net.cqueues: Fixes hardcoded timeout for first iteration

This was originally put in place as a fix for what ended up a cqueues bug: https://github.com/wahern/cqueues/issues/40
A check for a cqueues version with the bug fix is included.

diff --git a/net/cqueues.lua b/net/cqueues.lua
index a67e405a13249ad9ea31c9fdbe24b31ad5dfba87..f6bfd9491fb9fdf7f6ad141fb7ff8194fe0a83e9 100644 (file)
--- a/net/cqueues.lua
+++ b/net/cqueues.lua
@@ -9,6 +9,7 @@
 
 local server = require "net.server";
 local cqueues = require "cqueues";
+assert(cqueues.VERSION >= 20150112, "cqueues newer than 20151013 required")
 
 -- Create a single top level cqueue
 local cq;
@@ -43,23 +44,27 @@ elseif server.event and server.base then -- server_event
        cq = cqueues.new();
        -- Only need to listen for readable; cqueues handles everything under the hood
        local EV_READ = server.event.EV_READ;
+       -- Convert a cqueues timeout to an acceptable timeout for luaevent
+       local function luaevent_safe_timeout(cq)
+               local t = cq:timeout();
+               -- if you give luaevent 0 or nil, it re-uses the previous timeout.
+               if t == 0 then
+                       t = 0.000001; -- 1 microsecond is the smallest that works (goes into a `struct timeval`)
+               elseif t == nil then -- pick something big if we don't have one
+                       t = 0x7FFFFFFF; -- largest 32bit int
+               end
+               return t
+       end
        local event_handle;
        event_handle = server.base:addevent(cq:pollfd(), EV_READ, function(e)
                        -- Need to reference event_handle or this callback will get collected
                        -- This creates a circular reference that can only be broken if event_handle is manually :close()'d
                        local _ = event_handle;
+                       -- Run as many cqueues things as possible (with a timeout of 0)
+                       -- If an error is thrown, it will break the libevent loop; but prosody resumes after logging a top level error
                        assert(cq:loop(0));
-                       -- Convert a cq timeout to an acceptable timeout for luaevent
-                       local t = cq:timeout();
-                       if t == 0 then -- if you give luaevent 0, it won't call this callback again
-                               t = 0.000001; -- 1 microsecond is the smallest that works (goes into a `struct timeval`)
-                       elseif t == nil then -- you always need to give a timeout, pick something big if we don't have one
-                               t = 0x7FFFFFFF; -- largest 32bit int
-                       end
-                       return EV_READ, t;
-               end,
-               -- Schedule the callback to fire on first tick to ensure any cq:wrap calls that happen during start-up are serviced.
-               0.000001);
+                       return EV_READ, luaevent_safe_timeout(cq);
+               end, luaevent_safe_timeout(cq));
 else
        error "NYI"
 end