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| | # Copyright (C) 2013-2019 all contributors <dtas-all@nongnu.org>
# License: GPL-3.0+ <https://www.gnu.org/licenses/gpl-3.0.txt>
# frozen_string_literal: true
# used in various places for safe wakeups from IO.select via signals
# This requires a modern GNU/Linux system with eventfd(2) support
require_relative '../nonblock'
require 'fiddle'
class DTAS::Sigevent # :nodoc:
EventFD = Fiddle::Function.new(DTAS.libc['eventfd'],
[ Fiddle::TYPE_INT, Fiddle::TYPE_INT ], # initval, flags
Fiddle::TYPE_INT) # fd
attr_reader :to_io
ONE = [ 1 ].pack('Q').freeze
def initialize
fd = EventFD.call(0, 02000000|00004000) # EFD_CLOEXEC|EFD_NONBLOCK
raise "eventfd failed: #{Fiddle.last_error}" if fd < 0
@to_io = DTAS::Nonblock.for_fd(fd)
@buf = ''.b
end
def signal
@to_io.syswrite(ONE)
end
def readable_iter
@to_io.read_nonblock(8, @buf, exception: false)
yield self, nil # calls DTAS::Process.reaper
:wait_readable
end
def close
@to_io.close
end
end
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