733696 - ObserversManager might report invalid cached value if notification is disabled

Status: RESOLVED FIXED

(Core :: Hardware Abstraction Layer (HAL), defect)

Description

[Kan-Ru Chen [:kanru] (UTC+9)]

As discussed in bug 697132 comment 133,

if we call GetCurrentInformation and notifications are disabled, we'll set mHasValidCache to true, which doesn't seem right.  If notifications are disabled, the cache is invalid the moment GetCurrentInformationInternal returns.

Comment 1

[Mounir Lamouri (:mounir)]

You should not call GetCurrentInformation if notifications are disabled. At least, it was not planned when designing this. Why do you want to do that?

Comment 2

[Kan-Ru Chen [:kanru] (UTC+9)]

(In reply to Mounir Lamouri (:volkmar) (:mounir) from comment #1)
> You should not call GetCurrentInformation if notifications are disabled. At
> least, it was not planned when designing this. Why do you want to do that?

Well, I didn't know the original intention so only looked at the interface and guess I can call it. And it is reasonable that one might want to implement a one-shot query API based on that.

Comment 3

[Mounir Lamouri (:mounir)]

Attachment: Patch v1

I think that |mHasValidCache = true;| is indeed wrong.

Comment 4

[Ed Morley [:emorley]]

https://hg.mozilla.org/mozilla-central/rev/31176cfa4ff1