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diff --git a/code/spyglass/docs/master.html b/code/spyglass/docs/master.html new file mode 100644 index 0000000..11f2abc --- /dev/null +++ b/code/spyglass/docs/master.html @@ -0,0 +1,268 @@ +<!DOCTYPE html> + +<html> +<head> + <title>master.rb</title> + <meta http-equiv="content-type" content="text/html; charset=UTF-8"> + <meta name="viewport" content="width=device-width, target-densitydpi=160dpi, initial-scale=1.0; maximum-scale=1.0; user-scalable=0;"> + <link rel="stylesheet" media="all" href="docco.css" /> +</head> +<body> + <div id="container"> + <div id="background"></div> + + <ul id="jump_to"> + <li> + <a class="large" href="javascript:void(0);">Jump To …</a> + <a class="small" href="javascript:void(0);">+</a> + <div id="jump_wrapper"> + <div id="jump_page"> + + + <a class="source" href="configurator.html"> + configurator.rb + </a> + + + <a class="source" href="logging.html"> + logging.rb + </a> + + + <a class="source" href="lookout.html"> + lookout.rb + </a> + + + <a class="source" href="master.html"> + master.rb + </a> + + + <a class="source" href="server.html"> + server.rb + </a> + + + <a class="source" href="worker.html"> + worker.rb + </a> + + </div> + </li> + </ul> + + <ul class="sections"> + + <li id="title"> + <div class="annotation"> + <h1>master.rb</h1> + </div> + </li> + + + + <li id="section-1"> + <div class="annotation"> + + <div class="pilwrap "> + <a class="pilcrow" href="#section-1">¶</a> + </div> + + </div> + + <div class="content"><div class='highlight'><pre><span class="class"><span class="keyword">module</span> <span class="title">Spyglass</span></span> + <span class="class"><span class="keyword">class</span> <span class="title">Master</span></span> + <span class="keyword">include</span> <span class="constant">Logging</span> + + <span class="function"><span class="keyword">def</span> <span class="title">initialize</span><span class="params">(connection, socket)</span></span> + <span class="variable">@connection</span>, <span class="variable">@socket</span> = connection, socket + <span class="variable">@worker_pids</span> = []</pre></div></div> + + </li> + + + <li id="section-2"> + <div class="annotation"> + + <div class="pilwrap "> + <a class="pilcrow" href="#section-2">¶</a> + </div> + <p>The Master shares this pipe with each of its worker processes. It +passes the writable end down to each spawned worker while it listens +on the readable end. Each worker will write to the pipe each time +it accepts a new connection. If The Master doesn't get anything on +the pipe before <code>Config.timeout</code> elapses then it kills its workers +and exits. </p> + + </div> + + <div class="content"><div class='highlight'><pre> <span class="variable">@readable_pipe</span>, <span class="variable">@writable_pipe</span> = <span class="constant">IO</span>.pipe + <span class="keyword">end</span></pre></div></div> + + </li> + + + <li id="section-3"> + <div class="annotation"> + + <div class="pilwrap "> + <a class="pilcrow" href="#section-3">¶</a> + </div> + <p>This method starts the Master. It enters an infinite loop where it creates +processes to handle web requests and ensures that they stay active. It takes +a connection as an argument from the Lookout instance. A Master will only +be started when a connection is received by the Lookout.</p> + + </div> + + <div class="content"><div class='highlight'><pre> <span class="function"><span class="keyword">def</span> <span class="title">start</span></span> + trap_signals + + load_app + out <span class="string">"Loaded the app"</span></pre></div></div> + + </li> + + + <li id="section-4"> + <div class="annotation"> + + <div class="pilwrap "> + <a class="pilcrow" href="#section-4">¶</a> + </div> + <p>The first worker we spawn has to handle the connection that was already +passed to us.</p> + + </div> + + <div class="content"><div class='highlight'><pre> spawn_worker(<span class="variable">@connection</span>)</pre></div></div> + + </li> + + + <li id="section-5"> + <div class="annotation"> + + <div class="pilwrap "> + <a class="pilcrow" href="#section-5">¶</a> + </div> + <p>The Master can now close its handle on the client socket since the +forked worker also got a handle on the same socket. Since this one +is now closed it's up to the Worker process to close its handle when +it's done. At that point the client connection will perceive that +it's been closed on their end.