Delayed cron runs

Bumping to current version, because this is still current.

Adding a setting to make poormanscron only fire on authenticated sessions might be interesting for some sites where the site admin/team is often online, but might be inappropriate for "publish" sites, which receive mostly anonymous visitors, which are served pages from cache.

Going further, 5.0 agressive caching is already incompatible with the module anyway.

What do oyther think of this ?

Something I implemented on 5.0. 5.0 has stuff that uses Curl. Curl gives a way to quickly return to the user. If you are already using Curl then the Curl part of this approach will work. The second part is an alternative for occasions when Curl is not available. I created the second part then added the first part without bothering to delete the second part.

1/ Rename poormanscron_exit to poormanscron_exit_process then add the following new poormanscron_exit followed by the extra menu entry.

poormanscron_exit will start poormanscron_exit_process as another page request and wait only for the header. Curl is instructed, by the NOBODY option, to get only the header which means Curl should get a status code of 200 immediately the headers are sent and return to poormanscron_exit.

I use this on a site where Drupal is running from the base directory, not from a subdirectory and am not using multisite.

2/
The test for $_REQUEST['form_id'] should bypass poormanscron whenever the processing is within pages that pass forms information the the next page. If the Curl stuff is not usable then the check for form_id will take care of some problems with slow responses at the wrong time. You could add in other checks to exclude occasions where you are within items called from Ajax.

function poormanscron_exit() {
/* From PeterMoulding.com.
1/ Remove Poormanscron processing from page end.
2/ Stop Poormanscron during forms processing.
*/
	if(arg(0) == 'poormanscron' // Do not process when within process.
	or isset($_REQUEST['form_id'])) // Do not process when within forms handling process.
		{
		return;
		}
	$url = 'http://' . $_SERVER['HTTP_HOST'] . '/poormanscron';
	$curly = curl_init($url);
	curl_setopt($curly, CURLOPT_NOBODY, true);
	curl_setopt($curly, CURLOPT_RETURNTRANSFER, true);
	$result = curl_exec($curly);
	if($result)
		{
		watchdog('cron', 'poormanscron_exit-process: process started successfully.', WATCHDOG_NOTICE);
		}
	else
		{
		watchdog('cron', 'poormanscron_exit-process: process failed: '
			. curl_errno($curly). ': ' . curl_error($curly), WATCHDOG_NOTICE);
		}
	curl_close($curly);
	}

/* From PeterMoulding.com.
2/ Stop Poormanscron during forms processing.
*/
		$items[] = array('path' => 'poormanscron',
			'title' => t('Cronline module'),
			'callback' => 'poormanscron_exit_process',
			'access' => user_access('access content'),
			'type' => MENU_CALLBACK);

Not much point in Curling if it is not time so add the following check after the check of arg(0) and for form_id.

	// Calculate when the next poormanscron run is due.
	$lastrun = variable_get('poormanscron_lastrun', 0);
	$nextrun = $lastrun + 60 * variable_get('poormanscron_interval', 60);
	// If it is not yet time, do not start the next poormanscron run.
	if(time() < $nextrun)
		{
		return;
		}

Did you already try to register drupal_run_cron() as a shutdown function?
http://php.net/manual/en/function.register-shutdown-function.php

Of course, drupal_run_cron() is related to #119094: Use drupal_cron_run() (fixes FeedAPI compatibility problem and multiple simultaneous runs)

Will be fixed with #589438: PoormansCron: The Next Generation.