From f3533551c3a7e3a08239fee25f55de7cdcb81d70 Mon Sep 17 00:00:00 2001
From: Arndt Kaiser <42686074+madmajestro@users.noreply.github.com>
Date: Fri, 7 Mar 2025 19:06:54 +0100
Subject: [PATCH] Cleanup of entries should not be skipped when using default
 settings

By default (apc.smart = 0), apc_cache_default_expunge() should not skip
cleanup of old entries. This may cause insertion of new entries to
fail unnecessarily, which is unexpected behavior.
---
 apc_cache.c | 52 +++++++++++++++++++++++-----------------------------
 1 file changed, 23 insertions(+), 29 deletions(-)

diff --git a/apc_cache.c b/apc_cache.c
index 3544c097..9652a03d 100644
--- a/apc_cache.c
+++ b/apc_cache.c
@@ -735,8 +735,7 @@ PHP_APCU_API void apc_cache_clear(apc_cache_t* cache)
 PHP_APCU_API void apc_cache_default_expunge(apc_cache_t* cache, size_t size)
 {
 	time_t t;
-	size_t suitable = 0L;
-	size_t available = 0L;
+	size_t i;
 
 	if (!cache) {
 		return;
@@ -751,43 +750,38 @@ PHP_APCU_API void apc_cache_default_expunge(apc_cache_t* cache, size_t size)
 		return;
 	}
 
-	/* make suitable selection */
-	suitable = (cache->smart > 0L) ? (size_t) (cache->smart * size) : (size_t) (cache->sma->size/2);
-
 	/* gc */
 	apc_cache_wlocked_gc(cache);
 
-	/* get available */
-	available = apc_sma_get_avail_mem(cache->sma);
-
 	/* check that expunge is necessary */
-	if (available < suitable) {
-		size_t i;
-
-		/* look for junk */
-		for (i = 0; i < cache->nslots; i++) {
-			apc_cache_entry_t **entry = &cache->slots[i];
-			while (*entry) {
-				if (apc_cache_entry_expired(cache, *entry, t)) {
-					apc_cache_wlocked_remove_entry(cache, entry);
-					continue;
-				}
+	if (cache->smart > 0L && apc_sma_get_avail_mem(cache->sma) >= (size_t) (cache->smart * size)) {
+		apc_cache_wunlock(cache);
+		return;
+	}
 
-				/* grab next entry */
-				entry = &(*entry)->next;
+	/* look for junk */
+	for (i = 0; i < cache->nslots; i++) {
+		apc_cache_entry_t **entry = &cache->slots[i];
+		while (*entry) {
+			if (apc_cache_entry_expired(cache, *entry, t)) {
+				apc_cache_wlocked_remove_entry(cache, entry);
+				continue;
 			}
-		}
 
-		/* if the cache now has space, then reset last key */
-		if (apc_sma_get_avail_size(cache->sma, size)) {
-			/* wipe lastkey */
-			memset(&cache->header->lastkey, 0, sizeof(apc_cache_slam_key_t));
-		} else {
-			/* with not enough space left in cache, we are forced to expunge */
-			apc_cache_wlocked_real_expunge(cache);
+			/* grab next entry */
+			entry = &(*entry)->next;
 		}
 	}
 
+	/* if the cache now has space, then reset last key */
+	if (apc_sma_get_avail_size(cache->sma, size)) {
+		/* wipe lastkey */
+		memset(&cache->header->lastkey, 0, sizeof(apc_cache_slam_key_t));
+	} else {
+		/* with not enough space left in cache, we are forced to expunge */
+		apc_cache_wlocked_real_expunge(cache);
+	}
+
 	apc_cache_wunlock(cache);
 }
 /* }}} */