patches/server/0878-Fix-deadlock-on-watchdog-crash.patch


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From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Jason Penilla <11360596+jpenilla@users.noreply.github.com>
Date: Fri, 4 Mar 2022 00:12:49 -0700
Subject: [PATCH] Fix deadlock on watchdog crash

The watchdog thread sets MinecraftServer#forceTicks to true which will
cause waitUntilNextTick to hang when the task queue is drained.

diff --git a/src/main/java/net/minecraft/server/MinecraftServer.java b/src/main/java/net/minecraft/server/MinecraftServer.java
index 17e87875a95495940899b862eabf98b3d6a365da..07c382f30ed3736ed15b5b71f48dc4a1de958242 100644
--- a/src/main/java/net/minecraft/server/MinecraftServer.java
+++ b/src/main/java/net/minecraft/server/MinecraftServer.java
@@ -1012,7 +1012,7 @@ public abstract class MinecraftServer extends ReentrantBlockableEventLoop<TickTa
                 }, false);
             }
 
-            this.waitUntilNextTick();
+            this.managedBlock(() -> !this.canSleepForTickNoOversleep() || this.getPendingTasksCount() == 0); // Paper - based on waitUntilNextTick
         }
 
         this.saveAllChunks(false, true, false);