Paper/Spigot-Server-Patches/0468-Forced-Watchdog-Crash-support-and-Improve-Async-Shut.patch
Aikar fcf89e852e
Improve mid tick chunk loading, Fix Oversleep, other improvements
Process loads outside of any canSleep check. Original intent was to
only apply those restrictions to generations but realized I had some
checks higher up the call chain.

Reworked the back off strategy to just run every 1 millisecond per world,
and to apply the per tick limit to generations only.

This guarantees that your chunk will load with at most around 1ms delay.

Additionally, fire midTick processing in a few more places, notably the
oversleep section so we can keep processing loads here too which has
a large up to 50ms window...

Speaking of oversleep, we had a bug in our implementation changes for
Timings that caused oversleep to not sleep the correct amount.

Because we now moved it into the NEXT tick instead of THIS tick, the
value of nextTick had already been increased to +50ms, resulting in
the risk of sleeping more than it should, but, more importantly, this
caused every task that was trying to NOT run during oversleep to actually
run during oversleep.

This is now fixed.

Another small tweak is to the /tps command, to no longer show the star when
TPS is right at 20.

Due to ineffeciencies in the sleep precision, TPS is commonly 20.02.
This causes the star to show up almost constantly, so now only show it if
we actually hit a real "catchup".

This commit also improves the changes to the CallbackExecutor, in that
it now is also recursion safe.

It was possible that the executor could run tasks out of desired order
if the executor task scheduled more executor tasks.

We solve this by ensuring new additions do not enter the currently iterated queue.

Each depth level will have its own queue.

