Properly-handle-async-calls-to-restart-the-server.patch
@@ -15,13 +15,60 @@ restart command, and adds separate handling for async calls, such as those from
 the watchdog thread.
 
 When calling from the watchdog thread, we cannot assume the main thread is in a
-tickable state; it may be completely deadlocked. Therefore, we kill that thread
-right then and there.
+tickable state; it may be completely deadlocked. In order to handle this, we mark
+the server as stopping, in order to account for situations where the server should
+complete a tick reasonbly soon, i.e. 99% of cases.
+
+Should the server not enter a state where it is stopping within 10 seconds, We
+will assume that the server has in fact deadlocked and will proceed to force
+kill the server.
+
+This modification does not force restart the server should we actually enter a
+deadlocked state where the server is stopping, whereas this will in most cases
+exit within a reasonable amount of time, to put a fixed limit on a process that
+will have plugins and worlds saving to the disk has a high potential to result
+in corruption/dataloss.
 
 diff --git a/src/main/java/net/minecraft/server/MinecraftServer.java b/src/main/java/net/minecraft/server/MinecraftServer.java
-index 8df30e3d0..df3077c9d 100644
+index 8df30e3d0..9fdd61c7c 100644
 --- a/src/main/java/net/minecraft/server/MinecraftServer.java
 +++ b/src/main/java/net/minecraft/server/MinecraftServer.java
+@@ -0,0 +0,0 @@ public abstract class MinecraftServer implements Runnable, ICommandListener, IAs
+     public WorldServer[] worldServer;
+     private PlayerList v;
+     private boolean isRunning = true;
++    private boolean isRestarting = false; // Paper - flag to signify we're attempting to restart
+     private boolean isStopped;
+     private int ticks;
+     protected final Proxy e;
+@@ -0,0 +0,0 @@ public abstract class MinecraftServer implements Runnable, ICommandListener, IAs
+         if (this.v != null) {
+             MinecraftServer.LOGGER.info("Saving players");
+             this.v.savePlayers();
+-            this.v.u();
++            this.v.u(isRestarting);
+             try { Thread.sleep(100); } catch (InterruptedException ex) {} // CraftBukkit - SPIGOT-625 - give server at least a chance to send packets
+         }
+ 
+@@ -0,0 +0,0 @@ public abstract class MinecraftServer implements Runnable, ICommandListener, IAs
+         return this.isRunning;
+     }
+ 
++    // Paper start - allow passing of the intent to restart
+     public void safeShutdown() {
++        safeShutdown(false);
++    }
++
++    public void safeShutdown(boolean isRestarting) {
+         this.isRunning = false;
++        this.isRestarting = isRestarting;
+     }
+ 
++    // Paper end
++
+     // Paper start - Further improve server tick loop
+     private static final int TPS = 20;
+     private static final long SEC_IN_NANO = 1000000000;
 @@ -0,0 +0,0 @@ public abstract class MinecraftServer implements Runnable, ICommandListener, IAs
          return this.ab;
      }
@@ -30,13 +77,58 @@ index 8df30e3d0..df3077c9d 100644
      public Thread aI() {
          return this.serverThread;
      }
+diff --git a/src/main/java/net/minecraft/server/PlayerList.java b/src/main/java/net/minecraft/server/PlayerList.java
+index 034bdb7cf..34236c622 100644
+--- a/src/main/java/net/minecraft/server/PlayerList.java
++++ b/src/main/java/net/minecraft/server/PlayerList.java
+@@ -0,0 +0,0 @@ public abstract class PlayerList {
+         entityplayer.playerInteractManager.b(world.getWorldData().getGameType());
+     }
+ 
++    // Paper start - Extract method to allow for restarting flag
+     public void u() {
++        u(false);
++    }
++
++    public void u(boolean isRestarting) {
+         // CraftBukkit start - disconnect safely
+         for (EntityPlayer player : this.players) {
+-            player.playerConnection.disconnect(this.server.server.getShutdownMessage()); // CraftBukkit - add custom shutdown message
++            player.playerConnection.disconnect(!isRestarting ? this.server.server.getShutdownMessage() : org.spigotmc.SpigotConfig.restartMessage); // CraftBukkit - add custom shutdown message // Paper - add isRestarting flag
+         }
+         // CraftBukkit end
+         // Paper start - Remove collideRule team if it exists
+@@ -0,0 +0,0 @@ public abstract class PlayerList {
+         }
+         // Paper end
+     }
++    // Paper end
+ 
+     // CraftBukkit start
+     public void sendMessage(IChatBaseComponent[] iChatBaseComponents) {
 diff --git a/src/main/java/org/spigotmc/RestartCommand.java b/src/main/java/org/spigotmc/RestartCommand.java
-index 49768734d..35c828805 100644
+index 49768734d..e1bc3e64e 100644
 --- a/src/main/java/org/spigotmc/RestartCommand.java
 +++ b/src/main/java/org/spigotmc/RestartCommand.java
 @@ -0,0 +0,0 @@ public class RestartCommand extends Command
-                 // Disable Watchdog
-                 WatchdogThread.doStop();
+         AsyncCatcher.enabled = false; // Disable async catcher incase it interferes with us
+         try
+         {
+-            if ( script.isFile() )
+-            {
+-                System.out.println( "Attempting to restart with " + SpigotConfig.restartScript );
++            // Paper - extract method and cleanup
++            boolean isRestarting = addShutdownHook(script);
++            if (isRestarting) {
++                System.out.println("Attempting to restart with " + SpigotConfig.restartScript);
++            } else {
++                System.out.println( "Startup script '" + SpigotConfig.restartScript + "' does not exist! Stopping server." );
++            }
+ 
+-                // Disable Watchdog
+-                WatchdogThread.doStop();
++            // Stop the watchdog
++            WatchdogThread.doStop();
  
