4 server.lua based on lua/libevent by blastbeat
7 -- when using luaevent, never register 2 or more EV_READ at one socket, same for EV_WRITE
8 -- you cant even register a new EV_READ/EV_WRITE callback inside another one
9 -- to do some of the above, use timeout events or something what will called from outside
10 -- dont let garbagecollect eventcallbacks, as long they are running
11 -- when using luasec, there are 4 cases of timeout errors: wantread or wantwrite during reading or writing
15 local SCRIPT_NAME = "server_event.lua"
16 local SCRIPT_VERSION = "0.05"
17 local SCRIPT_AUTHOR = "blastbeat"
18 local LAST_MODIFIED = "2009/11/20"
21 MAX_CONNECTIONS = 100000, -- max per server connections (use "ulimit -n" on *nix)
22 MAX_HANDSHAKE_ATTEMPTS= 1000, -- attempts to finish ssl handshake
23 HANDSHAKE_TIMEOUT = 60, -- timeout in seconds per handshake attempt
24 MAX_READ_LENGTH = 1024 * 1024 * 1024 * 1024, -- max bytes allowed to read from sockets
25 MAX_SEND_LENGTH = 1024 * 1024 * 1024 * 1024, -- max bytes size of write buffer (for writing on sockets)
26 ACCEPT_DELAY = 10, -- seconds to wait until the next attempt of a full server to accept
27 READ_TIMEOUT = 60 * 60 * 6, -- timeout in seconds for read data from socket
28 WRITE_TIMEOUT = 180, -- timeout in seconds for write data on socket
29 CONNECT_TIMEOUT = 20, -- timeout in seconds for connection attempts
30 CLEAR_DELAY = 5, -- seconds to wait for clearing interface list (and calling ondisconnect listeners)
31 DEBUG = true, -- show debug messages
34 local function use(x) return rawget(_G, x); end
35 local ipairs = use "ipairs"
36 local string = use "string"
37 local select = use "select"
38 local require = use "require"
39 local tostring = use "tostring"
40 local coroutine = use "coroutine"
41 local setmetatable = use "setmetatable"
43 local t_insert = table.insert
44 local t_concat = table.concat
47 local socket = use "socket" or require "socket"
49 local log = require ("util.logger").init("socket")
51 local function debug(...)
52 return log("debug", ("%s "):rep(select('#', ...)), ...)
56 local bitor = ( function( ) -- thx Rici Lake
57 local hasbit = function( x, p )
58 return x % ( p + p ) >= p
60 return function( x, y )
63 local limit = x > y and x or y
65 if hasbit( x, p ) or hasbit( y, p ) then
74 local event = require "luaevent.core"
75 local base = event.new( )
76 local EV_READ = event.EV_READ
77 local EV_WRITE = event.EV_WRITE
78 local EV_TIMEOUT = event.EV_TIMEOUT
79 local EV_SIGNAL = event.EV_SIGNAL
81 local EV_READWRITE = bitor( EV_READ, EV_WRITE )
83 local interfacelist = ( function( ) -- holds the interfaces for sockets
86 return function( method, arg )
87 if "add" == method then
92 elseif "delete" == method then
94 return nil, "array is already empty"
96 local position = arg:_position() -- get position in array
97 if position ~= len then
98 local interface = array[ len ] -- get last interface
99 array[ position ] = interface -- copy it into free position
100 array[ len ] = nil -- free last position
101 interface:_position( position ) -- set new position in array
102 else -- free last position
113 -- Client interface methods
116 interface_mt = {}; interface_mt.__index = interface_mt;
118 local addevent = base.addevent
119 local coroutine_wrap, coroutine_yield = coroutine.wrap,coroutine.yield
122 function interface_mt:_position(new_position)
123 self.position = new_position or self.position
124 return self.position;
126 function interface_mt:_close()
127 return self:_destroy();
130 function interface_mt:_start_connection(plainssl) -- should be called from addclient
131 local callback = function( event )
132 if EV_TIMEOUT == event then -- timeout during connection
133 self.fatalerror = "connection timeout"
134 self:ontimeout() -- call timeout listener
136 debug( "new connection failed. id:", self.id, "error:", self.fatalerror )
138 if plainssl and ssl then -- start ssl session
139 self:starttls(self._sslctx, true)
140 else -- normal connection
141 self:_start_session(true)
143 debug( "new connection established. id:", self.id )
145 self.eventconnect = nil
148 self.eventconnect = addevent( base, self.conn, EV_WRITE, callback, cfg.CONNECT_TIMEOUT )
151 function interface_mt:_start_session(call_onconnect) -- new session, for example after startssl
152 if self.type == "client" then
153 local callback = function( )
154 self:_lock( false, false, false )
155 --vdebug( "start listening on client socket with id:", self.id )
156 self.eventread = addevent( base, self.conn, EV_READ, self.readcallback, cfg.READ_TIMEOUT ); -- register callback
157 if call_onconnect then
160 self.eventsession = nil
163 self.eventsession = addevent( base, nil, EV_TIMEOUT, callback, 0 )
166 --vdebug( "start listening on server socket with id:", self.id )
167 self.eventread = addevent( base, self.conn, EV_READ, self.readcallback ) -- register callback
171 function interface_mt:_start_ssl(call_onconnect) -- old socket will be destroyed, therefore we have to close read/write events first
172 --vdebug( "starting ssl session with client id:", self.id )
174 _ = self.eventread and self.eventread:close( ) -- close events; this must be called outside of the event callbacks!
