1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
| | # -*- encoding: binary -*-
require 'fcntl'
require 'etc'
require 'rack'
require 'unicorn/socket_helper'
require 'unicorn/const'
require 'unicorn/http_request'
require 'unicorn/configurator'
require 'unicorn/util'
require 'unicorn/tee_input'
require 'unicorn/http_response'
# Unicorn module containing all of the classes (include C extensions) for running
# a Unicorn web server. It contains a minimalist HTTP server with just enough
# functionality to service web application requests fast as possible.
module Unicorn
# raised inside TeeInput when a client closes the socket inside the
# application dispatch. This is always raised with an empty backtrace
# since there is nothing in the application stack that is responsible
# for client shutdowns/disconnects.
class ClientShutdown < EOFError
end
class << self
def run(app, options = {})
HttpServer.new(app, options).start.join
end
# This returns a lambda to pass in as the app, this does not "build" the
# app (which we defer based on the outcome of "preload_app" in the
# Unicorn config). The returned lambda will be called when it is
# time to build the app.
def builder(ru, opts)
if ru =~ /\.ru\z/
# parse embedded command-line options in config.ru comments
/^#\\(.*)/ =~ File.read(ru) and opts.parse!($1.split(/\s+/))
end
lambda do ||
inner_app = case ru
when /\.ru$/
raw = File.read(ru)
raw.sub!(/^__END__\n.*/, '')
eval("Rack::Builder.new {(#{raw}\n)}.to_app", TOPLEVEL_BINDING, ru)
else
require ru
Object.const_get(File.basename(ru, '.rb').capitalize)
end
pp({ :inner_app => inner_app }) if $DEBUG
# return value, matches rackup defaults based on env
case ENV["RACK_ENV"]
when "development"
Rack::Builder.new do
use Rack::CommonLogger, $stderr
use Rack::ShowExceptions
use Rack::Lint
run inner_app
end.to_app
when "deployment"
Rack::Builder.new do
use Rack::CommonLogger, $stderr
run inner_app
end.to_app
else
inner_app
end
end
end
# returns an array of strings representing TCP listen socket addresses
# and Unix domain socket paths. This is useful for use with
# Raindrops::Middleware under Linux: http://raindrops.bogomips.org/
def listener_names
HttpServer::LISTENERS.map { |io| SocketHelper.sock_name(io) }
end
end
# This is the process manager of Unicorn. This manages worker
# processes which in turn handle the I/O and application process.
# Listener sockets are started in the master process and shared with
# forked worker children.
class HttpServer < Struct.new(:app, :timeout, :worker_processes,
:before_fork, :after_fork, :before_exec,
:logger, :pid, :listener_opts, :preload_app,
:reexec_pid, :orig_app, :init_listeners,
:master_pid, :config, :ready_pipe, :user)
include ::Unicorn::SocketHelper
# prevents IO objects in here from being GC-ed
IO_PURGATORY = []
# all bound listener sockets
LISTENERS = []
