123456789_123456789_123456789_123456789_123456789_

Class: EventMachine::DeferrableChildProcess

Relationships & Source Files
Super Chains via Extension / Inclusion / Inheritance
Class Chain:
self, Connection
Instance Chain:
self, Deferrable, Connection
Inherits: EventMachine::Connection
Defined in: lib/em/processes.rb

Overview

EM::DeferrableChildProcess is a sugaring of a common use-case involving EM::popen. Call the #open method on EM::DeferrableChildProcess, passing a command-string. #open immediately returns an EM::Deferrable object. It also schedules the forking of a child process, which will execute the command passed to #open. When the forked child terminates, the Deferrable will be signalled and execute its callbacks, passing the data that the child process wrote to stdout.

Constant Summary

Deferrable - Included

Pool

Class Method Summary

Connection - Inherited

.new

Override .new so subclasses don't have to call super and can ignore connection-specific arguments.

Instance Attribute Summary

Connection - Inherited

#comm_inactivity_timeout

comm_inactivity_timeout returns the current value (float in seconds) of the inactivity-timeout property of network-connection and datagram-socket objects.
#comm_inactivity_timeout=

Allows you to set the inactivity-timeout property for a network connection or datagram socket.
#error?

Returns true if the connection is in an error state, false otherwise.
#notify_readable=

Watches connection for readability.
#notify_readable?,
#notify_writable=

Watches connection for writeability.
#notify_writable?

Returns true if the connection is being watched for writability.
#paused?,
#pending_connect_timeout

The duration after which a TCP connection in the connecting state will fail.
#pending_connect_timeout=

Sets the duration after which a TCP connection in a connecting state will fail.
#signature, #watch_only?

Instance Method Summary

Deferrable - Included

#callback

Specify a block to be executed if and when the Deferrable object receives a status of :succeeded.
#cancel_callback

Cancels an outstanding callback to &block if any.
#cancel_errback

Cancels an outstanding errback to &block if any.
#cancel_timeout

Cancels an outstanding timeout if any.
#errback

Specify a block to be executed if and when the Deferrable object receives a status of :failed.
#fail

Sugar for set_deferred_status(:failed, ...).
#set_deferred_failure

Alias for Deferrable#fail.
#set_deferred_status

Sets the "disposition" (status) of the Deferrable object.
#set_deferred_success

Alias for Deferrable#succeed.
#succeed

Sugar for set_deferred_status(:succeeded, ...).
#timeout

Setting a timeout on a Deferrable causes it to go into the failed state after the Timeout expires (passing no arguments to the object's errbacks).

Connection - Inherited

#associate_callback_target

conn_associate_callback_target.
#close_connection

EventMachine::Connection#close_connection is called only by user code, and never by the event loop.
#close_connection_after_writing

A variant of #close_connection.
#connection_completed

Called by the event loop when a remote TCP connection attempt completes successfully.
#detach

Removes given connection from the event loop.
#disable_keepalive

t_disable_keepalive.
#enable_keepalive

t_enable_keepalive.
#get_cipher_bits, #get_cipher_name, #get_cipher_protocol,
#get_idle_time

The number of seconds since the last send/receive activity on this connection.
#get_outbound_data_size

conn_get_outbound_data_size.
#get_peer_cert

If TLS is active on the connection, returns the remote X509 certificate as a string, in the popular PEM format.
#get_peername

This method is used with stream-connections to obtain the identity of the remotely-connected peer.
#get_pid

Returns the PID (kernel process identifier) of a subprocess associated with this Connection object.
#get_proxied_bytes

The number of bytes proxied to another connection.
#get_sni_hostname, #get_sock_opt,
#get_sockname

Used with stream-connections to obtain the identity of the local side of the connection.
#get_status

Returns a subprocess exit status.
#initialize

Stubbed initialize so legacy superclasses can safely call super.
#original_method,
#pause

Pause a connection so that #send_data and #receive_data events are not fired until #resume is called.
#post_init

Called by the event loop immediately after the network connection has been established, and before resumption of the network loop.
#proxy_completed

called when the reactor finished proxying all of the requested bytes.
#proxy_incoming_to

EventMachine::Connection#proxy_incoming_to is called only by user code.
#proxy_target_unbound

Called by the reactor after attempting to relay incoming data to a descriptor (set as a proxy target descriptor with enable_proxy) that has already been closed.
#receive_data

Called by the event loop whenever data has been received by the network connection.
#reconnect

Reconnect to a given host/port with the current instance.
#resume

Resume a connection's #send_data and #receive_data events.
#send_data

Call this method to send data to the remote end of the network connection.
#send_datagram

Sends UDP messages.
#send_file_data

Like Connection#send_data, this sends data to the remote end of the network connection.
#set_sock_opt,
#ssl_handshake_completed

Called by ::EventMachine when the SSL/TLS handshake has been completed, as a result of calling #start_tls to initiate SSL/TLS on the connection.
#ssl_verify_peer

Called by ::EventMachine when :verify_peer => true has been passed to #start_tls.
#start_tls

Call #start_tls at any point to initiate TLS encryption on connected streams.
#stop_proxying

A helper method for disable_proxy
#stream_file_data

Open a file on the filesystem and send it to the remote peer.
#unbind

called by the framework whenever a connection (either a server or client connection) is closed.

Constructor Details

.new ⇒ DeferrableChildProcess

This method is for internal use only.
[ GitHub ] 

  


# File 'lib/em/processes.rb', line 43



def initialize
  super
  @data = []
end


  







Class Method Details



  

    .open(cmd)  
  



  

    
Sugars a common use-case involving forked child processes.



open takes a String argument containing an shell command



string (including arguments if desired). #open immediately
returns an Deferrable object, without blocking.



It also invokes EventMachine#popen to run the passed-in
command in a forked child process.



When the forked child terminates, the Deferrable that



open calls its callbacks, passing the data returned



from the child process.


  



  [ GitHub ]


  

  


# File 'lib/em/processes.rb', line 60



def self.open cmd
  EventMachine.popen( cmd, DeferrableChildProcess )
end


  







Instance Method Details



  

    #receive_data(data)  
  

  

    This method is for internal use only.
  

  [ GitHub ]


  

  


# File 'lib/em/processes.rb', line 65



def receive_data data
  @data << data
end


  








  

    #unbind  
  

  

    This method is for internal use only.
  

  [ GitHub ]


  

  


# File 'lib/em/processes.rb', line 70



def unbind
  succeed( @data.join )
end