Merge branch 'master' into registered-server

.gitignore

@@ -135,3 +135,4 @@ logs/
 server-icon.png
 /bin/
 run/
+plugins/

api/src/main/java/com/velocitypowered/api/proxy/messages/MinecraftChannelIdentifier.java

@@ -10,7 +10,7 @@ import java.util.regex.Pattern;
  * Represents a Minecraft 1.13+ channel identifier. This class is immutable and safe for multi-threaded use.
  */
 public final class MinecraftChannelIdentifier implements ChannelIdentifier {
-    private static final Pattern VALID_IDENTIFIER_REGEX = Pattern.compile("[a-z0-9\\-_]+", Pattern.CASE_INSENSITIVE);
+    private static final Pattern VALID_IDENTIFIER_REGEX = Pattern.compile("[a-z0-9\\-_]+");
 
     private final String namespace;
     private final String name;

api/src/main/java/com/velocitypowered/api/proxy/server/ServerPing.java

@@ -74,6 +74,7 @@ public class ServerPing {
         builder.favicon = favicon;
         builder.nullOutModinfo = modinfo == null;
         if (modinfo != null) {
+            builder.modType = modinfo.type;
             builder.mods.addAll(modinfo.modList);
         }
         return builder;
@@ -91,6 +92,7 @@ public class ServerPing {
         private int onlinePlayers;
         private int maximumPlayers;
         private final List<SamplePlayer> samplePlayers = new ArrayList<>();
+        private String modType;
         private final List<Mod> mods = new ArrayList<>();
         private Component description;
         private Favicon favicon;
@@ -121,6 +123,11 @@ public class ServerPing {
             return this;
         }
 
+        public Builder modType(String modType) {
+            this.modType = Preconditions.checkNotNull(modType, "modType");
+            return this;
+        }
+
         public Builder mods(Mod... mods) {
             this.mods.addAll(Arrays.asList(mods));
             return this;
@@ -158,7 +165,7 @@ public class ServerPing {
 
         public ServerPing build() {
             return new ServerPing(version, nullOutPlayers ? null : new Players(onlinePlayers, maximumPlayers, samplePlayers), description, favicon,
-                    nullOutModinfo ? null : new Modinfo(mods));
+                    nullOutModinfo ? null : new Modinfo(modType, mods));
         }
 
         public Version getVersion() {
@@ -185,6 +192,10 @@ public class ServerPing {
             return favicon;
         }
 
+        public String getModType() {
+            return modType;
+        }
+
         public List<Mod> getMods() {
             return mods;
         }
@@ -196,6 +207,7 @@ public class ServerPing {
                     ", onlinePlayers=" + onlinePlayers +
                     ", maximumPlayers=" + maximumPlayers +
                     ", samplePlayers=" + samplePlayers +
+                    ", modType=" + modType +
                     ", mods=" + mods +
                     ", description=" + description +
                     ", favicon=" + favicon +
@@ -291,12 +303,13 @@ public class ServerPing {
     }
 
     public static class Modinfo {
-        public static final Modinfo DEFAULT = new Modinfo(ImmutableList.of());
+        public static final Modinfo DEFAULT = new Modinfo("FML", ImmutableList.of());
 
-        private final String type = "FML";
+        private final String type;
         private final List<Mod> modList;
 
-        public Modinfo(List<Mod> modList) {
+        public Modinfo(String type, List<Mod> modList) {
+            this.type = Preconditions.checkNotNull(type, "type");
             this.modList = ImmutableList.copyOf(modList);
         }
     }

native/src/main/java/com/velocitypowered/natives/util/NativeCodeLoader.java

@@ -8,7 +8,7 @@ import java.util.function.Supplier;
 
 public class NativeCodeLoader<T> implements Supplier<T> {
     private final List<Variant<T>> variants;
-    private Variant<T> selected;
+    private volatile Variant<T> selected;
 
     public NativeCodeLoader(List<Variant<T>> variants) {
         this.variants = ImmutableList.copyOf(variants);
@@ -16,36 +16,41 @@ public class NativeCodeLoader<T> implements Supplier<T> {
 
