C2ME Port

[Titaniumtown]

(supersedes #375)

Here are some performance numbers: (retested by ishland)

JVM Flags: -Xms12G -Xmx12G -XX:+UseG1GC -XX:+ParallelRefProcEnabled -XX:MaxGCPauseMillis=200 -XX:+UnlockExperimentalVMOptions -XX:+AlwaysPreTouch -XX:G1NewSizePercent=30 -XX:G1MaxNewSizePercent=40 -XX:G1HeapRegionSize=8M -XX:G1ReservePercent=20 -XX:G1HeapWastePercent=5 -XX:G1MixedGCCountTarget=4 -XX:InitiatingHeapOccupancyPercent=15 -XX:G1MixedGCLiveThresholdPercent=90 -XX:G1RSetUpdatingPauseTimePercent=5 -XX:SurvivorRatio=32 -XX:MaxTenuringThreshold=1 -Ddebug.rewriteForIde=true -Dusing.aikars.flags=https://mcflags.emc.gs -Daikars.new.flags=true JVM: GraalVM 21.0.0.2 with Java11

ver/1.16.5 (main branch) (radius: 2048):

commit: 8d157f9be64fba5adb8d202417b3f8c80adb2c5a

• 96.56 cps

C2ME Port (parallelism: 8 allow-threaded-features: true) (radius: 4096):

commit: 2ee8c246065be9980d5484ed561d7a3c0ec07a45

• 565.95 cps

C2ME Port (parallelism: 8 allow-threaded-features: false) (radius: 4096):

commit: 2ee8c246065be9980d5484ed561d7a3c0ec07a45

• 319.77cps

Old Threaded Worldgen Branch* (2 featuregen threads, 6 worldgen threads) (radius: 4096):

commit: 8e6a62ab90c9afeaeee2f49cca26f5ce264acb6d

• 373.29 cps

*This PR is way more safer than Threaded Worldgen, fixing a lot of the issues people reported with #375.

[Titaniumtown]

Just a note: Java 11 or higher is required to run this PR as C2ME takes advantage of features only found in java 11 or higher. Since 49.4% (at the time of writing this comment) of servers use java 8, some decisions are going to have to be made on how to proceed with this PR.

[Titaniumtown]

Ok, the port is complete and everything is in place. A decision just needs to be made on how we're going to handle the new java version requirement.

[foss-mc]

Ok, the port is complete and everything is in place. A decision just needs to be made on how we're going to handle the new java version requirement.

A possible solution is to port it to java8 and remove the patch when Yatopia is updated to 1.17

From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: foss-mc <[email protected]>
Date: Mon, 3 May 2021 03:24:03 +0000
Subject: [PATCH] port AsyncCombinedLock to java8


diff --git a/src/main/java/org/yatopiamc/c2me/commom/util/AsyncCombinedLock.java b/src/main/java/org/yatopiamc/c2me/commom/util/AsyncCombinedLock.java
index b20fa65c0b6cf349d02e613aaefff426b840ae50..f4b66241c84206e49f812cd6ec5f2fdf788fd8c2 100644
--- a/src/main/java/org/yatopiamc/c2me/commom/util/AsyncCombinedLock.java
+++ b/src/main/java/org/yatopiamc/c2me/commom/util/AsyncCombinedLock.java
@@ -24,7 +24,7 @@ public class AsyncCombinedLock {
     private final CompletableFuture<AsyncLock.LockToken> future = new CompletableFuture<>();
 
     public AsyncCombinedLock(Set<AsyncLock> lockHandles) {
-        this.lockHandles = Set.copyOf(lockHandles);
+        this.lockHandles = new java.util.HashSet(lockHandles);
         lockWorker.execute(this::tryAcquire);
     }
 
@@ -34,18 +34,18 @@ public class AsyncCombinedLock {
         for (AsyncLock lockHandle : lockHandles) {
             final LockEntry entry = new LockEntry(lockHandle, lockHandle.tryLock());
             tryLocks.add(entry);
-            if (entry.lockToken.isEmpty()) {
+            if (!entry.lockToken.isPresent()) {
                 allAcquired = false;
                 break;
             }
         }
         if (allAcquired) {
-            future.complete(new CombinedLockToken(tryLocks.stream().flatMap(lockEntry -> lockEntry.lockToken.stream()).collect(Collectors.toUnmodifiableSet())));
+            future.complete(new CombinedLockToken(tryLocks.stream().filter(lockEntry -> lockEntry.lockToken.isPresent()).map(lockEntry -> lockEntry.lockToken.get()).collect(Collectors.toSet())));
         } else {
             boolean triedRelock = false;
             for (LockEntry entry : tryLocks) {
                 entry.lockToken.ifPresent(AsyncLock.LockToken::releaseLock);
-                if (!triedRelock && entry.lockToken.isEmpty()) {
+                if (!triedRelock && !entry.lockToken.isPresent()) {
                     entry.lock.acquireLock().thenCompose(lockToken -> {
                         lockToken.releaseLock();
                         return CompletableFuture.runAsync(this::tryAcquire, lockWorker);
@@ -80,7 +80,7 @@ public class AsyncCombinedLock {
         private final Set<AsyncLock.LockToken> delegates;
 
         private CombinedLockToken(Set<AsyncLock.LockToken> delegates) {
-            this.delegates = Set.copyOf(delegates);
+            this.delegates = delegates;
         }
 
         @Override

[josephworks]

Also, we could use java 11, but if java 8 is detected, it will download java 11 and use that.

[Titaniumtown]

cea262e21c3a606070a65dd48bca63d4375cb72d actually added java 8 compat, but it failed to build recently (which I just now noticed) so I reverted that commit in b1d79deff45fe32f9197da441d517496fe7cdf6f.