Class: Puma::Server

Inherits:
Object
  • Object
show all
Extended by:
Forwardable
Includes:
Const, Request
Defined in:
lib/puma/server.rb

Overview

The HTTP Server itself. Serves out a single Rack app.

This class is used by the `Puma::Single` and `Puma::Cluster` classes to generate one or more `Puma::Server` instances capable of handling requests. Each Puma process will contain one `Puma::Server` instance.

The `Puma::Server` instance pulls requests from the socket, adds them to a `Puma::Reactor` where they get eventually passed to a `Puma::ThreadPool`.

Each `Puma::Server` will have one reactor and one thread pool.

Constant Summary collapse

ThreadLocalKey =
:puma_server
UNPACK_TCP_STATE_FROM_TCP_INFO =
"C".freeze
STAT_METHODS =

List of methods invoked by #stats.

Version:

  • 5.0.0

[:backlog, :running, :pool_capacity, :max_threads, :requests_count].freeze

Constants included from Request

Request::BODY_LEN_MAX, Request::CUSTOM_STAT, Request::IO_BODY_MAX, Request::IO_BUFFER_LEN_MAX, Request::SOCKET_WRITE_ERR_MSG

Constants included from Const

Const::BANNED_HEADER_KEY, Const::CGI_VER, Const::CHUNKED, Const::CHUNK_SIZE, Const::CLOSE, Const::CLOSE_CHUNKED, Const::CODE_NAME, Const::COLON, Const::CONNECTION_CLOSE, Const::CONNECTION_KEEP_ALIVE, Const::CONTENT_LENGTH, Const::CONTENT_LENGTH2, Const::CONTENT_LENGTH_S, Const::CONTINUE, Const::DELETE, Const::DQUOTE, Const::EARLY_HINTS, Const::ERROR_RESPONSE, Const::FAST_TRACK_KA_TIMEOUT, Const::GATEWAY_INTERFACE, Const::GET, Const::HALT_COMMAND, Const::HEAD, Const::HIJACK, Const::HIJACK_IO, Const::HIJACK_P, Const::HTTP, Const::HTTPS, Const::HTTPS_KEY, Const::HTTP_10_200, Const::HTTP_11, Const::HTTP_11_100, Const::HTTP_11_200, Const::HTTP_CONNECTION, Const::HTTP_EXPECT, Const::HTTP_HEADER_DELIMITER, Const::HTTP_HOST, Const::HTTP_VERSION, Const::HTTP_X_FORWARDED_FOR, Const::HTTP_X_FORWARDED_PROTO, Const::HTTP_X_FORWARDED_SCHEME, Const::HTTP_X_FORWARDED_SSL, Const::ILLEGAL_HEADER_KEY_REGEX, Const::ILLEGAL_HEADER_VALUE_REGEX, Const::KEEP_ALIVE, Const::LINE_END, Const::LOCALHOST, Const::LOCALHOST_IPV4, Const::LOCALHOST_IPV6, Const::MAX_BODY, Const::MAX_HEADER, Const::NEWLINE, Const::OPTIONS, Const::PATCH, Const::PATH_INFO, Const::PORT_443, Const::PORT_80, Const::POST, Const::PROXY_PROTOCOL_V1_REGEX, Const::PUMA_CONFIG, Const::PUMA_PEERCERT, Const::PUMA_SERVER_STRING, Const::PUMA_SOCKET, Const::PUMA_TMP_BASE, Const::PUMA_VERSION, Const::PUT, Const::QUERY_STRING, Const::RACK_AFTER_REPLY, Const::RACK_INPUT, Const::RACK_URL_SCHEME, Const::REMOTE_ADDR, Const::REQUEST_METHOD, Const::REQUEST_PATH, Const::REQUEST_URI, Const::RESTART_COMMAND, Const::SERVER_NAME, Const::SERVER_PORT, Const::SERVER_PROTOCOL, Const::SERVER_SOFTWARE, Const::STOP_COMMAND, Const::SUPPORTED_HTTP_METHODS, Const::TRACE, Const::TRANSFER_ENCODING, Const::TRANSFER_ENCODING2, Const::TRANSFER_ENCODING_CHUNKED, Const::UNSPECIFIED_IPV4, Const::UNSPECIFIED_IPV6, Const::WRITE_TIMEOUT

Class Attribute Summary collapse

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Methods included from Request

#default_server_port, #handle_request, #prepare_response

Constructor Details

#initialize(app, events = nil, options = {}) ⇒ Server

Note:

Several instance variables exist so they are available for testing, and have default values set via fetch. Normally the values are set via `::Puma::Configuration.puma_default_options`.

