From 5d72c4f0b49dc1425ba8ac469b7005e5a49b6786 Mon Sep 17 00:00:00 2001
From: Matthew Messinger <mattmess1221@gmail.com>
Date: Tue, 4 Sep 2018 18:51:07 -0400
Subject: [PATCH] Fix parseSkin race condition (final2)

---
 .../voxelmodpack/hdskins/HDSkinManager.java   | 55 ++++++-------------
 .../hdskins/util/CallableFutures.java         | 14 +++++
 2 files changed, 32 insertions(+), 37 deletions(-)

diff --git a/src/hdskins/java/com/voxelmodpack/hdskins/HDSkinManager.java b/src/hdskins/java/com/voxelmodpack/hdskins/HDSkinManager.java
index 22b7543c..cf3fc6ff 100644
--- a/src/hdskins/java/com/voxelmodpack/hdskins/HDSkinManager.java
+++ b/src/hdskins/java/com/voxelmodpack/hdskins/HDSkinManager.java
@@ -24,6 +24,7 @@ import com.voxelmodpack.hdskins.skins.LegacySkinServer;
 import com.voxelmodpack.hdskins.skins.ServerType;
 import com.voxelmodpack.hdskins.skins.SkinServer;
 import com.voxelmodpack.hdskins.skins.ValhallaSkinServer;
+import com.voxelmodpack.hdskins.util.CallableFutures;
 import com.voxelmodpack.hdskins.util.PlayerUtil;
 import com.voxelmodpack.hdskins.util.ProfileTextureUtil;
 import net.minecraft.client.Minecraft;
@@ -310,49 +311,29 @@ public final class HDSkinManager implements IResourceManagerReloadListener {
     }
 
     public void parseSkin(GameProfile profile, Type type, ResourceLocation resource, MinecraftProfileTexture texture) {
-        TextureManager tm = Minecraft.getMinecraft().getTextureManager();
 
-        try {
-            // this runs in a separate thread anyway, so just get with a timeout.
-            getUntilNonnull(() -> tm.getTexture(resource)).get(1, TimeUnit.SECONDS);
-        } catch (InterruptedException | ExecutionException | TimeoutException e) {
-            throw new CompletionException(e);
-        }
+        CallableFutures.scheduleTask(() -> {
 
-        // grab the metadata object via reflection. Object is live.
-        Map<String, String> metadata = ProfileTextureUtil.getMetadata(texture);
+            // grab the metadata object via reflection. Object is live.
+            Map<String, String> metadata = ProfileTextureUtil.getMetadata(texture);
 
-        boolean wasNull = metadata == null;
+            boolean wasNull = metadata == null;
 
-        if (wasNull) {
-            metadata = new HashMap<>();
-        }
-
-        for (ISkinParser parser : skinParsers) {
-            try {
-                parser.parse(profile, type, resource, metadata);
-            } catch (Throwable t) {
-                logger.error("Exception thrown while parsing skin: ", t);
-            }
-        }
-
-        if (wasNull && !metadata.isEmpty()) {
-            ProfileTextureUtil.setMetadata(texture, metadata);
-        }
-    }
-
-    /**
-     * Continuously gets a item in a new thread until it returns nonnull.
-     */
-    private static <T> CompletableFuture<T> getUntilNonnull(Supplier<T> getter) {
-        return CompletableFuture.supplyAsync(() -> {
-            T res = null;
-
-            while (res == null) {
-                res = getter.get();
+            if (wasNull) {
+                metadata = new HashMap<>();
             }
 
-            return res;
+            for (ISkinParser parser : skinParsers) {
+                try {
+                    parser.parse(profile, type, resource, metadata);
+                } catch (Throwable t) {
+                    logger.error("Exception thrown while parsing skin: ", t);
+                }
+            }
+
+            if (wasNull && !metadata.isEmpty()) {
+                ProfileTextureUtil.setMetadata(texture, metadata);
+            }
         });
     }
 
diff --git a/src/hdskins/java/com/voxelmodpack/hdskins/util/CallableFutures.java b/src/hdskins/java/com/voxelmodpack/hdskins/util/CallableFutures.java
index 9afc4be3..4b98f309 100644
--- a/src/hdskins/java/com/voxelmodpack/hdskins/util/CallableFutures.java
+++ b/src/hdskins/java/com/voxelmodpack/hdskins/util/CallableFutures.java
@@ -1,12 +1,19 @@
 package com.voxelmodpack.hdskins.util;
 
+import net.minecraft.client.Minecraft;
+
 import java.util.concurrent.Callable;
 import java.util.concurrent.CompletableFuture;
 import java.util.concurrent.Executor;
+import java.util.concurrent.Executors;
+import java.util.concurrent.ScheduledExecutorService;
+import java.util.concurrent.TimeUnit;
 import java.util.function.BiFunction;
 
 public class CallableFutures {
 
+    private static final ScheduledExecutorService executor = Executors.newSingleThreadScheduledExecutor();
+
     public static <T> CompletableFuture<T> asyncFailableFuture(Callable<T> call, Executor exec) {
         CompletableFuture<T> ret = new CompletableFuture<>();
         exec.execute(() -> {
@@ -31,4 +38,11 @@ public class CallableFutures {
             return null;
         };
     }
+
+    public static void scheduleTask(Runnable task) {
+        // schedule a task for next tick.
+        executor.schedule(() -> {
+            Minecraft.getMinecraft().addScheduledTask(task);
+        }, 50, TimeUnit.MILLISECONDS);
+    }
 }