     @Override
     public T get() {
-        if (selected == null) {
-            selected = select();
-        }
-        return selected.object;
+        return tryLoad().object;
     }
 
-    private Variant<T> select() {
-        for (Variant<T> variant : variants) {
-            T got = variant.get();
-            if (got == null) {
-                continue;
-            }
-            return variant;
+    private Variant<T> tryLoad() {
+        if (selected != null) {
+            return selected;
+        }
+
+        synchronized (this) {
+            if (selected != null) {
+                return selected;
+            }
+
+            for (Variant<T> variant : variants) {
+                T got = variant.get();
+                if (got == null) {
+                    continue;
+                }
+                selected = variant;
+                return selected;
+            }
+            throw new IllegalArgumentException("Can't find any suitable variants");
         }
-        throw new IllegalArgumentException("Can't find any suitable variants");
     }
 
     public String getLoadedVariant() {
-        if (selected == null) {
-            selected = select();
-        }
-        return selected.name;
+        return tryLoad().name;
     }
 
     static class Variant<T> {
-        private boolean available;
+        private volatile boolean available;
         private final Runnable setup;
         private final String name;
         private final T object;
-        private boolean hasBeenSetup = false;
+        private volatile boolean hasBeenSetup = false;
 
         Variant(BooleanSupplier available, Runnable setup, String name, T object) {
             this.available = available.getAsBoolean();
@@ -54,27 +59,34 @@ public class NativeCodeLoader<T> implements Supplier<T> {
             this.object = object;
         }
 
-        private void setup() {
-            if (available && !hasBeenSetup) {
-                try {
-                    setup.run();
-                    hasBeenSetup = true;
-                } catch (Exception e) {
-                    available = false;
+        public T get() {
+            if (!available) {
+                return null;
+            }
+
+            // Make sure setup happens only once
+            if (!hasBeenSetup) {
+                synchronized (this) {
+                    // We change availability if need be below, may as well check it again here for sanity.
+                    if (!available) {
+                        return null;
+                    }
+
+                    // Okay, now try the setup if we haven't done so yet.
+                    if (!hasBeenSetup) {
+                        try {
+                            setup.run();
+                            hasBeenSetup = true;
+                            return object;
+                        } catch (Exception e) {
+                            available = false;
+                            return null;
+                        }
+                    }
                 }
             }
-        }
 
-        public T get() {
-            if (!hasBeenSetup) {
-                setup();
-            }
-
-            if (available) {
-                return object;
-            }
-
-            return null;
+            return object;
         }
     }
 

proxy/src/main/java/com/velocitypowered/proxy/protocol/StateRegistry.java

@@ -23,7 +23,7 @@ public enum StateRegistry {
     },
     STATUS {
         {
-            SERVERBOUND.register(StatusRequest.class, StatusRequest::new,
+            SERVERBOUND.register(StatusRequest.class, () -> StatusRequest.INSTANCE,
                     genericMappings(0x00));
             SERVERBOUND.register(StatusPing.class, StatusPing::new,
                     genericMappings(0x01));

proxy/src/main/java/com/velocitypowered/proxy/protocol/packet/StatusRequest.java

@@ -5,6 +5,12 @@ import com.velocitypowered.proxy.protocol.MinecraftPacket;
 import io.netty.buffer.ByteBuf;
 
 public class StatusRequest implements MinecraftPacket {
+    public static final StatusRequest INSTANCE = new StatusRequest();
+
+    private StatusRequest() {
+
+    }
+
     @Override
     public void decode(ByteBuf buf, ProtocolConstants.Direction direction, int protocolVersion) {
 
@@ -14,4 +20,9 @@ public class StatusRequest implements MinecraftPacket {
     public void encode(ByteBuf buf, ProtocolConstants.Direction direction, int protocolVersion) {
 
     }
+
+    @Override
+    public String toString() {
+        return "StatusRequest";
+    }
 }