Fix high memory use of non ticking chunks

The nibble pooling for NBT Tags was 'semi' leaked from loaded chunks
as we store the NBT Tag of Tile Entities in a Chunk, but don't process
them and remove them until chunk reaches Entity Ticking status....

This caused some phantom references to persist causing high memory use
of these chunks.

So I just got rid of pooling from NBT deserialization and we'll have to
take the hit on memory allocations there because too many cascading concerns
with anyone using NBT Tag Byte Arrays.

Fixes #3431
This commit is contained in:
Aikar 2020-05-22 18:58:26 -04:00
parent ee9f0d513f
commit e1c451968c
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GPG key ID: 401ADFC9891FAAFE

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@ -9,50 +9,20 @@ an object pool for these.
Uses lots of advanced new capabilities of the Paper codebase :)
diff --git a/src/main/java/net/minecraft/server/ChunkRegionLoader.java b/src/main/java/net/minecraft/server/ChunkRegionLoader.java
index e625842e524f18e469f7695b27d52d4d04892266..49d95bb12083c306c8d257b202735066bad4388b 100644
index e625842e524f18e469f7695b27d52d4d04892266..d752e793f13a9caf5d255293f7ce9d562fd50064 100644
--- a/src/main/java/net/minecraft/server/ChunkRegionLoader.java
+++ b/src/main/java/net/minecraft/server/ChunkRegionLoader.java
@@ -105,7 +105,11 @@ public class ChunkRegionLoader {
if (flag) {
if (nbttagcompound2.hasKeyOfType("BlockLight", 7)) {
// Paper start - delay this task since we're executing off-main
- NibbleArray blockLight = new NibbleArray(nbttagcompound2.getByteArray("BlockLight"));
+ // Pool safe get and clean
+ NBTTagByteArray blockLightArray = nbttagcompound2.getByteArrayTag("BlockLight");
+ // NibbleArray will copy the data in the ctor
+ NibbleArray blockLight = new NibbleArray().markPoolSafe().cloneAndSet(blockLightArray.getBytesPoolSafe()); // This is going to light engine which handles releasing
+ blockLightArray.cleanPooledBytes();
// Note: We move the block light nibble array creation here for perf & in case the compound is modified
tasksToExecuteOnMain.add(() -> {
lightengine.a(EnumSkyBlock.BLOCK, SectionPosition.a(chunkcoordintpair, b0), blockLight);
@@ -115,7 +119,11 @@ public class ChunkRegionLoader {
if (flag2 && nbttagcompound2.hasKeyOfType("SkyLight", 7)) {
// Paper start - delay this task since we're executing off-main
- NibbleArray skyLight = new NibbleArray(nbttagcompound2.getByteArray("SkyLight"));
+ // Pool safe get and clean
+ NBTTagByteArray skyLightArray = nbttagcompound2.getByteArrayTag("SkyLight");
+ // NibbleArray will copy the data in the ctor
+ NibbleArray skyLight = new NibbleArray().markPoolSafe().cloneAndSet(skyLightArray.getBytesPoolSafe()); // This is going to light engine which handles releasing
+ skyLightArray.cleanPooledBytes();
// Note: We move the block light nibble array creation here for perf & in case the compound is modified
tasksToExecuteOnMain.add(() -> {
lightengine.a(EnumSkyBlock.SKY, SectionPosition.a(chunkcoordintpair, b0), skyLight);
@@ -387,11 +395,15 @@ public class ChunkRegionLoader {
@@ -387,11 +387,11 @@ public class ChunkRegionLoader {
}
if (nibblearray != null && !nibblearray.c()) {
- nbttagcompound2.setByteArray("BlockLight", nibblearray.asBytes());
+ byte[] bytes = nibblearray.getCloneIfSet(); // Paper
+ nbttagcompound2.setByteArray("BlockLight", bytes); // Paper
+ MCUtil.registerCleaner(nbttagcompound2, bytes, NibbleArray::releaseBytes); // Paper - we can't really hook when this chunk is done without a ton of yuck efort, so just reclaim it once GC gets to it.
