[HADOOP-11494] Lock acquisition on WrappedInputStream#unwrappedRpcBuffer may race with another thread

• Type: Bug
• Status: Closed
• Priority: Minor
• Resolution: Fixed
• Fix Version/s: 2.7.0
• Assignee: Ted Yu
• Reporter: Ted Yu
• Created: 20/Jan/15 20:08
• Updated: 24/Apr/15 22:49
• Resolved: 02/Feb/15 18:51

Description

In SaslRpcClient, starting at line 576:

    public int read(byte[] buf, int off, int len) throws IOException {
      synchronized(unwrappedRpcBuffer) {
        // fill the buffer with the next RPC message
        if (unwrappedRpcBuffer.remaining() == 0) {
          readNextRpcPacket();
        }

readNextRpcPacket() may assign another ByteBuffer to unwrappedRpcBuffer, making the lock on previous ByteBuffer not useful.