* Refactored the forking code from runJobs.php to a new class called ForkController. Implemented the same sort of forking in gearmanWorker.php.

* Fixed debugging code left in in gearmanRefreshLinks.php

1 files changed, 103 insertions, 0 deletions

diff --git a/includes/ForkController.php b/includes/ForkController.php
new file mode 100644
index 000000000000..689b9c8de294
--- /dev/null
+++ b/includes/ForkController.php
@@ -0,0 +1,103 @@
+<?php
+
+/**
+ * Class for managing forking command line scripts.
+ * Currently just does forking and process control, but it could easily be extended 
+ * to provide IPC and job dispatch.
+ */
+class ForkController {
+	var $children = array();
+	var $termReceived = false;
+
+	public function __construct() {
+		if ( php_sapi_name() != 'cli' ) {
+			throw new MWException( "MultiProcess cannot be used from the web." );
+		}
+	}
+
+	protected function prepareEnvironment() {
+		global $wgCaches, $wgMemc;
+		// Don't share DB or memcached connections
+		wfGetLBFactory()->destroyInstance();
+		$wgCaches = array();
+		unset( $wgMemc );
+	}
+
+	/**
+	 * Fork a number of worker processes.
+	 *
+	 * This should only be called from the command line. It should be called 
+	 * as early as possible during execution. It will return 'child' in the 
+	 * child processes and 'parent' in the parent process. The parent process
+	 * should then call monitor(). 
+	 *
+	 * This function requires the posix and pcntl extensions.
+	 */
+	public function forkWorkers( $numProcs ) {
+		global $wgMemc, $wgCaches, $wgMainCacheType;
+	
+		$this->prepareEnvironment();
+
+		// Create the child processes
+		for ( $i = 0; $i < $numProcs; $i++ ) {
+			// Do the fork
+			$pid = pcntl_fork();
+			if ( $pid === -1 || $pid === false ) {
+				echo "Error creating child processes\n";
+				exit( 1 );
+			}
+
+			if ( !$pid ) {
+				$this->initChild();
+				$this->children = null;
+				return 'child';
+			} else {
+				// This is the parent process
+				$this->children[$pid] = true;
+			}
+		}
+
+		return 'parent';
+	}
+
+	/**
+	 * The parent process main loop
+	 */
+	public function runParent() {
+		// Trap SIGTERM
+		pcntl_signal( SIGTERM, array( $this, 'handleTermSignal' ), false );
+
+		do {
+			$status = false;
+			$deadPid = pcntl_wait( $status );
+
+			if ( $deadPid > 0 ) {
+				unset( $this->children[$deadPid] );
+			}
+
+			// Run signal handlers
+			if ( function_exists( 'pcntl_signal_dispatch' ) ) {
+				pcntl_signal_dispatch();
+			} else {
+				declare (ticks=1) { $status = $status; } 
+			}
+			// Respond to TERM signal
+			if ( $this->termReceived ) {
+				foreach ( $this->children as $childPid => $unused ) {
+					posix_kill( $childPid, SIGTERM );
+				}
+				$this->termReceived = false;
+			}
+		} while ( count( $this->children ) );
+		pcntl_signal( SIGTERM, SIG_DFL );
+	}
+
+	protected function initChild() {
+		global $wgMemc, $wgMainCacheType;
+		$wgMemc = wfGetCache( $wgMainCacheType );
+	}
+
+	protected function handleTermSignal( $signal ) {
+		$this->termReceived = true;
+	}
+}