# This hash maps PIDs to Workers
WORKERS = {}
# We use SELF_PIPE differently in the master and worker processes:
#
# * The master process never closes or reinitializes this once
# initialized. Signal handlers in the master process will write to
# it to wake up the master from IO.select in exactly the same manner
# djb describes in http://cr.yp.to/docs/selfpipe.html
#
# * The workers immediately close the pipe they inherit from the
# master and replace it with a new pipe after forking. This new
# pipe is also used to wakeup from IO.select from inside (worker)
# signal handlers. However, workers *close* the pipe descriptors in
# the signal handlers to raise EBADF in IO.select instead of writing
# like we do in the master. We cannot easily use the reader set for
# IO.select because LISTENERS is already that set, and it's extra
# work (and cycles) to distinguish the pipe FD from the reader set
# once IO.select returns. So we're lazy and just close the pipe when
# a (rare) signal arrives in the worker and reinitialize the pipe later.
SELF_PIPE = []
# signal queue used for self-piping
SIG_QUEUE = []
# constant lookups are faster and we're single-threaded/non-reentrant
REQUEST = HttpRequest.new
# We populate this at startup so we can figure out how to reexecute
# and upgrade the currently running instance of Unicorn
# This Hash is considered a stable interface and changing its contents
# will allow you to switch between different installations of Unicorn
# or even different installations of the same applications without
# downtime. Keys of this constant Hash are described as follows:
#
# * 0 - the path to the unicorn/unicorn_rails executable
# * :argv - a deep copy of the ARGV array the executable originally saw
# * :cwd - the working directory of the application, this is where
# you originally started Unicorn.
#
# To change your unicorn executable to a different path without downtime,
# you can set the following in your Unicorn config file, HUP and then
# continue with the traditional USR2 + QUIT upgrade steps:
#
# Unicorn::HttpServer::START_CTX[0] = "/home/bofh/1.9.2/bin/unicorn"
START_CTX = {
:argv => ARGV.map { |arg| arg.dup },
:cwd => lambda {
# favor ENV['PWD'] since it is (usually) symlink aware for
# Capistrano and like systems
begin
a = File.stat(pwd = ENV['PWD'])
b = File.stat(Dir.pwd)
a.ino == b.ino && a.dev == b.dev ? pwd : Dir.pwd
rescue
Dir.pwd
end
}.call,
0 => $0.dup,
}
# This class and its members can be considered a stable interface
# and will not change in a backwards-incompatible fashion between
# releases of Unicorn. You may need to access it in the
# before_fork/after_fork hooks. See the Unicorn::Configurator RDoc
# for examples.
class Worker < Struct.new(:nr, :tmp, :switched)
# worker objects may be compared to just plain numbers
def ==(other_nr)
self.nr == other_nr
end
# Changes the worker process to the specified +user+ and +group+
# This is only intended to be called from within the worker
# process from the +after_fork+ hook. This should be called in
# the +after_fork+ hook after any priviledged functions need to be
# run (e.g. to set per-worker CPU affinity, niceness, etc)
#
# Any and all errors raised within this method will be propagated
# directly back to the caller (usually the +after_fork+ hook.
# These errors commonly include ArgumentError for specifying an
# invalid user/group and Errno::EPERM for insufficient priviledges
def user(user, group = nil)
# we do not protect the caller, checking Process.euid == 0 is
# insufficient because modern systems have fine-grained
# capabilities. Let the caller handle any and all errors.
uid = Etc.getpwnam(user).uid
gid = Etc.getgrnam(group).gid if group
Unicorn::Util.chown_logs(uid, gid)
tmp.chown(uid, gid)
if gid && Process.egid != gid
Process.initgroups(user, gid)
Process::GID.change_privilege(gid)
end
Process.euid != uid and Process::UID.change_privilege(uid)
self.switched = true
end
end
# Creates a working server on host:port (strange things happen if
# port isn't a Number). Use HttpServer::run to start the server and
# HttpServer.run.join to join the thread that's processing
# incoming requests on the socket.
def initialize(app, options = {})
self.app = app
self.reexec_pid = 0
self.ready_pipe = options.delete(:ready_pipe)
self.init_listeners = options[:listeners] ? options[:listeners].dup : []
self.config = Configurator.new(options.merge(:use_defaults => true))
