GEARMANCLIENT.ADDTASKBACKGROUND(3)					 1					GEARMANCLIENT.ADDTASKBACKGROUND(3)

GearmanClient::addTaskBackground - Add a background task to be run in parallel

SYNOPSIS

       public GearmanTask GearmanClient::addTaskBackground (string  $function_name, string  $workload, [mixed  &$context], [string  $unique])

DESCRIPTION

	Adds  a  background task to be run in parallel with other tasks. Call this method for all the tasks to be run in parallel, then call Gear-
       manClient::runTasks to perform the work.

PARAMETERS

	      o $function_name
		- A registered function the worker is to execute

	      o $workload
		- Serialized data to be processed

	      o $context
		- Application context to associate with a task

	      o $unique
		- A unique ID used to identify a particular task

RETURN VALUES

	A GearmanTask object or FALSE if the task could not be added.

EXAMPLES

       Example #1

	      Two tasks, one background and one not

	       This example illustrates the difference between running a background task and a normal task. The client adds two tasks  to  execute
	      the  same  function, but one is added with addTaskBackground. A callback is set so that progress of the job can be tracked. A simple
	      worker with an artificial delay reports on the job progress and the client picks this up through the callback. Two workers  are  run
	      for this example. Note that the background task does not show in the client output.

	      <?php

	      # The client script

	      # create our gearman client
	      $gmc= new GearmanClient();

	      # add the default job server
	      $gmc->addServer();

	      # set a couple of callbacks so we can track progress
	      $gmc->setCompleteCallback("reverse_complete");
	      $gmc->setStatusCallback("reverse_status");

	      # add a task for the "reverse" function
	      $task= $gmc->addTask("reverse", "Hello World!", null, "1");

	      # add another task, but this one to run in the background
	      $task= $gmc->addTaskBackground("reverse", "!dlroW olleH", null, "2");

	      if (! $gmc->runTasks())
	      {
		  echo "ERROR " . $gmc->error() . "
";
		  exit;
	      }

	      echo "DONE
";

	      function reverse_status($task)
	      {
		  echo "STATUS: " . $task->unique() . ", " . $task->jobHandle() . " - " . $task->taskNumerator() .
		       "/" . $task->taskDenominator() . "
";
	      }

	      function reverse_complete($task)
	      {
		  echo "COMPLETE: " . $task->unique() . ", " . $task->data() . "
";
	      }

	      ?>

	      <?php

	      # The worker script

	      echo "Starting
";

	      # Create our worker object.
	      $gmworker= new GearmanWorker();

	      # Add default server (localhost).
	      $gmworker->addServer();

	      # Register function "reverse" with the server.
	      $gmworker->addFunction("reverse", "reverse_fn");

	      print "Waiting for job...
";
	      while($gmworker->work())
	      {
		if ($gmworker->returnCode() != GEARMAN_SUCCESS)
		{
		  echo "return_code: " . $gmworker->returnCode() . "
";
		  break;
		}
	      }

	      function reverse_fn($job)
	      {
		echo "Received job: " . $job->handle() . "
";

		$workload = $job->workload();
		$workload_size = $job->workloadSize();

		echo "Workload: $workload ($workload_size)
";

		# This status loop is not needed, just showing how it works
		for ($x= 0; $x < $workload_size; $x++)
		{
		  echo "Sending status: " . ($x + 1) . "/$workload_size complete
";
		  $job->sendStatus($x+1, $workload_size);
		  $job->sendData(substr($workload, $x, 1));
		  sleep(1);
		}

		$result= strrev($workload);
		echo "Result: $result
";

		# Return what we want to send back to the client.
		return $result;
	      }

	      ?>

	       Worker output for two workers running:

	      Received job: H:foo.local:65
	      Workload: !dlroW olleH (12)
	      1/12 complete
	      Received job: H:foo.local:66
	      Workload: Hello World! (12)
	      Sending status: 1/12 complete
	      Sending status: 2/12 complete
	      Sending status: 2/12 complete
	      Sending status: 3/12 complete
	      Sending status: 3/12 complete
	      Sending status: 4/12 complete
	      Sending status: 4/12 complete
	      Sending status: 5/12 complete
	      Sending status: 5/12 complete
	      Sending status: 6/12 complete
	      Sending status: 6/12 complete
	      Sending status: 7/12 complete
	      Sending status: 7/12 complete
	      Sending status: 8/12 complete
	      Sending status: 8/12 complete
	      Sending status: 9/12 complete
	      Sending status: 9/12 complete
	      Sending status: 10/12 complete
	      Sending status: 10/12 complete
	      Sending status: 11/12 complete
	      Sending status: 11/12 complete
	      Sending status: 12/12 complete
	      Sending status: 12/12 complete
	      Result: !dlroW olleH
	      Result: Hello World!

	       Client output:

	      STATUS: 1, H:foo.local:66 - 1/12
	      STATUS: 1, H:foo.local:66 - 2/12
	      STATUS: 1, H:foo.local:66 - 3/12
	      STATUS: 1, H:foo.local:66 - 4/12
	      STATUS: 1, H:foo.local:66 - 5/12
	      STATUS: 1, H:foo.local:66 - 6/12
	      STATUS: 1, H:foo.local:66 - 7/12
	      STATUS: 1, H:foo.local:66 - 8/12
	      STATUS: 1, H:foo.local:66 - 9/12
	      STATUS: 1, H:foo.local:66 - 10/12
	      STATUS: 1, H:foo.local:66 - 11/12
	      STATUS: 1, H:foo.local:66 - 12/12
	      COMPLETE: 1, !dlroW olleH
	      DONE

SEE ALSO

       GearmanClient::addTask,	   GearmanClient::addTaskHigh,	   GearmanClient::addTaskLow,	 GearmanClient::addTaskHighBackground,	  Gearman-
       Client::addTaskLowBackground, GearmanClient::runTasks.

PHP Documentation Group 											GEARMANCLIENT.ADDTASKBACKGROUND(3)