Class: Synapse::PublicLock

Inherits:
Object
  • Object
show all
Defined in:
lib/synapse/common/concurrency/public_lock.rb

Overview

Lock that tracks the thread owning the lock and any waiting threads

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize ⇒ undefined 



11
12
13
14
 
# File 'lib/synapse/common/concurrency/public_lock.rb', line 11

def initialize
  @mutex = Mutex.new
  @waiting = Array.new
end

Instance Attribute Details

#owner ⇒ Thread (readonly)

Returns The current owner of the thread, if any.

Returns:

  • (Thread) —

    The current owner of the thread, if any



5
6
7
 
# File 'lib/synapse/common/concurrency/public_lock.rb', line 5

def owner
  @owner
end

#waiting ⇒ Array (readonly)

Returns The list of threads waiting for this lock.

Returns:

  • (Array) —

    The list of threads waiting for this lock



8
9
10
 
# File 'lib/synapse/common/concurrency/public_lock.rb', line 8

def waiting
  @waiting
end

Instance Method Details

#lock ⇒ undefined

Returns:

  • (undefined)

See Also:

  • Mutex#lock


44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
 
# File 'lib/synapse/common/concurrency/public_lock.rb', line 44

def lock
  @mutex.synchronize do
    if @owner == Thread.current
      raise ThreadError, 'Lock is already owned by the current thread'
    end

    while @owner
      @waiting.push Thread.current

      begin
        @mutex.sleep
      ensure
        @waiting.delete Thread.current
      end
    end

    @owner = Thread.current
  end
end

#owned? ⇒ Boolean

Returns true if the calling thread owns this lock

Returns:

  • (Boolean)

See Also:

  • Mutex#owned?


20
21
22
 
# File 'lib/synapse/common/concurrency/public_lock.rb', line 20

def owned?
  @owner == Thread.current
end

#owned_by?(thread) ⇒ Boolean

Returns true if the given thread owns this lock

Returns:

  • (Boolean) 


26
27
28
 
# File 'lib/synapse/common/concurrency/public_lock.rb', line 26

def owned_by?(thread)
  @owner == thread
end

#synchronize ⇒ undefined

Returns:

  • (undefined)

See Also:

  • Mutex#synchronize


32
33
34
35
36
37
38
39
40
 
# File 'lib/synapse/common/concurrency/public_lock.rb', line 32

def synchronize
  lock

  begin
    yield
  ensure
    unlock rescue nil
  end
end

#try_lock ⇒ Boolean

Returns ].

Returns:

  • (Boolean) —

    ]

See Also:

  • Mutex#try_lock


81
82
83
84
85
86
87
88
89
90
91
92
93
 
# File 'lib/synapse/common/concurrency/public_lock.rb', line 81

def try_lock
  @mutex.synchronize do
    if @owner == Thread.current
      raise ThreadError, 'Lock is already owned by the current thread'
    end

    return false if @owner

    @owner = Thread.current
  end

  true
end

#unlock ⇒ undefined

Returns:

  • (undefined)

See Also:

  • Mutex#unlock


66
67
68
69
70
71
72
73
74
75
76
77
 
# File 'lib/synapse/common/concurrency/public_lock.rb', line 66

def unlock
  @mutex.synchronize do
    if @owner == Thread.current
      @owner = nil

      first_waiter = @waiting.first
      first_waiter.wakeup if first_waiter
    else
      raise ThreadError, 'Lock is not owned by the current thread'
    end
  end
end