Be careful, do not read input imaged in _open() method. It can create serious problems for example with OFX plugins.
2012/6/7 Steven Booth <sbo...@legend3d.com>: > Ah! Got it. I tend to do such things in the _open method, actually, and then > use the threaded, parallel engine calls to actually render the data computed > in open. > > > > Steve > > > > From: nuke-dev-boun...@support.thefoundry.co.uk > [mailto:nuke-dev-boun...@support.thefoundry.co.uk] On Behalf Of Kin Ming > Mike WONG > Sent: Wednesday, June 06, 2012 10:25 PM > To: Nuke plug-in development discussion > Subject: Re: [Nuke-dev] need advice about single-thread engine() call > > > > hi steve, > > > > about "typical", i was referring to using the { Guard guard(_lock); } > approach to achieve a single threaded engine() call, sorry for the > confusion. > > > > it's because I need to do a parallel reduction on the image data using > existing tbb processing function, so it's important to get the tile/image > processed as quickly as possible by upstream nodes from my single-threaded > engine() call and then forward the data to my processor. any suggestion on > this ? > > thanks, > > mike > > > > On Wed, Jun 6, 2012 at 10:56 PM, Steven Booth <sbo...@legend3d.com> wrote: > > Mike, > > > > Each node is implemented as a separate class, and each has a unique > instantiation of the associated engine method. It is therefore not the case > that a single, one-threadded node will cause all nodes above it to operate > in single-threaded mode. That presumes there is one and only one node > connected to each output, which may not be the case. It is, however, true > that your single-threadded node will create a bottleneck, slowing down > whatever path your node is in. > > > > Although it is true that you can request Tiles in multi-threadded mode, if > you’re only going to process it in a single thread, it won’t speed things > up. > > > > It’s a bit strange, though, that you call a single-threadded engine > ‘typical’, because the normal methodology is multi-threaded. > > > > Might I ask why you need to process things single-threadded in your node? > > > > Steve > > > > > > From: nuke-dev-boun...@support.thefoundry.co.uk > [mailto:nuke-dev-boun...@support.thefoundry.co.uk] On Behalf Of > mike.artixels > Sent: Wednesday, June 06, 2012 4:38 AM > To: nuke-dev@support.thefoundry.co.uk > Subject: [Nuke-dev] need advice about single-thread engine() call > > > > Hello everyone, > > I have a small plug-in which relies on typical single thread engine() call > using Guard to do some pre-processing of the upstream image data, and if I > understand correctly, this single threaded call will simply turn every > upstream nodes running single-threadedly too .... so everything slows down. > > Is there any trick that I could pull data from upstream multi-threaded ? or > am I missing or misunderstood anything here .... > > many thanks !! > > Mike > > (CONFIDENTIALITY NOTICE: The information contained in this email may be > confidential and/or privileged. This email is intended to be reviewed by > only the individual or organization named above. If you are not the intended > recipient, or an authorized representative of the intended recipient, you > are hereby notified that any review, dissemination or copying of this email, > or the information contained herein is strictly prohibited. If you have > received this communication in error, please notify the sender by return > email and delete this email from your system. Thank You.) > > > > > _______________________________________________ > Nuke-dev mailing list > Nuke-dev@support.thefoundry.co.uk, http://forums.thefoundry.co.uk/ > http://support.thefoundry.co.uk/cgi-bin/mailman/listinfo/nuke-dev > > > > (CONFIDENTIALITY NOTICE: The information contained in this email may be > confidential and/or privileged. This email is intended to be reviewed by > only the individual or organization named above. If you are not the intended > recipient, or an authorized representative of the intended recipient, you > are hereby notified that any review, dissemination or copying of this email, > or the information contained herein is strictly prohibited. If you have > received this communication in error, please notify the sender by return > email and delete this email from your system. Thank You.) > > > _______________________________________________ > Nuke-dev mailing list > Nuke-dev@support.thefoundry.co.uk, http://forums.thefoundry.co.uk/ > http://support.thefoundry.co.uk/cgi-bin/mailman/listinfo/nuke-dev > _______________________________________________ Nuke-dev mailing list Nuke-dev@support.thefoundry.co.uk, http://forums.thefoundry.co.uk/ http://support.thefoundry.co.uk/cgi-bin/mailman/listinfo/nuke-dev
