Default to 0 (until v1.0) and document in README

Author: smudge

README.md

@@ -432,6 +432,10 @@ Delayed::Worker.read_ahead = 5
 
 # If a worker finds no jobs, it will sleep this number of seconds in between attempts:
 Delayed::Worker.sleep_delay = 5
+
+# Until version 1.0, the worker will not sleep at all between attemps if it finds jobs.
+# This can be configured by setting the minimum reserve interval:
+Delayed::Worker.min_reserve_interval = 0.5 # seconds
 ```
 
 If a job fails, it will be rerun up to 25 times (with an exponential back-off). Jobs will also

lib/delayed/worker.rb

@@ -12,7 +12,7 @@ class Worker
     include Runnable
 
     cattr_accessor :sleep_delay, instance_writer: false, default: 5
-    cattr_accessor :min_reserve_interval, instance_writer: false, default: 1
+    cattr_accessor :min_reserve_interval, instance_writer: false, default: 0
     cattr_accessor :max_attempts, instance_writer: false, default: 25
     cattr_accessor :max_claims, instance_writer: false, default: 5
     cattr_accessor :max_run_time, instance_writer: false, default: 20.minutes

spec/helper.rb

@@ -120,6 +120,10 @@ class SingletonClass
     sleep_delay_was = Delayed::Worker.sleep_delay
     min_reserve_interval_was = Delayed::Worker.min_reserve_interval
 
+    if Gem.loaded_specs['delayed'].version >= Gem::Version.new('1.0') && min_reserve_interval_was.zero?
+      raise "Min reserve interval should be nonzero in v1.0 release"
+    end
+
     Delayed::Worker.sleep_delay = TEST_SLEEP_DELAY
     Delayed::Worker.min_reserve_interval = TEST_MIN_RESERVE_INTERVAL