+ nbttagcompound2.setByteArray("BlockLight", nibblearray.asBytesPoolSafe().clone()); // Paper
}
if (nibblearray1 != null && !nibblearray1.c()) {
- nbttagcompound2.setByteArray("SkyLight", nibblearray1.asBytes());
+ byte[] bytes = nibblearray1.getCloneIfSet(); // Paper
+ nbttagcompound2.setByteArray("SkyLight", bytes); // Paper
+ MCUtil.registerCleaner(nbttagcompound2, bytes, NibbleArray::releaseBytes); // Paper - we can't really hook when this chunk is done without a ton of yuck efort, so just reclaim it once GC gets to it.
+ nbttagcompound2.setByteArray("SkyLight", nibblearray1.asBytesPoolSafe().clone()); // Paper
}
nbttaglist.add(nbttagcompound2);
@ -92,7 +62,7 @@ index 278aec8846d3bd448e359095063a711e78213ee5..f17b16d5c52cd77dd53807222dff4631
}
diff --git a/src/main/java/net/minecraft/server/LightEngineStorageSky.java b/src/main/java/net/minecraft/server/LightEngineStorageSky.java
index 06bc8371fe9de4d23fdd47e5a3919541bb399fd8..c15fbd8602d33955d8a625d4a86cdcd8ca7489f5 100644
index 06bc8371fe9de4d23fdd47e5a3919541bb399fd8..097f58e9ac3f4096d3b9dad75b6ebe76021fa92c 100644
--- a/src/main/java/net/minecraft/server/LightEngineStorageSky.java
+++ b/src/main/java/net/minecraft/server/LightEngineStorageSky.java
@@ -166,9 +166,9 @@ public class LightEngineStorageSky extends LightEngineStorage<LightEngineStorage
@ -107,99 +77,25 @@ index 06bc8371fe9de4d23fdd47e5a3919541bb399fd8..c15fbd8602d33955d8a625d4a86cdcd8
}
}
}
diff --git a/src/main/java/net/minecraft/server/NBTTagByteArray.java b/src/main/java/net/minecraft/server/NBTTagByteArray.java
index 034244c2465b9999c6fba63ab2310becef51b887..5310246ec97b8a78848214b152a67195fd8ddef9 100644
--- a/src/main/java/net/minecraft/server/NBTTagByteArray.java
+++ b/src/main/java/net/minecraft/server/NBTTagByteArray.java
@@ -17,10 +17,17 @@ public class NBTTagByteArray extends NBTList<NBTTagByte> {
com.google.common.base.Preconditions.checkArgument( j < 1 << 24); // Spigot
@@ -197,7 +197,7 @@ public class LightEngineStorageSky extends LightEngineStorage<LightEngineStorage
((LightEngineStorageSky.a) this.f).a(i);
}
nbtreadlimiter.a(8L * (long) j);
- byte[] abyte = new byte[j];
+ byte[] abyte = j == 2048 ? NibbleArray.BYTE_2048.acquire() : new byte[j]; // Paper - use nibble buffer if right size
datainput.readFully(abyte);
- return new NBTTagByteArray(abyte);
+ // Paper start - use pooled
+ NBTTagByteArray nbt = new NBTTagByteArray(abyte);
+ if (abyte.length == 2048) {
+ // register cleaner
+ nbt.cleaner = MCUtil.registerCleaner(nbt, abyte, NibbleArray::releaseBytes);
+ }
+ return nbt;
+ // Paper end
}
@Override
@@ -121,6 +128,35 @@ public class NBTTagByteArray extends NBTList<NBTTagByte> {
}
public byte[] getBytes() {
+ // Paper start
+ Runnable cleaner = this.cleaner;
+ if (cleaner != null) { // This will only be possible for 2048 byte arrays
+ // cleaners are thread safe if it tries to run twice, if getBytes is accessed concurrently, worse
+ // case is multiple clones
+ this.data = this.data.clone();
+ this.cleaner = null;
+ cleaner.run();
+ }
+ if (this.data == null) {
+ new Throwable("Horrible thing happened! Something hooked into Chunk Loading internals and accessed NBT after chunk was done loading. Please tell plugin to stop doing this, clone the memory before hand.").printStackTrace();
+ }
+ return this.data;
+ }
+ Runnable cleaner;
+ public void cleanPooledBytes() {
+ Runnable cleaner = this.cleaner;
+ if (cleaner != null) { // This will only be possible for 2048 byte arrays
+ this.cleaner = null;
+ this.data = null;
+ cleaner.run();
+ }
+ }
+ /**
+ * Use ONLY if you know the life of your usage of the bytes matches the life of the nbt node itself.
