From 296dfee228fa6471e26b9d4d697ba514cf5db998 Mon Sep 17 00:00:00 2001 From: Aikar Date: Mon, 3 Sep 2018 22:18:38 -0400 Subject: [PATCH] Fix concurrency and performance issues in DataFixers We are seeing issues with DataFixers being not thread safe in async chunks and even in some spigot packet sending code. There are a few more global objects that are mutated that need to be synchronized to be safe for use over multiple threads. There may be more cases, but these are extremely obvious ones. Also replaced quite a few bad uses of Map.containsKey containsKey is a common newbie mistake that "reads" cleaner, but results in double the performance cost of all map operations as containsKey in MOST cases where null values are not used is identical to get() == null Considering how deep datafixers go in call stacks, with tons of map lookups, this micro optimization could provide some gains. Additionally, many of the containsKey/get/put style operations were also a concurrency risk, resulting in multiple computation/insertions. diff --git a/src/main/java/com/mojang/datafixers/DataFixerUpper.java b/src/main/java/com/mojang/datafixers/DataFixerUpper.java index fb2c380f8a..a4922a35a2 100644 --- a/src/main/java/com/mojang/datafixers/DataFixerUpper.java +++ b/src/main/java/com/mojang/datafixers/DataFixerUpper.java @@ -65,7 +65,7 @@ public class DataFixerUpper implements DataFixer { private final Int2ObjectSortedMap schemas; private final List globalList; private final IntSortedSet fixerVersions; - private final Long2ObjectMap rules = new Long2ObjectOpenHashMap<>(); + private final Long2ObjectMap rules = it.unimi.dsi.fastutil.longs.Long2ObjectMaps.synchronize(new Long2ObjectOpenHashMap<>()); // Paper protected DataFixerUpper(final Int2ObjectSortedMap schemas, final List globalList, final IntSortedSet fixerVersions) { this.schemas = schemas; @@ -125,7 +125,7 @@ public class DataFixerUpper implements DataFixer { final int expandedDataVersion = DataFixUtils.makeKey(dataVersion); final long key = (long) expandedVersion << 32 | expandedDataVersion; - if (!rules.containsKey(key)) { + return rules.computeIfAbsent(key, k -> { // Paper final List rules = Lists.newArrayList(); for (final DataFix fix : globalList) { final int fixVersion = fix.getVersionKey(); @@ -137,9 +137,8 @@ public class DataFixerUpper implements DataFixer { rules.add(fixRule); } } - this.rules.put(key, TypeRewriteRule.seq(rules)); - } - return rules.get(key); + return TypeRewriteRule.seq(rules); // Paper + }); // Paper } protected IntSortedSet fixerVersions() { diff --git a/src/main/java/com/mojang/datafixers/NamedChoiceFinder.java b/src/main/java/com/mojang/datafixers/NamedChoiceFinder.java index 2c259d74e9..17481fb6e6 100644 --- a/src/main/java/com/mojang/datafixers/NamedChoiceFinder.java +++ b/src/main/java/com/mojang/datafixers/NamedChoiceFinder.java @@ -71,8 +71,10 @@ final class NamedChoiceFinder implements OpticFinder { }*/ if (targetType instanceof TaggedChoice.TaggedChoiceType) { final TaggedChoice.TaggedChoiceType choiceType = (TaggedChoice.TaggedChoiceType) targetType; - if (choiceType.types().containsKey(name)) { - final Type elementType = choiceType.types().get(name); + // Paper start - performance - don't use containsKey + final Type elementType = choiceType.types().get(name); + if (elementType != null) { + // Paper end if (!Objects.equals(type, elementType)) { return Either.right(new Type.FieldNotFoundException(String.format("Type error for choice type \"%s\": expected type: %s, actual type: %s)", name, targetType, elementType))); } diff --git a/src/main/java/com/mojang/datafixers/functions/PointFree.java b/src/main/java/com/mojang/datafixers/functions/PointFree.java index 0d88490f77..4d2af956a0 100644 --- a/src/main/java/com/mojang/datafixers/functions/PointFree.java +++ b/src/main/java/com/mojang/datafixers/functions/PointFree.java @@ -9,15 +9,19 @@ import java.util.Optional; import java.util.function.Function; public abstract class PointFree { - private boolean initialized; + private volatile boolean initialized; @Nullable private Function, T> value; @SuppressWarnings("ConstantConditions") public Function, T> evalCached() { if (!initialized) { - initialized = true; - value = eval(); + synchronized (this) { + if (!initialized) { + value = eval(); + initialized = true; + } + } } return value; } diff --git a/src/main/java/com/mojang/datafixers/schemas/Schema.java b/src/main/java/com/mojang/datafixers/schemas/Schema.java index 7c67d989e0..d81e8d1a1a 100644 --- a/src/main/java/com/mojang/datafixers/schemas/Schema.java +++ b/src/main/java/com/mojang/datafixers/schemas/Schema.java @@ -50,8 +50,11 @@ public class Schema { for (final String name : TYPE_TEMPLATES.keySet()) { final Type type; - if (RECURSIVE_TYPES.containsKey(name)) { - type = family.apply(RECURSIVE_TYPES.getInt(name)); + // Paper start - concurrency and performance improvement, don't use containsKey + int recurseId = RECURSIVE_TYPES.getOrDefault(name, -1); + if (recurseId != -1) { + type = family.apply(recurseId); + // Paper end } else { type = getTemplate(name).apply(family).apply(-1); } @@ -89,8 +92,11 @@ public class Schema { } public TypeTemplate id(final String name) { - if (RECURSIVE_TYPES.containsKey(name)) { - return DSL.id(RECURSIVE_TYPES.get(name)); + // Paper start - improve concurrency and performance + int id = RECURSIVE_TYPES.getOrDefault(name, -1); + if (id != -1) { + return DSL.id(id); + // Paper end } return getTemplate(name); } diff --git a/src/main/java/com/mojang/datafixers/types/DynamicOps.java b/src/main/java/com/mojang/datafixers/types/DynamicOps.java index 3c76929f24..f21531b3cd 100644 --- a/src/main/java/com/mojang/datafixers/types/DynamicOps.java +++ b/src/main/java/com/mojang/datafixers/types/DynamicOps.java @@ -151,10 +151,10 @@ public interface DynamicOps { default Optional getGeneric(final T input, final T key) { return getMapValues(input).flatMap(map -> { - if (map.containsKey(key)) { - return Optional.of(map.get(key)); - } - return Optional.empty(); + // Paper start - performance - don't use containsKey + T value = map.get(key); + return value != null ? Optional.of(value) : Optional.empty(); + // Paper end }); } diff --git a/src/main/java/com/mojang/datafixers/types/Type.java b/src/main/java/com/mojang/datafixers/types/Type.java index a80e3fee91..2d5bae7a37 100644 --- a/src/main/java/com/mojang/datafixers/types/Type.java +++ b/src/main/java/com/mojang/datafixers/types/Type.java @@ -27,8 +27,10 @@ import javax.annotation.Nullable; import java.util.Map; import java.util.Objects; import java.util.Optional; +import java.util.concurrent.CompletableFuture; public abstract class Type implements App { + private static final Map, TypeRewriteRule, PointFreeRule>, CompletableFuture>>> PENDING_REWRITE_CACHE = Maps.newConcurrentMap(); private static final Map, TypeRewriteRule, PointFreeRule>, Optional>> REWRITE_CACHE = Maps.newConcurrentMap(); public static class Mu implements K1 {} @@ -155,11 +157,34 @@ public abstract class Type implements App { @SuppressWarnings("unchecked") public Optional> rewrite(final TypeRewriteRule rule, final PointFreeRule fRule) { final Triple, TypeRewriteRule, PointFreeRule> key = Triple.of(this, rule, fRule); - if (!REWRITE_CACHE.containsKey(key)) { - final Optional> result = rule.rewrite(this).flatMap(r -> r.view().rewrite(fRule).map(view -> RewriteResult.create(view, r.recData()))); + // Paper start - concurrency and performance boost - this code under contention would generate multiple rewrites + // rewrite this to use a CompletableFuture for pending rewrites. We can not use computeIfAbsent because this is + // a recursive call that will block server startup during the Bootstrap phrase thats trying to precache these rewrites + Optional> rewrite = REWRITE_CACHE.get(key); + //noinspection OptionalAssignedToNull + if (rewrite != null) { + return (Optional>) rewrite; + } + CompletableFuture>> pending; + boolean needsCreate; + synchronized (PENDING_REWRITE_CACHE) { + pending = PENDING_REWRITE_CACHE.get(key); + needsCreate = pending == null; + if (pending == null) { + pending = new CompletableFuture<>(); + PENDING_REWRITE_CACHE.put(key, pending); + } + } + if (needsCreate) { + Optional> result = rule.rewrite(this).flatMap(r -> r.view().rewrite(fRule).map(view -> RewriteResult.create(view, r.recData()))); REWRITE_CACHE.put(key, result); + pending.complete(result); + PENDING_REWRITE_CACHE.remove(key); + return result; + } else { + return (Optional>) pending.join(); } - return (Optional>) REWRITE_CACHE.get(key); + // Paper end } public Type getSetType(final