 -                // Kick all players
 -                for ( EntityPlayer p : (List< EntityPlayer>) MinecraftServer.getServer().getPlayerList().players )
@@ -60,7 +152,13 @@ index 49768734d..35c828805 100644
 -                } catch ( InterruptedException ex )
 -                {
 -                }
--
++            shutdownServer(isRestarting);
++        } catch ( Exception ex )
++        {
++            ex.printStackTrace();
++        }
++    }
+ 
 -                // Actually shutdown
 -                try
 -                {
@@ -68,17 +166,8 @@ index 49768734d..35c828805 100644
 -                } catch ( Throwable t )
 -                {
 -                }
-+                shutdownServer(); // Paper - Moved to function that will handle sync and async
- 
-                 // This will be done AFTER the server has completely halted
-                 Thread shutdownHook = new Thread()
-@@ -0,0 +0,0 @@ public class RestartCommand extends Command
-             ex.printStackTrace();
-         }
-     }
-+
 +    // Paper start - sync copied from above with minor changes, async added
-+    private static void shutdownServer()
++    private static void shutdownServer(boolean isRestarting)
 +    {
 +        if (MinecraftServer.getServer().isMainThread())
 +        {
@@ -94,20 +183,75 @@ index 49768734d..35c828805 100644
 +            } catch ( InterruptedException ex )
 +            {
 +            }
-+
+ 
+-                // This will be done AFTER the server has completely halted
+-                Thread shutdownHook = new Thread()
+-                {
+-                    @Override
+-                    public void run()
+-                    {
+-                        try
+-                        {
+-                            String os = System.getProperty( "os.name" ).toLowerCase(java.util.Locale.ENGLISH);
+-                            if ( os.contains( "win" ) )
+-                            {
+-                                Runtime.getRuntime().exec( "cmd /c start " + script.getPath() );
+-                            } else
+-                            {
+-                                Runtime.getRuntime().exec( new String[]
+-                                {
+-                                    "sh", script.getPath()
+-                                } );
+-                            }
+-                        } catch ( Exception e )
+-                        {
+-                            e.printStackTrace();
+-                        }
+-                    }
+-                };
 +            closeSocket();
-+
+ 
+-                shutdownHook.setDaemon( true );
+-                Runtime.getRuntime().addShutdownHook( shutdownHook );
+-            } else
 +            // Actually shutdown
 +            try
-+            {
+             {
+-                System.out.println( "Startup script '" + SpigotConfig.restartScript + "' does not exist! Stopping server." );
 +                MinecraftServer.getServer().stop();
 +            } catch ( Throwable t )
 +            {
 +            }
 +        } else
 +        {
++            // Mark the server to shutdown at the end of the tick
++            MinecraftServer.getServer().safeShutdown(isRestarting);
+ 
+-                // Actually shutdown
+-                try
+-                {
+-                    MinecraftServer.getServer().stop();
+-                } catch ( Throwable t )
+-                {
+-                }
++
++            // wait 10 seconds to see if we're actually going to try shutdown
++            try
++            {
++                Thread.sleep(10000);
++            }
++            catch (InterruptedException ignored)
++            {
+             }
++
++            // Check if we've actually hit a state where the server is going to safely shutdown
++            // if we have, let the server stop as usual
++            if (MinecraftServer.getServer().isStopped()) return;
++
++            // If the server hasn't stopped by now, assume worse case and kill
 +            closeSocket();
-+            MinecraftServer.getServer().getServerThread().stop();
+             System.exit( 0 );
+-        } catch ( Exception ex )
 +        }
 +    }
 +
@@ -118,12 +262,44 @@ index 49768734d..35c828805 100644
 +
 +        // Give time for it to kick in
 +        try
-+        {
+         {
+-            ex.printStackTrace();
 +            Thread.sleep( 100 );
 +        } catch ( InterruptedException ex )
 +        {
 +        }
 +    }
 +    // Paper end
++
++    // Paper - copied from above and modified to return if the hook registered
++    private static boolean addShutdownHook(final File script) {
++
++        if (script.isFile()) {
++            Thread shutdownHook = new Thread() {
++                @Override
++                public void run() {
++                    try {
++                        String os = System.getProperty("os.name").toLowerCase(java.util.Locale.ENGLISH);
++                        if (os.contains("win")) {
++                            Runtime.getRuntime().exec("cmd /c start " + script.getPath());
++                        } else {
++                            Runtime.getRuntime().exec(new String[]
++                                    {
++                                            "sh", script.getPath()
++                                    });
++                        }
++                    } catch (Exception e) {
++                        e.printStackTrace();
++                    }
++                }
++            };
++
++            shutdownHook.setDaemon(true);
++            Runtime.getRuntime().addShutdownHook(shutdownHook);
++            return true;
++        } else {
++            return false;
+         }
+     }
  }
 --
\ No newline at end of file