GearmanClient::doBackground

(PECL gearman >= 0.5.0)

GearmanClient::doBackground — Run a task in the background

说明

public GearmanClient::doBackground ( string $function_name , string $workload , string $unique = ? ) : string

Runs a task in the background, returning a job handle which can be used to get the status of the running task.

参数

function_name: 由程序自动执行的已注册函数。
workload: 被处理的序列化数据。
unique: 用于标识特定任务的唯一性 ID。

返回值

The job handle for the submitted task.

范例

Example #1 Submit and monitor a background job

The worker in this example has an artificial delay introduced to mimic a long running job. The client script periodically checks the status of the running job.


<?php

/* create our object */
$gmclient= new GearmanClient();

/* add the default server */
$gmclient->addServer();

/* run reverse client */
$job_handle = $gmclient->doBackground("reverse", "this is a test");

if ($gmclient->returnCode() != GEARMAN_SUCCESS)
{
  echo "bad return code\n";
  exit;
}

$done = false;
do
{
   sleep(3);
   $stat = $gmclient->jobStatus($job_handle);
   if (!$stat[0]) // the job is known so it is not done
      $done = true;
   echo "Running: " . ($stat[1] ? "true" : "false") . ", numerator: " . $stat[2] . ", denominator: " . $stat[3] . "\n";
}
while(!$done);

echo "done!\n";

?>

以上例程的输出类似于：

Running: true, numerator: 3, denominator: 14
Running: true, numerator: 6, denominator: 14
Running: true, numerator: 9, denominator: 14
Running: true, numerator: 12, denominator: 14
Running: false, numerator: 0, denominator: 0
done!

参见

GearmanClient::doNormal() - Run a single task and return a result
GearmanClient::doHigh() - Run a single high priority task
GearmanClient::doLow() - Run a single low priority task
GearmanClient::doHighBackground() - Run a high priority task in the background
GearmanClient::doLowBackground() - Run a low priority task in the background

User Contributed Notes

felix at passcod dot name 18-Aug-2017 01:16


Behaviour of the unique ID argument:



If it's not provided, it defaults to a UUIDv1 (timestamp + mac address).



Otherwise, if a job with the same unique ID exists (i.e. is either queued or currently executing), then that job is used, not the one you're submitting. This does not apply to past (completed) jobs, and works across the entire job server pool, assuming no partitioning.



Or with code (the values in [brackets] are the server-assigned job identifiers):



<?php



$gearman->doBackground('sleep', '3', '123'); // [H:host:1] Starts sleep(3)

$gearman->doBackground('sleep', '5', '456'); // [H:host:2] Queues sleep(5)

$gearman->doBackground('sleep', '3', '123'); // [H:host:1] Does nothing

$gearman->doBackground('sleep', '1', '123'); // [H:host:1] Also does nothing (diff args don't trigger new jobs)



sleep (3);

// Job 123 [sleep(3)] has finished by now



$gearman->doBackground('sleep', '3', '123'); // [H:host:3] Starts a new job



?>