+ * If this NBT node can go unreachable before your usage of the bytes is over with, DO NOT use this
+ */
+ public byte[] getBytesPoolSafe() {
+ // Paper end
return this.data;
}
diff --git a/src/main/java/net/minecraft/server/NBTTagCompound.java b/src/main/java/net/minecraft/server/NBTTagCompound.java
index 02a2ed1baa3f82d302432b7bc627f3179751f886..5f38c962115f732fae20b61410dfc35b09248f4c 100644
--- a/src/main/java/net/minecraft/server/NBTTagCompound.java
+++ b/src/main/java/net/minecraft/server/NBTTagCompound.java
@@ -298,6 +298,20 @@ public class NBTTagCompound implements NBTBase {
return new byte[0];
}
+ // Paper start
+ public NBTTagByteArray getByteArrayTag(String s) {
+ try {
+ if (this.hasKeyOfType(s, 7)) {
+ return ((NBTTagByteArray) this.map.get(s));
+ }
+ } catch (ClassCastException classcastexception) {
+ throw new ReportedException(this.a(s, NBTTagByteArray.a, classcastexception));
+ }
+
+ return new NBTTagByteArray(new byte[0]);
+ }
+ // Paper end
+
public int[] getIntArray(String s) {
try {
if (this.hasKeyOfType(s, 11)) {
- Arrays.fill(this.a(i, true).asBytes(), (byte) -1);
+ Arrays.fill(this.a(i, true).asBytesPoolSafe(), (byte) -1); // Paper
k = SectionPosition.c(SectionPosition.b(i));
l = SectionPosition.c(SectionPosition.c(i));
int i1 = SectionPosition.c(SectionPosition.d(i));
diff --git a/src/main/java/net/minecraft/server/NibbleArray.java b/src/main/java/net/minecraft/server/NibbleArray.java
index 996c8326387b5a7fe62db6a76e000144565cb85b..073e16a4f08bf00b7d9187a5bfdfdbf84ed05593 100644
index 996c8326387b5a7fe62db6a76e000144565cb85b..8cedfdd820cc02a76607b53e0b054fc74654f907 100644
--- a/src/main/java/net/minecraft/server/NibbleArray.java
+++ b/src/main/java/net/minecraft/server/NibbleArray.java
@@ -1,16 +1,73 @@
@@ -1,16 +1,75 @@
package net.minecraft.server;
+import com.destroystokyo.paper.util.pooled.PooledObjects; // Paper
+
+import javax.annotation.Nonnull;
import javax.annotation.Nullable;
public class NibbleArray {
@ -272,7 +168,7 @@ index 996c8326387b5a7fe62db6a76e000144565cb85b..073e16a4f08bf00b7d9187a5bfdfdbf8
if (abyte.length != 2048) {
throw (IllegalArgumentException) SystemUtils.c(new IllegalArgumentException("ChunkNibbleArrays should be 2048 bytes not: " + abyte.length));
}
@@ -44,7 +101,8 @@ public class NibbleArray {
@@ -44,7 +103,8 @@ public class NibbleArray {
public void a(int i, int j) { // PAIL: private -> public
if (this.a == null) {
@ -282,17 +178,36 @@ index 996c8326387b5a7fe62db6a76e000144565cb85b..073e16a4f08bf00b7d9187a5bfdfdbf8
}
int k = this.d(i);
@@ -65,7 +123,8 @@ public class NibbleArray {
@@ -66,14 +126,36 @@ public class NibbleArray {
public byte[] asBytes() {
if (this.a == null) {
- this.a = new byte[2048];
this.a = new byte[2048];
+ } else { // Paper start
+ // Accessor may need this object past garbage collection so need to clone it and return pooled value
