signal.lua
local sig = require "posix.signal"
local unistd = require "posix.unistd"
local syswait = require "posix.sys.wait"
local function go (fn, ...)
local cpid = unistd.fork ()
if cpid == 0 then unistd._exit (fn (...) or 0)
else
return cpid
end
end
local verbose = #arg > 0
local function sleepx (secs)
while true do
secs = unistd.sleep (secs)
if verbose then print ("sleep", secs) end
if secs == 0 then return end
end
end
local nchild, nsig = 0, 0
sig.signal (sig.SIGCHLD, function()
local pid, status, code = syswait.wait (-1, syswait.WNOHANG)
while pid do
if pid ~= 0 then
if verbose then print ("wait", pid, status, code) end
nchild = nchild + 1
end
pid, status, code = syswait.wait (-1, syswait.WNOHANG)
end
end)
local function handler (signo)
if verbose then print ("handled", signo) end
nsig = nsig + 1
end
sig.signal (sig.SIGUSR1, handler)
sig.signal (sig.SIGUSR2, handler)
sig.signal (60, handler)
local function killp (nsig)
return sig.kill (unistd.getppid (), nsig)
end
c1 = go (function() unistd.sleep (1); killp (sig.SIGUSR1); killp (sig.SIGUSR2) end)
c2 = go (function() unistd.sleep (2); killp (sig.SIGUSR2); end)
c3 = go (function() unistd.sleep (2); killp (sig.SIGUSR1) end)
sleepx(3)
if verbose then
print ("children", nchild, "signals", nsig)
else
assert (nchild == 3)
assert (nsig == 4)
print '+++ tests OK +++'
end