[RATIS-1163] RefCountingMap is not thread-safe

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Component/s: metrics
• Assignee: Tsz-wo Sze
• Reporter: Tsz-wo Sze
• Created: 18/Nov/20 08:44
• Updated: 18/Nov/20 23:44
• Resolved: 18/Nov/20 23:44

Description

• The refCount field in RefCountingMap.Payload is not thread-safe.

  //RefCountingMap.Payload
      private int refCount;
  

• Also, there are a few javac warnings in ratis-metrics.

  [WARNING] /Users/tszwosze/ratis/apache-ratis/ratis-metrics/src/main/java/org/apache/ratis/metrics/impl/RefCountingMap.java:[51,15] [unchecked] unchecked call to Payload(V) as a member of the raw type Payload
    where V is a type-variable:
      V extends Object declared in class Payload
  [WARNING] /Users/tszwosze/ratis/apache-ratis/ratis-metrics/src/main/java/org/apache/ratis/metrics/impl/RefCountingMap.java:[46,35] [unchecked] unchecked method invocation: method compute in class ConcurrentHashMap is applied to given types
    required: K#1,BiFunction<? super K#1,? super V#1,? extends V#1>
    found: K#2,BiFunction<K#2,Payload<V#2>,Payload<V#2>>
    where K#1,V#1,K#2,V#2 are type-variables:
      K#1 extends Object declared in class ConcurrentHashMap
      V#1 extends Object declared in class ConcurrentHashMap
      K#2 extends Object declared in class RefCountingMap
      V#2 extends Object declared in class RefCountingMap
  [WARNING] /Users/tszwosze/ratis/apache-ratis/ratis-metrics/src/main/java/org/apache/ratis/metrics/impl/RefCountingMap.java:[46,35] [unchecked] unchecked cast
    required: Payload<V>
    found:    Payload
    where V is a type-variable:
      V extends Object declared in class RefCountingMap
  [WARNING] /Users/tszwosze/ratis/apache-ratis/ratis-metrics/src/main/java/org/apache/ratis/metrics/MetricRegistriesLoader.java:[68,81] [unchecked] unchecked cast
    required: Class<MetricRegistries>
    found:    Class<CAP#1>
    where CAP#1 is a fresh type-variable:
      CAP#1 extends Object from capture of ?
  [INFO] 
  

Issue Links

• links to: GitHub Pull Request #285