reduce lock in disklayer (#447)

* Don't block all write access to all buckets when doing GatherReferences/CollectGarbage

1 files changed, 22 insertions, 10 deletions

diff --git a/src/zenserver/cache/cachedisklayer.cpp b/src/zenserver/cache/cachedisklayer.cpp
index 7ce713de9..fafc6bbee 100644
--- a/src/zenserver/cache/cachedisklayer.cpp
+++ b/src/zenserver/cache/cachedisklayer.cpp
@@ -1805,12 +1805,18 @@ ZenCacheDiskLayer::CollectGarbage(GcContext& GcCtx)
 {
 	ZEN_TRACE_CPU("Z$::Disk::CollectGarbage");
 
-	RwLock::SharedLockScope _(m_Lock);
-
-	for (auto& Kv : m_Buckets)
+	std::vector<CacheBucket*> Buckets;
+	{
+		RwLock::SharedLockScope _(m_Lock);
+		Buckets.reserve(m_Buckets.size());
+		for (auto& Kv : m_Buckets)
+		{
+			Buckets.push_back(Kv.second.get());
+		}
+	}
+	for (CacheBucket* Bucket : Buckets)
 	{
-		CacheBucket& Bucket = *Kv.second;
-		Bucket.CollectGarbage(GcCtx);
+		Bucket->CollectGarbage(GcCtx);
 	}
 }
 
@@ -2261,12 +2267,18 @@ ZenCacheDiskLayer::GatherReferences(GcContext& GcCtx)
 {
 	ZEN_TRACE_CPU("Z$::Disk::GatherReferences");
 
-	RwLock::SharedLockScope _(m_Lock);
-
-	for (auto& Kv : m_Buckets)
+	std::vector<CacheBucket*> Buckets;
+	{
+		RwLock::SharedLockScope _(m_Lock);
+		Buckets.reserve(m_Buckets.size());
+		for (auto& Kv : m_Buckets)
+		{
+			Buckets.push_back(Kv.second.get());
+		}
+	}
+	for (CacheBucket* Bucket : Buckets)
 	{
-		CacheBucket& Bucket = *Kv.second;
-		Bucket.GatherReferences(GcCtx);
+		Bucket->GatherReferences(GcCtx);
 	}
 }