self.listener_opts = {}
# we try inheriting listeners first, so we bind them later.
# we don't write the pid file until we've bound listeners in case
# unicorn was started twice by mistake. Even though our #pid= method
# checks for stale/existing pid files, race conditions are still
# possible (and difficult/non-portable to avoid) and can be likely
# to clobber the pid if the second start was in quick succession
# after the first, so we rely on the listener binding to fail in
# that case. Some tests (in and outside of this source tree) and
# monitoring tools may also rely on pid files existing before we
# attempt to connect to the listener(s)
config.commit!(self, :skip => [:listeners, :pid])
self.orig_app = app
end
# Runs the thing. Returns self so you can run join on it
def start
BasicSocket.do_not_reverse_lookup = true
# inherit sockets from parents, they need to be plain Socket objects
# before they become UNIXServer or TCPServer
inherited = ENV['UNICORN_FD'].to_s.split(/,/).map do |fd|
io = Socket.for_fd(fd.to_i)
set_server_sockopt(io, listener_opts[sock_name(io)])
IO_PURGATORY << io
logger.info "inherited addr=#{sock_name(io)} fd=#{fd}"
server_cast(io)
end
config_listeners = config[:listeners].dup
LISTENERS.replace(inherited)
# we start out with generic Socket objects that get cast to either
# TCPServer or UNIXServer objects; but since the Socket objects
# share the same OS-level file descriptor as the higher-level *Server
# objects; we need to prevent Socket objects from being garbage-collected
config_listeners -= listener_names
if config_listeners.empty? && LISTENERS.empty?
config_listeners << Unicorn::Const::DEFAULT_LISTEN
init_listeners << Unicorn::Const::DEFAULT_LISTEN
START_CTX[:argv] << "-l#{Unicorn::Const::DEFAULT_LISTEN}"
end
config_listeners.each { |addr| listen(addr) }
raise ArgumentError, "no listeners" if LISTENERS.empty?
# this pipe is used to wake us up from select(2) in #join when signals
# are trapped. See trap_deferred.
init_self_pipe!
# setup signal handlers before writing pid file in case people get
# trigger happy and send signals as soon as the pid file exists.
# Note that signals don't actually get handled until the #join method
QUEUE_SIGS.each { |sig| trap_deferred(sig) }
trap(:CHLD) { |_| awaken_master }
self.pid = config[:pid]
self.master_pid = $$
build_app! if preload_app
maintain_worker_count
self
end
# replaces current listener set with +listeners+. This will
# close the socket if it will not exist in the new listener set
def listeners=(listeners)
cur_names, dead_names = [], []
listener_names.each do |name|
if ?/ == name[0]
# mark unlinked sockets as dead so we can rebind them
(File.socket?(name) ? cur_names : dead_names) << name
else
cur_names << name
end
end
set_names = listener_names(listeners)
dead_names.concat(cur_names - set_names).uniq!
LISTENERS.delete_if do |io|
if dead_names.include?(sock_name(io))
IO_PURGATORY.delete_if do |pio|
pio.fileno == io.fileno && (pio.close rescue nil).nil? # true
end
(io.close rescue nil).nil? # true
else
set_server_sockopt(io, listener_opts[sock_name(io)])
false
end
end
(set_names - cur_names).each { |addr| listen(addr) }
end
def stdout_path=(path); redirect_io($stdout, path); end
def stderr_path=(path); redirect_io($stderr, path); end
def logger=(obj)
HttpRequest::DEFAULTS["rack.logger"] = super
end
# sets the path for the PID file of the master process
def pid=(path)
if path
if x = valid_pid?(path)
return path if pid && path == pid && x == $$
raise ArgumentError, "Already running on PID:#{x} " \
"(or pid=#{path} is stale)"
end
end
unlink_pid_safe(pid) if pid
if path
fp = begin
tmp = "#{File.dirname(path)}/#{rand}.#$$"
File.open(tmp, File::RDWR|File::CREAT|File::EXCL, 0644)
rescue Errno::EEXIST
retry
end
fp.syswrite("#$$\n")
File.rename(fp.path, path)
fp.close
end
super(path)
