Closed Bug 18078 Opened 20 years ago Closed 20 years ago

[arch] need consistent shortcuts for accessing threads

Categories

(Core :: XPCOM, defect, P3)

All
Other
defect

Tracking

()

RESOLVED FIXED

People

(Reporter: warrensomebody, Assigned: warrensomebody)

Details

It turns out that nsIProxyObjectManager uses NULL to mean "the UI thread"
whereas necko has various places where NULL means "the current thread". I'd like
to see this cleaned up.

I think the best way to approach this is to do this: Add the following special
constants to nsIEventQueueService.h:

#define NS_CURRENT_THREAD    ((PRThread*)0)
#define NS_UI_THREAD         ((PRThread*)1)

Then fix nsEventQueueServiceImpl::GetThreadEventQueue to handle these special
constants.

Then fix nsAsyncStreamObserver::Init to not special case NULL so that it simply
propagates its arguments to nsIEventQueueServiceImpl::GetThreadEventQueue.

Then fix up the callers of nsAsyncStreamObserver::Init to be explicit about
using the constants instead of NULL for clarity (e.g. NS_NewAsyncStreamObserver,
NS_NewAsyncStreamListener, nsIChannel::AsyncOpen, AsyncRead, ... (you'll have to
find everything that flows into here)). Also you should fix the callers of the
nsIProxyObjectManager routines.

Let me know if you want me to take this. I don't mind.

One final note: Maybe nsIThread should factor into this equation in some way
too. Ideally, everyone would use nsIThread instead of PRThread, but that's a
much bigger task. If we could achieve this, the constants would become arguments
to nsIThread::GetIThread, and nsIEventQueueService would deal with nsIThreads
instead of PRThreads.
OS: Windows NT → other
Hardware: PC → All
Target Milestone: M12
Those SIG_IGN like castings of small ints are great worse-is-better hacking.
The choice of ((PRThread*)1) for UI is good too, because another better-is-worse
long term thing we should do is multithread or apartment-thread our UI/layout
code, so this constant goes away.  Whether that happens before we switch from
PRThread to nsIThread, I would not want to guess!

/be
Status: NEW → ASSIGNED
I am fixing this now.  I think that I will ask you warren to take a look at
converting necko to these new defines.

I also have to add two more defines so that we do not have to case, so here is
the total list:

#define NS_CURRENT_THREAD    ((PRThread*)0)
#define NS_CURRENT_EVENTQ    ((nsIEventQueue*)0)

#define NS_UI_THREAD         ((PRThread*)1)
#define NS_UI_THREAD_EVENTQ  ((nsIEventQueue*)1)
Cool. Assign it to me when your done.
Assignee: dougt → warren
Status: ASSIGNED → NEW
Fixes checked in.  Warren, you can update necko.
Status: NEW → RESOLVED
Closed: 20 years ago
Resolution: --- → FIXED
Doug: Looks like you already updated all the call sites. Marking fixed.
Blocks: 21564
No longer blocks: 21564
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