[HAMA-971] An increment to a volatile field isn't atomic

• Type: Bug
• Status: Patch Available
• Priority: Minor
• Resolution: Unresolved
• Component/s: bsp core
• Assignee: Unassigned
• Reporter: JongYoon Lim
• Created: 28/Aug/15 08:47
• Updated: 10/Sep/15 07:38

Description

I found a defect from FindBugs Analysis.

// AsyncRcvdMsgCheckpointImpl.java
volatile private long checkpointMessageCount;
...
++checkpointMessageCount;

// Server.java
private volatile int rpcCount = 0; // number of outstanding rpcs
...
rpcCount--;
rpcCount++;

This code increments a volatile field. Increments of volatile fields aren't atomic. If more than one thread is incrementing the field at the same time, increments could be lost.

I think AtomicInteger and AtomicLong can be used instead of volatile fields.