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require File.expand_path('../spec_helper', __FILE__)
require 'tempfile'
require 'fcntl'
describe Cool.io::AsyncWatcher, :env => :exclude_win do
it "does not signal on spurious wakeups" do
aw = Cool.io::AsyncWatcher.new
tmp = Tempfile.new('coolio_async_watcher_test')
nr_fork = 2 # must be at least two for spurious wakeups
# We have aetter chance of failing if this overflows the pipe buffer
# which POSIX requires >= 512 bytes, Linux 2.6 uses 4096 bytes
nr_signal = 4096 * 4
append = File.open(tmp.path, "ab")
append.sync = true
rd, wr = ::IO.pipe
aw.on_signal { append.syswrite("#$$\n") }
children = nr_fork.times.map do
fork do
trap(:TERM) { exit!(0) }
rloop = Cool.io::Loop.default
aw.attach(rloop)
wr.write '.' # signal to master that we're ready
rloop.run
exit!(1) # should not get here
end
end
# ensure children are ready
nr_fork.times { expect(rd.sysread(1)).to eq('.') }
# send our signals
nr_signal.times { aw.signal }
# wait for the pipe buffer to be consumed by the children
sleep 1 while tmp.stat.ctime >= (Time.now - 4)
children.each do |pid|
Process.kill(:TERM, pid)
_, status = Process.waitpid2(pid)
expect(status.exitstatus).to eq(0)
end
# we should've written a line for every signal we sent
lines = tmp.readlines
expect(lines.size).to eq(nr_signal)
# theoretically a bad kernel scheduler could give us fewer...
expect(lines.sort.uniq.size).to eq(nr_fork)
tmp.close!
end
end
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