Fix locking in ReflectionComposablePart.ImportsCache (#103660)

omajid · web-flow · commit 2fc073f9ca3d · 2024-06-18T21:45:36.000-07:00
The second check needs to use the value from the field (to see updates made by other threads), not the local variable. Fixes: #103650
diff --git a/src/libraries/System.ComponentModel.Composition/src/System/ComponentModel/Composition/ReflectionModel/ReflectionComposablePart.cs b/src/libraries/System.ComponentModel.Composition/src/System/ComponentModel/Composition/ReflectionModel/ReflectionComposablePart.cs
@@ -87,6 +87,7 @@ private Dictionary<ImportDefinition, ImportingItem> ImportsCache
                 {
                     lock (_lock)
                     {
+                        value = _importsCache;
                         if (value == null)
                         {
                             value = new Dictionary<ImportDefinition, ImportingItem>();

Original file line number	Diff line number	Diff line change
`@@ -87,6 +87,7 @@ private Dictionary<ImportDefinition, ImportingItem> ImportsCache`
`87`	`87`	`{`
`88`	`88`	`lock (_lock)`
`89`	`89`	`{`
	`90`	`+ value = _importsCache;`
`90`	`91`	`if (value == null)`
`91`	`92`	`{`
`92`	`93`	`value = new Dictionary<ImportDefinition, ImportingItem>();`