CPU Usage and A5

[Bob Houle]

Concerning the CPU Usage issue of Alpha Five (both version 4.5 and 5).

I've tried using the -NODBCHECK switch, but haven't had any success.
(I asked Cian for a usage sample, but haven't gotten a reply yet. See Msg ID: 2383)

While waiting for the above help, I decided to use a small program that shows
CPU usage while 'ANY' programs are running. The scale is 0 to 100%. I've included
it so you can try it yourselves. (AlphaCPU.ZIP above)

It shockingly shows Alpha Five using 100% of the CPU time! Because
Alpha does not insist on a 'high' process priority, I'm at least able to have my
CPU program return results when Alpha does give up a time slice.

While that may not be much of a concern to a single user running only their
Alpha program, it really impacts anyone running multiple programs on a single machine
or anyone running Alpha on a machine that doles out data to others on a network.

Any other program being used this way will have it's performance severely limited.

Thinking that it might only react in this manner because I had developed forms with
unusual controls, such as a tab control, I stripped everything down to a minimum.
But it appears as if Alpha itself is the user of all the available CPU cycles.

Start Alpha and unload any program you've developed. The CPU Monitor still shows 100% use.
As soon as you highlight a menu item (e.g. Help then About), the CPU usage drops to ZERO.

Since Alpha exhibits 100% CPU usage even when no programs are loaded, I'm not too sure the
-NODBCHECK switch would work. I kinda think this is a cludgy fix anyway. Developers shouldn't
need to resort to things like this to be Windows compatible.

Well lets hope we get this critical issue resolved. Perhaps some information could be put in the
'Announcements' area so developers could be kept updated.

Perhaps I'm wrong about this issue and it's not that important. Let's hear from the experts.

Cian?

Best Regards,
--Bob

[BWilliams]

RE: CPU Usage and A5

I have noticed via task manager that while idle A5 takes 99% CPU usage, but I haven't noticed it degrading my performance. Is it just taking the place of system idle process?

[Finian Lennon]

RE: CPU Usage and A5

Bob:

Using the WinXP Pro Task Manager/Performance tab I see a different result. Loading A5V5 from a desktop shortcut without the -NODBCHECK switch, V5 processor usage climbs to 100% when a form is loaded and stays there for a good percentage of the time afterwards.

However, when I add the switch to the startup, the processor usage climbs briefly to 100% during a form load and drops back immediately after and only climbs back to to the 100% range during form loads or major script processing and then it is usually transient.

Finian

[David Day]

RE: CPU Usage and A5

How do you put the switch in? I know it used to be appexe -command. I tried that and got no where. What am I doing wrong?

[Van Jones]

RE: CPU Usage and A5

"C:\Program Files\A5V5\alpha5.exe" -NODBCHECK

My shortcut has the above in the target field and I don't experience the constant high cpu utilization when alpha5 is started from this shortcut. I also changed -NODBCHECK to -nodbcheck and it works either way, with the argument in lower case or upper case. Now, when I take the -nodbcheck off, then all available cpu is used by a5.

vkj

[David Day]

RE: CPU Usage and A5

Thanks for the correct syntax. I was including the -nodbcheck within the parenthesis. Havn't done that since Dos! Your are right too. It makes a big difference.

[Van Jones]

RE: CPU Usage and A5

I noticed that there are more details as to the effect of using this switch in the FAQ.

>> (the side effect is that when you add forms or tables >> to a database they will not show up very quickly, and >> you may need to close/reopen the database

To the alpha guys: Would it be possible to add a button on the menu bar that would allow us to scan the adb on demand (for those of us that decide to use the -nodbcheck switch)? So if we create a new form or table, hit the button to refresh, instead of having to close/reopen the database?


Thanks,
vkj

[JerryBrightbill]

RE: CPU Usage and A5

The real question concerns the need for the checking in a runtime application. If the primary purpose for checking the adb file is to track changes, why include it in the runtime that the user can't change? Using the switch really reduces CPU usage. Maybe a switch option in settings would be appropriate.

Jerry

[Cian Chambliss]

RE: CPU Usage and A5

You are right - the runtime should not need this option since the user of a runtime app never changes the contents of an .ADB file - I will add that change to my 5.0 buglist.

[Brad Olson]

RE: CPU Usage and A5

Cian,

I notice the slowdown most when trying to import or print jpeg images with A5v5.

I'm only guessing at A5 internals here, but it seems to me A5 is doing some VERY persistent polling of the .adb for changes without the nodbcheck switch. Instead of "never" or "all the time" as the only two choices, might it be possible to let developers choose how often to check for changes. Even limiting the check to once per second and only when the control panel has focus would free up a lot of processor time.

[William Kohlnstein]

RE: CPU Usage and A5

This sounds great. Although I am waiting for my boss to get Ver 5 in the mail, (any day now,) this will let me leave it on while in development(speed for me) - but turn it off for users(computer speed for them). I presume that on a network, as long as ALL users have the same shortcut flag, then the servers CPUsage is what is controlled.

[Tom Cone Jr]

RE: CPU Usage and A5

William,

I would assume that the cpu usage on the machine that loads Alpha Five would be the one affected by the switch. If loaded at a workstation, I don't think the cpu on the server will be affected. Is my cap pointing in the wrong direction (again!) ?

-- tom

[William Kohlnstein]

RE: CPU Usage and A5

now that I think about it - by golly - you have to be right - since the runtime is on each workstation - thank's

[Brad Olson]

RE: CPU Usage and A5

Cian,

Again, guessing at internals, but what if the ADB scanning used file modify time as a test for needing to rescan, an algorithm something like this:

W = 500 ' Number of milliseconds to wait
L = 0 ' file date and time when last scanned

WHILE .t.
F = file_get_numeric_date_time( MyADBName)
if F > L then
L = F
Rescan MyADBName
end if
Pause this thread for W milliseconds
END WHILE

[Cian Chambliss]

RE: CPU Usage and A5

Yes it does do something like this. I suspect that the
constant locking the that 'structured store' .ADB file has a lot to do with all the time taken - I think that if we kept the list of tables & .ADB settings in a data dictionary (i.e. ALB) instead, it would be far more efficient.