util.signal: Add support for signalfd(2) on Linux
signalfd allows handling signal events using the same method as sockets,
via file descriptors. Thus all signal dispatch can go through the same
main event loop as everything else, removing need for thread-scary
signal handling where execution would just jump to the signal handler
regardless of the state of Lua, and needing to keep track of Lua
states/threads.
local st = require "prosody.util.stanza";
local xmlns_csi = "urn:xmpp:csi:0";
local csi_feature = st.stanza("csi", { xmlns = xmlns_csi });
local change = module:metric("counter", "changes", "events", "CSI state changes", {"csi_state"});
module:hook("stream-features", function (event)
if event.origin.username then
event.features:add_child(csi_feature);
end
end);
function refire_event(name)
return function (event)
if event.origin.username then
event.origin.state = event.stanza.name;
change:with_labels(event.stanza.name):add(1);
module:fire_event(name, event);
return true;
end
end;
end
module:hook("stanza/"..xmlns_csi..":active", refire_event("csi-client-active"));
module:hook("stanza/"..xmlns_csi..":inactive", refire_event("csi-client-inactive"));