From 481cd708acfd3291eed7eba6af596c541651963c Mon Sep 17 00:00:00 2001
From: Friendika <info@friendika.com>
Date: Thu, 30 Jun 2011 21:56:07 -0700
Subject: [PATCH] allow polling to mostly survive minor memory shortages.

---
 addon/facebook/facebook.php | 10 ++++++++--
 boot.php                    | 12 ++++++++++++
 include/poller.php          | 32 +++++++++++++++++++++++++++++---
 3 files changed, 49 insertions(+), 5 deletions(-)

diff --git a/addon/facebook/facebook.php b/addon/facebook/facebook.php
index 49f1938043..c54d5b5f09 100644
--- a/addon/facebook/facebook.php
+++ b/addon/facebook/facebook.php
@@ -376,9 +376,12 @@ function facebook_cron($a,$b) {
 
 	logger('facebook_cron');
 
-	set_config('facebook','last_poll', time());
 
-	$r = q("SELECT * FROM `pconfig` WHERE `cat` = 'facebook' AND `k` = 'post' AND `v` = '1' ");
+	// Find the FB users on this site and randomize in case one of them
+	// uses an obscene amount of memory. It may kill this queue run
+	// but hopefully we'll get a few others through on each run. 
+
+	$r = q("SELECT * FROM `pconfig` WHERE `cat` = 'facebook' AND `k` = 'post' AND `v` = '1' ORDER BY RAND() ");
 	if(count($r)) {
 		foreach($r as $rr) {
 			// check for new friends once a day
@@ -392,6 +395,9 @@ function facebook_cron($a,$b) {
 			fb_consume_all($rr['uid']);
 		}
 	}	
+
+	set_config('facebook','last_poll', time());
+
 }
 
 
diff --git a/boot.php b/boot.php
index 27c801923f..b81bd9cfc7 100644
--- a/boot.php
+++ b/boot.php
@@ -2908,3 +2908,15 @@ function get_plugin_info($plugin){
 	}
 	return $info;
 }}
+
+if(! function_exists('return_bytes')) {
+function return_bytes ($size_str) {
+    switch (substr ($size_str, -1))
+    {
+        case 'M': case 'm': return (int)$size_str * 1048576;
+        case 'K': case 'k': return (int)$size_str * 1024;
+        case 'G': case 'g': return (int)$size_str * 1073741824;
+        default: return $size_str;
+    }
+}}
+
diff --git a/include/poller.php b/include/poller.php
index 4cab5a3b83..666748cbc0 100644
--- a/include/poller.php
+++ b/include/poller.php
@@ -2,6 +2,7 @@
 
 require_once("boot.php");
 
+
 function poller_run($argv, $argc){
 	global $a, $db;
 
@@ -47,18 +48,26 @@ function poller_run($argv, $argc){
 		proc_run('php','include/expire.php');
 	}
 
-
 	// clear old cache
 	q("DELETE FROM `cache` WHERE `updated` < '%s'",
 		dbesc(datetime_convert('UTC','UTC',"now - 30 days")));
 
 	$manual_id  = 0;
+	$generation = 0;
 	$hub_update = false;
 	$force      = false;
+	$restart    = false;
 
 	if(($argc > 1) && ($argv[1] == 'force'))
 		$force = true;
 
+	if(($argc > 1) && ($argv[1] == 'restart')) {
+		$restart = true;
+		$generation = intval($argv[2]);
+		if(! $generation)
+			killme();		
+	}
+
 	if(($argc > 1) && intval($argv[1])) {
 		$manual_id = intval($argv[1]);
 		$force     = true;
@@ -70,7 +79,8 @@ function poller_run($argv, $argc){
 
 	$d = datetime_convert();
 
-	call_hooks('cron', $d);
+	if(! $restart)
+		call_hooks('cron', $d);
 
 
 	$contacts = q("SELECT `id` FROM `contact` 
@@ -95,7 +105,7 @@ function poller_run($argv, $argc){
 			continue;
 
 		foreach($res as $contact) {
-
+			logger('processing a contact');
 			$xml = false;
 
 			if($manual_id)
@@ -154,6 +164,22 @@ function poller_run($argv, $argc){
 					continue;
 			}
 
+			// Check to see if we are running out of memory - if so spawn a new process and kill this one
+
+			$avail_memory = return_bytes(ini_get('memory_limit'));
+			$memused = memory_get_peak_usage(true);
+			if(intval($avail_memory)) {
+				if(($memused / $avail_memory) > 0.95) {
+					if($generation + 1 > 10) {
+						logger('poller: maximum number of spawns exceeded. Terminating.');
+						killme();
+					}
+					logger('poller: memory exceeded. ' . $memused . ' bytes used. Spawning new poll.');
+					proc_run('php', 'include/poller.php', 'restart', (string) $generation + 1);
+					killme();
+				}
+			}
+
 			$importer_uid = $contact['uid'];
 		
 			$r = q("SELECT * FROM `contact` WHERE `uid` = %d AND `self` = 1 LIMIT 1",