The 1-wire bus is relatively slow. Except perhaps for powered temperature conversions the limitation is bus communication rather than slave processing. The surest speedup is to add bus masters, since the library can handle multiple bus conversations. Otherwise the threading is mainly a program design issue.
"Joshua J. Kugler" <jos...@azariah.com> wrote: >On Friday 22 October 2010, Paul Alfille elucidated thus: >> > 2010/10/22 Joshua J. Kugler <jos...@azariah.com> >> > >> >> Reading through the Python module, there doesn't seem to be any >> >> kind of lock or semaphore preventing simultaneous reads. Is there >> >> such a thing at the libow C level? >> I can't speak for the python module -- there may be threading issues >> in global variables or io code. >> >> The underlying libow is definitely thread safe for calls to read. >> write and list directories. Actually we wrap locks around slave >> access, and bus master access (since there can be some interspersing >> of communication) as well as locks everything for dynamic additions >> of new bus masters, scanning the usb or mdns system, and cache >> additions and deletions. >> >> Obviously, since the entire library is linked in, calls to low-level >> routines might not be properly serialized, but linking at a higher >> level is safe (that's what owcapi does). > >So, what I'm understanding is: there is *NO* speed advantage to >threading reading retrievals, since all calls are serialized by the >library. > >Is that correct? > >j > >-- >Joshua J. Kugler - Fairbanks, Alaska >Azariah Enterprises - Programming and Website Design >jos...@azariah.com - Jabber: pedah...@gmail.com >PGP Key: http://pgp.mit.edu/ ID 0x73B13B6A > >------------------------------------------------------------------------------ >Nokia and AT&T present the 2010 Calling All Innovators-North America contest >Create new apps & games for the Nokia N8 for consumers in U.S. and Canada >$10 million total in prizes - $4M cash, 500 devices, nearly $6M in marketing >Develop with Nokia Qt SDK, Web Runtime, or Java and Publish to Ovi Store >http://p.sf.net/sfu/nokia-dev2dev >_______________________________________________ >Owfs-developers mailing list >Owfs-developers@lists.sourceforge.net >https://lists.sourceforge.net/lists/listinfo/owfs-developers The information in this e-mail is intended only for the person to whom it is addressed. If you believe this e-mail was sent to you in error and the e-mail contains patient information, please contact the Partners Compliance HelpLine at http://www.partners.org/complianceline . If the e-mail was sent to you in error but does not contain patient information, please contact the sender and properly dispose of the e-mail. ------------------------------------------------------------------------------ Nokia and AT&T present the 2010 Calling All Innovators-North America contest Create new apps & games for the Nokia N8 for consumers in U.S. and Canada $10 million total in prizes - $4M cash, 500 devices, nearly $6M in marketing Develop with Nokia Qt SDK, Web Runtime, or Java and Publish to Ovi Store http://p.sf.net/sfu/nokia-dev2dev _______________________________________________ Owfs-developers mailing list Owfs-developers@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/owfs-developers
