Hi,
just wanted to ask whether someone already thought about the idea to use unique timer IDs, like autoincrement, for avoiding race conditions between multiple users or processes adding or removing timers. The associated renumbering between DELT operations can lead to hitting the wrong timer. If all timers had unique numbers, the issue would be gone implicitly, but timers.conf would have to carry the ID requiring a file layout change.
What do you think?
– Matthias
On Montag, 23. Februar 2009, Matthias Wächter wrote:
Hi,
just wanted to ask whether someone already thought about the idea to use unique timer IDs, like autoincrement, for avoiding race conditions between multiple users or processes adding or removing timers. The associated renumbering between DELT operations can lead to hitting the wrong timer. If all timers had unique numbers, the issue would be gone implicitly, but timers.conf would have to carry the ID requiring a file layout change.
To me this sounds like a good idea.
Even better would be to then properly protect the VDR internal data structures, and finally just allow concurrent access to them. Like multiple svdrp connections etc.
Matthias
Hi,
2009/2/23 Matthias Wächter matthias@waechter.wiz.at:
Hi,
just wanted to ask whether someone already thought about the idea to use unique timer IDs, like autoincrement, for avoiding race conditions between multiple users or processes adding or removing timers. The associated renumbering between DELT operations can lead to hitting the wrong timer. If all timers had unique numbers, the issue would be gone implicitly, but timers.conf would have to carry the ID requiring a file layout change.
What do you think?
Why do you only want them for timers? IMHO they should be unique for _any_ id used in SVDRP, like recordings, channels and timers.
IIRC Klaus likes this idea but it has low priority. But he might accept patches...
Regards, Andreas
– Matthias
vdr mailing list vdr@linuxtv.org http://www.linuxtv.org/cgi-bin/mailman/listinfo/vdr
On 24.02.2009 08:11, Andreas Mair wrote:
Hi,
2009/2/23 Matthias Wächter matthias@waechter.wiz.at:
Hi,
just wanted to ask whether someone already thought about the idea to use unique timer IDs, like autoincrement, for avoiding race conditions between multiple users or processes adding or removing timers. The associated renumbering between DELT operations can lead to hitting the wrong timer. If all timers had unique numbers, the issue would be gone implicitly, but timers.conf would have to carry the ID requiring a file layout change.
What do you think?
Why do you only want them for timers? IMHO they should be unique for _any_ id used in SVDRP, like recordings, channels and timers.
IIRC Klaus likes this idea but it has low priority. But he might accept patches...
I know that concurrent SVDRP sessions are "wished" and that there are several things to consider when implementing them. However, as you stated correctly, this has low priority to me. Currently I'm working on making VDR fully HD capable, so any patches that might be posted for other things would either take time off the HD topic, or just be ignored altogether right now...
Klaus
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Andreas Mair -
Klaus Schmidinger -
Matthias Schwarzott -
Matthias Wächter