 03 Jan 2019, Konstantin Olchanski, Info, note on the midas event buffer code, part 7, event buffer polling frequencies
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> > > > > In this technical note, I write down the workings of the midas event buffer code
> > > > > we need to understand and write down how the event buffer code works.
> > > > > bm_send_event() does this ...
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03 Jan 2019, Konstantin Olchanski, Info, note on the midas event buffer code, part 8, writer and reader communications
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> > > > > > In this technical note, I write down the workings of the midas event buffer code
Event buffer readers and writers need to communicate following information:
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10 Jan 2019, Konstantin Olchanski, Info, note on the midas event buffer code, part 8, writer and reader communications
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> > > > > > > In this technical note, I write down the workings of the midas event buffer code
> Event buffer readers and writers need to communicate following information:
>
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 10 Jan 2019, Konstantin Olchanski, Info, removal of cm_watchdog()
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cm_watchdog() has been removed from the latest midas sources. The watchdog functions performed by cm_watchdog() were
moved to cm_yield() - those are - maintaining odb and event buffer "last active" timestamps and checking for and removing of
timed-out clients.
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18 Jan 2019, Konstantin Olchanski, Info, bitbucket issue tracker "feature"
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It turns out the bitbucket issue tracker has a feature - I cannot make it automatically add me
to the watcher list of all new issues.
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21 Jan 2019, Konstantin Olchanski, Info, removal of cm_watchdog()
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> cm_watchdog() has been removed from the latest midas sources
> Removal of cm_watchdog() solves many problems in the midas code base:
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24 Jan 2019, Konstantin Olchanski, Info, removal of cm_watchdog()
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> > cm_watchdog() has been removed from the latest midas sources
> > Removal of cm_watchdog() solves many problems in the midas code base:
> Removal of cm_watchdog() creates new problems:
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07 Feb 2019, Stefan Ritt, Info, History panels in custom pages 
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A new tag has been implemented to display history panels in custom pages, integrated in the
new custom page design from 2017. The full documentation can be found at
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08 Feb 2019, Thomas Lindner, Info, History panels in custom pages
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> A new tag has been implemented to display history panels in custom pages, integrated in the
> new custom page design from 2017. The full documentation can be found at
>
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11 Feb 2019, Konstantin Olchanski, Info, json-rpc request for ODB /Script and /CustomScript.
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I added json-rpc requests for ODB /Script and /CustomScript (the first one shows up on the status page in the left hand side menu, the
second one is "hidden", intended for use by custom pages).
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20 Feb 2019, Konstantin Olchanski, Info, odb needs protection against ctrl-c
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Even with the cm_watchdog signal removed, some trouble from UNIX signals remains.
This time, when one presses Ctrl-C at the wrong time, the Ctrl-C signal handler will run at the wrong time
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20 Feb 2019, Stefan Ritt, Info, odb needs protection against ctrl-c
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Not sure if you realized, but there is a two-stage Ctrl-C handling inside midas. The first time you hit ctrl-c, the handler just sets a flag for the main
event loop, so that the program can gracefully exit without trouble. This is
done inside cm_ctrlc_handler(), which sets _ctrlc_pressed true if called. Then cm_yield() tests this flag and returns RPC_SHUTDOWN if so. I agree not very |
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20 Feb 2019, Konstantin Olchanski, Info, odb needs protection against ctrl-c
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Commit f81ff3c protects db_lock/unlock, but not any of the other functions. What if we do ctrl-c in the middle
of some odb write operation in the middle of memory allocation, etc.
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20 Feb 2019, Konstantin Olchanski, Info, odb needs protection against ctrl-c
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> Not sure if you realized, but there is a two-stage Ctrl-C handling inside midas.
Hmm... I am looking at the ctrl-c handler inside odbedit.
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20 Feb 2019, Stefan Ritt, Info, odb needs protection against ctrl-c
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Have you read what I wrote? The current ctrl-c handler just sets the _ctrlc_pressed flag. It might be that some programs do not correctly interprete the
return of cm_yield(), certainly the frontend does it correctly. On the SECOND ctrl-c, the program gets
(internally) hard aborted, equivalent to calling abort(). Not sure if the code works everywhere, I see now that cm_yield(() should maybe return SS_ABORT |
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27 Feb 2019, Konstantin Olchanski, Info, mhttpd magic urls
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Here is the list of mhttpd magic URLs.
http "get" path:
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28 Feb 2019, Konstantin Olchanski, Info, resource file search path, mhttpd magic urls
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> url contains midas.js -> send_resource("midas.js")
mhttpd looks for resource files in these directories in this order:
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01 Mar 2019, Konstantin Olchanski, Info, Gyrations of custom pages and ODB /Custom/Path
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Before the days of javascript and ajax and web 2.0, MIDAS introduced "custom pages" for
building graphical display that could show "live" data from MIDAS and that could
have buttons and controls to operate slow controls equipment, etc.
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04 Mar 2019, Stefan Ritt, Info, Gyrations of custom pages and ODB /Custom/Path
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Parsing all URL in mhttpd to prevent /etc/passwd etc. to be returned is tricky, because people can use escape sequences etc. Therefore I think it is much
better to restrict file access
on the file system level when opening a file. The only escape there one could have is "..", which can be tested easily.
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04 Mar 2019, Thomas Lindner, Info, Gyrations of custom pages and ODB /Custom/Path
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Hi Stefan and Konstantin,
I think that this proposal sounds fairly reasonable. I agree that we might as well move to a secure final solution at this point.
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