File

spec/util_debug_spec.lua @ 11665:148075532021

net.server_epoll: Prevent stack overflow of opportunistic writes net.http.files serving a big enough file on a fast enough connection with opportunistic_writes enabled could trigger a stack overflow through repeatedly serving more data that immediately gets sent, draining the buffer and triggering more data to be sent. This also blocked the server on a single task until completion or an error. This change prevents nested opportunistic writes, which should prevent the stack overflow, at the cost of reduced download speed, but this is unlikely to be noticeable outside of Gbit networks. Speed at the cost of blocking other processing is not worth it, especially with the risk of stack overflow.
author Kim Alvefur <zash@zash.se>
date Sun, 11 Jul 2021 09:39:21 +0200
parent 11177:37dc2a6144d1
line wrap: on
line source

local dbg = require "util.debug";

describe("util.debug", function ()
	describe("traceback()", function ()
		it("works", function ()
			local tb = dbg.traceback();
			assert.is_string(tb);
		end);
	end);
	describe("get_traceback_table()", function ()
		it("works", function ()
			local count = 0;
			-- MUST stay in sync with the line numbers of these functions:
			local f1_defined, f3_defined = 43, 15;
			local function f3(f3_param) --luacheck: ignore 212/f3_param
				count = count + 1;

				for i = 1, 2 do
					local tb = dbg.get_traceback_table(i == 1 and coroutine.running() or nil, 0);
					assert.is_table(tb);
					--print(dbg.traceback(), "\n\n\n", require "util.serialization".serialize(tb, { fatal = false, unquoted = true}));
					local found_f1, found_f3;
					for _, frame in ipairs(tb) do
						if frame.info.linedefined == f1_defined then
							assert.equal(0, #frame.locals);
							assert.equal("f2", frame.upvalues[1].name);
							assert.equal("f1_upvalue", frame.upvalues[2].name);
							found_f1 = true;
						elseif frame.info.linedefined == f3_defined then
							assert.equal("f3_param", frame.locals[1].name);
							found_f3 = true;
						end
					end
					assert.is_true(found_f1);
					assert.is_true(found_f3);
				end
			end
			local function f2()
				local f2_local = "hello";
				return f3(f2_local);
			end
			local f1_upvalue = "upvalue1";
			local function f1()
				f2(f1_upvalue);
			end

			-- ok/err are caught and re-thrown so that
			-- busted gets to handle them in its own way
			local ok, err;
			local function hook()
				debug.sethook();
				ok, err = pcall(f1);
			end

			-- Test the traceback is correct in various
			-- types of caller environments

			-- From a Lua hook
			debug.sethook(hook, "crl", 1);
			local a = string.sub("abcdef", 3, 4);
			assert.equal("cd", a);
			debug.sethook();
			assert.equal(1, count);

			if not ok then
				error(err);
			end
			ok, err = nil, nil;

			-- From a signal handler (C hook)
			require "util.signal".signal("SIGUSR1", hook);
			require "util.signal".raise("SIGUSR1");
			assert.equal(2, count);

			if not ok then
				error(err);
			end
			ok, err = nil, nil;

			-- Inside a coroutine
			local co = coroutine.create(function ()
				hook();
			end);
			coroutine.resume(co);

			if not ok then
				error(err);
			end

			assert.equal(3, count);
		end);
	end);
end);