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2017.03.17 14:29 "TIFFSetErrorHandler vs TIFFSetErrorHandlerExt", by Dinesh Iyer
2017.03.17 14:53 "Re: TIFFSetErrorHandler vs TIFFSetErrorHandlerExt", by Bob Friesenhahn
2017.03.17 15:53 "Re: TIFFSetErrorHandler vs TIFFSetErrorHandlerExt", by Dinesh Iyer
2017.03.17 16:07 "Re: TIFFSetErrorHandler vs TIFFSetErrorHandlerExt", by Dinesh Iyer
2017.03.17 17:01 "Re: TIFFSetErrorHandler vs TIFFSetErrorHandlerExt", by Dinesh Iyer
2017.03.17 17:06 "Re: TIFFSetErrorHandler vs TIFFSetErrorHandlerExt", by Bob Friesenhahn
2017.03.17 17:19 "Re: TIFFSetErrorHandler vs TIFFSetErrorHandlerExt", by Yakov Galka
2017.03.17 17:02 "Re: TIFFSetErrorHandler vs TIFFSetErrorHandlerExt", by Bob Friesenhahn
2017.03.17 21:02 "Re: TIFFSetErrorHandler vs TIFFSetErrorHandlerExt", by <rleigh@codelibre.net>
2017.03.17 21:08 "Re: TIFFSetErrorHandler vs TIFFSetErrorHandlerExt", by Bob Friesenhahn
2017.03.17 22:23 "Re: TIFFSetErrorHandler vs TIFFSetErrorHandlerExt", by Roger Leigh
2017.03.17 22:40 "Re: TIFFSetErrorHandler vs TIFFSetErrorHandlerExt", by Paavo Helde
2017.03.17 23:03 "Re: TIFFSetErrorHandler vs TIFFSetErrorHandlerExt", by Bob Friesenhahn
2017.03.18 10:53 "Re: TIFFSetErrorHandler vs TIFFSetErrorHandlerExt", by Yakov Galka

2017.03.17 15:53 "Re: TIFFSetErrorHandler vs TIFFSetErrorHandlerExt", by Dinesh Iyer

Thanks Bob.

If I understand you correctly, I cannot have multiple threads each with its
own handler throwing errors/warnings. i need to ensure that only one thread
does the error handling, am I correct?

As a follow up, do i have to set the client_data field with a pointer to my
class such that it is accessible in the callbacks?

Regards
Dinesh

On Fri, Mar 17, 2017 at 10:53 AM, Bob Friesenhahn <
bfriesen@simple.dallas.tx.us> wrote:

> On Fri, 17 Mar 2017, Dinesh Iyer wrote:
>
> Hi team,
>> I need to do some custom error handling which requires me to pass in the
>> pointer to my class that is doing the TIFF I/O. I need this because I need
>> to deliver warnings/errors to my application through a specific mechanism.
>>
>> I noticed that TIFFSetErrorHandlerExt does allow me to pass that as the
>> first argument. I was wondering if it is sufficient to set one of the
>> error
>> handlers or do I have to set both. The same applies for warning handlers
>> as
>> well.
>>
>
> These functions are redudant and both may be used at once.  If
> TIFFSetErrorHandler() was used, then its error handler will be called. If
> TIFFSetErrorHandlerExt() was used, then its error handler will be called.
> They are called in succession.
>
> This means that you can just use TIFFSetErrorHandlerExt() and be happy.
>
> The main problem with these interfaces is that the internal storage
> location is shared across threads so threads can't use different handlers
> unless they serialize access to libtiff.
>
> Bob
> --
> Bob Friesenhahn
> bfriesen@simple.dallas.tx.us, http://www.simplesystems.org/users/bfriesen/
> GraphicsMagick Maintainer,    http://www.GraphicsMagick.org/
>