Class: Async::IO::Trap

Inherits:
Object
  • Object
show all
Defined in:
lib/async/io/trap.rb

Overview

A cross-reactor/process notification pipe.

Instance Method Summary collapse

Constructor Details

#initialize(name) ⇒ Trap 



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# File 'lib/async/io/trap.rb', line 29

def initialize(name)
  @name = name
  @notifications = []
  
  @installed = false
  @mutex = Mutex.new
end

Instance Method Details

#ignore! ⇒ Object

Ignore the trap within the current process. Can be invoked before forking and/or invoking install! to assert default behaviour.



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# File 'lib/async/io/trap.rb', line 38

def ignore!
  Signal.trap(@name, "IGNORE")
end

#install! ⇒ Boolean

Install the trap into the current process. Thread safe.



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# File 'lib/async/io/trap.rb', line 44

def install!
  return if @installed
  
  @mutex.synchronize do
    return if @installed
    
    Signal.trap(@name, &self.method(:trigger))
    
    @installed = true
  end
  
  return true
end

#trap ⇒ Object

Block the calling task until the signal occurs.



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# File 'lib/async/io/trap.rb', line 59

def trap
  task = Task.current
  task.annotate("waiting for signal #{@name}")
  
  notification = Notification.new
  @notifications << notification
  
  while true
    notification.wait
    yield
  end
ensure
  if notification
    notification.close
    @notifications.delete(notification)
  end
end

#trigger(signal_number = nil) ⇒ void

This method returns an undefined value.

Signal all waiting tasks that the trap occurred.



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# File 'lib/async/io/trap.rb', line 79

def trigger(signal_number = nil)
  @notifications.each(&:signal)
end