hg: jdk7/hotspot-comp/hotspot: 6782260: Memory leak in CodeBuffer::create_patch_overflow

[Volker Simonis]

Hi Tom,

by incidence I've just found this problem while playing around with
the Arena memory allocation in HS14. Now that I saw your change I'm
confident that I've also done the right fix myself :)

There's just one question I have regarding your solution: isn't
"CodeBuffer::take_over_code_from()" a problem here, because it copies
"_overflow_arena" from one CodeBuffer into another one. I think this
may potentially lead to a double delete of the same Arena. Or isn't
this possible logically. Perhaps it would be more secure to add
another line like:

  DEBUG_ONLY(cb->_overflow_arena = (BufferBlob*)badAddress);

to "CodeBuffer::take_over_code_from()" or even better set
"_overflow_arena" to NULL after it was copied?

What do you think?

Regards,
Volker


On Wed, Feb 4, 2009 at 5:29 AM,  <thomas.rodriguez at sun.com> wrote:
> Changeset: 5bfdb08ea692
> Author:    never
> Date:      2009-02-03 18:05 -0800
> URL:       http://hg.openjdk.java.net/jdk7/hotspot-comp/hotspot/rev/5bfdb08ea692
>
> 6782260: Memory leak in CodeBuffer::create_patch_overflow
> Reviewed-by: phh, kvn
>
> ! src/share/vm/asm/codeBuffer.cpp
>
>