Q About Cocoa & CF Prefs..

[David Phillip Oster]

In article <no-EA814A.20172229072003@netnews.upenn.edu>,
Mark Haase <no@spam.please> wrote:

> It is my understanding that when you use the core foundation calls to
> write to an application's preferences, those prefs are not necessarily
> written out to file immediately, but cached in memory for a bit so that
> potentially several can be written at once at a later point in time?
>
> What happens if your program crashes before the prefs get written out?
> They're lost I suppose?

Not only that, if the same preference file is accessed by multiple apps
simultaneously, the last app to quit overwrites any preferences written
by the other apps. (According to the tips in the latest issue of
MacAddict)

Not only that, but if one app changes the preferences, the other apps
that are accessing the preferences don't get an event to inform them
that preferences have changed. (According to CarbonEvents.h)

The entire API seems to have been written by programmers with room
temperature IQs.

To Apple: Get a clue guys! the file system handles robust multiple
asynchronous access with updating, the preferences system could too.

[James W. Walker]

In article <no-EA814A.20172229072003@netnews.upenn.edu>, Mark Haase
<no@spam.please> wrote:

> It is my understanding that when you use the core foundation calls to
> write to an application's preferences, those prefs are not necessarily
> written out to file immediately, but cached in memory for a bit so that
> potentially several can be written at once at a later point in time?

Yes, but you can explicitly flush the cache.

[Thomas Engelmeier]

In article
<oster-F5C4C7.20193229072003@newssvr23-ext.news.prodigy.com>,
David Phillip Oster <oster@ieee.org> wrote:

> > What happens if your program crashes before the prefs get written out?
> > They're lost I suppose?

>
> Not only that, if the same preference file is accessed by multiple apps
> simultaneously, the last app to quit overwrites any preferences written
> by the other apps. (According to the tips in the latest issue of
> MacAddict)
>
> Not only that, but if one app changes the preferences, the other apps
> that are accessing the preferences don't get an event to inform them
> that preferences have changed. (According to CarbonEvents.h)

My favorite "feature" is the complete loss of (unmodified) preferences
in Dock, Finder, ... if the boot disk runs out of swap space :-(((

Well, according to Files.h PBExchangeFiles appeared in InterfaceLib 7.1,
so the write-and-swap-if-successful paradigm is only 10+ years old.


Regards,
Tom_E