From 3e25f7fd1a842ed48518ef310fe80d0e9f5cfafa Mon Sep 17 00:00:00 2001
From: "rick.parker" <rick.parker@r3cev.com>
Date: Fri, 25 Nov 2022 09:31:41 +0000
Subject: [PATCH] ENT-8817 OS port of compute deadlock changes

---
 .../net/corda/node/utilities/InfrequentlyMutatedCache.kt   | 7 +++++--
 .../corda/node/utilities/InfrequentlyMutatedCacheTest.kt   | 5 +++++
 2 files changed, 10 insertions(+), 2 deletions(-)

diff --git a/node/src/main/kotlin/net/corda/node/utilities/InfrequentlyMutatedCache.kt b/node/src/main/kotlin/net/corda/node/utilities/InfrequentlyMutatedCache.kt
index 9f9698164f..4121a92cb9 100644
--- a/node/src/main/kotlin/net/corda/node/utilities/InfrequentlyMutatedCache.kt
+++ b/node/src/main/kotlin/net/corda/node/utilities/InfrequentlyMutatedCache.kt
@@ -73,7 +73,7 @@ class InfrequentlyMutatedCache<K : Any, V : Any>(name: String, cacheFactory: Nam
         backingCache.invalidateAll()
     }
 
-    private fun invalidate(key: K, value: Wrapper.Invalidated<V>): Wrapper.Invalidated<V> {
+    private fun invalidate(key: K, value: Wrapper.Invalidated<V>): Wrapper.Invalidated<V>? {
         val tx = contextTransactionOrNull
         value.invalidators.incrementAndGet()
         currentlyInvalid[key] = value
@@ -81,7 +81,10 @@ class InfrequentlyMutatedCache<K : Any, V : Any>(name: String, cacheFactory: Nam
             // When we close, we can't start using caching again until all simultaneously open transactions are closed.
             tx.onClose { tx.database.onAllOpenTransactionsClosed { decrementInvalidators(key, value) } }
         } else {
-            decrementInvalidators(key, value)
+            if (value.invalidators.decrementAndGet() == 0) {
+                currentlyInvalid.remove(key)
+                return null
+            }
         }
         return value
     }
diff --git a/node/src/test/kotlin/net/corda/node/utilities/InfrequentlyMutatedCacheTest.kt b/node/src/test/kotlin/net/corda/node/utilities/InfrequentlyMutatedCacheTest.kt
index fab9b1d7be..bfc6a377f6 100644
--- a/node/src/test/kotlin/net/corda/node/utilities/InfrequentlyMutatedCacheTest.kt
+++ b/node/src/test/kotlin/net/corda/node/utilities/InfrequentlyMutatedCacheTest.kt
@@ -25,6 +25,11 @@ class InfrequentlyMutatedCacheTest {
         database.close()
     }
 
+    @Test(timeout = 300_000)
+    fun `invalidate outside transaction should not hang`() {
+        cache.invalidate("Fred")
+    }
+
     @Test(timeout=300_000)
 	fun `get from empty cache returns result of loader`() {
         database.transaction {