On Tue, 29 Oct 2019, Marcel Taeumel wrote:
Hi Christoph.
However, currently, a #deprecated call in a drawing method makes the image unusable ...
Yes, there is a lot of room for improvement in Squeak's strategy to keep the image alive and in a recoverable state. Annoying things include errors in event handlers (such as #mouseOver:) and the thing about Warnings you mentioned for #displayWorldSafely.
Since the exception mechanism can be used to implement dynamic scope (see CurrentReadOnlySourceFiles), we should never catch Exception in general to install such handlers.
Warning might be a nice addition to #displayWorldSafely.
[Error] bench '219,000,000 per second. 4.57 nanoseconds per run.' [Error, Halt] bench '11,900,000 per second. 84.4 nanoseconds per run.' [Error, Halt, Warning] bench '9,910,000 per second. 101 nanoseconds per run.'
#bench is not suitable to measure things that are fairly quick, because [] bench doesn't give 0 ns. It's not too far off, but definitely not accurate, especially if you compare ratios.
#bench doesn't measure the effects of allocation/gc well. The last two code puts pressure on the garbage collector.
Since this is called only once to fourteen times per frame (see DamageRecorder) -- but usually only once -- we are good with 100 nanoseconds, given that 60 frames-per-second translate to 16 666 667 nanoseconds per frame.
Not all machines (physical and virtual) running Squeak are as fast as yours. What's 100ns on your machine, may take up to 3 magnitudes longer on others. In that case, you only have 16 666 microseconds to render, and you spend 100 microseconds on something that could be almost 0.
If there were a class variable holding the exception set, it could be reused with no additional cost. It would also let users to add their own exceptions to the set without modifying Trunk code.
Levente
Best, Marcel
Am 25.10.2019 20:46:52 schrieb Thiede, Christoph <christoph.thiede@student.hpi.uni-potsdam.de>: I see, but isn't it just their existence what we want to test for to prevent from loads of Debuggers appearing? Or should we go the other way around and signal a "DebuggerRaisedNotification" each time before opening a debugger? However, currently, a #deprecated call in a drawing method makes the image unusable ...
Von: Squeak-dev squeak-dev-bounces@lists.squeakfoundation.org im Auftrag von Taeumel, Marcel Gesendet: Mittwoch, 23. Oktober 2019 15:48:15 An: John Pfersich via Squeak-dev Betreff: Re: [squeak-dev] The Trunk: System-mt.1093.mcz
Why isn't it sufficient to test for UnhandledError instead? Otherwise, we would also need to test for Warning etc. ...
UnhandledError and UnhandledWarning are (private) implementation details of Squeak's exception handling mechanism. They should never be exposed to (or used by) applications/frameworks.
Best, Marcel
Am 22.10.2019 18:50:59 schrieb Thiede, Christoph <christoph.thiede@student.hpi.uni-potsdam.de>: Why isn't it sufficient to test for UnhandledError instead? Otherwise, we would also need to test for Warning etc. ...
Von: Squeak-dev squeak-dev-bounces@lists.squeakfoundation.org im Auftrag von Taeumel, Marcel Gesendet: Dienstag, 15. Oktober 2019 13:18:26 An: gettimothy via Squeak-dev Betreff: Re: [squeak-dev] The Trunk: System-mt.1093.mcz Yeah, I wonder whether we should expand "Error" to "Error, Halt"? Best, Marcel
Am 15.10.2019 12:45:42 schrieb Balázs Kósi <rebmekop@gmail.com>: Hi Hannes!
This morning I've just run into this exact same situation: putting a halt into a method, called by a morph's #drawOn: makes the image unusable.
The problem stems from WorldState >> displayWorldSafely: being safe only for Errors and not for other kind of Exceptions, and Halt being only an Exception not an Error.
For a quick fix add Halt to the handled exceptions in #displayWorldSafely: [aWorld displayWorld. finished := true] on: Error, Halt do: [:ex | Balázs