Add lua-ev poller backend.

examples/poller.lua

@@ -0,0 +1,45 @@
+-- Copyright (c) 2012 Robert G. Jakabosky <bobby@sharedrealm.com>
+--
+-- Permission is hereby granted, free of charge, to any person obtaining a copy
+-- of this software and associated documentation files (the "Software"), to deal
+-- in the Software without restriction, including without limitation the rights
+-- to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+-- copies of the Software, and to permit persons to whom the Software is
+-- furnished to do so, subject to the following conditions:
+--
+-- The above copyright notice and this permission notice shall be included in
+-- all copies or substantial portions of the Software.
+--
+-- THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+-- IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+-- FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+-- AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+-- LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+-- OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+-- THE SOFTWARE.
+
+-- safe require.
+local require = require
+local function safe_require(...)
+	return pcall(require, ...)
+end
+
+local mod_name = ...
+
+local backends = {
+	"epoll",
+	"ev",
+}
+
+for i=1,#backends do
+	local backend = backends[i]
+	local name = mod_name .. '.' .. backend
+	local status, mod = safe_require(name)
+	if status then
+		--print("Loaded backend:", name)
+		return mod
+	end
+end
+
+error("Failed to load backend for: " .. mod_name)
+

examples/poller/ev.lua

@@ -0,0 +1,117 @@
+-- Copyright (c) 2012 Robert G. Jakabosky <bobby@sharedrealm.com>
+--
+-- Permission is hereby granted, free of charge, to any person obtaining a copy
+-- of this software and associated documentation files (the "Software"), to deal
+-- in the Software without restriction, including without limitation the rights
+-- to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+-- copies of the Software, and to permit persons to whom the Software is
+-- furnished to do so, subject to the following conditions:
+--
+-- The above copyright notice and this permission notice shall be included in
+-- all copies or substantial portions of the Software.
+--
+-- THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+-- IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+-- FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+-- AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+-- LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+-- OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+-- THE SOFTWARE.
+
+local ev = require'ev'
+local ev_READ = ev.READ
+local ev_WRITE = ev.WRITE
+local loop = ev.Loop.default
+
+assert(ev.Idle,"Need version > 1.3 of lua-ev that supports Idle watchers.")
+
+local poller_meths = {}
+local poller_mt = {__index = poller_meths}
+
+local function poller_new()
+	local self = {
+		work_cur = {},
+		work_last = {},
+		io_events = 0,
+		reads = {},
+		idle_enabled = false,
+	}
+
+	self.idle = ev.Idle.new(function()
+		local tasks = #self.work_cur
+		-- check if there is any work
+		if tasks > 0 then
+			-- swap work queues.
+			local last, cur = self.work_cur, self.work_last
+			self.work_cur, self.work_last = cur, last
+			for i=1,tasks do
+				local task = last[i]
+				last[i] = nil
+				task()
+			end
+			-- check if there is more work.
+			if #cur > 0 then
+				return -- don't disable idle watcher, when we have work.
+			end
+		end
+--print("STOP IDLE:", #self.work_cur, #self.work_last)
+		-- stop idle watcher, no work.
+		self.idle_enabled = false
+		self.idle:stop(loop)
+	end)
+
+	return setmetatable(self, poller_mt)
+end
+
+function poller_meths:add_work(task)
+	local idx = #self.work_cur + 1
+	-- add task to current work queue.
+	self.work_cur[idx] = task
+	-- make sure the idle watcher is enabled.
+	if not self.idle_enabled then
+		self.idle_enabled = true
+		self.idle:start(loop)
+	end
+end
+
+function poller_meths:add_read(fd, cb)
+	local io_read = self.reads[fd]
+	-- make sure read event hasn't been registered yet.
+	if not io_read then
+		self.io_events = self.io_events + 1
+		io_read = ev.IO.new(function()
+			cb(fd)
+		end, fd, ev_READ)
+		self.reads[fd] = io_read
+		io_read:start(loop)
+	else
+		-- update read callback?
+		io_read:callback(cb)
+		-- need to re-start watcher?
+		if not io_read:is_active() then
+			io_read:start(loop)
+		end
+	end
+end
+
+function poller_meths:remove_read(fd)
+	local io_read = self.reads[fd]
+	-- make sure there was a read event registered.
+	if io_read then
+		self.io_events = self.io_events - 1
+		io_read:stop(loop)
+	end
+end
+
+function poller_meths:start()
+	return loop:loop()
+end
+
+function poller_meths:stop()
+	return loop:unloop()
+end
+
+-- module only exports a 'new' function.
+return {
+new = poller_new,
+}