Note:

The `events` parameter is set to nil, and set to `Events.new` in code. Often `options` needs to be passed, but `events` does not. Using nil allows calling code to not require events.rb.

Create a server for the rack app app.

log_writer is a Puma::LogWriter object used to log info and error messages.

events is a Puma::Events object used to notify application status events.

Server#run returns a thread that you can join on to wait for the server to do its work.


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# File 'lib/puma/server.rb', line 74

def initialize(app, events = nil, options = {})
  @app = app
  @events = events || Events.new

  @check, @notify = nil
  @status = :stop

  @thread = nil
  @thread_pool = nil

  @options = if options.is_a?(UserFileDefaultOptions)
    options
  else
    UserFileDefaultOptions.new(options, Configuration::DEFAULTS)
  end

  @log_writer          = @options.fetch :log_writer, LogWriter.stdio
  @early_hints         = @options[:early_hints]
  @first_data_timeout  = @options[:first_data_timeout]
  @min_threads         = @options[:min_threads]
  @max_threads         = @options[:max_threads]
  @persistent_timeout  = @options[:persistent_timeout]
  @queue_requests      = @options[:queue_requests]
  @max_fast_inline     = @options[:max_fast_inline]
  @io_selector_backend = @options[:io_selector_backend]

  temp = !!(@options[:environment] =~ /\A(development|test)\z/)
  @leak_stack_on_error = @options[:environment] ? temp : true

  @binder = Binder.new(log_writer)

  ENV['RACK_ENV'] ||= "development"

  @mode = :http

  @precheck_closing = true

  @requests_count = 0
end

Class Attribute Details

.currentObject (readonly)


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# File 'lib/puma/server.rb', line 120

def current
  Thread.current[ThreadLocalKey]
end

Instance Attribute Details

#appObject

Returns the value of attribute app.


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# File 'lib/puma/server.rb', line 49

def app
  @app
end

#auto_trim_timeObject (readonly)

TODO:

the following may be deprecated in the future


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# File 'lib/puma/server.rb', line 45

def auto_trim_time
  @auto_trim_time
end

#backlogObject (readonly)


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# File 'lib/puma/server.rb', line 198

def backlog
  @thread_pool&.backlog
end

#binderObject

Returns the value of attribute binder.


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# File 'lib/puma/server.rb', line 50

def binder
  @binder
end

#early_hintsObject (readonly)

TODO:

the following may be deprecated in the future


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# File 'lib/puma/server.rb', line 45

def early_hints
  @early_hints
end

#eventsObject (readonly)

Returns the value of attribute events.


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# File 'lib/puma/server.rb', line 40

def events
  @events
end

#first_data_timeoutObject (readonly)

TODO:

the following may be deprecated in the future


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# File 'lib/puma/server.rb', line 45

def first_data_timeout
  @first_data_timeout
end

#leak_stack_on_errorObject (readonly)

TODO:

the following may be deprecated in the future


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# File 'lib/puma/server.rb', line 45

def leak_stack_on_error
  @leak_stack_on_error
end

#log_writerObject (readonly)

Returns the value of attribute log_writer.


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# File 'lib/puma/server.rb', line 39

def log_writer
  @log_writer
end

#max_threadsObject (readonly)

for #stats


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# File 'lib/puma/server.rb', line 41

def max_threads
  @max_threads
end

#min_threadsObject (readonly)

for #stats


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# File 'lib/puma/server.rb', line 41

def min_threads
  @min_threads
end

#persistent_timeoutObject (readonly)

TODO:

the following may be deprecated in the future


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# File 'lib/puma/server.rb', line 45

def persistent_timeout
  @persistent_timeout
end

#pool_capacityObject (readonly)

This number represents the number of requests that the server is capable of taking right now.

For example if the number is 5 then it means there are 5 threads sitting idle ready to take a request. If one request comes in, then the value would be 4 until it finishes processing.


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# File 'lib/puma/server.rb', line 216

def pool_capacity
  @thread_pool&.pool_capacity
end

#reaping_timeObject (readonly)

TODO:

the following may be deprecated in the future


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# File 'lib/puma/server.rb', line 45

def reaping_time
  @reaping_time
end

#requests_countObject (readonly)

Version:

  • 5.0.0


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# File 'lib/puma/server.rb', line 42

def requests_count
  @requests_count
end

#runningObject (readonly)


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# File 'lib/puma/server.rb', line 203

def running
  @thread_pool&.spawned
end

#statsObject (readonly)

Returns a hash of stats about the running server for reporting purposes.

