1=================
2FastCGI Internals
3=================
4
5---------------
6Module: fastcgi
7---------------
8
9:Author: Jan Kneschke
10:Date: $Date: 2004/08/01 07:01:29 $
11:Revision: $Revision: 1.1 $
12
13:abstract:
14  This is a short summary of the state-engine which is driving the FastCGI
15  module. It describes the basic concepts and the way the different parts
16  of the module are connected.
17
18.. meta::
19  :keywords: lighttpd, state-engine, fastcgi
20
21.. contents:: Table of Contents
22
23Description
24===========
25
26States
27------
28
29The state-engine is currently made of 6 states which are walk-through on
30the way each connection.
31
32:init:
33  prepare fastcgi-connection
34:connect:
35  waiting for a connection
36:prepwrite:
37  build the fastcgi-request
38:write:
39  write the fastcgi-request to the network
40:read:
41  read fastcgi-response from network and push it to the write-queue
42:close:
43  terminate the connection
44
45.. image:: fastcgi-state.png
46
47Delays
48------
49
50connect, write and read may need to wait for an fdevent. That's the reason
51for the loop in the state-diagram.
52