[PD] close all patches on quit sourceforge patch

[Ivica Ico Bukvic]

Hans and Iohannes,

The following is FYI.

Several months ago I integrated the close all patches before quitting patch
in pd-l2ork and since then I've been experiencing extremely sporadic crashes
on close that would hang pd-l2ork. Now, I am not sure this is because of
architectural differences between regular pd and pd-l2ork but I doubt it
since most of the said components are very similar if not identical.

The bottom line is this only occurs on very low-powered machines (e.g.
netbook) and relatively large patches and even then it does so very
sporadically. Consequently, I implemented an improvement to the closing
mechanism that consists of 2 additional steps and apparently alleviates said
problems entirely:

1) disable further redraws (this prevents calling functions that may be
referencing null pointers)--I have a special global var for this which is
also being used to optimize redrawing (many actions in pd-l2ork are several
times faster than regular pd as a result of this implementation--just look
for do_not_redraw call in the source if curious)

2) suspend dsp before going through the patches (all sub-patches try to
suspend it and resume it but for some reason, due to asynchronous nature of
communication between tcl and c funny things occasionally happen on
low-powered machines, so this way we ensure it is entirely off throughout
the whole destruction process)

Hope this helps!

Ivica Ico Bukvic, D.M.A.
Composition, Music Technology
Director, DISIS Interactive Sound & Intermedia Studio
Director, L2Ork Linux Laptop Orchestra
Head, ICAT IMPACT Studio
Virginia Tech
Dept. of Music - 0240
Blacksburg, VA 24061
(540) 231-6139
(540) 231-5034 (fax)
ico at vt.edu
http://www.music.vt.edu/faculty/bukvic/