Re: [equinox-dev] Safe logging from a WeavingHook?

[Stephan Herrmann <stephan.herrmann@xxxxxxxxx>]

Nice trick this ping-pong-log-listener :)
For simple experiments I can directly see it working.
May re-exercise my original stress-test later,

thanks, Tom, much appreciated!
Stephan

On 05/16/2016 06:31 PM, Thomas Watson wrote:
>  > From: Stephan Herrmann
>  > Hi Tom,
>  >
>  > Thanks for your comprehensive answer.
>  > Yes, we can easily agree that SynchronousLogListener is dangerous :)
>  >
>  > More questions inline ...
>  >
>  >
>  > Sounds promising, but ...
>  >
>  > >  But be aware that nobody is going to see your logs until there is
>  > a org.osgi.service.log.LogService registered to
>  > > listen to your logs.
>  >
>  > ... is that s.t. I have to register? How?
>  > Can I hook this up so that all entries do (eventually) appear in the
>  > Errors view and perhaps the persistent log file?
>
> I did not mean LogService there.  I meant org.osgi.service.log.LogListener.  You would have to register a LogListener with the
> LogReaderService using the method:
>
> org.osgi.service.log.LogReaderService.addLogListener(LogListener)
>
> This would be a bit tricky, this listener would get LogEntry events asynchronously.  It could then turn around and call the Equinox
> Logger for the with the name "org.eclipse.equinox.logger" to force it into the persistent log (which shows up in the log view.
>
>  >
>  > > The one exception to this rule is when the LogEntry is of type
>  > ERROR, in that case the log will be sent to the
>  > > persistent eclipse log file BUT it WILL NOT be sent to the
>  > listeners registered with the org.eclipse.core.runtime.ILog.
>  > >
>  > > I'm unsure what you are trying to log, but if it is simply ERRORs
>  > then I would use the standard org.osgi.service.log.LogService
>  >
>  > I'm using it for all kinds of things. The particular dangerous case
>  > was logging
>  > profiling data at level INFO.
>  >
>  >
>
> Then I suggest you use your own logger name and use it to call org.eclipse.equinox.log.ExtendedLogService.getLogger(String) and use
> the Logger to log all your messages.  Then register a LogListener with the method
> org.eclipse.equinox.log.ExtendedLogReaderService.addLogListener(LogListener, LogFilter) with a filter that returns true only when
> the loggerName equals your logger name.  This LogListener would then turn around and call the Logger with the name
> "org.eclipse.equinox.logger" to post the messages to the persistent log.  Note this will also send the log to the pesky synchronous
> ILog listeners, but now we are on a separate thread.
>
> Tom
>
>
>
> _______________________________________________
> equinox-dev mailing list
> equinox-dev@xxxxxxxxxxx
> To change your delivery options, retrieve your password, or unsubscribe from this list, visit
> https://dev.eclipse.org/mailman/listinfo/equinox-dev