end
# add a given address to the +listeners+ set, idempotently
# Allows workers to add a private, per-process listener via the
# after_fork hook. Very useful for debugging and testing.
# +:tries+ may be specified as an option for the number of times
# to retry, and +:delay+ may be specified as the time in seconds
# to delay between retries.
# A negative value for +:tries+ indicates the listen will be
# retried indefinitely, this is useful when workers belonging to
# different masters are spawned during a transparent upgrade.
def listen(address, opt = {}.merge(listener_opts[address] || {}))
address = config.expand_addr(address)
return if String === address && listener_names.include?(address)
delay = opt[:delay] || 0.5
tries = opt[:tries] || 5
begin
io = bind_listen(address, opt)
unless TCPServer === io || UNIXServer === io
IO_PURGATORY << io
io = server_cast(io)
end
logger.info "listening on addr=#{sock_name(io)} fd=#{io.fileno}"
LISTENERS << io
io
rescue Errno::EADDRINUSE => err
logger.error "adding listener failed addr=#{address} (in use)"
raise err if tries == 0
tries -= 1
logger.error "retrying in #{delay} seconds " \
"(#{tries < 0 ? 'infinite' : tries} tries left)"
sleep(delay)
retry
rescue => err
logger.fatal "error adding listener addr=#{address}"
raise err
end
end
# monitors children and receives signals forever
# (or until a termination signal is sent). This handles signals
# one-at-a-time time and we'll happily drop signals in case somebody
# is signalling us too often.
def join
respawn = true
last_check = Time.now
proc_name 'master'
logger.info "master process ready" # test_exec.rb relies on this message
if ready_pipe
ready_pipe.syswrite($$.to_s)
ready_pipe.close rescue nil
self.ready_pipe = nil
end
begin
loop do
reap_all_workers
case SIG_QUEUE.shift
when nil
# avoid murdering workers after our master process (or the
# machine) comes out of suspend/hibernation
if (last_check + timeout) >= (last_check = Time.now)
murder_lazy_workers
else
# wait for workers to wakeup on suspend
master_sleep(timeout/2.0 + 1)
end
maintain_worker_count if respawn
master_sleep(1)
when :QUIT # graceful shutdown
break
when :TERM, :INT # immediate shutdown
stop(false)
break
when :USR1 # rotate logs
logger.info "master reopening logs..."
Unicorn::Util.reopen_logs
logger.info "master done reopening logs"
kill_each_worker(:USR1)
when :USR2 # exec binary, stay alive in case something went wrong
reexec
when :WINCH
if Process.ppid == 1 || Process.getpgrp != $$
respawn = false
logger.info "gracefully stopping all workers"
kill_each_worker(:QUIT)
else
logger.info "SIGWINCH ignored because we're not daemonized"
end
when :TTIN
self.worker_processes += 1
when :TTOU
self.worker_processes -= 1 if self.worker_processes > 0
when :HUP
respawn = true
if config.config_file
load_config!
redo # immediate reaping since we may have QUIT workers
else # exec binary and exit if there's no config file
logger.info "config_file not present, reexecuting binary"
reexec
break
end
end
end
rescue Errno::EINTR
retry
rescue => e
logger.error "Unhandled master loop exception #{e.inspect}."
logger.error e.backtrace.join("\n")
retry
end
stop # gracefully shutdown all workers on our way out
logger.info "master complete"
unlink_pid_safe(pid) if pid
end
# Terminates all workers, but does not exit master process
def stop(graceful = true)
self.listeners = []
limit = Time.now + timeout
until WORKERS.empty? || Time.now > limit
kill_each_worker(graceful ? :QUIT : :TERM)
sleep(0.1)
reap_all_workers
end
kill_each_worker(:KILL)