Version:

  • 5.0.0


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# File 'lib/puma/server.rb', line 612

def stats
  STAT_METHODS.map {|name| [name, send(name) || 0]}.to_h
end

#threadObject (readonly)

Returns the value of attribute thread.


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# File 'lib/puma/server.rb', line 38

def thread
  @thread
end

Class Method Details

.closed_socket_supported?Boolean

:nodoc:

Returns:

  • (Boolean)

Version:

  • 5.0.0


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# File 'lib/puma/server.rb', line 132

def closed_socket_supported?
  Socket.const_defined?(:TCP_INFO) && Socket.const_defined?(:IPPROTO_TCP)
end

.tcp_cork_supported?Boolean

:nodoc:

Returns:

  • (Boolean)

Version:

  • 5.0.0


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# File 'lib/puma/server.rb', line 126

def tcp_cork_supported?
  Socket.const_defined?(:TCP_CORK) && Socket.const_defined?(:IPPROTO_TCP)
end

Instance Method Details

#begin_restart(sync = false) ⇒ Object


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# File 'lib/puma/server.rb', line 596

def begin_restart(sync=false)
  notify_safely(RESTART_COMMAND)
  @thread.join if @thread && sync
end

#client_error(e, client) ⇒ Object

Handle various error types thrown by Client I/O operations.


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# File 'lib/puma/server.rb', line 496

def client_error(e, client)
  # Swallow, do not log
  return if [ConnectionError, EOFError].include?(e.class)

  lowlevel_error(e, client.env)
  case e
  when MiniSSL::SSLError
    @log_writer.ssl_error e, client.io
  when HttpParserError
    client.write_error(400)
    @log_writer.parse_error e, client
  when HttpParserError501
    client.write_error(501)
    @log_writer.parse_error e, client
  else
    client.write_error(500)
    @log_writer.unknown_error e, nil, "Read"
  end
end

#closed_socket?(socket) ⇒ Boolean

Returns:

  • (Boolean)

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# File 'lib/puma/server.rb', line 175

def closed_socket?(socket)
  skt = socket.to_io
  return false unless skt.kind_of?(TCPSocket) && @precheck_closing

  begin
    tcp_info = skt.getsockopt(Socket::IPPROTO_TCP, Socket::TCP_INFO)
  rescue IOError, SystemCallError
    Puma::Util.purge_interrupt_queue
    @precheck_closing = false
    false
  else
    state = tcp_info.unpack(UNPACK_TCP_STATE_FROM_TCP_INFO)[0]
    # TIME_WAIT: 6, CLOSE: 7, CLOSE_WAIT: 8, LAST_ACK: 9, CLOSING: 11
    (state >= 6 && state <= 9) || state == 11
  end
end

#cork_socket(socket) ⇒ Object

6 == Socket::IPPROTO_TCP 3 == TCP_CORK 1/0 == turn on/off


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# File 'lib/puma/server.rb', line 147

def cork_socket(socket)
  skt = socket.to_io
  begin
    skt.setsockopt(Socket::IPPROTO_TCP, Socket::TCP_CORK, 1) if skt.kind_of? TCPSocket
  rescue IOError, SystemCallError
    Puma::Util.purge_interrupt_queue
  end
end

#graceful_shutdownObject

Wait for all outstanding requests to finish.


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# File 'lib/puma/server.rb', line 539

def graceful_shutdown
  if @options[:shutdown_debug]
    threads = Thread.list
    total = threads.size

    pid = Process.pid

    $stdout.syswrite "#{pid}: === Begin thread backtrace dump ===\n"

    threads.each_with_index do |t,i|
      $stdout.syswrite "#{pid}: Thread #{i+1}/#{total}: #{t.inspect}\n"
      $stdout.syswrite "#{pid}: #{t.backtrace.join("\n#{pid}: ")}\n\n"
    end
    $stdout.syswrite "#{pid}: === End thread backtrace dump ===\n"
  end

  if @status != :restart
    @binder.close
  end

  if @thread_pool
    if timeout = @options[:force_shutdown_after]
      @thread_pool.shutdown timeout.to_f
    else
      @thread_pool.shutdown
    end
  end
end

#halt(sync = false) ⇒ Object


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# File 'lib/puma/server.rb', line 591

def halt(sync=false)
  notify_safely(HALT_COMMAND)
  @thread.join if @thread && sync
end

#handle_checkObject

:nodoc:


