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| | # -*- encoding: binary -*-
require 'revactor'
# workaround revactor 0.1.4 still using the old Rev::Buffer
# ref: http://rubyforge.org/pipermail/revactor-talk/2009-October/000034.html
defined?(Rev::Buffer) or Rev::Buffer = IO::Buffer
module Rainbows
# Enables use of the Actor model through
# {Revactor}[http://revactor.org] under Ruby 1.9. It spawns one
# long-lived Actor for every listen socket in the process and spawns a
# new Actor for every client connection accept()-ed.
# +worker_connections+ will limit the number of client Actors we have
# running at any one time.
#
# Applications using this model are required to be reentrant, but
# generally do not have to worry about race conditions. Multiple
# instances of the same app may run in the same address space
# sequentially (but at interleaved points). Any network dependencies
# in the application using this model should be implemented using the
# \Revactor library as well.
module Revactor
require 'rainbows/revactor/tee_input'
include Base
# 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)
buf = client.read or return # this probably does not happen...
hp = HttpParser.new
env = {}
remote_addr = ::Revactor::TCP::Socket === client ?
client.remote_addr : LOCALHOST
begin
while ! hp.headers(env, buf)
buf << client.read
end
env[Const::RACK_INPUT] = 0 == hp.content_length ?
HttpRequest::NULL_IO :
Rainbows::Revactor::TeeInput.new(client, env, hp, buf)
env[Const::REMOTE_ADDR] = remote_addr
response = app.call(env.update(RACK_DEFAULTS))
if 100 == response.first.to_i
client.write(Const::EXPECT_100_RESPONSE)
env.delete(Const::HTTP_EXPECT)
response = app.call(env)
end
out = [ hp.keepalive? ? CONN_ALIVE : CONN_CLOSE ] if hp.headers?
HttpResponse.write(client, response, out)
end while hp.keepalive? and hp.reset.nil? and env.clear
client.close
# 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
rescue EOFError,Errno::ECONNRESET,Errno::EPIPE,Errno::EINVAL,Errno::EBADF
emergency_response(client, Const::ERROR_500_RESPONSE)
rescue HttpParserError # try to tell the client they're bad
buf.empty? or emergency_response(client, Const::ERROR_400_RESPONSE)
rescue Object => e
emergency_response(client, Const::ERROR_500_RESPONSE)
logger.error "Read error: #{e.inspect}"
logger.error e.backtrace.join("\n")
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)
alive = worker.tmp # tmp is our lifeline to the master process
trap(:USR1) { reopen_worker_logs(worker.nr) }
trap(:QUIT) { alive = false; LISTENERS.each { |s| s.close rescue nil } }
[:TERM, :INT].each { |sig| trap(sig) { exit!(0) } } # instant shutdown
root = Actor.current
root.trap_exit = true
limit = worker_connections
listeners = revactorize_listeners
logger.info "worker=#{worker.nr} ready with Revactor"
clients = 0
listeners.map! do |s|
Actor.spawn(s) do |l|
begin
while clients >= limit
logger.info "busy: clients=#{clients} >= limit=#{limit}"
Actor.receive { |filter| filter.when(:resume) {} }
end
actor = Actor.spawn(l.accept) { |c| process_client(c) }
clients += 1
root.link(actor)
rescue Errno::EAGAIN, Errno::ECONNABORTED
rescue Object => e
if alive
logger.error "Unhandled listen loop exception #{e.inspect}."
logger.error e.backtrace.join("\n")
end
end while alive
end
end
nr = 0
begin
Actor.receive do |filter|
filter.after(1) do
if alive
alive.chmod(nr = 0 == nr ? 1 : 0)
listeners.each { |l| alive = false if l.dead? }
ppid == Process.ppid or alive = false
end
end
filter.when(Case[:exit, Actor, Object]) do |_,actor,_|
orig = clients
clients -= 1
orig >= limit and listeners.each { |l| l << :resume }
end
end
end while alive || clients > 0
end
private
# write a response without caring if it went out or not
# This is in the case of untrappable errors
def emergency_response(client, response_str)
client.instance_eval do
# this is Revactor implementation dependent
@_io.write_nonblock(response_str) rescue nil
end
client.close rescue nil
end
def revactorize_listeners
LISTENERS.map do |s|
if TCPServer === s
::Revactor::TCP.listen(s, nil)
elsif defined?(::Revactor::UNIX) && UNIXServer === s
::Revactor::UNIX.listen(s)
else
logger.error "your version of Revactor can't handle #{s.inspect}"
nil
end
end.compact
end
end
end
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