end
private
# list of signals we care about and trap in master.
QUEUE_SIGS = [ :WINCH, :QUIT, :INT, :TERM, :USR1, :USR2, :HUP,
:TTIN, :TTOU ]
# defer a signal for later processing in #join (master process)
def trap_deferred(signal)
trap(signal) do |sig_nr|
if SIG_QUEUE.size < 5
SIG_QUEUE << signal
awaken_master
else
logger.error "ignoring SIG#{signal}, queue=#{SIG_QUEUE.inspect}"
end
end
end
# wait for a signal hander to wake us up and then consume the pipe
# Wake up every second anyways to run murder_lazy_workers
def master_sleep(sec)
begin
ready = IO.select([SELF_PIPE.first], nil, nil, sec) or return
ready.first && ready.first.first or return
loop { SELF_PIPE.first.read_nonblock(Const::CHUNK_SIZE) }
rescue Errno::EAGAIN, Errno::EINTR
end
end
def awaken_master
begin
SELF_PIPE.last.write_nonblock('.') # wakeup master process from select
rescue Errno::EAGAIN, Errno::EINTR
# pipe is full, master should wake up anyways
retry
end
end
# reaps all unreaped workers
def reap_all_workers
begin
loop do
wpid, status = Process.waitpid2(-1, Process::WNOHANG)
wpid or break
if reexec_pid == wpid
logger.error "reaped #{status.inspect} exec()-ed"
self.reexec_pid = 0
self.pid = pid.chomp('.oldbin') if pid
proc_name 'master'
else
worker = WORKERS.delete(wpid) and worker.tmp.close rescue nil
logger.info "reaped #{status.inspect} " \
"worker=#{worker.nr rescue 'unknown'}"
end
end
rescue Errno::ECHILD
end
end
# reexecutes the START_CTX with a new binary
def reexec
if reexec_pid > 0
begin
Process.kill(0, reexec_pid)
logger.error "reexec-ed child already running PID:#{reexec_pid}"
return
rescue Errno::ESRCH
self.reexec_pid = 0
end
end
if pid
old_pid = "#{pid}.oldbin"
prev_pid = pid.dup
begin
self.pid = old_pid # clear the path for a new pid file
rescue ArgumentError
logger.error "old PID:#{valid_pid?(old_pid)} running with " \
"existing pid=#{old_pid}, refusing rexec"
return
rescue => e
logger.error "error writing pid=#{old_pid} #{e.class} #{e.message}"
return
end
end
self.reexec_pid = fork do
listener_fds = LISTENERS.map { |sock| sock.fileno }
ENV['UNICORN_FD'] = listener_fds.join(',')
Dir.chdir(START_CTX[:cwd])
cmd = [ START_CTX[0] ].concat(START_CTX[:argv])
# avoid leaking FDs we don't know about, but let before_exec
# unset FD_CLOEXEC, if anything else in the app eventually
# relies on FD inheritence.
(3..1024).each do |io|
next if listener_fds.include?(io)
io = IO.for_fd(io) rescue nil
io or next
IO_PURGATORY << io
io.fcntl(Fcntl::F_SETFD, Fcntl::FD_CLOEXEC)
end
logger.info "executing #{cmd.inspect} (in #{Dir.pwd})"
before_exec.call(self)
exec(*cmd)
end
proc_name 'master (old)'
