[PATCH libubox 4/4] examples/lua: attempt to highlight some traps
Karl Palsson
karlp at etactica.com
Tue Jun 30 06:38:44 EDT 2020
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 at etactica.com>
---
examples/uloop-example.lua | 8 +++++---
1 file changed, 5 insertions(+), 3 deletions(-)
diff --git a/examples/uloop-example.lua b/examples/uloop-example.lua
index 9b0684e..511b9ea 100755
--- 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");
@@ -18,10 +18,10 @@ 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()
-- process
@@ -46,6 +46,8 @@ uloop.timer(
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)
--
2.21.3
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