OpticFinder optic, final Type newType) { diff --git a/src/main/java/com/mojang/datafixers/types/families/RecursiveTypeFamily.java b/src/main/java/com/mojang/datafixers/types/families/RecursiveTypeFamily.java index 4a1f906837..93c2f565fd 100644 --- a/src/main/java/com/mojang/datafixers/types/families/RecursiveTypeFamily.java +++ b/src/main/java/com/mojang/datafixers/types/families/RecursiveTypeFamily.java @@ -32,7 +32,7 @@ public final class RecursiveTypeFamily implements TypeFamily { private final TypeTemplate template; private final int size; - private final Int2ObjectMap> types = new Int2ObjectOpenHashMap<>(); + private final Int2ObjectMap> types = it.unimi.dsi.fastutil.ints.Int2ObjectMaps.synchronize(new Int2ObjectOpenHashMap<>()); // Paper private final int hashCode; public RecursiveTypeFamily(final String name, final TypeTemplate template) { diff --git a/src/main/java/com/mojang/datafixers/types/templates/Tag.java b/src/main/java/com/mojang/datafixers/types/templates/Tag.java index ece3fb5f88..396637bbd1 100644 --- a/src/main/java/com/mojang/datafixers/types/templates/Tag.java +++ b/src/main/java/com/mojang/datafixers/types/templates/Tag.java @@ -173,8 +173,10 @@ public final class Tag implements TypeTemplate { public Pair> read(final DynamicOps ops, final T input) { final Optional> map = ops.getMapValues(input); final T nameObject = ops.createString(name); - if (map.isPresent() && map.get().containsKey(nameObject)) { - final T elementValue = map.get().get(nameObject); + // Paper start - performance - don't use containsKey + final T elementValue; + if (map.isPresent() && (elementValue = map.get().get(nameObject)) != null) { + // Paper end final Optional value = element.read(ops, elementValue).getSecond(); if (value.isPresent()) { return Pair.of(ops.createMap(map.get().entrySet().stream().filter(e -> !Objects.equals(e.getKey(), nameObject)).collect(Collectors.toMap(Map.Entry::getKey, Map.Entry::getValue))), value); diff --git a/src/main/java/com/mojang/datafixers/types/templates/TaggedChoice.java b/src/main/java/com/mojang/datafixers/types/templates/TaggedChoice.java index e6dd31233a..77d64362b1 100644 --- a/src/main/java/com/mojang/datafixers/types/templates/TaggedChoice.java +++ b/src/main/java/com/mojang/datafixers/types/templates/TaggedChoice.java @@ -187,17 +187,25 @@ public final class TaggedChoice implements TypeTemplate { if (values.isPresent()) { final Map map = values.get(); final T nameObject = ops.createString(name); - if (map.containsKey(nameObject)) { - final Optional key = keyType.read(ops, map.get(nameObject)).getSecond(); - if (!key.isPresent() || !types.containsKey(key.get())) { + // Paper start - performance - don't use containsKey + T mapValue = map.get(nameObject); + if (mapValue != null) { + final Optional key = keyType.read(ops, mapValue).getSecond(); + // also skip containsKey here + //noinspection OptionalIsPresent + K keyValue = key.isPresent() ? key.get() : null; + Type type = keyValue != null ? types.get(keyValue) : null; + if (type == null) { if (DataFixerUpper.ERRORS_ARE_FATAL) { - throw new IllegalArgumentException("Unsupported key: " + key.get() + " in " + this); + throw new IllegalArgumentException("Unsupported key: " + keyValue + " in " + this); } else { - LOGGER.warn("Unsupported key: {} in {}", key.get(), this); + LOGGER.warn("Unsupported key: {} in {}", keyValue, this); return Pair.of(input, Optional.empty()); } } - return types.get(key.get()).read(ops, input).mapSecond(vo -> vo.map(v -> Pair.of(key.get(), v))); + + return type.read(ops, input).mapSecond(vo -> vo.map(v -> Pair.of(keyValue, v))); + // Paper end } } return Pair.of(input, Optional.empty()); @@ -205,12 +213,14 @@ public final class TaggedChoice implements TypeTemplate { @Override public T write(final DynamicOps ops, final T rest, final Pair value) { - if (!types.containsKey(value.getFirst())) { + // Paper start - performance - don't use containsKey + final Type type = types.get(value.getFirst()); + if (type == null) { // TODO: better error handling? // TODO: See todo in read method throw new IllegalArgumentException("Unsupported key: " + value.getFirst() + " in " + this); } - final Type type = types.get(value.getFirst()); + // Paper end return capWrite(ops, type, value.getFirst(), value.getSecond(), rest); } -- 2.19.1