RFR: 8234466: Class loading deadlock involving X509Factory#commitEvent()

[Seán Coffey]

The recent crypto event logging mechanism (JDK-8148188) has introduced a 
regression whereby the System Logger may be invoked too early in the 
bootstrap phase. This causes issue when JarFile objects are locked by 
JarFile verifier initialization code. The logging work records an X509 
Certificate which is used during the jar file 
verification/initialization phase and hence leads to an early 
System.Logger call.

One thread invokes the initialization of the Logger framework via 
ServiceLoader and waits to lock a JarFile in use via another thread. 
Unfortunately that other thread is also waiting for the System Logger to 
initialize. For now, I think we can avoid the early Logger 
initialization via use of a ThreadLocal. I've tried reproducing the 
reported issue through manual and automated tests but to no avail. I've 
added a new ServiceLoader test which has concurrent threads. One is 
loading providers and another is initializing JarFile verifiers. Hope it 
helps improve code coverage for the future.

JBS record: https://bugs.openjdk.java.net/browse/JDK-8234466
webrev : http://cr.openjdk.java.net/~coffeys/webrev.8234466/webrev/

-- 
Regards,
Sean.