diff options
Diffstat (limited to 'lib/unicorn.rb')
| -rw-r--r-- | lib/unicorn.rb | 452 |
1 files changed, 300 insertions, 152 deletions
diff --git a/lib/unicorn.rb b/lib/unicorn.rb index 49435d8..7a1ef34 100644 --- a/lib/unicorn.rb +++ b/lib/unicorn.rb @@ -1,3 +1,5 @@ +# -*- encoding: binary -*- + require 'fcntl' require 'unicorn/socket_helper' autoload :Rack, 'rack' @@ -6,10 +8,19 @@ autoload :Rack, 'rack' # 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 + autoload :Const, 'unicorn/const' autoload :HttpRequest, 'unicorn/http_request' autoload :HttpResponse, 'unicorn/http_response' autoload :Configurator, 'unicorn/configurator' + autoload :TeeInput, 'unicorn/tee_input' autoload :Util, 'unicorn/util' class << self @@ -22,8 +33,12 @@ module Unicorn # 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 - attr_reader :logger + + class HttpServer < Struct.new(:listener_opts, :timeout, :worker_processes, + :before_fork, :after_fork, :before_exec, + :logger, :pid, :app, :preload_app, + :reexec_pid, :orig_app, :init_listeners, + :master_pid, :config, :ready_pipe) include ::Unicorn::SocketHelper # prevents IO objects in here from being GC-ed @@ -35,7 +50,23 @@ module Unicorn # This hash maps PIDs to Workers WORKERS = {} - # See: http://cr.yp.to/docs/selfpipe.html + # 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 @@ -46,19 +77,82 @@ module Unicorn # 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. + # + # The following example may be used in your Unicorn config file to + # change your working directory during a config reload (HUP) without + # upgrading or restarting: + # + # Dir.chdir(Unicorn::HttpServer::START_CTX[:cwd] = path) + # + # 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 }, - # don't rely on Dir.pwd here since it's not symlink-aware, and - # symlink dirs are the default with Capistrano... - :cwd => `/bin/sh -c pwd`.chomp("\n"), + :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) + + autoload :Etc, 'etc' + # 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) + end + end # Creates a working server on host:port (strange things happen if @@ -66,14 +160,25 @@ module Unicorn # HttpServer.run.join to join the thread that's processing # incoming requests on the socket. def initialize(app, options = {}) - @app = app - @pid = nil - @reexec_pid = 0 - @init_listeners = options[:listeners] ? options[:listeners].dup : [] - @config = Configurator.new(options.merge(:use_defaults => true)) - @listener_opts = {} - @config.commit!(self, :skip => [:listeners, :pid]) - @orig_app = app + 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 @@ -84,13 +189,13 @@ module Unicorn # 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)]) + 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 + config_listeners = config[:listeners].dup LISTENERS.replace(inherited) # we start out with generic Socket objects that get cast to either @@ -100,11 +205,14 @@ module Unicorn 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? - self.pid = @config[:pid] - build_app! if @preload_app + self.pid = config[:pid] + self.master_pid = $$ + build_app! if preload_app maintain_worker_count self end @@ -114,7 +222,7 @@ module Unicorn def listeners=(listeners) cur_names, dead_names = [], [] listener_names.each do |name| - if "/" == name[0..0] + if ?/ == name[0] # mark unlinked sockets as dead so we can rebind them (File.socket?(name) ? cur_names : dead_names) << name else @@ -122,8 +230,7 @@ module Unicorn end end set_names = listener_names(listeners) - dead_names += cur_names - set_names - dead_names.uniq! + dead_names.concat(cur_names - set_names).uniq! LISTENERS.delete_if do |io| if dead_names.include?(sock_name(io)) @@ -132,7 +239,7 @@ module Unicorn end (io.close rescue nil).nil? # true else - set_server_sockopt(io, @listener_opts[sock_name(io)]) + set_server_sockopt(io, listener_opts[sock_name(io)]) false end end @@ -144,30 +251,49 @@ module Unicorn def stderr_path=(path); redirect_io($stderr, path); end def logger=(obj) - REQUEST.logger = @logger = obj + HttpRequest::DEFAULTS["rack.logger"] = super end # sets the path for the PID file of the master process def pid=(path) if path if x = valid_pid?(path) - return path if @pid && path == @pid && x == $$ + return path if pid && path == pid && x == $$ raise ArgumentError, "Already running on PID:#{x} " \ "(or pid=#{path} is stale)" end end - unlink_pid_safe(@pid) if @pid - File.open(path, 'wb') { |fp| fp.syswrite("#$$\n") } if path - @pid = path + 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. - def listen(address, opt = {}.merge(@listener_opts[address] || {})) + # 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, tries = 0.5, 5 + delay = opt[:delay] || 0.5 + tries = opt[:tries] || 5 begin io = bind_listen(address, opt) unless TCPServer === io || UNIXServer === io @@ -176,14 +302,18 @@ module Unicorn end logger.info "listening on addr=#{sock_name(io)} fd=#{io.fileno}" LISTENERS << io - return 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} tries