No, it needs to be done lazily, only when needed. In particular, it is
not yet ready when the constructor is called.
On 4/19/2013 7:06 AM, Liang Zhao wrote:
> Is it available to move
>> controller = controllerProvider.get();
> to constructor so that it will be initialized only once?
>
> Sent from my iPhone
>
> On Apr 19, 2013, at 6:42 PM, John Wells <john.wells_at_oracle.com> wrote:
>
>> I would like an exception for the following "findbugs" find:
>>
>> I have a method like this:
>>
>> private RunLevelController getController() {
>> if (controller != null) return controller;
>>
>> synchronized (this) {
>> if (controller != null) return controller;
>>
>> controller = controllerProvider.get();
>> return controller;
>> }
>> }
>>
>> What I get from findbugs is this:
>>
>> jwells: nucleus/core/kernel/src/main/java/com/sun/enterprise/v3/server/AppServerStartup.java:590: DC_DOUBLECHECK: Possible doublecheck on com.sun.enterprise.v3.server.AppServerStartup$AppInstanceListener.controller in com.sun.enterprise.v3.server.AppServerStartup$AppInstanceListener.getController()
>> jwells: nucleus/core/kernel/src/main/java/com/sun/enterprise/v3/server/AppServerStartup.java:590: IS2_INCONSISTENT_SYNC: Inconsistent synchronization of com.sun.enterprise.v3.server.AppServerStartup$AppInstanceListener.controller; locked 57% of time
>> jwells: nucleus/core/kernel/src/main/java/com/sun/enterprise/v3/server/AppServerStartup.java:590: IS2_INCONSISTENT_SYNC: Inconsistent synchronization of com.sun.enterprise.v3.server.AppServerStartup$AppInstanceListener.controller; locked 57% of time
>> jwells: nucleus/core/kernel/src/main/java/com/sun/enterprise/v3/server/AppServerStartup.java:593: IS2_INCONSISTENT_SYNC: Inconsistent synchronization of com.sun.enterprise.v3.server.AppServerStartup$AppInstanceListener.controller; locked 57% of time
>> jwells: nucleus/core/kernel/src/main/java/com/sun/enterprise/v3/server/AppServerStartup.java:593: IS2_INCONSISTENT_SYNC: Inconsistent synchronization of com.sun.enterprise.v3.server.AppServerStartup$AppInstanceListener.controller; locked 57% of time
>> jwells: nucleus/core/kernel/src/main/java/com/sun/enterprise/v3/server/AppServerStartup.java:595: IS2_INCONSISTENT_SYNC: Inconsistent synchronization of com.sun.enterprise.v3.server.AppServerStartup$AppInstanceListener.controller; locked 57% of time
>> jwells: nucleus/core/kernel/src/main/java/com/sun/enterprise/v3/server/AppServerStartup.java:596: IS2_INCONSISTENT_SYNC: Inconsistent synchronization of com.sun.enterprise.v3.server.AppServerStartup$AppInstanceListener.controller; locked 57% of time
>>
>> This is the only thing in the file that ever sets the controller variable, and the variable never becomes unset. To me this is valid java...
>>
>> John Wells
>> john.wells_at_oracle.comNOSPAM
>>
>>