</p> + + </div> + + <div class="content"><div class='highlight'><pre> <span class="variable">@connection</span>.close</pre></div></div> + + </li> + + + <li id="section-6"> + <div class="annotation"> + + <div class="pilwrap "> + <a class="pilcrow" href="#section-6">¶</a> + </div> + <p>We spawn the rest of the workers.</p> + + </div> + + <div class="content"><div class='highlight'><pre> (<span class="constant">Config</span>.workers - <span class="number">1</span>).times { spawn_worker } + out <span class="string">"Spawned <span class="subst">#{<span class="constant">Config</span>.workers}</span> workers. Babysitting now..."</span> + + loop <span class="keyword">do</span> + <span class="keyword">if</span> timed_out?(<span class="constant">IO</span>.select([<span class="variable">@readable_pipe</span>], <span class="keyword">nil</span>, <span class="keyword">nil</span>, <span class="constant">Config</span>.timeout)) + out <span class="string">"Timed out after <span class="subst">#{<span class="constant">Config</span>.timeout}</span> s. Exiting."</span> + + kill_workers(<span class="symbol">:QUIT</span>) + exit + <span class="keyword">else</span></pre></div></div> + + </li> + + + <li id="section-7"> + <div class="annotation"> + + <div class="pilwrap "> + <a class="pilcrow" href="#section-7">¶</a> + </div> + <p>Clear the data on the pipe so it doesn't appear to be readable +next time around the loop.</p> + + </div> + + <div class="content"><div class='highlight'><pre> <span class="variable">@readable_pipe</span>.read_nonblock <span class="number">1</span> + <span class="keyword">end</span> + <span class="keyword">end</span> + <span class="keyword">end</span> + + <span class="function"><span class="keyword">def</span> <span class="title">timed_out?</span><span class="params">(select_result)</span></span> + !select_result + <span class="keyword">end</span> + + <span class="function"><span class="keyword">def</span> <span class="title">spawn_worker</span><span class="params">(connection = <span class="keyword">nil</span>)</span></span> + <span class="variable">@worker_pids</span> << fork { <span class="constant">Worker</span>.new(<span class="variable">@socket</span>, <span class="variable">@app</span>, <span class="variable">@writable_pipe</span>, connection).start } + <span class="keyword">end</span> + + <span class="function"><span class="keyword">def</span> <span class="title">trap_signals</span></span></pre></div></div> + + </li> + + + <li id="section-8"> + <div class="annotation"> + + <div class="pilwrap "> + <a class="pilcrow" href="#section-8">¶</a> + </div> + <p>The QUIT signal triggers a graceful shutdown. The master shuts down +immediately and lets each worker finish the request they are currently +processing.</p> + + </div> + + <div class="content"><div class='highlight'><pre> trap(<span class="symbol">:QUIT</span>) <span class="keyword">do</span> + verbose <span class="string">"Received QUIT"</span> + + kill_workers(<span class="symbol">:QUIT</span>) + exit + <span class="keyword">end</span> + + trap(<span class="symbol">:CHLD</span>) <span class="keyword">do</span> + dead_worker = <span class="constant">Process</span>.wait + <span class="variable">@worker_pids</span>.delete(dead_worker) + + <span class="variable">@worker_pids</span>.each <span class="keyword">do</span> |wpid| + <span class="keyword">begin</span> + dead_worker = <span class="constant">Process</span>.waitpid(wpid, <span class="constant">Process::WNOHANG</span>) + <span class="variable">@worker_pids</span>.delete(dead_worker) + <span class="keyword">rescue</span> <span class="constant">Errno::ECHILD</span> + <span class="keyword">end</span> + <span class="keyword">end</span> + + spawn_worker + <span class="keyword">end</span> + <span class="keyword">end</span> + + <span class="function"><span class="keyword">def</span> <span class="title">kill_workers</span><span class="params">(sig)</span></span> + <span class="variable">@worker_pids</span>.each <span class="keyword">do</span> |wpid| + <span class="constant">Process</span>.kill(sig, wpid) + <span class="keyword">end</span> + <span class="keyword">end</span> + + <span class="function"><span class="keyword">def</span> <span class="title">load_app</span></span> + <span class="variable">@app</span>, options = <span class="constant">Rack::Builder</span>.parse_file(<span class="constant">Config</span>.config_ru_path) + <span class="keyword">end</span> + <span class="keyword">end</span> +<span class="keyword">end</span></pre></div></div> + + </li> + + </ul> + </div> +</body> +</html> |