Concurrent Chunk Management Engine for Forge -The Twilight Forest fix

Describes

Fix the compatibility between c2mef and Twilight Forest, while fixing bugs and improving performance

Fixed

Thread Safety Fixes

• Fixed race condition in ConcurrentFlagMatrix.setif()

  • Location: c2me_fixes_worldgen_threading_issues/.../ConcurrentFlagMatrix.java
  • Issue: Race condition between read and write locks in setif() method
  • Solution: Use write lock throughout the entire operation for atomicity

• Prevented potential deadlocks in lock acquisition

  • Location: c2me_base/.../AsyncCombinedLock.java, SchedulingAsyncCombinedLock.java
  • Issue: Unordered lock acquisition could cause deadlocks
  • Solution: Sort lock names to ensure consistent acquisition order

• Fixed infinite recursion in error handling

  • Location: AsyncCombinedLock.java, SchedulingAsyncCombinedLock.java
  • Issue: Recursive calls in error path could cause stack overflow
  • Solution: Throw IllegalStateException instead of recursing

• Enhanced object pool safety

  • Location: c2me_base/.../SimpleObjectPool.java
  • Added: Null checks and object state cleanup before return to pool

Changed

Error Handling Improvements

• Replaced printStackTrace() with proper logging

  • Location: SchedulingAsyncCombinedLock.java, NeighborLockingTask.java, NoTickSystem.java, MixinChunkStatus.java, C2MEMod.java
  • Changed: Use SLF4J Logger instead of stack trace printing / System.out.printf for better log management

• Added ForkJoinPool compatibility

  • Location: c2me_fixes_chunkio_threading_issues/.../SynchronizedCodec.java
  • Added: ManagedBlocker support to prevent ForkJoinPool thread starvation

Performance

Chunk Generation Speed Optimizations

• Aggressive spin-wait strategy for ultra-low latency

  • Location: c2me_base/.../CFUtil.java
  • Optimization: 10,000 pure spins + 1ns park to minimize thread context switching
  • Effect: Minimized task completion wait time

• High-throughput I/O thread optimization

  • Location: c2me_rewrites_chunkio/.../C2MEStorageThread.java
  • Optimization: 10,000 spins + 100ns park, optimized read request processing
  • Effect: Maximized disk I/O throughput

• Scheduler batch processing optimization

  • Location: c2me_base/.../SchedulingManager.java
  • Optimization: Removed unused timing code, immediate rescheduling in finally block, batch task scheduling
  • Effect: Keep scheduler running at full capacity

• Priority queue fast path

  • Location: c2me_base/.../DynamicPriorityQueue.java
  • Added: isEmpty() method for O(1) fast checking
  • Effect: Reduced queue checking overhead

• Optimized lock checking in NeighborLockingTask

  • Location: c2me_base/.../NeighborLockingTask.java
  • Optimization: Use indexed for loop instead of enhanced for loop, cache array length
  • Effect: Reduced allocation and improved loop performance

• Optimized priority distance calculation

  • Location: c2me_base/.../SchedulingManager.java
  • Optimization: Use long-based Chebyshev distance calculation instead of creating ChunkPos objects
  • Effect: Reduced object allocation during priority updates