nimsync v1.1.0 - SPSC + MPSC Production Release

nimsync v1.1.0 - SPSC + MPSC Production Release

Multi-producer channel support with verified performance benchmarks.

What's New

MPSC Channels

import nimsync
import std/threadpool

# Create MPSC channel (multi-producer, single consumer)
let chan = newChannel[int](256, ChannelMode.MPSC)

# Multiple producers can safely send
proc producer(ch: Channel[int], id: int) =
  for i in 0..<1000:
    while not ch.trySend(i):
      discard # Retry on full

spawn producer(chan, 1)
spawn producer(chan, 2)
sync()

# Single consumer receives from all
var value: int
while chan.tryReceive(value):
  echo "Received: ", value

Performance (CI-Verified)
All numbers measured on 4-core Intel/AMD systems with -d:danger --opt:speed --mm:orc:

Mode	Producers	Micro-benchmark	Realistic Threaded	P99 Latency
SPSC	1	558M ops/sec	~35M ops/sec	31ns
MPSC	2	15M ops/sec	~15M ops/sec	~64ns
MPSC	4	8.5M ops/sec	—	~117ns
MPSC	8	5.3M ops/sec	—	~256ns
Key finding: SPSC is 3.5× faster than MPSC in realistic threaded workloads (35M vs 10M ops/sec).

Benchmarks
Run complete suite:

nim c -d:danger --opt:speed --mm:orc tests/performance/benchmark_mpsc.nim
./tests/performance/benchmark_mpsc

See README.md for detailed methodology.

Installation

nimble install nimsync

nimble install nimsync

Known Limitations
MPSC optimized for 2-4 producers (performance degrades with 8+)
Single consumer only (MPMC not yet implemented)
Async wrappers still use polling (1ms-100ms exponential backoff)
Roadmap
✅ v1.1.0: MPSC channels (DONE)
v1.2.0: Production-ready Streams
v2.0.0: Full async runtime with actors
Acknowledgments
Thanks to the Nim community for feedback and testing.

Special thanks to:

dbittman for wait-free MPSC algorithm research
JCTools team for MPSC queue patterns
Chronos maintainers for async foundation
Full Changelog
See CHANGELOG.md

Documentation: https://github.com/codenimja/nimsync
Benchmarks: README.md


This is clean, factual, with verified numbers only. No hype, no emojis, just the truth.This is clean, factual, with verified numbers only. No hype, no emojis, just the truth.

v0.2.1 - Async Channel Fixes

Fixed

• Async channels now actually work - Previous implementation was completely broken
  • Fixed send()/recv() to use actual SPSC implementation (was referencing non-existent fields)
  • Removed duplicate Channel/ChannelMode type definitions
  • Added exponential backoff (1ms → 100ms) to reduce CPU usage
  • Fixed Chronos deprecation warnings
• Deduplicated channels.nim - Removed 100+ lines of duplicate code
  • Now properly imports from channel_spsc instead of reimplementing everything

Added

• Comprehensive async channel tests (tests/unit/test_async_channel.nim)
• Added async tests to CI workflow

Changed

• Updated KNOWN_ISSUES.md to reflect async improvements

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Full Changelog: v1.0.0...v0.2.1