RFR: 8077846: improve locking strategy for readConfiguration(), reset(), and initializeGlobalHandlers()

[Mandy Chung]

On 04/30/2015 07:42 AM, Daniel Fuchs wrote:
>
> http://cr.openjdk.java.net/~dfuchs/webrev_8077846/webrev.00/ 

>> http://cr.openjdk.java.net/~plevart/misc/LogManager.synchronization/webrev.02/ 
>>

I reviewed both of the above webrevs.

TestConfigurationLock.java
    Copyright year should be 2015

TestConfigurationLock.properties
    It would be good to delete all commented lines except the lines
    relevant to the setting to make it obvious what the configuration is.

LogManager.java

I actually like having one state variable to describe the global handler 
(re-)initialization that to me is a simplification.  I couldn't 
immediately match the constant names in following the code right away.  
I read these states as:
     STATE_UNINITIALIZED - request reinitialization or invalidate the 
RootLogger
             (called from readConfiguration and after reset)
     STATE_INITIALIZED - reinitialization complete or error during 
readConfiguration
     STATE_INITIALIZING - global handlers are being initialized

Perhaps renaming the constant names to GLOBAL_HANDLERS_INVALIDATED etc 
might help.

I'm less sure about shutdown and the global handlers can skip 
reinitialization during shutdown and keeping it as separate variable 
makes it more explicit.  It may eliminate the configurationLock.lock() 
in the Cleaner.run() method.

A minor point - I wonder if a private reset method taking a boolean 
argument to indicate if the state change to STATE_INITIALIZED is 
required would make it little easier to follow.

Mandy