jenkins-bot has submitted this change and it was merged.
Change subject: Cleanups to WANObjectCache::getWithSetCallback code
......................................................................
Cleanups to WANObjectCache::getWithSetCallback code
* Do not use lock() for tombstoned keys unless lockTSE was set
* Moved the is_callable() check down a bit further
* Also removed one inaccurate comment
Change-Id: I904e0681faa48b1dc2bc2a3c005a29d2f8347065
---
M includes/libs/objectcache/WANObjectCache.php
1 file changed, 16 insertions(+), 14 deletions(-)
Approvals:
Gilles: Looks good to me, approved
jenkins-bot: Verified
diff --git a/includes/libs/objectcache/WANObjectCache.php
b/includes/libs/objectcache/WANObjectCache.php
index 8d202c7..6ec7e48 100755
--- a/includes/libs/objectcache/WANObjectCache.php
+++ b/includes/libs/objectcache/WANObjectCache.php
@@ -404,16 +404,12 @@
return $value;
}
- if ( !is_callable( $callback ) ) {
- throw new InvalidArgumentException( "Invalid cache miss
callback provided." );
- }
-
+ $isTombstone = ( $curTTL !== null && $value === false );
// Assume a key is hot if requested soon after invalidation
$isHot = ( $curTTL !== null && $curTTL <= 0 && abs( $curTTL )
<= $lockTSE );
- $isTombstone = ( $curTTL !== null && $value === false );
$locked = false;
- if ( $isHot || $isTombstone ) {
+ if ( $isHot ) {
// Acquire a cluster-local non-blocking lock
if ( $this->cache->lock( $key, 0, self::LOCK_TTL ) ) {
// Lock acquired; this thread should update the
key
@@ -421,17 +417,23 @@
} elseif ( $value !== false ) {
// If it cannot be acquired; then the stale
value can be used
return $value;
- } else {
- // Either another thread has the lock or the
lock failed.
- // Use the stash value, which is likely from
the prior thread.
- $value = $this->cache->get(
self::STASH_KEY_PREFIX . $key );
- // Regenerate on timeout or if the other thread
failed
- if ( $value !== false ) {
- return $value;
- }
}
}
+ if ( !$locked && ( $isTombstone || $isHot ) ) {
+ // Use the stash value for tombstoned keys to reduce
regeneration load.
+ // For hot keys, either another thread has the lock or
the lock failed;
+ // use the stash value from the last thread that
regenerated it.
+ $value = $this->cache->get( self::STASH_KEY_PREFIX .
$key );
+ if ( $value !== false ) {
+ return $value;
+ }
+ }
+
+ if ( !is_callable( $callback ) ) {
+ throw new InvalidArgumentException( "Invalid cache miss
callback provided." );
+ }
+
// Generate the new value from the callback...
$value = call_user_func_array( $callback, array( $cValue, &$ttl
) );
// When delete() is called, writes are write-holed by the
tombstone,
--
To view, visit https://gerrit.wikimedia.org/r/211082
To unsubscribe, visit https://gerrit.wikimedia.org/r/settings
Gerrit-MessageType: merged
Gerrit-Change-Id: I904e0681faa48b1dc2bc2a3c005a29d2f8347065
Gerrit-PatchSet: 2
Gerrit-Project: mediawiki/core
Gerrit-Branch: master
Gerrit-Owner: Aaron Schulz <asch...@wikimedia.org>
Gerrit-Reviewer: Gilles <gdu...@wikimedia.org>
Gerrit-Reviewer: jenkins-bot <>
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