left)" + 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 @@ -196,17 +326,27 @@ module Unicorn # are trapped. See trap_deferred init_self_pipe! respawn = true + last_check = Time.now QUEUE_SIGS.each { |sig| trap_deferred(sig) } trap(:CHLD) { |sig_nr| awaken_master } 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 - murder_lazy_workers + # 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 + end maintain_worker_count if respawn master_sleep when :QUIT # graceful shutdown @@ -230,12 +370,12 @@ module Unicorn logger.info "SIGWINCH ignored because we're not daemonized" end when :TTIN - @worker_processes += 1 + self.worker_processes += 1 when :TTOU - @worker_processes -= 1 if @worker_processes > 0 + self.worker_processes -= 1 if self.worker_processes > 0 when :HUP respawn = true - if @config.config_file + 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 @@ -247,36 +387,33 @@ module Unicorn end rescue Errno::EINTR retry - rescue Object => e + 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 + unlink_pid_safe(pid) if pid end # Terminates all workers, but does not exit master process def stop(graceful = true) self.listeners = [] - kill_each_worker(graceful ? :QUIT : :TERM) - timeleft = @timeout - step = 0.2 - reap_all_workers - until WORKERS.empty? - sleep(step) + limit = Time.now + timeout + until WORKERS.empty? || Time.now > limit + kill_each_worker(graceful ? :QUIT : :TERM) + sleep(0.1) reap_all_workers - (timeleft -= step) > 0 and next - kill_each_worker(:KILL) 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 ].freeze + :TTIN, :TTOU ] # defer a signal for later processing in #join (master process) def trap_deferred(signal) @@ -314,15 +451,15 @@ module Unicorn def reap_all_workers begin loop do - pid, status = Process.waitpid2(-1, Process::WNOHANG) - pid or break - if @reexec_pid == pid + wpid, status = Process.waitpid2(-1, Process::WNOHANG) + wpid or break + if reexec_pid == wpid logger.error "reaped #{status.inspect} exec()-ed" - @reexec_pid = 0 - self.pid = @pid.chomp('.oldbin') if @pid + self.reexec_pid = 0 + self.pid = pid.chomp('.oldbin') if pid proc_name 'master' else - worker = WORKERS.delete(pid) and worker.tmp.close rescue nil + worker = WORKERS.delete(wpid) and worker.tmp.close rescue nil logger.info "reaped #{status.inspect} " \ "worker=#{worker.nr rescue 'unknown'}" end @@ -333,32 +470,32 @@ module Unicorn # reexecutes the START_CTX with a new binary def reexec - if @reexec_pid > 0 + if reexec_pid > 0 begin - Process.kill(0, @reexec_pid) - logger.error "reexec-ed child already running PID:#{@reexec_pid}" + Process.kill(0, reexec_pid) + logger.error "reexec-ed child already running PID:#{reexec_pid}" return rescue Errno::ESRCH - @reexec_pid = 0 + self.reexec_pid = 0 end end - if @pid - old_pid = "#{@pid}.oldbin" - prev_pid = @pid.dup + 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 Object => e + rescue => e logger.error "error writing pid=#{old_pid} #{e.class} #{e.message}" return end end - @reexec_pid = fork do + self.reexec_pid = fork do listener_fds = LISTENERS.map { |sock| sock.fileno } ENV['UNICORN_FD'] = listener_fds.join(',') Dir.chdir(START_CTX[:cwd]) @@ -375,86 +512,91 @@ module Unicorn io.fcntl(Fcntl::F_SETFD, Fcntl::FD_CLOEXEC) end logger.info "executing #{cmd.inspect} (in #{Dir.pwd})" - @before_exec.call(self) + before_exec.call(self) exec(*cmd) end proc_name 'master (old)' end - # forcibly terminate all workers that haven't checked in in @timeout + # 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 + # is stale for >timeout seconds, then we'll kill the corresponding # worker. def murder_lazy_workers - diff = stat = nil - WORKERS.dup.each_pair do |pid, worker| - stat = begin - worker.tmp.stat - rescue => e - logger.warn "worker=#{worker.nr} PID:#{pid} stat error: #{e.inspect}" - kill_worker(:QUIT, pid) - next - end - stat.mode == 0100000 and next - (diff = (Time.now - stat.ctime)) <= @timeout and next - logger.error "worker=#{worker.nr} PID:#{pid} timeout " \ - "(#{diff}s > #{@timeout}s), killing" - kill_worker(:KILL, pid) # take no prisoners for @timeout violations + 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| + (0...worker_processes).each do |worker_nr| WORKERS.values.include?(worker_nr) and next - begin - Dir.chdir(START_CTX[:cwd]) - rescue Errno::ENOENT => err - logger.fatal "#{err.inspect} (#{START_CTX[:cwd]})" - SIG_QUEUE << :QUIT # forcibly emulate SIGQUIT - return - end worker = Worker.new(worker_nr, Unicorn::Util.tmpio) - @before_fork.call(self, worker) - pid = fork { worker_loop(worker) } - WORKERS[pid] = worker + 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 = WORKERS.size - worker_processes) == 0 and return off < 0 and return spawn_missing_workers - WORKERS.dup.each_pair { |pid,w| - w.nr >= @worker_processes and kill_worker(:QUIT, pid) rescue nil + WORKERS.dup.each_pair { |wpid,w| + w.nr >= worker_processes and kill_worker(:QUIT, wpid) 