175 _ = self.eventwrite and self.eventwrite:close( )
176 self.eventread, self.eventwrite = nil, nil
178 self.conn, err = ssl.wrap( self.conn, self._sslctx )
180 self.fatalerror = err
181 self.conn = nil -- cannot be used anymore
182 if call_onconnect then
183 self.ondisconnect = nil -- dont call this when client isnt really connected
186 debug( "fatal error while ssl wrapping:", err )
189 self.conn:settimeout( 0 ) -- set non blocking
190 local handshakecallback = coroutine_wrap(
194 local maxattempt = cfg.MAX_HANDSHAKE_ATTEMPTS
195 while attempt < maxattempt do -- no endless loop
196 attempt = attempt + 1
197 debug( "ssl handshake of client with id:"..tostring(self)..", attempt:"..attempt )
198 if attempt > maxattempt then
199 self.fatalerror = "max handshake attempts exceeded"
200 elseif EV_TIMEOUT == event then
201 self.fatalerror = "timeout during handshake"
203 _, err = self.conn:dohandshake( )
205 self:_lock( false, false, false ) -- unlock the interface; sending, closing etc allowed
206 self.send = self.conn.send -- caching table lookups with new client object
207 self.receive = self.conn.receive
208 if not call_onconnect then -- trigger listener
209 self:onstatus("ssl-handshake-complete");
211 self:_start_session( call_onconnect )
212 debug( "ssl handshake done" )
213 self.eventhandshake = nil
216 if err == "wantwrite" then
218 elseif err == "wantread" then
221 debug( "ssl handshake error:", err )
222 self.fatalerror = err
225 if self.fatalerror then
226 if call_onconnect then
227 self.ondisconnect = nil -- dont call this when client isnt really connected
230 debug( "handshake failed because:", self.fatalerror )
231 self.eventhandshake = nil
234 event = coroutine_yield( event, cfg.HANDSHAKE_TIMEOUT ) -- yield this monster...
238 debug "starting handshake..."
239 self:_lock( false, true, true ) -- unlock read/write events, but keep interface locked
240 self.eventhandshake = addevent( base, self.conn, EV_READWRITE, handshakecallback, cfg.HANDSHAKE_TIMEOUT )
243 function interface_mt:_destroy() -- close this interface + events and call last listener
244 debug( "closing client with id:", self.id, self.fatalerror )
245 self:_lock( true, true, true ) -- first of all, lock the interface to avoid further actions
247 _ = self.eventread and self.eventread:close( )
248 if self.type == "client" then
249 _ = self.eventwrite and self.eventwrite:close( )
250 _ = self.eventhandshake and self.eventhandshake:close( )
251 _ = self.eventstarthandshake and self.eventstarthandshake:close( )
252 _ = self.eventconnect and self.eventconnect:close( )
253 _ = self.eventsession and self.eventsession:close( )
254 _ = self.eventwritetimeout and self.eventwritetimeout:close( )
255 _ = self.eventreadtimeout and self.eventreadtimeout:close( )
256 _ = self.ondisconnect and self:ondisconnect( self.fatalerror ~= "client to close" and self.fatalerror) -- call ondisconnect listener (wont be the case if handshake failed on connect)
257 _ = self.conn and self.conn:close( ) -- close connection
258 _ = self._server and self._server:counter(-1);
259 self.eventread, self.eventwrite = nil, nil
260 self.eventstarthandshake, self.eventhandshake, self.eventclose = nil, nil, nil
261 self.readcallback, self.writecallback = nil, nil
264 self.eventread, self.eventclose = nil, nil
265 self.interface, self.readcallback = nil, nil
267 interfacelist( "delete", self )
271 function interface_mt:_lock(nointerface, noreading, nowriting) -- lock or unlock this interface or events
272 self.nointerface, self.noreading, self.nowriting = nointerface, noreading, nowriting
273 return nointerface, noreading, nowriting
277 function interface_mt:lock_read(switch)
281 return self:resume();
285 function interface_mt:pause()
286 return self:_lock(self.nointerface, true, self.nowriting);
289 function interface_mt:resume()
290 self:_lock(self.nointerface, false, self.nowriting);
291 if not self.eventread then
292 self.eventread = addevent( base, self.conn, EV_READ, self.readcallback, cfg.READ_TIMEOUT ); -- register callback
296 function interface_mt:counter(c)
