uloop: add support for interval timers

[project/libubox.git] / examples / uloop-example.lua

diff --git a/examples/uloop-example.lua b/examples/uloop-example.lua
index ba34ec52db3525ea13cebf9a68182a3a567ab4de..f3aef60debad4a2a8f19611e001ef9dd9ce1fba8 100755 (executable)
--- a/examples/uloop-example.lua
+++ b/examples/uloop-example.lua
@@ -9,7 +9,7 @@ local udp = socket.udp()
 udp:settimeout(0)
 udp:setsockname('*', 8080)
 
--- timer example 1
+-- timer example 1 (will run repeatedly)
 local timer
 function t()
        print("1000 ms timer run");
@@ -18,12 +18,29 @@ end
 timer = uloop.timer(t)
 timer:set(1000)
 
--- timer example 2
+-- timer example 2 (will run once)
 uloop.timer(function() print("2000 ms timer run"); end, 2000)
 
--- timer example 3
+-- timer example 3 (will never run)
 uloop.timer(function() print("3000 ms timer run"); end, 3000):cancel()
 
+-- periodic interval timer
+local intv
+intv = uloop.interval(function()
+       print(string.format("Interval expiration #%d - %dms until next expiration",
+               intv:expirations(), intv:remaining()))
+
+       -- after 5 expirations, lower interval to 500ms
+       if intv:expirations() >= 5 then
+               intv:set(500)
+       end
+
+       -- cancel after 10 expirations
+       if intv:expirations() >= 10 then
+               intv:cancel()
+       end
+end, 1000)
+
 -- process
 function p1(r)
        print("Process 1 completed")
@@ -46,20 +63,33 @@ uloop.timer(
        end, 2000
 )
 
-uloop.fd_add(udp, function(ufd, events)
+-- 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 = 'Hello!'
+               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_send_timer:set(1000)
+               udp_count = udp_count + 1
        end, 3000
 )