Fixes #3220
2020-04-26 01:14:52 -04:00

350 lines
18 KiB
Diff

From 2f634c7ef7576d0011a745b806127c13c4856c14 Mon Sep 17 00:00:00 2001
From: Aikar <aikar@aikar.co>
Date: Sun, 12 Apr 2020 15:50:48 -0400
Subject: [PATCH] Forced Watchdog Crash support and Improve Async Shutdown
If the request to shut down the server is received while we are in
a watchdog hang, immediately treat it as a crash and begin the shutdown
process. Shutdown process is now improved to also shutdown cleanly when
not using restart scripts either.
If a server is deadlocked, a server owner can send SIGUP (or any other signal
the JVM understands to shut down as it currently does) and the watchdog
will no longer need to wait until the full timeout, allowing you to trigger
a close process and try to shut the server down gracefully, saving player and
world data.
Previously there was no way to trigger this outside of waiting for a full watchdog
timeout, which may be set to a really long time...
Additionally, fix everything to do with shutting the server down asynchronously.
Previously, nearly everything about the process was fragile and unsafe. Main might
not have actually been frozen, and might still be manipulating state.
Or, some reuest might ask main to do something in the shutdown but main is dead.
Or worse, other things might start closing down items such as the Console or Thread Pool
before we are fully shutdown.
This change tries to resolve all of these issues by moving everything into the stop
method and guaranteeing only one thread is stopping the server.
We then issue Thread Death to the main thread of another thread initiates the stop process.
We have to ensure Thread Death propagates correctly though to stop main completely.
This is to ensure that if main isn't truely stuck, it's not manipulating state we are trying to save.
diff --git a/src/main/java/net/minecraft/server/CrashReport.java b/src/main/java/net/minecraft/server/CrashReport.java
index 3de19c998b..c7dc8787cc 100644
--- a/src/main/java/net/minecraft/server/CrashReport.java
+++ b/src/main/java/net/minecraft/server/CrashReport.java
@@ -257,6 +257,7 @@ public class CrashReport {
}
public static CrashReport a(Throwable throwable, String s) {
+ if (throwable instanceof ThreadDeath) com.destroystokyo.paper.util.SneakyThrow.sneaky(throwable); // Paper
while (throwable instanceof CompletionException && throwable.getCause() != null) {
throwable = throwable.getCause();
}
diff --git a/src/main/java/net/minecraft/server/DedicatedServer.java b/src/main/java/net/minecraft/server/DedicatedServer.java
index 1ef7890da5..e62ca0543f 100644
--- a/src/main/java/net/minecraft/server/DedicatedServer.java
+++ b/src/main/java/net/minecraft/server/DedicatedServer.java
@@ -750,7 +750,7 @@ public class DedicatedServer extends MinecraftServer implements IMinecraftServer
@Override
public void stop() {
super.stop();
- SystemUtils.f();
+ //SystemUtils.f(); // Paper - moved into super
}
@Override
diff --git a/src/main/java/net/minecraft/server/IAsyncTaskHandler.java b/src/main/java/net/minecraft/server/IAsyncTaskHandler.java
index cfe43e882e..2632c7c3ec 100644
--- a/src/main/java/net/minecraft/server/IAsyncTaskHandler.java
+++ b/src/main/java/net/minecraft/server/IAsyncTaskHandler.java
@@ -135,6 +135,7 @@ public abstract class IAsyncTaskHandler<R extends Runnable> implements Mailbox<R
try {
r0.run();
} catch (Exception exception) {
+ if (exception.getCause() instanceof ThreadDeath) throw exception; // Paper
IAsyncTaskHandler.LOGGER.fatal("Error executing task on {}", this.bi(), exception);
}
diff --git a/src/main/java/net/minecraft/server/MinecraftServer.java b/src/main/java/net/minecraft/server/MinecraftServer.java
index 01534d19d4..94daf684b1 100644
--- a/src/main/java/net/minecraft/server/MinecraftServer.java
+++ b/src/main/java/net/minecraft/server/MinecraftServer.java
@@ -144,6 +144,7 @@ public abstract class MinecraftServer extends IAsyncTaskHandlerReentrant<TickTas