298 self._connections = self._connections + c
300 return self._connections
304 function interface_mt:write(data)
305 if self.nowriting then return nil, "locked" end
306 --vdebug( "try to send data to client, id/data:", self.id, data )
307 data = tostring( data )
309 local total = len + self.writebufferlen
310 if total > cfg.MAX_SEND_LENGTH then -- check buffer length
311 local err = "send buffer exceeded"
312 debug( "error:", err ) -- to much, check your app
315 t_insert(self.writebuffer, data) -- new buffer
316 self.writebufferlen = total
317 if not self.eventwrite then -- register new write event
318 --vdebug( "register new write event" )
319 self.eventwrite = addevent( base, self.conn, EV_WRITE, self.writecallback, cfg.WRITE_TIMEOUT )
323 function interface_mt:close()
324 if self.nointerface then return nil, "locked"; end
325 debug( "try to close client connection with id:", self.id )
326 if self.type == "client" then
327 self.fatalerror = "client to close"
328 if self.eventwrite then -- wait for incomplete write request
329 self:_lock( true, true, false )
330 debug "closing delayed until writebuffer is empty"
331 return nil, "writebuffer not empty, waiting"
333 self:_lock( true, true, true )
338 debug( "try to close server with id:", tostring(self.id))
339 self.fatalerror = "server to close"
346 function interface_mt:socket()
350 function interface_mt:server()
351 return self._server or self;
354 function interface_mt:port()
358 function interface_mt:serverport()
359 return self._serverport
362 function interface_mt:ip()
366 function interface_mt:ssl()
367 return self._usingssl
370 function interface_mt:type()
371 return self._type or "client"
374 function interface_mt:connections()
375 return self._connections
378 function interface_mt:address()
382 function interface_mt:set_sslctx(sslctx)
383 self._sslctx = sslctx;
385 self.starttls = nil; -- use starttls() of interface_mt
387 self.starttls = false; -- prevent starttls()
391 function interface_mt:set_mode(pattern)
393 self._pattern = pattern;
395 return self._pattern;
398 function interface_mt:set_send(new_send)
399 -- No-op, we always use the underlying connection's send
402 function interface_mt:starttls(sslctx, call_onconnect)
403 debug( "try to start ssl at client id:", self.id )
405 self._sslctx = sslctx;
406 if self._usingssl then -- startssl was already called
407 err = "ssl already active"
410 debug( "error:", err )
413 self._usingssl = true
414 self.startsslcallback = function( ) -- we have to start the handshake outside of a read/write event
415 self.startsslcallback = nil
416 self:_start_ssl(call_onconnect);
417 self.eventstarthandshake = nil
420 if not self.eventwrite then
421 self:_lock( true, true, true ) -- lock the interface, to not disturb the handshake
422 self.eventstarthandshake = addevent( base, nil, EV_TIMEOUT, self.startsslcallback, 0 ) -- add event to start handshake
423 else -- wait until writebuffer is empty
424 self:_lock( true, true, false )
425 debug "ssl session delayed until writebuffer is empty..."
427 self.starttls = false;
431 function interface_mt:setoption(option, value)
432 if self.conn.setoption then
433 return self.conn:setoption(option, value);
435 return false, "setoption not implemented";
438 function interface_mt:setlistener(listener)
439 self.onconnect, self.ondisconnect, self.onincoming, self.ontimeout, self.onstatus
440 = listener.onconnect, listener.ondisconnect, listener.onincoming, listener.ontimeout, listener.onstatus;
444 function interface_mt:onconnect()
446 function interface_mt:onincoming()
448 function interface_mt:ondisconnect()
450 function interface_mt:ontimeout()
452 function interface_mt:ondrain()
454 function interface_mt:onstatus()
458 -- End of client interface methods
462 local string_sub = string.sub -- caching table lookups
463 local addevent = base.addevent
464 local socket_gettime = socket.gettime
465 function handleclient( client, ip, port, server, pattern, listener, sslctx ) -- creates an client interface
466 --vdebug("creating client interfacce...")
