Class: Cod::ExclusiveSection

Inherits:
Object
  • Object
show all
Defined in:
lib/cod/work_queue.rb

Overview

A section of code that is entered only once. Instead of blocking threads that are waiting to enter, it just returns nil.

Instance Method Summary collapse

Constructor Details

#initialize ⇒ ExclusiveSection

:nodoc:



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# File 'lib/cod/work_queue.rb', line 123

def initialize
  @mutex = Mutex.new
  @threads_in_block = 0
end

Instance Method Details

#enter ⇒ Object

If no one is in the block given to #enter currently, this will yield to the block. If one thread is already executing that block, it will return nil.



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# File 'lib/cod/work_queue.rb', line 132

def enter
  @mutex.synchronize { 
    return if @threads_in_block > 0
    @threads_in_block += 1 }
  begin
    yield
  ensure
    fail "Assert fails, #{@threads_in_block} threads in block" \
      if @threads_in_block != 1
    @mutex.synchronize { 
      @threads_in_block -= 1 }
  end
end