[Rd] Windows Rgui.exe 4.2.0: Call of txtProgressBar() slows down dramatically after subsequent calls

[Tomas Kalibera]

On 5/19/22 22:34, Paulo Barata wrote:
>
> There runs of Tobias' foo function on different versions of R that I 
> have installed here.
>
> R version 4.1.1 Patched (2021-09-30 r80997)
> elapsed time of three trials: 1.31 / 1.33 / 1.35
>
> R version 4.1.2 Patched (2021-11-02 r81131)
> elapsed time of three trials: 1.34 / 1.34 / 1.34
>
> R version 4.1.3 Patched (2022-03-10 r81878)
> elapsed time of three trials: 1.33 / 1.34 / 1.37
>
> R version 4.2.0 Patched (2022-05-17 r82371 ucrt)
> elapsed time of three trials: 7.14 / 17.56 / 27.21
>
> Platform is always: x86_64-w64-mingw32/x64 (64-bit)
> RGui.exe running on Windows 10 Professional 64-bit (build 19044.1706)
>
> Not only, as Tobias has shown, there is an increasing time among the 
> three trials in R 4.2.0 Patched, but also the average time for each of 
> the 4.1.X Patched versions (with nearly constant time each) is well 
> smaller than the first trial with R 4.2.0 Patched.

Thanks, yes, I can reproduce the problem. Changing the implementation of 
the progress bar to print "\n" instead of "\r" makes the problem go away 
(and type=2 and 3 have the problem and use \r, while type=1 doesn't have 
the problem nor uses \r). Perhaps the carriage return is not interpreted 
correctly and the line somehow internally keeps the previously printed 
characters, always adding the new ones at the end. That is also 
consistent with that the time is increasing linearly. I will investigate 
further.

Best
Tomas

>
> Regards,
>
> Paulo Barata
>
> (Rio de Janeiro - Brazil)
>
> ----------------------------------------------------------
>
> On 19/05/2022 15:37, Tobias Schoch wrote:
>> The issue appears in Rgui.exe version 4.2.0 (called "new" version; 
>> see bottom). The issue does NOT appear with Rterm.exe (same R version).
>>
>> I provide a minimal example (foo) below. If I run function foo 3 
>> times in a row, the execution time increases considerably (although 
>> it should not).
>>
>> 1st foo call: 5 seconds
>> 2nd foo call: 13 seconds
>> 3rd foo call: 20 seconds
>>
>> The execution time keeps increasing when I call foo more often. In 
>> addition, Rgui.exe becomes laggy in taking input from the keyboard.
>>
>> Sometimes, but rarely, I observe that Rgui.exe terminates with 
>> "Error: C stack usage is too close to the limit". Unfortunately, I 
>> cannot reproduce the stack error consistently.
>>
>> On the "old" Rgui.exe version 4.1.2, execution time stays roughly 
>> constant over consecutive calls of foo (as expected). Unfortunately, 
>> I do not have a running 4.1.3 version; thus, I cannot tell how it 
>> behaves there.
>>
>> Do you have any clue why this happens?
>>
>> Kind regards,
>> Tobias
>>
>>
>> #------------------------------
>> # minimal working example: interestingly, the issue does not occur
>> # when 'style = 1' in txtProgressBar()
>> foo <- function(n)
>> {
>>      p_bar <- txtProgressBar(style = 3)
>>      for (i in 1:n) {
>>          Sys.sleep(0.01)
>>          setTxtProgressBar(p_bar, i / n)
>>      }
>>      close(p_bar)
>> }
>> # 1st call
>> system.time(foo(100))
>> # 2nd call
>> system.time(foo(100))
>> # 3rd call
>> system.time(foo(100))
>> #------------------------------
>>
>>
>> My R versions:
>>
>> "Old" Rgui.exe
>>      R version 4.1.2 (2021-11-01)
>>      Platform: x86_64-w64-mingw32/x64 (64-bit)
>>      Running under: Windows 10 x64 (build 19044)
>>
>> "New" Rgui.exe
>>      R version 4.2.0 (2022-04-22 ucrt)
>>      Platform: x86_64-w64-mingw32/x64 (64-bit)
>>      Running under: Windows 10 x64 (build 19044)
>>
>>
>> ------------------------------------------------------------------
>> Fachhochschule Nordwestschweiz FHNW
>> Hochschule für Wirtschaft
>> Institute for Competitiveness and Communication
>> Empirische Wirtschafts- und Sozialforschung
>>
>> Prof. Dr. Tobias Schoch
>> Riggenbachstrasse 16
>> CH-4600 Olten
>> Schweiz / Switzerland
>> ------------------------------------------------------------------
>> T +41 62 957 21 02
>> Mail tobias.schoch using fhnw.ch
>> http://www.fhnw.ch/de/personen/tobias-schoch
>>
>> ______________________________________________
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>
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