Module: SignalTrampoline

Defined in:
lib/raad/signal_trampoline.rb

Constant Summary collapse

SIGNALS = 
{
  :EXIT => 0, :HUP => 1, :INT => 2, :QUIT => 3, :ILL => 4, :TRAP => 5, :IOT => 6, :ABRT => 6, :FPE => 8, :KILL => 9,
  :BUS => 7, :SEGV => 11, :SYS => 31, :PIPE => 13, :ALRM => 14, :TERM => 15, :URG => 23, :STOP => 19, :TSTP => 20, 
  :CONT => 18, :CHLD => 17, :CLD => 17, :TTIN => 21, :TTOU => 22, :IO => 29, :XCPU => 24, :XFSZ => 25, :VTALRM => 26, 
  :PROF => 27, :WINCH => 28, :USR1 => 10, :USR2 => 12, :PWR => 30, :POLL => 29
}

Class Method Summary collapse

Class Method Details

.detach_handler_thread ⇒ Object 



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# File 'lib/raad/signal_trampoline.rb', line 29

def detach_handler_thread
  Thread.new do
    Thread.current.abort_on_exception = true
    loop do
      s = @signal_q.pop
      @handlers[s].call if @handlers[s]
    end
  end
end

.trap(signal, &block) ⇒ Object

using threads to bounce signal using a thread-safe queue seem the most robust way to handle signals. it minimizes the code in the trap block and reissue the signal and its handling in the normal Ruby flow, within normal threads.



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# File 'lib/raad/signal_trampoline.rb', line 22

def trap(signal, &block)
  raise("unknown signal") unless SIGNALS.has_key?(signal)
  @handler_thread ||= detach_handler_thread
  @handlers[signal] = block
  Kernel.trap(signal) {Thread.new{@signal_q << signal}}
end