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(app, client) - client.fcntl(Fcntl::F_SETFD, Fcntl::FD_CLOEXEC) - HttpResponse.write(client, app.call(REQUEST.read(client))) # 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 - client.write_nonblock(Const::ERROR_500_RESPONSE) rescue nil - client.close rescue nil - rescue HttpParserError # try to tell the client they're bad - client.write_nonblock(Const::ERROR_400_RESPONSE) rescue nil - client.close rescue nil - rescue Object => e - client.write_nonblock(Const::ERROR_500_RESPONSE) rescue nil - client.close rescue nil - logger.error "Read error: #{e.inspect}" - logger.error e.backtrace.join("\n") + 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 + # 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) } @@ -467,15 +609,15 @@ module Unicorn 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 - @timeout /= 2.0 # halve it for select() - build_app! unless @preload_app + after_fork.call(self, worker) # can drop perms + 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..." + logger.info "worker=#{worker_nr} reopening logs..." Unicorn::Util.reopen_logs - @logger.info "worker=#{worker_nr} done reopening logs" + logger.info "worker=#{worker_nr} done reopening logs" init_self_pipe! end @@ -483,25 +625,24 @@ module Unicorn # for connections and doesn't die until the parent dies (or is # given a INT, QUIT, or TERM signal) def worker_loop(worker) - master_pid = Process.ppid # slightly racy, but less memory usage + 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 - t = ti = 0 # 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" - app = @app + 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 + # 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, @@ -509,13 +650,13 @@ module Unicorn # 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). - t == (ti = Time.now.to_i) or alive.chmod(t = ti) + alive.chmod(m = 0 == m ? 1 : 0) ready.each do |sock| begin - process_client(app, sock.accept_nonblock) + process_client(sock.accept_nonblock) nr += 1 - t == (ti = Time.now.to_i) or alive.chmod(t = ti) + alive.chmod(m = 0 == m ? 1 : 0) rescue Errno::EAGAIN, Errno::ECONNABORTED end break if nr < 0 @@ -523,22 +664,22 @@ module Unicorn # 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 every listener + # and do a speculative accept_nonblock on ready listeners # before we sleep again in select(). redo unless nr == 0 # (nr < 0) => reopen logs - master_pid == Process.ppid or return - alive.chmod(t = 0) + 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 + 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 Object => e + rescue => e if alive logger.error "Unhandled listen loop exception #{e.inspect}." logger.error e.backtrace.join("\n") @@ -548,21 +689,23 @@ module Unicorn # delivers a signal to a worker and fails gracefully if the worker # is no longer running. - def kill_worker(signal, pid) + def kill_worker(signal, wpid) begin - Process.kill(signal, pid) + Process.kill(signal, wpid) rescue Errno::ESRCH - worker = WORKERS.delete(pid) and worker.tmp.close rescue nil + 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 { |pid| kill_worker(signal, pid) } + WORKERS.keys.each { |wpid| kill_worker(signal, wpid) } end # unlinks a PID file at given +path+ if it contains the current PID - # useful as an at_exit handler. + # 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 @@ -570,29 +713,30 @@ module Unicorn # returns a PID if a given path contains a non-stale PID file, # nil otherwise. def valid_pid?(path) - if File.exist?(path) && (pid = File.read(path).to_i) > 1 - begin - Process.kill(0, pid) - return pid - rescue Errno::ESRCH - end + 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 - nil + rescue Errno::ENOENT end def load_config! begin - logger.info "reloading config_file=#{@config.config_file}" - @config[:listeners].replace(@init_listeners) - @config.reload - @config.commit!(self) + 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 - @app = @orig_app - build_app! if @preload_app - logger.info "done reloading config_file=#{@config.config_file}" - rescue Object => e - logger.error "error reloading config_file=#{@config.config_file}: " \ + self.app = orig_app + build_app! if preload_app + logger.info "done reloading config_file=#{config.config_file}" + rescue => e + logger.error "error reloading config_file=#{config.config_file}: " \ "#{e.class} #{e.message}" end end @@ -603,12 +747,16 @@ module Unicorn end def build_app! - if @app.respond_to?(:arity) && @app.arity == 0 + if app.respond_to?(:arity) && app.arity == 0 + # exploit COW in case of preload_app. Also avoids race + # conditions in Rainbows! since load/require are not thread-safe + Unicorn.constants.each { |x| Unicorn.const_get(x) } + if defined?(Gem) && Gem.respond_to?(:refresh) logger.info "Refreshing Gem list" Gem.refresh end - @app = @app.call + self.app = app.call end end @@ -618,7 +766,7 @@ module Unicorn end def redirect_io(io, path) - File.open(path, 'a') { |fp| io.reopen(fp) } if path + File.open(path, 'ab') { |fp| io.reopen(fp) } if path io.sync = true end |