RFR [9] 8156841: sun.security.pkcs11.SunPKCS11 poller thread retains a strong reference to the context class loader

[Valerie Peng]

Changes look fine.
Thanks,
Valerie

On 8/10/2016 8:42 AM, Chris Hegarty wrote:
> The SunPKCS11 poller thread has no need of any user defined class loader,
> so should set its context class loader to null before starting, so as to not
> inadvertently retain a reference to the creating thread’s context class loader.
>
> In other areas that suffered from a similar issue we changed to use an
> InnocuousThread, but I cannot fully satisfy myself that this is a safe
> substation here, so I opted for the safest minimal fix. A future refactoring
> exercise should consider using InnocuousThread.
>
> diff -r 92c31ec731eb src/jdk.crypto.pkcs11/share/classes/sun/security/pkcs11/SunPKCS11.java
> --- a/src/jdk.crypto.pkcs11/share/classes/sun/security/pkcs11/SunPKCS11.java	Wed Aug 10 11:54:12 2016 +0100
> +++ b/src/jdk.crypto.pkcs11/share/classes/sun/security/pkcs11/SunPKCS11.java	Wed Aug 10 16:32:41 2016 +0100
> @@ -809,20 +809,21 @@
>           }
>       }
>   
>       // create the poller thread, if not already active
>       private void createPoller() {
>           if (poller != null) {
>               return;
>           }
>           final TokenPoller poller = new TokenPoller(this);
>           Thread t = new Thread(null, poller, "Poller " + getName(), 0, false);
> +        t.setContextClassLoader(null);
>           t.setDaemon(true);
>           t.setPriority(Thread.MIN_PRIORITY);
>           t.start();
>           this.poller = poller;
>       }
>   
>       // destroy the poller thread, if active
>       private void destroyPoller() {
>           if (poller != null) {
>               poller.disable();
>
> https://bugs.openjdk.java.net/browse/JDK-8156841
>
> -Chris.