From 01ea7722553c2632ddc90e9233d53d277f3559e2 Mon Sep 17 00:00:00 2001
From: Brian Quinion <openstreetmap@brian.quinion.co.uk>
Date: Mon, 10 Dec 2012 01:36:33 +0000
Subject: [PATCH] restrict to one sleep per bucket.  A second sleep while
 already sleeping results in a block.

---
 lib/init-website.php |  5 ++++-
 lib/leakybucket.php  | 33 ++++++++++++++++++++++++++++++++-
 utils/blocks.php     |  8 ++++----
 3 files changed, 40 insertions(+), 6 deletions(-)

diff --git a/lib/init-website.php b/lib/init-website.php
index 445bbc7c..8603e309 100644
--- a/lib/init-website.php
+++ b/lib/init-website.php
@@ -26,15 +26,17 @@
 			$m->add('sleepCounter', 0);
 			$iCurrentSleeping = $m->increment('sleepCounter');
 		}
-		if ($iCurrentSleeping >= CONST_ConnectionBucket_MaxSleeping)
+		if ($iCurrentSleeping >= CONST_ConnectionBucket_MaxSleeping || isBucketSleeping($aBucketKeys))
 		{
 			// Too many threads sleeping already.  This becomes a hard block.
 			$fBucketVal = doBucket($aBucketKeys, CONST_ConnectionBucket_BlockLimit, CONST_ConnectionBucket_LeakRate, CONST_ConnectionBucket_BlockLimit);
 		}
 		else
 		{
+			setBucketSleeping($aBucketKeys, true);
 			sleep(($fBucketVal - CONST_ConnectionBucket_WaitLimit)/CONST_ConnectionBucket_LeakRate);
 			$fBucketVal = doBucket($aBucketKeys, CONST_ConnectionBucket_LeakRate, CONST_ConnectionBucket_LeakRate, CONST_ConnectionBucket_BlockLimit);
+			setBucketSleeping($aBucketKeys, false);
 		}
 		$m->decrement('sleepCounter');
 	}
@@ -48,3 +50,4 @@
 	}
 
 	header('Content-type: text/html; charset=utf-8');
+
diff --git a/lib/leakybucket.php b/lib/leakybucket.php
index 778fe580..6d4e8f29 100644
--- a/lib/leakybucket.php
+++ b/lib/leakybucket.php
@@ -26,7 +26,7 @@
 		        $aCurrentBlock = $m->get($sKey);
 	        	if (!$aCurrentBlock)
 			{
-		                $aCurrentBlock = array($iRequestCost, $t);
+		                $aCurrentBlock = array($iRequestCost, $t, false);
         		}
 			else
 			{
@@ -87,6 +87,36 @@
 		return $iMaxVal;
         }
 
+	function isBucketSleeping($asKey)
+	{
+	        $m = getBucketMemcache();
+		if (!$m) return false;
+
+		foreach($asKey as $sKey)
+		{
+		        $aCurrentBlock = $m->get($sKey);
+			if ($aCurrentBlock[2]) return true;
+		}
+		return false;
+	}
+
+	function setBucketSleeping($asKey, $bVal)
+	{
+	        $m = getBucketMemcache();
+		if (!$m) return false;
+
+		$iMaxVal = 0;
+	        $t = time();
+
+		foreach($asKey as $sKey)
+		{
+		        $aCurrentBlock = $m->get($sKey);
+			$aCurrentBlock[2] = $bVal;
+			$m->set($sKey, $aCurrentBlock, $t + 1 + $aCurrentBlock[0]/CONST_ConnectionBucket_LeakRate);
+		}
+		return true;
+	}
+
 	function byValue1($a, $b)
 	{
 		if ($a[1] == $b[1])
@@ -120,6 +150,7 @@
 			$aBlockedList[$sKey] = array(
 				'totalBlocks' => $aDetails[0],
 				'lastBlockTimestamp' => $aDetails[1],
+				'isSleeping' => (isset($aCurrentBlock[2])?$aCurrentBlock[2]:false),
 				'currentBucketSize' => $iCurrentBucketSize,
 				'currentlyBlocked' => $iCurrentBucketSize + (CONST_ConnectionBucket_Cost_Reverse) >= CONST_ConnectionBucket_BlockLimit,
 				);
diff --git a/utils/blocks.php b/utils/blocks.php
index 6dee2845..bd5efd00 100755
--- a/utils/blocks.php
+++ b/utils/blocks.php
@@ -29,13 +29,13 @@
 
 		$aBlocks = getBucketBlocks();
 		echo "\n";
-		printf(" %-40s | %12s | %7s | %13s | %31s\n", "Key", "Total Blocks", "Current", "Still Blocked", "Last Block Time");
-		printf(" %'--40s-|-%'-12s-|-%'-7s-|-%'-13s-|-%'-31s\n", "", "", "", "", "");
+		printf(" %-40s | %12s | %7s | %13s | %31s | %8s\n", "Key", "Total Blocks", "Current", "Still Blocked", "Last Block Time", "Sleeping");
+		printf(" %'--40s-|-%'-12s-|-%'-7s-|-%'-13s-|-%'-31s-|-%'-8s\n", "", "", "", "", "", "");
 		foreach($aBlocks as $sKey => $aDetails)
 		{
-			printf(" %-40s | %12s | %7s | %13s | %31s\n", $sKey, $aDetails['totalBlocks'], 
+			printf(" %-40s | %12s | %7s | %13s | %31s | %8s\n", $sKey, $aDetails['totalBlocks'], 
 				(int)$aDetails['currentBucketSize'], $aDetails['currentlyBlocked']?'Y':'N', 
-				date("r", $aDetails['lastBlockTimestamp']));
+				date("r", $aDetails['lastBlockTimestamp']), $aDetails['isSleeping']?'Y':'N');
 		}
 		echo "\n";
 	}