470 currenttime = socket_gettime( ); -- safe the origin
471 writebuffer = {}; -- writebuffer
472 writebufferlen = 0; -- length of writebuffer
473 send = client.send; -- caching table lookups
474 receive = client.receive;
475 onconnect = listener.onconnect; -- will be called when client disconnects
476 ondisconnect = listener.ondisconnect; -- will be called when client disconnects
477 onincoming = listener.onincoming; -- will be called when client sends data
478 ontimeout = listener.ontimeout; -- called when fatal socket timeout occurs
479 onstatus = listener.onstatus; -- called for status changes (e.g. of SSL/TLS)
480 eventread = false, eventwrite = false, eventclose = false,
481 eventhandshake = false, eventstarthandshake = false; -- event handler
482 eventconnect = false, eventsession = false; -- more event handler...
483 eventwritetimeout = false; -- even more event handler...
484 eventreadtimeout = false;
485 fatalerror = false; -- error message
486 writecallback = false; -- will be called on write events
487 readcallback = false; -- will be called on read events
488 nointerface = true; -- lock/unlock parameter of this interface
489 noreading = false, nowriting = false; -- locks of the read/writecallback
490 startsslcallback = false; -- starting handshake callback
491 position = false; -- position of client in interfacelist
494 _ip = ip, _port = port, _server = server, _pattern = pattern,
495 _serverport = (server and server:port() or nil),
496 _sslctx = sslctx; -- parameters
497 _usingssl = false; -- client is using ssl;
499 if not ssl then interface.starttls = false; end
500 interface.id = tostring(interface):match("%x+$");
501 interface.writecallback = function( event ) -- called on write events
502 --vdebug( "new client write event, id/ip/port:", interface, ip, port )
503 if interface.nowriting or ( interface.fatalerror and ( "client to close" ~= interface.fatalerror ) ) then -- leave this event
504 --vdebug( "leaving this event because:", interface.nowriting or interface.fatalerror )
505 interface.eventwrite = false
508 if EV_TIMEOUT == event then -- took too long to write some data to socket -> disconnect
509 interface.fatalerror = "timeout during writing"
510 debug( "writing failed:", interface.fatalerror )
512 interface.eventwrite = false
515 if interface._usingssl then -- handle luasec
516 if interface.eventreadtimeout then -- we have to read first
517 local ret = interface.readcallback( ) -- call readcallback
518 --vdebug( "tried to read in writecallback, result:", ret )
520 if interface.eventwritetimeout then -- luasec only
521 interface.eventwritetimeout:close( ) -- first we have to close timeout event which where regged after a wantread error
522 interface.eventwritetimeout = false
525 interface.writebuffer = { t_concat(interface.writebuffer) }
526 local succ, err, byte = interface.conn:send( interface.writebuffer[1], 1, interface.writebufferlen )
527 --vdebug( "write data:", interface.writebuffer, "error:", err, "part:", byte )
528 if succ then -- writing succesful
529 interface.writebuffer[1] = nil
530 interface.writebufferlen = 0
532 if interface.fatalerror then
533 debug "closing client after writing"
534 interface:_close() -- close interface if needed
535 elseif interface.startsslcallback then -- start ssl connection if needed
536 debug "starting ssl handshake after writing"
537 interface.eventstarthandshake = addevent( base, nil, EV_TIMEOUT, interface.startsslcallback, 0 )
538 elseif interface.eventreadtimeout then
539 return EV_WRITE, EV_TIMEOUT
541 interface.eventwrite = nil
543 elseif byte and (err == "timeout" or err == "wantwrite") then -- want write again
544 --vdebug( "writebuffer is not empty:", err )
545 interface.writebuffer[1] = string_sub( interface.writebuffer[1], byte + 1, interface.writebufferlen ) -- new buffer
546 interface.writebufferlen = interface.writebufferlen - byte
547 if "wantread" == err then -- happens only with luasec
548 local callback = function( )
550 interface.eventwritetimeout = nil
553 interface.eventwritetimeout = addevent( base, nil, EV_TIMEOUT, callback, cfg.WRITE_TIMEOUT ) -- reg a new timeout event
554 debug( "wantread during write attempt, reg it in readcallback but dont know what really happens next..." )
