[Glass] Trying to NOT run out of gem space while having a decent profiling sample resolution

[Mariano Martinez Peck via Glass]

On Mon, May 29, 2017 at 7:29 PM, Mariano Martinez Peck <
marianopeck at gmail.com> wrote:

> Hi guys,
>
> Allen Otis suggested me a nice idea to use #computeInterval: so that I can
> get a decent number of samples based on the approx total time rather than a
> fixed interval value. The problem is, of course, the higher the sampling,
> the more gem temp space I need. I already increased my gem temp space quite
> a bit, but for certain scenarios I am still running out of memory.
> Basically, the profiler outputs:
>
> There was an error trying to profile: *a Error occurred (error 2517), 2
> failed attempts to signal AlmostOutOfMemory*
>
> So... besides the obvious solution of increase and increasing and
> increasing the gem temp space, I tried something similar to what I do with
> sixx...basically.. make that temp space to be persistence and do the stuff
> inside a memory handler that commits under pressure.
>
> My code looks like this:
>
> profile: aBlock estimatedTotalCpuTime: totalCpuTime tallyThreshold:
> tallyThreshold writingReportOn: aStream
>   "Profiles aBlock with a sample of miliseconds and writes the resulting
> report (limited to tallyThreshold number of invokations of a given method)
> into aStream "
>
>   | profMon startTime endTime persistentKey persistentDict |
>   persistentKey := ('PROFMONITOR' , Object new identityHash asString)
> asSymbol.
>   persistentDict := UserGlobals
>     at: #'ProfMonitorRoots'
>     ifAbsentPut: [ RcKeyValueDictionary new ].
>   [
>   FACompatibilityUtils current
>     commitOnAlmostOutOfMemoryDuring: [
>       startTime := System _timeGmtFloat.
>       profMon := ProfMonitorTree new.
>       persistentDict at: persistentKey put: profMon.
>       profMon intervalNs: (profMon class computeInterval: totalCpuTime) *
> 4.
>       profMon startMonitoring.
>       [ aBlock value ]
>         ensure: [
>           "This #ensure: is very important because the closure we are
> profiling may raise a signal... (like seaside request processing which uses
> notifications)..so without the #ensure: we do not write the report
> anywhere..."
>           [
>           endTime := System _timeGmtFloat.
>           profMon stopMonitoring.
>           profMon gatherResults.
>           aStream
>             nextPutAll:
>                 'Total time: ' , ((endTime - startTime) * 1000) asInteger
> asString;
>             cr;
>             cr.
>           aStream
>             nextPutAll: (profMon reportDownTo: tallyThreshold);
>             cr.
>           profMon removeResults ]
>             on: Error
>             do: [ :ex | aStream nextPutAll: 'There was an error trying to
> profile: ' , ex printString ] ] ]
>     threshold: 80 ]
>     ensure: [
>       persistentDict removeKey: persistentKey ifAbsent: [  ].
>       System commit ]
>
>
> What I cannot understand is that WITHOUT the #
> commitOnAlmostOutOfMemoryDuring:threshold:   logic, I only get the out of
> memory problem in a few scenarios (those scenarios that are really big).
>
> Now, WITH the logic of  #commitOnAlmostOutOfMemoryDuring:threshold: I
> thought I should get none (ideally) out of memory problem as the samples
> are now persistent. Yet... the funny part is that I am getting above error
> for every single profile I do..even for small ones. WTF!
>
> I am clearly doing something wrong, but I cannot see it.
>
> What does it mean exactly the exception *" 2 failed attempts to signal
> AlmostOutOfMemory" *????  How can someone fail to signal the exception ?
> What can I do so that it doesn't fail ?
>
>
>
BTW, I forgot to say I am able to create a continuation for the exception
and debug it.

Attached is the stack that throws that exception.



-- 
Mariano
http://marianopeck.wordpress.com
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