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# File 'lib/puma/server.rb', line 376

def handle_check
  cmd = @check.read(1)

  case cmd
  when STOP_COMMAND
    @status = :stop
    return true
  when HALT_COMMAND
    @status = :halt
    return true
  when RESTART_COMMAND
    @status = :restart
    return true
  end

  false
end

#handle_serversObject


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# File 'lib/puma/server.rb', line 300

def handle_servers
  begin
    check = @check
    sockets = [check] + @binder.ios
    pool = @thread_pool
    queue_requests = @queue_requests
    drain = @options[:drain_on_shutdown] ? 0 : nil

    addr_send_name, addr_value = case @options[:remote_address]
    when :value
      [:peerip=, @options[:remote_address_value]]
    when :header
      [:remote_addr_header=, @options[:remote_address_header]]
    when :proxy_protocol
      [:expect_proxy_proto=, @options[:remote_address_proxy_protocol]]
    else
      [nil, nil]
    end

    while @status == :run || (drain && shutting_down?)
      begin
        ios = IO.select sockets, nil, nil, (shutting_down? ? 0 : nil)
        break unless ios
        ios.first.each do |sock|
          if sock == check
            break if handle_check
          else
            pool.wait_until_not_full
            pool.wait_for_less_busy_worker(@options[:wait_for_less_busy_worker])

            io = begin
              sock.accept_nonblock
            rescue IO::WaitReadable
              next
            end
            drain += 1 if shutting_down?
            pool << Client.new(io, @binder.env(sock)).tap { |c|
              c.listener = sock
              c.send(addr_send_name, addr_value) if addr_value
            }
          end
        end
      rescue IOError, Errno::EBADF
        # In the case that any of the sockets are unexpectedly close.
        raise
      rescue StandardError => e
        @log_writer.unknown_error e, nil, "Listen loop"
      end
    end

    @log_writer.debug "Drained #{drain} additional connections." if drain
    @events.fire :state, @status

    if queue_requests
      @queue_requests = false
      @reactor.shutdown
    end
    graceful_shutdown if @status == :stop || @status == :restart
  rescue Exception => e
    @log_writer.unknown_error e, nil, "Exception handling servers"
  ensure
    # Errno::EBADF is infrequently raised
    [@check, @notify].each do |io|
      begin
        io.close unless io.closed?
      rescue Errno::EBADF
      end
    end
    @notify = nil
    @check = nil
  end

  @events.fire :state, :done
end

#inherit_binder(bind) ⇒ Object


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# File 'lib/puma/server.rb', line 114

def inherit_binder(bind)
  @binder = bind
end

#lowlevel_error(e, env, status = 500) ⇒ Object

A fallback rack response if @app raises as exception.


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# File 'lib/puma/server.rb', line 518

def lowlevel_error(e, env, status=500)
  if handler = @options[:lowlevel_error_handler]
    if handler.arity == 1
      return handler.call(e)
    elsif handler.arity == 2
      return handler.call(e, env)
    else
      return handler.call(e, env, status)
    end
  end

  if @leak_stack_on_error
    backtrace = e.backtrace.nil? ? '<no backtrace available>' : e.backtrace.join("\n")
    [status, {}, ["Puma caught this error: #{e.message} (#{e.class})\n#{backtrace}"]]
  else
    [status, {}, ["An unhandled lowlevel error occurred. The application logs may have details.\n"]]
  end
end

#process_client(client, buffer) ⇒ Object

Given a connection on client, handle the incoming requests, or queue the connection in the Reactor if no request is available.

This method is called from a ThreadPool worker thread.

This method supports HTTP Keep-Alive so it may, depending on if the client indicates that it supports keep alive, wait for another request before returning.

Return true if one or more requests were processed.


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# File 'lib/puma/server.rb', line 404

def process_client(client, buffer)
  # Advertise this server into the thread
  Thread.current[ThreadLocalKey] = self

  clean_thread_locals = @options[:clean_thread_locals]
  close_socket = true

  requests = 0

  begin
    if @queue_requests &&
      !client.eagerly_finish

      client.set_timeout(@first_data_timeout)
      if @reactor.add client
        close_socket = false
        return false
      end
    end

    with_force_shutdown(client) do
      client.finish(@first_data_timeout)
    end

    while true
      @requests_count += 1
      case handle_request(client, buffer, requests + 1)
      when false
        break
      when :async
        close_socket = false
        break
      when true
        buffer.reset

        ThreadPool.clean_thread_locals if clean_thread_locals

        requests += 1

        # As an optimization, try to read the next request from the
        # socket for a short time before returning to the reactor.
        fast_check = @status == :run

