call skynet.trace() in example

examples/agent.lua

@@ -50,7 +50,10 @@ skynet.register_protocol {
 	unpack = function (msg, sz)
 		return host:dispatch(msg, sz)
 	end,
-	dispatch = function (_, _, type, ...)
+	dispatch = function (fd, _, type, ...)
+		assert(fd == client_fd)	-- You can use fd to reply message
+		skynet.ignoreret()	-- session is fd, don't call skynet.ret
+		skynet.trace()
 		if type == "REQUEST" then
 			local ok, result  = pcall(request, ...)
 			if ok then
@@ -92,6 +95,7 @@ end
 
 skynet.start(function()
 	skynet.dispatch("lua", function(_,_, command, ...)
+		skynet.trace()
 		local f = CMD[command]
 		skynet.ret(skynet.pack(f(...)))
 	end)

lualib/skynet.lua

@@ -265,6 +265,8 @@ function suspend(co, result, command, param, param2)
 		return suspend(co, coroutine_resume(co, response))
 	elseif command == "EXIT" then
 		-- coroutine exit
+		local tag = session_coroutine_tracetag[co]
+		if tag then c.trace(tag, "end") end
 		local address = session_coroutine_address[co]
 		if address then
 			release_watching(address)