+ // If we know its safe for pre GC access, use asBytesPoolSafe(). If you just need read, use getIfSet()
+ Runnable cleaner = this.cleaner;
+ if (cleaner != null) {
+ this.a = this.a.clone();
+ cleaner.run(); // release the previously pooled value
+ this.cleaner = null;
+ }
+ }
+ // Paper end
+
+ return this.a;
+ }
+
+ @Nonnull
+ public byte[] asBytesPoolSafe() {
+ if (this.a == null) {
+ this.a = BYTE_2048.acquire(); // Paper
+ registerCleaner();// Paper
+ registerCleaner(); // Paper
}
+ //noinspection ConstantConditions
return this.a;
@@ -73,7 +132,7 @@ public class NibbleArray {
}
+ // Paper end
public NibbleArray copy() { return this.b(); } // Paper - OBFHELPER
public NibbleArray b() {
@ -302,9 +217,18 @@ index 996c8326387b5a7fe62db6a76e000144565cb85b..073e16a4f08bf00b7d9187a5bfdfdbf8
public String toString() {
diff --git a/src/main/java/net/minecraft/server/NibbleArrayFlat.java b/src/main/java/net/minecraft/server/NibbleArrayFlat.java
index 67c960292db9d99ac85b5d0dda50ae48ef942c1b..f7641156beea365a91a935667abf8c9539896dc0 100644
index 67c960292db9d99ac85b5d0dda50ae48ef942c1b..5e3efa1fa6c089df35971ce5c83da384f7dbd402 100644
--- a/src/main/java/net/minecraft/server/NibbleArrayFlat.java
+++ b/src/main/java/net/minecraft/server/NibbleArrayFlat.java
@@ -8,7 +8,7 @@ public class NibbleArrayFlat extends NibbleArray {
public NibbleArrayFlat(NibbleArray nibblearray, int i) {
super(128);
- System.arraycopy(nibblearray.asBytes(), i * 128, this.a, 0, 128);
+ System.arraycopy(nibblearray.getIfSet(), i * 128, this.a, 0, 128); // Paper
}
@Override
@@ -18,7 +18,7 @@ public class NibbleArrayFlat extends NibbleArray {
@Override
@ -410,3 +334,24 @@ index cd1ad45469aa163b9bc41774ae80adfa617fd97b..1946aae7424593100279834baa89c19f
} else {
this.d &= ~(1 << k);
if (nibblearray != null) {
diff --git a/src/main/java/org/bukkit/craftbukkit/CraftChunk.java b/src/main/java/org/bukkit/craftbukkit/CraftChunk.java
index 39ef95cbbb1d1d049354ae1e8991309e918d0462..ec3f560556c3056bdfc11cc6a7eb76420f13abad 100644
--- a/src/main/java/org/bukkit/craftbukkit/CraftChunk.java
+++ b/src/main/java/org/bukkit/craftbukkit/CraftChunk.java
@@ -271,14 +271,14 @@ public class CraftChunk implements Chunk {
sectionSkyLights[i] = emptyLight;
} else {
sectionSkyLights[i] = new byte[2048];
- System.arraycopy(skyLightArray.asBytes(), 0, sectionSkyLights[i], 0, 2048);
+ System.arraycopy(skyLightArray.getIfSet(), 0, sectionSkyLights[i], 0, 2048); // Paper
}
NibbleArray emitLightArray = lightengine.a(EnumSkyBlock.BLOCK).a(SectionPosition.a(x, i, z));
if (emitLightArray == null) {
sectionEmitLights[i] = emptyLight;
} else {
sectionEmitLights[i] = new byte[2048];
- System.arraycopy(emitLightArray.asBytes(), 0, sectionEmitLights[i], 0, 2048);
+ System.arraycopy(emitLightArray.getIfSet(), 0, sectionEmitLights[i], 0, 2048); // Paper
}
}
}