private final ResourcePackRepository<ResourcePackLoader> resourcePackRepository;
@Nullable
private ResourcePackSourceFolder resourcePackFolder;
+ public volatile Thread shutdownThread; // Paper
public CommandDispatcher commandDispatcher;
private final CraftingManager craftingManager;
private final TagRegistry tagRegistry;
@@ -176,7 +177,7 @@ public abstract class MinecraftServer extends IAsyncTaskHandlerReentrant<TickTas
public boolean serverAutoSave = false; // Paper
public File bukkitDataPackFolder;
public CommandDispatcher vanillaCommandDispatcher;
- private boolean forceTicks;
+ public boolean forceTicks; // Paper
// CraftBukkit end
// Spigot start
public static final int TPS = 20;
@@ -725,7 +726,12 @@ public abstract class MinecraftServer extends IAsyncTaskHandlerReentrant<TickTas
// CraftBukkit start - prevent double stopping on multiple threads
synchronized(stopLock) {
if (hasStopped) return;
+ shutdownThread = Thread.currentThread();
hasStopped = true;
+ org.spigotmc.WatchdogThread.doStop(); // Paper
+ if (!isMainThread()) {
+ this.getThread().stop();
+ }
}
// CraftBukkit end
MinecraftServer.LOGGER.info("Stopping server");
@@ -782,7 +788,18 @@ public abstract class MinecraftServer extends IAsyncTaskHandlerReentrant<TickTas
this.getUserCache().c(false); // Paper
}
// Spigot end
+ // Paper start - move final shutdown items here
+ LOGGER.info("Flushing Chunk IO");
com.destroystokyo.paper.io.PaperFileIOThread.Holder.INSTANCE.close(true, true); // Paper
+ LOGGER.info("Closing Thread Pool");
+ SystemUtils.shutdownServerThreadPool(); // Paper
+ LOGGER.info("Closing Server");
+ try {
+ net.minecrell.terminalconsole.TerminalConsoleAppender.close(); // Paper - Use TerminalConsoleAppender
+ } catch (Exception e) {
+ }
+ this.exit();
+ // Paper end
}
public String getServerIp() {
@@ -882,6 +899,7 @@ public abstract class MinecraftServer extends IAsyncTaskHandlerReentrant<TickTas
this.a(this.serverPing);
// Spigot start
+ org.spigotmc.WatchdogThread.tick(); // Paper
org.spigotmc.WatchdogThread.hasStarted = true; // Paper
Arrays.fill( recentTps, 20 );
long start = System.nanoTime(), curTime, tickSection = start; // Paper - Further improve server tick loop
@@ -938,6 +956,12 @@ public abstract class MinecraftServer extends IAsyncTaskHandlerReentrant<TickTas
this.a((CrashReport) null);
}
} catch (Throwable throwable) {
+ // Paper start
+ if (throwable instanceof ThreadDeath) {
+ MinecraftServer.LOGGER.error("Main thread terminated by WatchDog due to hard crash", throwable);
+ return;
+ }
+ // Paper end
MinecraftServer.LOGGER.error("Encountered an unexpected exception", throwable);
// Spigot Start
if ( throwable.getCause() != null )
@@ -969,14 +993,14 @@ public abstract class MinecraftServer extends IAsyncTaskHandlerReentrant<TickTas
} catch (Throwable throwable1) {
MinecraftServer.LOGGER.error("Exception stopping the server", throwable1);
} finally {
- org.spigotmc.WatchdogThread.doStop(); // Spigot
+ //org.spigotmc.WatchdogThread.doStop(); // Spigot // Paper - move into stop
// CraftBukkit start - Restore terminal to original settings
try {
- net.minecrell.terminalconsole.TerminalConsoleAppender.close(); // Paper - Use TerminalConsoleAppender
+ //net.minecrell.terminalconsole.TerminalConsoleAppender.close(); // Paper - Move into stop
} catch (Exception ignored) {
}
// CraftBukkit end
- this.exit();
+ //this.exit(); // Paper - moved into stop
}
}
@@ -1032,6 +1056,12 @@ public abstract class MinecraftServer extends IAsyncTaskHandlerReentrant<TickTas
@Override
protected TickTask postToMainThread(Runnable runnable) {
+ // Paper start - anything that does try to post to main during watchdog crash, run on watchdog
+ if (this.hasStopped && Thread.currentThread().equals(shutdownThread)) {
+ runnable.run();
+ runnable = () -> {};
+ }
+ // Paper end
return new TickTask(this.ticks, runnable);
}
diff --git a/src/main/java/net/minecraft/server/PlayerList.java b/src/main/java/net/minecraft/server/PlayerList.java
index dfe6251576..160476fa29 100644
