Class: Zookeeper::Common::QueueWithPipe

Inherits:
Object
  • Object
show all
Extended by:
Forwardable
Includes:
Logger
Defined in:
lib/zookeeper/common/queue_with_pipe.rb

Overview

Ceci n’est pas une pipe

Defined Under Namespace

Classes: ShutdownException

Constant Summary collapse

KILL_TOKEN = 
Object.new

Instance Method Summary collapse

Methods included from Logger

included, wrapped_logger, wrapped_logger=

Constructor Details

#initialize ⇒ QueueWithPipe

Returns a new instance of QueueWithPipe.



15
16
17
18
19
20
21
22
 
# File 'lib/zookeeper/common/queue_with_pipe.rb', line 15

def initialize
  @array = []

  @mutex    = Mutex.new
  @cond     = ConditionVariable.new
  @closed   = false
  @graceful = false
end

Instance Method Details

#clear ⇒ Object 



24
25
26
27
28
29
30
31
 
# File 'lib/zookeeper/common/queue_with_pipe.rb', line 24

def clear
  @mutex.lock
  begin
    @array.clear
  ensure
    @mutex.unlock rescue nil
  end
end

#close ⇒ Object 



94
95
96
97
98
99
100
101
102
103
 
# File 'lib/zookeeper/common/queue_with_pipe.rb', line 94

def close
  @mutex.lock
  begin
    return if @closed
    @closed = true
    @cond.broadcast
  ensure
    @mutex.unlock rescue nil
  end
end

#closed? ⇒ Boolean

Returns:

  • (Boolean) 


105
106
107
 
# File 'lib/zookeeper/common/queue_with_pipe.rb', line 105

def closed?
  @mutex.synchronize { !!@closed }
end

#graceful_close! ⇒ Object

close the queue and causes ShutdownException to be raised on waiting threads



71
72
73
74
75
76
77
78
79
80
81
82
 
# File 'lib/zookeeper/common/queue_with_pipe.rb', line 71

def graceful_close!
  @mutex.lock
  begin
    return if @graceful or @closed
    logger.debug { "#{self.class}##{__method__} gracefully closing" }
    @graceful = true
    @cond.broadcast
  ensure
    @mutex.unlock rescue nil
  end
  nil
end

#open ⇒ Object 



84
85
86
87
88
89
90
91
92
 
# File 'lib/zookeeper/common/queue_with_pipe.rb', line 84

def open
  @mutex.lock
  begin
    @closed = @graceful = false
    @cond.broadcast
  ensure
    @mutex.unlock rescue nil
  end
end

#pop(non_blocking = false) ⇒ Object 



44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
 
# File 'lib/zookeeper/common/queue_with_pipe.rb', line 44

def pop(non_blocking=false)
  rval = nil

  @mutex.lock
  begin

    begin
      raise ShutdownException if @closed  # this may get us in trouble

      rval = @array.shift

      unless rval
        raise ThreadError if non_blocking     # sigh, ruby's stupid behavior
        raise ShutdownException if @graceful  # we've processed all the remaining mesages

        @cond.wait(@mutex) until (@closed or @graceful or (@array.length > 0))
      end
    end until rval

    return rval

  ensure
    @mutex.unlock rescue nil
  end
end

#push(obj) ⇒ Object 



33
34
35
36
37
38
39
40
41
42
 
# File 'lib/zookeeper/common/queue_with_pipe.rb', line 33

def push(obj)
  @mutex.lock
  begin
#         raise ShutdownException if (@closed or @graceful)
    @array << obj
    @cond.signal
  ensure
    @mutex.unlock rescue nil
  end
end