[ 
https://issues.apache.org/jira/browse/GROOVY-10657?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
 ]

Jonathan Baxter updated GROOVY-10657:
-------------------------------------
    Affects Version/s: 4.0.3

> Generated code for overloaded assignment operator prevents garbage collection
> -----------------------------------------------------------------------------
>
>                 Key: GROOVY-10657
>                 URL: https://issues.apache.org/jira/browse/GROOVY-10657
>             Project: Groovy
>          Issue Type: Bug
>          Components: Compiler
>    Affects Versions: 4.0.3
>            Reporter: Jonathan Baxter
>            Priority: Major
>
> The groovy code 
> {code:java}
> obj["lhs"] = "rhs"{code}
> ostensibly converts to 
> {code:java}
> obj.putAt("lhs","rhs")
> {code}
> if {{obj}} has the appropriate {{putAt}} method.
> However , in the process of tracking down a memory leak, I discovered that 
> assignment is not exactly equivalent to invocation of the {{putAt}} method. 
> Specifically, the code generated by the compiler is equivalent to creating an 
> additional temporary variable to hold the rhs of the assignment, and then 
> invoking the {{putAt}} method with that temporary variable as its second 
> argument:
> {code:java}
> String string = "rhs"
> obj.putAt("lhs",string){code}
> The problem with this is that since {{"rhs"}} now has a live reference 
> ({{{}string{}}}), it is not eligible for garbage collection. 
> In my particular use case, {{"rhs"}} is a very large object that I would like 
> to be automatically garbage collected after the assignment is executed, but 
> before the script has finished. But that means I have to use the underlying 
> {{putAt}} method rather than the assignment operator, which rather negates 
> the benefits of overloading the assignment operator.
> One potential fix would be to simply null out any temporary variables 
> constructed by the compiler, so that 
> {code:java}
> obj["lhs"] = "rhs"
> {code}
>  becomes
> {code:java}
> String string = "rhs" 
> obj.putAt("lhs",string) 
> string = null <----- "rhs" is now eligible for garbage-collection{code}



--
This message was sent by Atlassian Jira
(v8.20.7#820007)

Reply via email to