Wrap per connection mutex around integrations with socket to make thr…

…ead safe

lib/beanstalk-client/connection.rb

@@ -19,6 +19,7 @@
 require 'fcntl'
 require 'yaml'
 require 'set'
+require 'thread'
 require 'beanstalk-client/errors'
 require 'beanstalk-client/job'
 
@@ -27,6 +28,7 @@ class Connection
     attr_reader :addr
 
     def initialize(addr, default_tube=nil)
+      @mutex = Mutex.new
       @waiting = false
       @addr = addr
       connect
@@ -80,6 +82,7 @@ def peek_buried()
 
     def reserve(timeout=nil)
       raise WaitingForJobError if @waiting
+      @mutex.lock
       if timeout.nil?
         @socket.write("reserve\r\n")
       else
@@ -97,6 +100,8 @@ def reserve(timeout=nil)
       end
 
       Job.new(self, *read_job('RESERVED'))
+    ensure
+      @mutex.unlock
     end
 
     def delete(id)
@@ -173,10 +178,13 @@ def list_tubes_watched(cached=false)
 
     def interact(cmd, rfmt)
       raise WaitingForJobError if @waiting
+      @mutex.lock
       @socket.write(cmd)
       return read_yaml('OK') if rfmt == :yaml
       return found_job if rfmt == :job
       check_resp(*rfmt)
+    ensure
+      @mutex.unlock
     end
 
     def get_resp()