end
# forcibly terminate all workers that haven't checked in in timeout
# seconds. The timeout is implemented using an unlinked File
# shared between the parent process and each worker. The worker
# runs File#chmod to modify the ctime of the File. If the ctime
# is stale for >timeout seconds, then we'll kill the corresponding
# worker.
def murder_lazy_workers
WORKERS.dup.each_pair do |wpid, worker|
stat = worker.tmp.stat
# skip workers that disable fchmod or have never fchmod-ed
stat.mode == 0100600 and next
(diff = (Time.now - stat.ctime)) <= timeout and next
logger.error "worker=#{worker.nr} PID:#{wpid} timeout " \
"(#{diff}s > #{timeout}s), killing"
kill_worker(:KILL, wpid) # take no prisoners for timeout violations
end
end
def spawn_missing_workers
(0...worker_processes).each do |worker_nr|
WORKERS.values.include?(worker_nr) and next
worker = Worker.new(worker_nr, Unicorn::Util.tmpio)
before_fork.call(self, worker)
WORKERS[fork {
ready_pipe.close if ready_pipe
self.ready_pipe = nil
worker_loop(worker)
}] = worker
end
end
def maintain_worker_count
(off = WORKERS.size - worker_processes) == 0 and return
off < 0 and return spawn_missing_workers
WORKERS.dup.each_pair { |wpid,w|
w.nr >= worker_processes and kill_worker(:QUIT, wpid) rescue nil
}
end
# if we get any error, try to write something back to the client
# assuming we haven't closed the socket, but don't get hung up
# if the socket is already closed or broken. We'll always ensure
# the socket is closed at the end of this function
def handle_error(client, e)
msg = case e
when EOFError,Errno::ECONNRESET,Errno::EPIPE,Errno::EINVAL,Errno::EBADF
Const::ERROR_500_RESPONSE
when HttpParserError # try to tell the client they're bad
Const::ERROR_400_RESPONSE
else
logger.error "Read error: #{e.inspect}"
logger.error e.backtrace.join("\n")
Const::ERROR_500_RESPONSE
end
client.write_nonblock(msg)
client.close
rescue
nil
end
# once a client is accepted, it is processed in its entirety here
# in 3 easy steps: read request, call app, write app response
def process_client(client)
client.fcntl(Fcntl::F_SETFD, Fcntl::FD_CLOEXEC)
response = app.call(env = REQUEST.read(client))
if 100 == response.first.to_i
client.write(Const::EXPECT_100_RESPONSE)
env.delete(Const::HTTP_EXPECT)
response = app.call(env)
end
HttpResponse.write(client, response, HttpRequest::PARSER.headers?)
rescue => e
handle_error(client, e)
end
# gets rid of stuff the worker has no business keeping track of
# to free some resources and drops all sig handlers.
# traps for USR1, USR2, and HUP may be set in the after_fork Proc
# by the user.
def init_worker_process(worker)
QUEUE_SIGS.each { |sig| trap(sig, nil) }
trap(:CHLD, 'DEFAULT')
SIG_QUEUE.clear
proc_name "worker[#{worker.nr}]"
START_CTX.clear
init_self_pipe!
WORKERS.values.each { |other| other.tmp.close rescue nil }
WORKERS.clear
LISTENERS.each { |sock| sock.fcntl(Fcntl::F_SETFD, Fcntl::FD_CLOEXEC) }
worker.tmp.fcntl(Fcntl::F_SETFD, Fcntl::FD_CLOEXEC)
after_fork.call(self, worker) # can drop perms
worker.user(*user) if user.kind_of?(Array) && ! worker.switched
self.timeout /= 2.0 # halve it for select()
build_app! unless preload_app
end
def reopen_worker_logs(worker_nr)
logger.info "worker=#{worker_nr} reopening logs..."
Unicorn::Util.reopen_logs
logger.info "worker=#{worker_nr} done reopening logs"
init_self_pipe!
end
# runs inside each forked worker, this sits around and waits
# for connections and doesn't die until the parent dies (or is
# given a INT, QUIT, or TERM signal)
def worker_loop(worker)
ppid = master_pid
init_worker_process(worker)
nr = 0 # this becomes negative if we need to reopen logs
alive = worker.tmp # tmp is our lifeline to the master process
ready = LISTENERS
# closing anything we IO.select on will raise EBADF
trap(:USR1) { nr = -65536; SELF_PIPE.first.close rescue nil }
trap(:QUIT) { alive = nil; LISTENERS.each { |s| s.close rescue nil } }
[:TERM, :INT].each { |sig| trap(sig) { exit!(0) } } # instant shutdown
logger.info "worker=#{worker.nr} ready"
m = 0
begin
nr < 0 and reopen_worker_logs(worker.nr)
