redis-read-write-locks
Distributed read-write locks for Ruby backed by Redis.
- Multiple readers can hold the lock simultaneously
- Writers get exclusive access (blocks all readers and other writers)
- Locks expire automatically via TTL — no deadlock on crash
- Atomic operations via Lua scripts
Installation
gem "redis-read-write-locks"Usage
require "redis"
require "redis_read_write_locks"
client = RedisReadWriteLocks::Client.new(Redis.new(url: "redis://localhost:6379/0"))
# Block form — acquires, yields, releases
client.read_lock("my_resource") { read_data }
client.write_lock("my_resource") { write_data }
# Manual acquire/release
lock = client.read_lock("my_resource")
lock.acquire # => true / false (non-blocking)
lock.release
# Block on contention — retries for up to N seconds
lock.acquire(timeout: 5) # raises LockTimeoutError if timeout exceeded
lock.synchronize(timeout: 5) { } # acquire + yield + release
# Per-lock TTL override
client.write_lock("my_resource", ttl: 60) { long_operation }Client options
client = RedisReadWriteLocks::Client.new(redis, default_ttl: 60)Options
| Option | Default | Description |
|---|---|---|
ttl |
30 |
Lock TTL in seconds. Lock auto-expires if holder crashes. |
Errors
| Error | When |
|---|---|
LockNotAcquiredError |
synchronize (no timeout) called when lock is contended |
LockTimeoutError |
acquire(timeout:) or synchronize(timeout:) exceeded timeout |
Redis key structure
rw_lock:writer:<name> # String, holds owner token, TTL = lock TTL
rw_lock:readers:<name> # Sorted set, member = token, score = expiry timestamp
Requirements
- Ruby >= 2.7
- Redis >= 5.0
-
redisgem >= 4.0
License
MIT