skynet.init rework, See #1322 (#1323)

* skynet.init rework, See #1322

* restore init_list #1322

* xpcall init_all, See #1322

lualib/loader.lua

@@ -45,4 +45,6 @@ if LUA_PRELOAD then
 	LUA_PRELOAD = nil
 end
 
+_G.require = (require "skynet.require").require
+
 main(select(2, table.unpack(args)))

lualib/skynet.lua

@@ -1,5 +1,6 @@
 -- read https://github.com/cloudwu/skynet/wiki/FAQ for the module "skynet.core"
 local c = require "skynet.core"
+local skynet_require = require "skynet.require"
 local tostring = tostring
 local coroutine = coroutine
 local assert = assert
@@ -925,49 +926,16 @@ do
 	}
 end
 
-local init_func = {}
-
-function skynet.init(f, name)
-	assert(type(f) == "function")
-	if init_func == nil then
-		f()
-	else
-		tinsert(init_func, f)
-		if name then
-			assert(type(name) == "string")
-			assert(init_func[name] == nil)
-			init_func[name] = f
-		end
-	end
-end
-
-local function init_all()
-	local funcs = init_func
-	init_func = nil
-	if funcs then
-		for _,f in ipairs(funcs) do
-			f()
-		end
-	end
-end
-
-local function ret(f, ...)
-	f()
-	return ...
-end
-
-local function init_template(start, ...)
-	init_all()
-	init_func = {}
-	return ret(init_all, start(...))
-end
-
-function skynet.pcall(start, ...)
-	return xpcall(init_template, traceback, start, ...)
-end
+skynet.init = skynet_require.init
+-- skynet.pcall is deprecated, use pcall directly
+skynet.pcall = pcall
 
 function skynet.init_service(start)
-	local ok, err = skynet.pcall(start)
+	local function main()
+		skynet_require.init_all()
+		start()
+	end
+	local ok, err = xpcall(main, traceback)
 	if not ok then
 		skynet.error("init service failed: " .. tostring(err))
 		skynet.send(".launcher","lua", "ERROR")

lualib/skynet/multicast.lua

@@ -95,6 +95,6 @@ local function init()
 	}
 end
 
-skynet.init(init, "multicast")
+skynet.init(init)
 
 return multicast

lualib/skynet/require.lua

@@ -0,0 +1,51 @@
+-- skynet module two-step initialize . When you require a skynet module :
+-- 1. Run module main function as official lua module behavior.
+-- 2. Run the functions register by skynet.init() during the step 1,
+--      unless calling `require` in main thread .
+-- If you call `require` in main thread ( service main function ), the functions
+-- registered by skynet.init() do not execute immediately, they will be executed
+-- by skynet.start() before start function.
+
+local M = {}
+
+local mainthread, ismain = coroutine.running()
+assert(ismain, "skynet.require must initialize in main thread")
+
+local context = {
+	[mainthread] = {},
+}
+
+do
+	local require = _G.require
+	function M.require(...)
+		local co, main = coroutine.running()
+		if main then
+			return require(...)
+		else
+			local old_init_list = context[co]
+			local init_list = {}
+			context[co] = init_list
+			local ret = require(...)
+			for _, f in ipairs(init_list) do
+				f()
+			end
+			context[co] = old_init_list
+			return ret
+		end
+	end
+end
+
+function M.init_all()
+	for _, f in ipairs(context[mainthread]) do
+		f()
+	end
+	context[mainthread] = nil
+end
+
+function M.init(f)
+	assert(type(f) == "function")
+	local co = coroutine.running()
+	table.insert(context[co], f)
+end
+
+return M