Class: SyncQueue

Inherits:
Object
  • Object
show all
Defined in:
lib/devp2p/sync_queue.rb

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(max_size = nil) ⇒ SyncQueue

Returns a new instance of SyncQueue.



9
10
11
12
13
14
15
16
17
18
 
# File 'lib/devp2p/sync_queue.rb', line 9

def initialize(max_size=nil)
  @queue = []
  @num_waiting = 0

  @max_size = max_size

  @mutex = Mutex.new
  @cond_full = ConditionVariable.new
  @cond_empty = ConditionVariable.new
end

Instance Attribute Details

#queue ⇒ Object (readonly)

Returns the value of attribute queue.



7
8
9
 
# File 'lib/devp2p/sync_queue.rb', line 7

def queue
  @queue
end

Instance Method Details

#clear ⇒ Object 



103
104
105
 
# File 'lib/devp2p/sync_queue.rb', line 103

def clear
  @queue.clear
end

#deq(non_block = false) ⇒ Object 



46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
 
# File 'lib/devp2p/sync_queue.rb', line 46

def deq(non_block=false)
  Thread.handle_interrupt(StandardError => :on_blocking) do
    loop do
      @mutex.synchronize do
        if empty?
          if non_block
            raise ThreadError, 'queue empty'
          else
            begin
              @num_waiting += 1
              @cond_empty.wait @mutex
            ensure
              @num_waiting -= 1
            end
          end
        else
          obj = @queue.shift
          @cond_full.signal
          return obj
        end
      end
    end
  end
end

#empty? ⇒ Boolean

Returns:

  • (Boolean) 


99
100
101
 
# File 'lib/devp2p/sync_queue.rb', line 99

def empty?
  @queue.empty?
end

#enq(obj, non_block = false) ⇒ Object Also known as: << 



20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
 
# File 'lib/devp2p/sync_queue.rb', line 20

def enq(obj, non_block=false)
  Thread.handle_interrupt(StandardError => :on_blocking) do
    loop do
      @mutex.synchronize do
        if full?
          if non_block
            raise ThreadError, 'queue full'
          else
            begin
              @num_waiting += 1
              @cond_full.wait @mutex
            ensure
              @num_waiting -= 1
            end
          end
        else
          @queue.push obj
          @cond_empty.signal
          return obj
        end
      end
    end
  end
end

#full? ⇒ Boolean

Returns:

  • (Boolean) 


95
96
97
 
# File 'lib/devp2p/sync_queue.rb', line 95

def full?
  @max_size && @queue.size >= @max_size
end

#length ⇒ Object Also known as: size 



107
108
109
 
# File 'lib/devp2p/sync_queue.rb', line 107

def length
  @queue.length
end

#num_waiting ⇒ Object

Returns the number of threads waiting on the queue.



113
114
115
 
# File 'lib/devp2p/sync_queue.rb', line 113

def num_waiting
  @num_waiting
end

#peek(non_block = false) ⇒ Object

Same as pop except it will not remove the element from queue, just peek.



72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
 
# File 'lib/devp2p/sync_queue.rb', line 72

def peek(non_block=false)
  Thread.handle_interrupt(StandardError => :on_blocking) do
    loop do
      @mutex.synchronize do
        if empty?
          if non_block
            raise ThreadError, 'queue empty'
          else
            begin
              @num_waiting += 1
              @cond_empty.wait @mutex
            ensure
              @num_waiting -= 1
            end
          end
        else
          return @queue[0]
        end
      end
    end
  end
end