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--
-- This file is part of LEM, a Lua Event Machine.
-- Copyright 2013 Asbjørn Sloth Tønnesen
--
-- LEM is free software: you can redistribute it and/or modify it
-- under the terms of the GNU Lesser General Public License as
-- published by the Free Software Foundation, either version 3 of
-- the License, or (at your option) any later version.
--
-- LEM is distributed in the hope that it will be useful, but
-- WITHOUT ANY WARRANTY; without even the implied warranty of
-- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
-- GNU Lesser General Public License for more details.
--
-- You should have received a copy of the GNU Lesser General Public
-- License along with LEM. If not, see <http://www.gnu.org/licenses/>.
--
local core = require 'lem.signal.core'
local queues = {}
local function fire(signal, ...)
local queue = queues[signal]
for i = 1, #queue do
queue[i](signal, ...)
end
end
local install_signal_handler
do
local installed = false
function install_signal_handler()
if not installed then
core.sethandler(function(signal, ...)
fire(signal, ...)
end)
installed = true
end
end
end
local signal_install, signal_uninstall
do
local installed = {}
function signal_install(sig)
if installed[sig] then
return true
end
install_signal_handler()
local ret, err = core.watch(sig)
if not ret then return nil, err end
installed[sig] = true
return true
end
function signal_uninstall(sig)
if not installed[sig] then
return true
end
local ret, err = core.unwatch(sig)
if not ret then return nil, err end
installed[sig] = nil
return true
end
end
local M = {}
function M.register(signum, func)
if not signum then return nil, 'unknown signal' end
local queue = queues[signum]
if queue == nil then
queue = {}
queues[signum] = queue
end
table.insert(queue, func)
return signal_install(signum)
end
function M.unregister(signum, func)
if not signum then return nil, 'unknown signal' end
local queue = queues[signum]
if queue then
for i = 1, #queue do
if queue[i] == func then
table.remove(queue, i)
end
end
if #queue == 0 then
return signal_uninstall(signum)
end
end
return true
end
return M
-- vim: ts=2 sw=2 noet:
|