        # Always pass the client back to the reactor after a reasonable
        # number of inline requests if there are other requests pending.
        fast_check = false if requests >= @max_fast_inline &&
          @thread_pool.backlog > 0

        next_request_ready = with_force_shutdown(client) do
          client.reset(fast_check)
        end

        unless next_request_ready
          break unless @queue_requests
          client.set_timeout @persistent_timeout
          if @reactor.add client
            close_socket = false
            break
          end
        end
      end
    end
    true
  rescue StandardError => e
    client_error(e, client)
    # The ensure tries to close +client+ down
    requests > 0
  ensure
    buffer.reset

    begin
      client.close if close_socket
    rescue IOError, SystemCallError
      Puma::Util.purge_interrupt_queue
      # Already closed
    rescue StandardError => e
      @log_writer.unknown_error e, nil, "Client"
    end
  end
end

#reactor_wakeup(client) ⇒ Object

This method is called from the Reactor thread when a queued Client receives data, times out, or when the Reactor is shutting down.

It is responsible for ensuring that a request has been completely received before it starts to be processed by the ThreadPool. This may be known as read buffering. If read buffering is not done, and no other read buffering is performed (such as by an application server such as nginx) then the application would be subject to a slow client attack.

For a graphical representation of how the request buffer works see [architecture.md](github.com/puma/puma/blob/master/docs/architecture.md#connection-pipeline).

The method checks to see if it has the full header and body with the `Puma::Client#try_to_finish` method. If the full request has been sent, then the request is passed to the ThreadPool (`@thread_pool << client`) so that a “worker thread” can pick up the request and begin to execute application logic. The Client is then removed from the reactor (return `true`).

If a client object times out, a 408 response is written, its connection is closed, and the object is removed from the reactor (return `true`).

If the Reactor is shutting down, all Clients are either timed out or passed to the ThreadPool, depending on their current state (#can_close?).

Otherwise, if the full request is not ready then the client will remain in the reactor (return `false`). When the client sends more data to the socket the `Puma::Client` object will wake up and again be checked to see if it's ready to be passed to the thread pool.


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# File 'lib/puma/server.rb', line 284

def reactor_wakeup(client)
  shutdown = !@queue_requests
  if client.try_to_finish || (shutdown && !client.can_close?)
    @thread_pool << client
  elsif shutdown || client.timeout == 0
    client.timeout!
  else
    client.set_timeout(@first_data_timeout)
    false
  end
rescue StandardError => e
  client_error(e, client)
  client.close
  true
end

#run(background = true, thread_name: 'srv') ⇒ Object

Runs the server.

If background is true (the default) then a thread is spun up in the background to handle requests. Otherwise requests are handled synchronously.


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# File 'lib/puma/server.rb', line 226

def run(background=true, thread_name: 'srv')
  BasicSocket.do_not_reverse_lookup = true

  @events.fire :state, :booting

  @status = :run

  @thread_pool = ThreadPool.new(thread_name, @options) { |a, b| process_client a, b }

  if @queue_requests
    @reactor = Reactor.new(@io_selector_backend) { |c| reactor_wakeup c }
    @reactor.run
  end


  @thread_pool.auto_reap! if @options[:reaping_time]
  @thread_pool.auto_trim! if @options[:auto_trim_time]

  @check, @notify = Puma::Util.pipe unless @notify

  @events.fire :state, :running

  if background
    @thread = Thread.new do
      Puma.set_thread_name thread_name
      handle_servers
    end
    return @thread
  else
    handle_servers
  end
end

#shutting_down?Boolean

Returns:

  • (Boolean)

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# File 'lib/puma/server.rb', line 601

def shutting_down?
  @status == :stop || @status == :restart
end

#stop(sync = false) ⇒ Object

Stops the acceptor thread and then causes the worker threads to finish off the request queue before finally exiting.


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# File 'lib/puma/server.rb', line 586

def stop(sync=false)
  notify_safely(STOP_COMMAND)
  @thread.join if @thread && sync
end

#uncork_socket(socket) ⇒ Object


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# File 'lib/puma/server.rb', line 156

def uncork_socket(socket)
  skt = socket.to_io
  begin
    skt.setsockopt(Socket::IPPROTO_TCP, Socket::TCP_CORK, 0) if skt.kind_of? TCPSocket
  rescue IOError, SystemCallError
    Puma::Util.purge_interrupt_queue
  end
end

#with_force_shutdown(client, &block) ⇒ Object

Triggers a client timeout if the thread-pool shuts down during execution of the provided block.


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# File 'lib/puma/server.rb', line 487

def with_force_shutdown(client, &block)
  @thread_pool.with_force_shutdown(&block)
rescue ThreadPool::ForceShutdown
  client.timeout!
end