我正在尝试理解并重新创建一个简单的预分叉服务器，就像独角兽一样，启动时的服务器派生4个进程，所有进程都在控制套接字上等待(接受)。
控制套接字@control_socket绑定到9799并产生4个等待接受连接的工作进程。每名工人所做的工作如下

def spawn_child
  fork do
    $STDOUT.puts "Forking child #{Process.pid}"
    loop do 
      @client = @control_socket.accept                                        
      loop do                     
        request = gets              

        if request                          
            respond(@inner_app.call(request))                           
        else
            $STDOUT.puts("No Request")
            @client.close                           
        end
      end
    end
  end
end

我使用了一个非常简单的Rack应用程序，它只返回一个状态代码为200、内容类型为Text/html的字符串。
我面临的问题是，当我读取传入请求时，我的服务器工作正常(通过使用gets而不是read或read_partial或read_nonblock点击“http://localhost:9799”)“处的URL)。当我使用非阻塞读取时，它似乎从未抛出EOFError，根据我的理解，这意味着它不会接收EOF状态。
这会导致读取loop无法完成。下面是完成这项工作的代码片段。

# Reads a file using IO.read_nonblock

# Returns end of file when using get but doesn't seem to return

# while using read_nonblock or readpartial

        # The fact that the method is named gets is just bad naming, please ignore
def gets
  buffer = ""         
  i =0
  loop do
    puts "loop #{i}"
    i += 1
    begin
      buffer << @client.read_nonblock(READ_CHUNK)
      puts "buffer is #{buffer}"
    rescue  Errno::EAGAIN => e
      puts "#{e.message}"
      puts "#{e.backtrace}"
      IO.select([@client])
      retry
    rescue EOFError
      $STDOUT.puts "-" * 50
      puts "request data is #{buffer}"    
      $STDOUT.puts "-" * 50
      break           
    end
  end
  puts "returning buffer"
  buffer
end

但是，如果i使用简单的gets而不是read或read_nonblock，或者如果将IO.select([@client])替换为break，则代码可以完美地运行。
下面是代码工作并返回响应的时间。我打算使用READ_NONBLOCK的原因是unicorn使用了使用kgio库的等价物，该库实现了非阻塞读取。

def gets
  @client.gets
end

接下来粘贴整个代码。

module Server   
  class Prefork
    # line break 
    CRLF  = "\r\n"
    # number of workers process to fork
    CONCURRENCY = 4
    # size of each non_blocking read
    READ_CHUNK = 1024

    $STDOUT = STDOUT
    $STDOUT.sync

    # creates a control socket which listens to port 9799
    def initialize(port = 21)
      @control_socket = TCPServer.new(9799)
      puts "Starting server..."
      trap(:INT) {
        exit
      }
    end

    # Reads a file using IO.read_nonblock
    # Returns end of file when using get but doesn't seem to return 
    # while using read_nonblock or readpartial
    def gets
      buffer = ""         
      i =0
      loop do
        puts "loop #{i}"
        i += 1
        begin
          buffer << @client.read_nonblock(READ_CHUNK)
          puts "buffer is #{buffer}"
        rescue  Errno::EAGAIN => e
          puts "#{e.message}"
          puts "#{e.backtrace}"
          IO.select([@client])
                              retry
        rescue EOFError
          $STDOUT.puts "-" * 50
          puts "request data is #{buffer}"    
          $STDOUT.puts "-" * 50
          break           
        end
      end
      puts "returning buffer"
      buffer
    end

    # responds with the data and closes the connection
    def respond(data)
      puts "request 2 Data is #{data.inspect}"
      status, headers, body = data
      puts "message is #{body}"
      buffer = "HTTP/1.1 #{status}\r\n" \
               "Date: #{Time.now.utc}\r\n" \
               "Status: #{status}\r\n" \
               "Connection: close\r\n"            
      headers.each {|key, value| buffer << "#{key}: #{value}\r\n"}          
      @client.write(buffer << CRLF)
      body.each {|chunk| @client.write(chunk)}            
    ensure 
      $STDOUT.puts "*" * 50
      $STDOUT.puts "Closing..."
      @client.respond_to?(:close) and @client.close
    end

    # The main method which triggers the creation of workers processes
    # The workers processes all wait to accept the socket on the same
    # control socket allowing the kernel to do the load balancing.
    # 
    # Working with a dummy rack app which returns a simple text message
    # hence the config.ru file read.
    def run         
      # copied from unicorn-4.2.1
      # refer unicorn.rb and lib/unicorn/http_server.rb           
      raw_data = File.read("config.ru")           
      app = "::Rack::Builder.new {\n#{raw_data}\n}.to_app"
      @inner_app = eval(app, TOPLEVEL_BINDING)
      child_pids = []
      CONCURRENCY.times do
        child_pids << spawn_child
      end

      trap(:INT) {
        child_pids.each do |cpid|
          begin 
            Process.kill(:INT, cpid)
          rescue Errno::ESRCH
          end
        end

        exit
      }

      loop do
        pid = Process.wait
        puts "Process quit unexpectedly #{pid}"
        child_pids.delete(pid)
        child_pids << spawn_child
      end
    end

    # This is where the real work is done.
    def spawn_child
      fork do
        $STDOUT.puts "Forking child #{Process.pid}"
        loop do 
          @client = @control_socket.accept                                        
          loop do                     
            request = gets              

            if request                          
              respond(@inner_app.call(request))                           
            else
              $STDOUT.puts("No Request")
              @client.close                           
            end
          end
        end
      end
    end
  end
end

p = Server::Prefork.new(9799)
p.run

谁能解释一下为什么read_partial或read_nonblock或read的读取失败。我真的很感激在这件事上能帮上忙。