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
| | # -*- encoding: binary -*-
# Copyright (C) 2013-2016 all contributors <yahns-public@yhbt.net>
# License: GPL-3.0+ (https://www.gnu.org/licenses/gpl-3.0.txt)
# frozen_string_literal: true
#
# This is the dangerous, low-level epoll interface for sleepy_penguin
# It is safe as long as you're aware of all potential concurrency
# issues given multithreading, GC, and epoll itself.
class Yahns::Queue < SleepyPenguin::Epoll::IO # :nodoc:
include SleepyPenguin
attr_accessor :fdmap # Yahns::Fdmap
# public
QEV_QUIT = Epoll::OUT # Level Trigger for QueueQuitter
QEV_RD = Epoll::IN | Epoll::ONESHOT
QEV_WR = Epoll::OUT | Epoll::ONESHOT
def self.new
super(Epoll::CLOEXEC)
end
# for HTTP and HTTPS servers, we rely on the io writing to us, first
# flags: QEV_RD/QEV_WR (usually QEV_RD)
def queue_add(io, flags)
# order is very important here, this thread cannot do anything with
# io once we've issued epoll_ctl() because another thread may use it
@fdmap.add(io)
epoll_ctl(Epoll::CTL_ADD, io, flags)
end
def queue_mod(io, flags)
epoll_ctl(Epoll::CTL_MOD, io, flags)
end
def queue_del(io)
epoll_ctl(Epoll::CTL_DEL, io, 0)
end
def thr_init
Thread.current[:yahns_rbuf] = ''.dup
Thread.current[:yahns_fdmap] = @fdmap
Thread.current[:yahns_queue] = self
end
# returns an infinitely running thread
def worker_thread(logger, max_events)
Thread.new do
thr_init
begin
epoll_wait(max_events) do |_, io| # don't care for flags for now
next if io.closed?
# Note: we absolutely must not do anything with io after
# we've called epoll_ctl on it, io is exclusive to this
# thread only until epoll_ctl is called on it.
case rv = io.yahns_step
when :wait_readable
epoll_ctl(Epoll::CTL_MOD, io, QEV_RD)
when :wait_writable
epoll_ctl(Epoll::CTL_MOD, io, QEV_WR)
when :ignore # only used by rack.hijack
# we cannot call Epoll::CTL_DEL after hijacking, the hijacker
# may have already closed it Likewise, io.fileno is not
# expected to work, so we had to erase it from fdmap before hijack
when nil, :close
# this must be the ONLY place where we call IO#close on
# things that got inside the queue AND fdmap
@fdmap.sync_close(io)
else
raise "BUG: #{io.inspect}#yahns_step returned: #{rv.inspect}"
end
end
rescue StandardError, LoadError, SyntaxError => e
break if closed? # can still happen due to shutdown_timeout
Yahns::Log.exception(logger, 'queue loop', e)
end while true
end
end
end
|