nr = 0
# we're a goner in timeout seconds anyways if alive.chmod
# breaks, so don't trap the exception. Using fchmod() since
# futimes() is not available in base Ruby and I very strongly
# prefer temporary files to be unlinked for security,
# performance and reliability reasons, so utime is out. No-op
# changes with chmod doesn't update ctime on all filesystems; so
# we change our counter each and every time (after process_client
# and before IO.select).
alive.chmod(m = 0 == m ? 1 : 0)
ready.each do |sock|
begin
process_client(sock.accept_nonblock)
nr += 1
alive.chmod(m = 0 == m ? 1 : 0)
rescue Errno::EAGAIN, Errno::ECONNABORTED
end
break if nr < 0
end
# make the following bet: if we accepted clients this round,
# we're probably reasonably busy, so avoid calling select()
# and do a speculative accept_nonblock on ready listeners
# before we sleep again in select().
redo unless nr == 0 # (nr < 0) => reopen logs
ppid == Process.ppid or return
alive.chmod(m = 0 == m ? 1 : 0)
begin
# timeout used so we can detect parent death:
ret = IO.select(LISTENERS, nil, SELF_PIPE, timeout) or redo
ready = ret.first
rescue Errno::EINTR
ready = LISTENERS
rescue Errno::EBADF
nr < 0 or return
end
rescue => e
if alive
logger.error "Unhandled listen loop exception #{e.inspect}."
logger.error e.backtrace.join("\n")
end
end while alive
end
# delivers a signal to a worker and fails gracefully if the worker
# is no longer running.
def kill_worker(signal, wpid)
begin
Process.kill(signal, wpid)
rescue Errno::ESRCH
worker = WORKERS.delete(wpid) and worker.tmp.close rescue nil
end
end
# delivers a signal to each worker
def kill_each_worker(signal)
WORKERS.keys.each { |wpid| kill_worker(signal, wpid) }
end
# unlinks a PID file at given +path+ if it contains the current PID
# still potentially racy without locking the directory (which is
# non-portable and may interact badly with other programs), but the
# window for hitting the race condition is small
def unlink_pid_safe(path)
(File.read(path).to_i == $$ and File.unlink(path)) rescue nil
end
# returns a PID if a given path contains a non-stale PID file,
# nil otherwise.
def valid_pid?(path)
wpid = File.read(path).to_i
wpid <= 0 and return nil
begin
Process.kill(0, wpid)
wpid
rescue Errno::ESRCH
# don't unlink stale pid files, racy without non-portable locking...
end
rescue Errno::ENOENT
end
def load_config!
loaded_app = app
begin
logger.info "reloading config_file=#{config.config_file}"
config[:listeners].replace(init_listeners)
config.reload
config.commit!(self)
kill_each_worker(:QUIT)
Unicorn::Util.reopen_logs
self.app = orig_app
build_app! if preload_app
logger.info "done reloading config_file=#{config.config_file}"
rescue StandardError, LoadError, SyntaxError => e
logger.error "error reloading config_file=#{config.config_file}: " \
"#{e.class} #{e.message}"
self.app = loaded_app
end
end
# returns an array of string names for the given listener array
def listener_names(listeners = LISTENERS)
listeners.map { |io| sock_name(io) }
end
def build_app!
if app.respond_to?(:arity) && app.arity == 0
if defined?(Gem) && Gem.respond_to?(:refresh)
logger.info "Refreshing Gem list"
Gem.refresh
end
self.app = app.call
end
end
def proc_name(tag)
$0 = ([ File.basename(START_CTX[0]), tag
]).concat(START_CTX[:argv]).join(' ')
end
def redirect_io(io, path)
File.open(path, 'ab') { |fp| io.reopen(fp) } if path
io.sync = true
end
def init_self_pipe!
SELF_PIPE.each { |io| io.close rescue nil }
SELF_PIPE.replace(IO.pipe)
SELF_PIPE.each { |io| io.fcntl(Fcntl::F_SETFD, Fcntl::FD_CLOEXEC) }
end
end
end
|