--- a/src/main/java/net/minecraft/server/PlayerList.java
+++ b/src/main/java/net/minecraft/server/PlayerList.java
@@ -398,7 +398,7 @@ public abstract class PlayerList {
cserver.getPluginManager().callEvent(playerQuitEvent);
entityplayer.getBukkitEntity().disconnect(playerQuitEvent.getQuitMessage());
- entityplayer.playerTick();// SPIGOT-924
+ if (server.isMainThread()) entityplayer.playerTick();// SPIGOT-924 // Paper - don't tick during emergency shutdowns (Watchdog)
// CraftBukkit end
// Paper start - Remove from collideRule team if needed
diff --git a/src/main/java/net/minecraft/server/SystemUtils.java b/src/main/java/net/minecraft/server/SystemUtils.java
index dc6d030621..bc8b904660 100644
--- a/src/main/java/net/minecraft/server/SystemUtils.java
+++ b/src/main/java/net/minecraft/server/SystemUtils.java
@@ -109,6 +109,7 @@ public class SystemUtils {
return SystemUtils.c;
}
+ public static void shutdownServerThreadPool() { f(); } // Paper - OBFHELPER
public static void f() {
SystemUtils.c.shutdown();
diff --git a/src/main/java/net/minecraft/server/World.java b/src/main/java/net/minecraft/server/World.java
index 5e6481f115..d530508b61 100644
--- a/src/main/java/net/minecraft/server/World.java
+++ b/src/main/java/net/minecraft/server/World.java
@@ -786,6 +786,7 @@ public abstract class World implements GeneratorAccess, AutoCloseable {
gameprofilerfiller.exit();
} catch (Throwable throwable) {
+ if (throwable instanceof ThreadDeath) throw throwable; // Paper
// Paper start - Prevent tile entity and entity crashes
String msg = "TileEntity threw exception at " + tileentity.world.getWorld().getName() + ":" + tileentity.position.getX() + "," + tileentity.position.getY() + "," + tileentity.position.getZ();
System.err.println(msg);
@@ -861,6 +862,7 @@ public abstract class World implements GeneratorAccess, AutoCloseable {
try {
consumer.accept(entity);
} catch (Throwable throwable) {
+ if (throwable instanceof ThreadDeath) throw throwable; // Paper
// Paper start - Prevent tile entity and entity crashes
String msg = "Entity threw exception at " + entity.world.getWorld().getName() + ":" + entity.locX() + "," + entity.locY() + "," + entity.locZ();
System.err.println(msg);
diff --git a/src/main/java/org/bukkit/craftbukkit/CraftServer.java b/src/main/java/org/bukkit/craftbukkit/CraftServer.java
index 8cc0f66ce5..dcc44be613 100644
--- a/src/main/java/org/bukkit/craftbukkit/CraftServer.java
+++ b/src/main/java/org/bukkit/craftbukkit/CraftServer.java
@@ -1705,7 +1705,7 @@ public final class CraftServer implements Server {
@Override
public boolean isPrimaryThread() {
- return Thread.currentThread().equals(console.serverThread); // Paper - Fix issues with detecting main thread properly
+ return Thread.currentThread().equals(console.serverThread) || Thread.currentThread().equals(net.minecraft.server.MinecraftServer.getServer().shutdownThread); // Paper - Fix issues with detecting main thread properly, the only time Watchdog will be used is during a crash shutdown which is a "try our best" scenario
}
@Override
diff --git a/src/main/java/org/bukkit/craftbukkit/util/ServerShutdownThread.java b/src/main/java/org/bukkit/craftbukkit/util/ServerShutdownThread.java
index 449e99d1b6..899a525209 100644
--- a/src/main/java/org/bukkit/craftbukkit/util/ServerShutdownThread.java
+++ b/src/main/java/org/bukkit/craftbukkit/util/ServerShutdownThread.java
@@ -12,12 +12,25 @@ public class ServerShutdownThread extends Thread {
@Override
public void run() {
try {
+ // Paper start - try to shutdown on main
+ server.safeShutdown(false, false);
+ for (int i = 1000; i > 0 && !server.hasStopped(); i -= 100) {
+ Thread.sleep(100);
+ }
+ if (server.hasStopped()) {
+ return;
+ }
+ // Looks stalled, close async
org.spigotmc.AsyncCatcher.enabled = false; // Spigot
org.spigotmc.AsyncCatcher.shuttingDown = true; // Paper
+ server.forceTicks = true;
server.close();
+ } catch (InterruptedException e) {
+ e.printStackTrace();
+ // Paper end
} finally {
try {
