Re: ca_create_channel memory management

[pthomas@ligo-wa.caltech.edu]

Is it possible to do this? Would you need a global variable referencing
each cleared channel?

> If your channel is doing any callbacks (e.g., you're monitoring it),
> you might have outstanding monitors at the time you decide to clear
> the channel.  You need to tell your callback routine to ignore any
> calls that come after you've called cleanup(), so it doesn't reference
> pUserPrivate after it's been freed.
> Tim
>
> ----- Original Message -----
>> From: pthomas@ligo-wa.caltech.edu
>> To: "Andrew Johnson" <anj@aps.anl.gov>
>> Cc: tech-talk@aps.anl.gov
>> Sent: Friday, January 28, 2011 11:56:37 AM
>> Subject: Re: ca_create_channel memory management
>> So:
>>
>> void cleanup(chid ChanID) {
>> void* pUserPrivate;
>>
>> pUserPrivate = ca_puser(ChanID);
>> free(pUserPrivate);
>> ca_clear_channel(ChanID);
>> }
>> ?
>>
>> > Hi Patrick,
>> >
>> > On Friday 28 January 2011 11:10:29 pthomas@ligo-wa.caltech.edu
>> > wrote:
>> >> If you allocate memory and send a pointer to it in the puser field
>> >> of
>> >> ca_create_channel, does it get freed when ca_clear_channel is
>> >> called, or
>> >> should I do that explicitly?
>> >
>> > There's no way the CA API could know whether it should do that or
>> > not, so
>> > it
>> > doesn't and it falls on you to do it yourself.
>> >
>> > - Andrew
>> > --
>> > If a man is offered a fact which goes against his instincts, he will
>> > scrutinize it closely, and unless the evidence is overwhelming, he
>> > will
>> > refuse to believe it. If, on the other hand, he is offered something
>> > which affords a reason for acting in accordance to his instincts, he
>> > will accept it even on the slightest evidence. -- Bertrand Russell
>> >
>> >
>
> --
> Tim Mooney (mooney@aps.anl.gov) (630)252-5417
> Software Services Group (www.aps.anl.gov)
> Advanced Photon Source, Argonne National Lab
>
>