524516 - Add a new thread access lock around the lifetime of the GCHeap for protection during OOM.

Status: VERIFIED FIXED

(Tamarin Graveyard :: Garbage Collection (mmGC), defect, P2)

Description

[Brent Getlin]

User-Agent:       Mozilla/4.0 (compatible; MSIE 8.0; Windows NT 6.0; Trident/4.0; SLCC1; .NET CLR 2.0.50727; Media Center PC 5.0; .NET CLR 3.5.30729; .NET CLR 3.0.30729)
Build Identifier: 

- Create a new static spinlock on the GCHeap Class.
- Create static methods for utilizing the new spinlock
- Protect the GCHeap refcount by obtaining the new spinlock before increment/decrement.
- Obtain the new spinlock during the "ENTER" macros so that the heap cannot be destroyed before setting the new EnterFrame 

Reproducible: Sometimes

Comment 1

[Brent Getlin]

Attachment: Patch

P4 change : 594536

Comment 2

[Lars T Hansen]

Substantive:

- Ideally Enter() would test that the lock is indeed held by the calling
  thread but I don't think we have an API for this now.

Stylistic:

- GCHeap::EnterDestroy should be called EnterLockDestroy to be symmetric
  with EnterLockInit; no reason why it should not also be static; no reason
  why it needs to be inline.
- GCHeap::EnterLockInit: never compare a boolean to false, always use the
  variable name by itself or prefixed by '!'
- GCHeap::Leave: blank lines inserted for no apparent reason

Comment 3

[Lars T Hansen]

Attachment: Identical patch, but in proper format

Comment 4

[Lars T Hansen]

Attachment: Slightly reengineered following comments; fixes for avmshell too

Comment 5

[Lars T Hansen]

redux changeset:   2882:0e4af8807e23

Comment 6

[Chris Peyer]

Engineering work item.  Marking as verified.