555 -- hopefully this works with luasec; its simply not possible to use 2 different write events on a socket in luaevent
558 return EV_WRITE, cfg.WRITE_TIMEOUT
559 else -- connection was closed during writing or fatal error
560 interface.fatalerror = err or "fatal error"
561 debug( "connection failed in write event:", interface.fatalerror )
563 interface.eventwrite = nil
569 interface.readcallback = function( event ) -- called on read events
570 --vdebug( "new client read event, id/ip/port:", tostring(interface.id), tostring(ip), tostring(port) )
571 if interface.noreading or interface.fatalerror then -- leave this event
572 --vdebug( "leaving this event because:", tostring(interface.noreading or interface.fatalerror) )
573 interface.eventread = nil
576 if EV_TIMEOUT == event then -- took too long to get some data from client -> disconnect
577 interface.fatalerror = "timeout during receiving"
578 debug( "connection failed:", interface.fatalerror )
580 interface.eventread = nil
583 if interface._usingssl then -- handle luasec
584 if interface.eventwritetimeout then -- ok, in the past writecallback was regged
585 local ret = interface.writecallback( ) -- call it
586 --vdebug( "tried to write in readcallback, result:", tostring(ret) )
588 if interface.eventreadtimeout then
589 interface.eventreadtimeout:close( )
590 interface.eventreadtimeout = nil
593 local buffer, err, part = interface.conn:receive( interface._pattern ) -- receive buffer with "pattern"
594 --vdebug( "read data:", tostring(buffer), "error:", tostring(err), "part:", tostring(part) )
595 buffer = buffer or part
596 if buffer and #buffer > cfg.MAX_READ_LENGTH then -- check buffer length
597 interface.fatalerror = "receive buffer exceeded"
598 debug( "fatal error:", interface.fatalerror )
600 interface.eventread = nil
603 if err and ( err ~= "timeout" and err ~= "wantread" ) then
604 if "wantwrite" == err then -- need to read on write event
605 if not interface.eventwrite then -- register new write event if needed
606 interface.eventwrite = addevent( base, interface.conn, EV_WRITE, interface.writecallback, cfg.WRITE_TIMEOUT )
608 interface.eventreadtimeout = addevent( base, nil, EV_TIMEOUT,
611 end, cfg.READ_TIMEOUT
613 debug( "wantwrite during read attempt, reg it in writecallback but dont know what really happens next..." )
614 -- to be honest i dont know what happens next, if it is allowed to first read, the write etc...
615 else -- connection was closed or fatal error
616 interface.fatalerror = err
617 debug( "connection failed in read event:", interface.fatalerror )
619 interface.eventread = nil
623 interface.onincoming( interface, buffer, err ) -- send new data to listener
625 if interface.noreading then
626 interface.eventread = nil;
629 return EV_READ, cfg.READ_TIMEOUT
633 client:settimeout( 0 ) -- set non blocking
634 setmetatable(interface, interface_mt)
635 interfacelist( "add", interface ) -- add to interfacelist
642 function handleserver( server, addr, port, pattern, listener, sslctx ) -- creates an server interface
643 debug "creating server interface..."
648 onconnect = listener.onconnect; -- will be called when new client connected
649 eventread = false; -- read event handler
650 eventclose = false; -- close event handler
651 readcallback = false; -- read event callback
652 fatalerror = false; -- error message
653 nointerface = true; -- lock/unlock parameter
655 _ip = addr, _port = port, _pattern = pattern,
658 interface.id = tostring(interface):match("%x+$");
659 interface.readcallback = function( event ) -- server handler, called on incoming connections
660 --vdebug( "server can accept, id/addr/port:", interface, addr, port )
661 if interface.fatalerror then
662 --vdebug( "leaving this event because:", self.fatalerror )
663 interface.eventread = nil
666 local delay = cfg.ACCEPT_DELAY
667 if EV_TIMEOUT == event then
668 if interface._connections >= cfg.MAX_CONNECTIONS then -- check connection count
669 debug( "to many connections, seconds to wait for next accept:", delay )
670 return EV_TIMEOUT, delay -- timeout...
672 return EV_READ -- accept again
675 --vdebug("max connection check ok, accepting...")