- net.minecrell.terminalconsole.TerminalConsoleAppender.close(); // Paper - Use TerminalConsoleAppender
+ //net.minecrell.terminalconsole.TerminalConsoleAppender.close(); // Paper - Move into stop
} catch (Exception e) {
}
}
diff --git a/src/main/java/org/spigotmc/RestartCommand.java b/src/main/java/org/spigotmc/RestartCommand.java
index aefea3a9a8..123de5ac90 100644
--- a/src/main/java/org/spigotmc/RestartCommand.java
+++ b/src/main/java/org/spigotmc/RestartCommand.java
@@ -139,7 +139,7 @@ public class RestartCommand extends Command
// Paper end
// Paper start - copied from above and modified to return if the hook registered
- private static boolean addShutdownHook(String restartScript)
+ public static boolean addShutdownHook(String restartScript)
{
String[] split = restartScript.split( " " );
if ( split.length > 0 && new File( split[0] ).isFile() )
diff --git a/src/main/java/org/spigotmc/WatchdogThread.java b/src/main/java/org/spigotmc/WatchdogThread.java
index 5bdcdcf9e8..fe4b8caf28 100644
--- a/src/main/java/org/spigotmc/WatchdogThread.java
+++ b/src/main/java/org/spigotmc/WatchdogThread.java
@@ -41,6 +41,7 @@ public class WatchdogThread extends Thread
{
if ( instance == null )
{
+ if (timeoutTime <= 0) timeoutTime = 300; // Paper
instance = new WatchdogThread( timeoutTime * 1000L, restart );
instance.start();
}
@@ -67,12 +68,13 @@ public class WatchdogThread extends Thread
// Paper start
Logger log = Bukkit.getServer().getLogger();
long currentTime = monotonicMillis();
- if ( lastTick != 0 && currentTime > lastTick + earlyWarningEvery && !Boolean.getBoolean("disable.watchdog") )
+ MinecraftServer server = MinecraftServer.getServer();
+ if (lastTick != 0 && hasStarted && (!server.isRunning() || (currentTime > lastTick + earlyWarningEvery && !Boolean.getBoolean("disable.watchdog")) ))
{
- boolean isLongTimeout = currentTime > lastTick + timeoutTime;
+ boolean isLongTimeout = currentTime > lastTick + timeoutTime || (!server.isRunning() && !server.hasStopped() && currentTime > lastTick + 1000);
// Don't spam early warning dumps
if ( !isLongTimeout && (earlyWarningEvery <= 0 || !hasStarted || currentTime < lastEarlyWarning + earlyWarningEvery || currentTime < lastTick + earlyWarningDelay)) continue;
- if ( !isLongTimeout && MinecraftServer.getServer().hasStopped()) continue; // Don't spam early watchdog warnings during shutdown, we'll come back to this...
+ if ( !isLongTimeout && server.hasStopped()) continue; // Don't spam early watchdog warnings during shutdown, we'll come back to this...
lastEarlyWarning = currentTime;
if (isLongTimeout) {
// Paper end
@@ -114,7 +116,7 @@ public class WatchdogThread extends Thread
log.log( Level.SEVERE, "------------------------------" );
log.log( Level.SEVERE, "Server thread dump (Look for plugins here before reporting to Paper!):" ); // Paper
ChunkTaskManager.dumpAllChunkLoadInfo(); // Paper
- dumpThread( ManagementFactory.getThreadMXBean().getThreadInfo( MinecraftServer.getServer().serverThread.getId(), Integer.MAX_VALUE ), log );
+ dumpThread( ManagementFactory.getThreadMXBean().getThreadInfo( server.serverThread.getId(), Integer.MAX_VALUE ), log );
log.log( Level.SEVERE, "------------------------------" );
//
// Paper start - Only print full dump on long timeouts
@@ -135,9 +137,24 @@ public class WatchdogThread extends Thread
if ( isLongTimeout )
{
- if ( restart && !MinecraftServer.getServer().hasStopped() )
+ if ( !server.hasStopped() )
{
- RestartCommand.restart();
+ AsyncCatcher.enabled = false; // Disable async catcher incase it interferes with us
+ AsyncCatcher.shuttingDown = true;
+ server.forceTicks = true;
+ if (restart) {
+ RestartCommand.addShutdownHook( SpigotConfig.restartScript );
+ }
+ // try one last chance to safe shutdown on main incase it 'comes back'
+ server.safeShutdown(false, restart);
+ try {
+ Thread.sleep(1000);
+ } catch (InterruptedException e) {
+ e.printStackTrace();
+ }
+ if (!server.hasStopped()) {
+ server.close();
+ }
}
break;
} // Paper end
--
2.26.2