libubox/examples/uloop-example.lua
Karl Palsson f4e9bf73ac examples/lua: attempt to highlight some traps
Ran into some issues with my fd event being garbage collected.  As I
never wanted to call :delete, I had seen no reason to keep the returned
object, as my callback and upvalues were still valid.

Signed-off-by: Karl Palsson <karlp@etactica.com>
2020-07-11 11:15:12 +02:00

80 lines
1.6 KiB
Lua
Executable file

#!/usr/bin/env lua
local socket = require "socket"
local uloop = require("uloop")
uloop.init()
local udp = socket.udp()
udp:settimeout(0)
udp:setsockname('*', 8080)
-- timer example 1 (will run repeatedly)
local timer
function t()
print("1000 ms timer run");
timer:set(1000)
end
timer = uloop.timer(t)
timer:set(1000)
-- timer example 2 (will run once)
uloop.timer(function() print("2000 ms timer run"); end, 2000)
-- timer example 3 (will never run)
uloop.timer(function() print("3000 ms timer run"); end, 3000):cancel()
-- process
function p1(r)
print("Process 1 completed")
print(r)
end
function p2(r)
print("Process 2 completed")
print(r)
end
uloop.timer(
function()
uloop.process("uloop_pid_test.sh", {"foo", "bar"}, {"PROCESS=1"}, p1)
end, 1000
)
uloop.timer(
function()
uloop.process("uloop_pid_test.sh", {"foo", "bar"}, {"PROCESS=2"}, p2)
end, 2000
)
-- Keep udp_ev reference, events will be gc'd, even if the callback is still referenced
-- .delete will manually untrack.
udp_ev = uloop.fd_add(udp, function(ufd, events)
local words, msg_or_ip, port_or_nil = ufd:receivefrom()
print('Recv UDP packet from '..msg_or_ip..':'..port_or_nil..' : '..words)
if words == "Stop!" then
udp_ev:delete()
end
end, uloop.ULOOP_READ)
udp_count = 0
udp_send_timer = uloop.timer(
function()
local s = socket.udp()
local words
if udp_count > 3 then
words = "Stop!"
udp_send_timer:cancel()
else
words = 'Hello!'
udp_send_timer:set(1000)
end
print('Send UDP packet to 127.0.0.1:8080 :'..words)
s:sendto(words, '127.0.0.1', 8080)
s:close()
udp_count = udp_count + 1
end, 3000
)
uloop.run()