676 local client, err = server:accept() -- try to accept; TODO: check err
678 if interface._connections >= cfg.MAX_CONNECTIONS then
679 client:close( ) -- refuse connection
680 debug( "maximal connections reached, refuse client connection; accept delay:", delay )
681 return EV_TIMEOUT, delay -- delay for next accept attempt
683 local client_ip, client_port = client:getpeername( )
684 interface._connections = interface._connections + 1 -- increase connection count
685 local clientinterface = handleclient( client, client_ip, client_port, interface, pattern, listener, sslctx )
686 --vdebug( "client id:", clientinterface, "startssl:", startssl )
687 if ssl and sslctx then
688 clientinterface:starttls(sslctx, true)
690 clientinterface:_start_session( true )
692 debug( "accepted incoming client connection from:", client_ip or "<unknown IP>", client_port or "<unknown port>", "to", port or "<unknown port>");
694 client, err = server:accept() -- try to accept again
699 server:settimeout( 0 )
700 setmetatable(interface, interface_mt)
701 interfacelist( "add", interface )
702 interface:_start_session()
707 local addserver = ( function( )
708 return function( addr, port, listener, pattern, sslcfg, startssl ) -- TODO: check arguments
709 --vdebug( "creating new tcp server with following parameters:", addr or "nil", port or "nil", sslcfg or "nil", startssl or "nil")
710 local server, err = socket.bind( addr, port, cfg.ACCEPT_QUEUE ) -- create server socket
712 debug( "creating server socket on "..addr.." port "..port.." failed:", err )
718 debug "fatal error: luasec not found"
719 return nil, "luasec not found"
723 debug( "error while creating new ssl context for server socket:", err )
727 local interface = handleserver( server, addr, port, pattern, listener, sslctx, startssl ) -- new server handler
728 debug( "new server created with id:", tostring(interface))
733 local addclient, wrapclient
735 function wrapclient( client, ip, port, listeners, pattern, sslctx )
736 local interface = handleclient( client, ip, port, nil, pattern, listeners, sslctx )
737 interface:_start_connection(sslctx)
738 return interface, client
739 --function handleclient( client, ip, port, server, pattern, listener, _, sslctx ) -- creates an client interface
742 function addclient( addr, serverport, listener, pattern, localaddr, localport, sslcfg, startssl )
743 local client, err = socket.tcp() -- creating new socket
745 debug( "cannot create socket:", err )
748 client:settimeout( 0 ) -- set nonblocking
750 local res, err = client:bind( localaddr, localport, -1 )
752 debug( "cannot bind client:", err )
757 if sslcfg then -- handle ssl/new context
759 debug "need luasec, but not available"
760 return nil, "luasec not found"
764 debug( "cannot create new ssl context:", err )
768 local res, err = client:connect( addr, serverport ) -- connect
769 if res or ( err == "timeout" ) then
770 local ip, port = client:getsockname( )
771 local interface = wrapclient( client, ip, serverport, listener, pattern, sslctx, startssl )
772 interface:_start_connection( startssl )
773 debug( "new connection id:", interface.id )
774 return interface, err
776 debug( "new connection failed:", err )
783 local loop = function( ) -- starts the event loop
788 local newevent = ( function( )
789 local add = base.addevent
790 return function( ... )
791 return add( base, ... )
795 local closeallservers = function( arg )
796 for _, item in ipairs( interfacelist( ) ) do
797 if item.type == "server" then
803 local function setquitting(yes)
811 local function get_backend()
812 return base:method();
815 -- We need to hold onto the events to stop them
816 -- being garbage-collected
817 local signal_events = {}; -- [signal_num] -> event object
818 local function hook_signal(signal_num, handler)
819 local function _handler(event)
820 local ret = handler();
821 if ret ~= false then -- Continue handling this signal?
822 return EV_SIGNAL; -- Yes
824 return -1; -- Close this event
826 signal_events[signal_num] = base:addevent(signal_num, EV_SIGNAL, _handler);
827 return signal_events[signal_num];
830 local function link(sender, receiver, buffersize)
833 function receiver:ondrain()
834 if sender_locked then
840 function sender:onincoming(data)
841 receiver:write(data);
842 if receiver.writebufferlen >= buffersize then
843 sender_locked = true;
858 addserver = addserver,
859 addclient = addclient,
860 wrapclient = wrapclient,
861 setquitting = setquitting,
862 closeall = closeallservers,
863 get_backend = get_backend,
864 hook_signal = hook_signal,
866 __NAME = SCRIPT_NAME,
867 __DATE = LAST_MODIFIED,
868 __AUTHOR = SCRIPT_AUTHOR,
869 __VERSION = SCRIPT_VERSION,