Class: Mistri::Locks::Hold

Inherits:
Object
  • Object
show all
Defined in:
lib/mistri/locks.rb

Overview

A held lease: one thread renews it on the heartbeat and watches the stop flag between renewals. Renewal runs on a monotonic deadline (the last sleep before it is the remaining fraction, never a full tick, so the cadence is exact and a lease can never lapse waiting for a tick to round up). release stops the thread (and joins it, so a mid-renewal tick can never re-stamp a lease that was just released) and deletes the key.

Instance Method Summary collapse

Constructor Details

#initialize(adapter, key, ttl, heartbeat, stop_key: nil, signal: nil) ⇒ Hold

Returns a new instance of Hold.



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# File 'lib/mistri/locks.rb', line 54

def initialize(adapter, key, ttl, heartbeat, stop_key: nil, signal: nil)
  @adapter = adapter
  @key = key
  @stopping = false
  @thread = Thread.new do
    deadline = now + heartbeat
    until @stopping
      sleep (deadline - now).clamp(0.01, 1.0)
      break if @stopping

      signal.abort!("stopped by user") if stop_key && signal && adapter.flag?(stop_key)
      if now >= deadline
        adapter.renew(key, ttl: ttl)
        deadline = now + heartbeat
      end
    end
  end
end

Instance Method Details

#release ⇒ Object 



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# File 'lib/mistri/locks.rb', line 73

def release
  @stopping = true
  @thread.kill
  @thread.join(2)
  @adapter.release(@key)
end