Class: Multitrap::Trap

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

Constant Summary collapse

RESERVED_SIGNALS = 
{
  'BUS' => 10,
  'SEGV' => 11,
  'ILL' => 4,
  'FPE' => 8,
  'VTALRM' => 26
}

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(old_trap) ⇒ Trap

Returns a new instance of Trap.



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# File 'lib/multitrap.rb', line 19

def initialize(old_trap)
  @old_trap = old_trap
  @traps = {}
  @mutex = Mutex.new
end

Class Method Details

.trap(sig, prc, old_trap, &block) ⇒ Object 



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# File 'lib/multitrap.rb', line 14

def self.trap(sig, prc, old_trap, &block)
  @multitrap ||= self.new(old_trap)
  @multitrap.add_trap(sig, prc, &block)
end

Instance Method Details

#add_trap(sig, prc, &block) ⇒ Object 



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# File 'lib/multitrap.rb', line 33

def add_trap(sig, prc, &block)
  if RESERVED_SIGNALS.key?(sig)
    raise ArgumentError, "can't trap reserved signal SIG#{sig}"
  end

  unless Signal.list.key?(sig)
    raise ArgumentError, "unsupported signal SIG#{sig}"
  end

  prc ||= block

  if prc.nil?
    raise ArgumentError, "tried to create Proc object without a block"
  end

  @traps[sig] ||= []

  @mutex.synchronize do
    if recursion?
      @traps[sig].pop
    else
      @traps[sig].push(prc || block)
    end
  end

  @old_trap.call(sig) do
    @traps[sig].each do |trap_handler|
      trap_handler.call(Signal.list[sig])
    end
  end

  @traps
end

#recursion? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/multitrap.rb', line 25

def recursion?
  frame = caller.find do |f|
    f =~ %r{multitrap/lib/multitrap\.rb.+`block in add_trap'}
  end

  true if frame
end