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best schematic capture/board editor program to learn for professional world?

  • Thread starter Michael J. Noone
  • Start date
K

Keith Williams

Exactly. I've been studying "Thinking in C++", in an attempt to learn
something, and the guy practically harps on memory leaks. "Watch out
for this bug, because it will give you a memory leak..."

I had always kind of thought that the OS was responsible for allocating
memory - what's the mechanism of a memory leak? Is it that the app
will request memory from the OS and not return it? In other words,
will the OS free all of the memory that the crappy app forgot to
release, or is it gone until you reboot?

The OS can't possibly know the app is done with the memory it's
allocated until the app releases it. If it doesn't, it's a memory
leak. The memory *may* be returned to the pool when the program
terminates, or maybe not.
 
J

John Woodgate

I read in sci.electronics.design that Keith Williams <[email protected]>
wrote (in <[email protected]>) about 'best
schematic capture/board editor program to learn for professional
world?', on Tue, 13 Sep 2005:
The OS can't possibly know the app is done with the memory it's
allocated until the app releases it. If it doesn't, it's a memory
leak. The memory *may* be returned to the pool when the program
terminates, or maybe not.

I understand that apps can also leak into areas of memory that they have
no business to be writing to.
 
K

Keith Williams

I read in sci.electronics.design that Keith Williams <[email protected]>
wrote (in <[email protected]>) about 'best
schematic capture/board editor program to learn for professional
world?', on Tue, 13 Sep 2005:


I understand that apps can also leak into areas of memory that they have
no business to be writing to.
I don't believe that's a memory "leak", per se. A "Memory leak" is
where memory is claimed and not returned to the free pool, causing
memory to be continually consumed. Sooner or later the system runs out
of even virtual memory and the universe ends.
 
R

Rich Grise

I read in sci.electronics.design that Keith Williams <[email protected]>
wrote (in <[email protected]>) about 'best
schematic capture/board editor program to learn for professional world?',


I understand that apps can also leak into areas of memory that they have
no business to be writing to.

That's why there's Linux. ;-D

Cheers!
Rich
 
D

David Brown

John said:
I read in sci.electronics.design that Keith Williams <[email protected]>
wrote (in <[email protected]>) about 'best
schematic capture/board editor program to learn for professional
world?', on Tue, 13 Sep 2005:

If a program requests memory and does not return it when finished, it's
the program's fault. If this leak causes the OS to crash because it
hands out memory continuously until it falls over, it is the OS's fault
(as windows may do). If the OS doesn't automatically free all the
program's memory when it is killed, then you are the proud owner of Win9x!
I understand that apps can also leak into areas of memory that they have
no business to be writing to.

That's only possible if the OS doesn't properly implement memory
management and inter-process security. In other words, it happens on
Win9x, but not on WinNT (including W2K and XP) or real OS's.
 
W

Winfield Hill

David Brown wrote...
If a program requests memory and does not return it when finished, it's
the program's fault. If this leak causes the OS to crash because it
hands out memory continuously until it falls over, it is the OS's fault
(as windows may do). If the OS doesn't automatically free all the
program's memory when it is killed, then you are the proud owner of Win9x!


That's only possible if the OS doesn't properly implement memory
management and inter-process security. In other words, it happens on
Win9x, but not on WinNT (including W2K and XP) or real OS's.

Yes and no. If I close all my open programs, Win-XP sometimes recovers,
but not always; frequently a reboot is required. The operating system
may indeed restore the lost memory if the application is terminated, but
I know many applications are rarely or never terminated. Whatever the
explanation, the painful scourge of memory leaks is alive and kicking.

Interesting factoid, my computer running Win-XP is far less stable than
my computer running Win-2000. This wasn't true at first, but degradation
of my Win-XP computer set in rapidly. BTW, it's treated with kid gloves,
behind a firewall, doesn't even run an email program, full security progs.
 
J

Jim Thompson

David Brown wrote...

Yes and no. If I close all my open programs, Win-XP sometimes recovers,
but not always; frequently a reboot is required. The operating system
may indeed restore the lost memory if the application is terminated, but
I know many applications are rarely or never terminated. Whatever the
explanation, the painful scourge of memory leaks is alive and kicking.

Interesting factoid, my computer running Win-XP is far less stable than
my computer running Win-2000. This wasn't true at first, but degradation
of my Win-XP computer set in rapidly. BTW, it's treated with kid gloves,
behind a firewall, doesn't even run an email program, full security progs.

Yep. Watching other's experiences with XP, I've stuck with Win2K.

...Jim Thompson
 
M

martin griffith

Yep. Watching other's experiences with XP, I've stuck with Win2K.

...Jim Thompson
Fat chance of finding a PDF reader that works, and isn't written by
those Adobe wankers?


martin
 
W

Winfield Hill

martin griffith wrote...
Fat chance of finding a PDF reader that works, and isn't
written by those Adobe wankers?

What's pdf-file software got to do with Win2k or WinXP?
 
J

Joerg

Hello Winfield,
Yes and no. If I close all my open programs, Win-XP sometimes recovers,
but not always; frequently a reboot is required. The operating system
may indeed restore the lost memory if the application is terminated, but
I know many applications are rarely or never terminated. Whatever the
explanation, the painful scourge of memory leaks is alive and kicking.

Tell me about it. For the new lab PC they didn't give me a joice
anymore. No, couldn't "downgrade" to NT this time, I had to accept XP.
What a pain.

The worst is the persistent bugging for attention by bubbles. They threw
in McAfee and it constantly splashes a stupid window over anything you
are working on. "Your computer needs an update and is in danger
blah...blah...blah". I turned everything off I could, didn't get rid of
it. Next is an un-install I guess.
Interesting factoid, my computer running Win-XP is far less stable than
my computer running Win-2000. This wasn't true at first, but degradation
of my Win-XP computer set in rapidly. BTW, it's treated with kid gloves,
behind a firewall, doesn't even run an email program, full security progs.

Same here. Not happy with XP at all. In the end none of these "operating
systems" is as good as DOS.

Regards, Joerg
 
J

Jim Thompson

Hello Winfield,


Tell me about it. For the new lab PC they didn't give me a joice
anymore. No, couldn't "downgrade" to NT this time, I had to accept XP.
What a pain.

The worst is the persistent bugging for attention by bubbles. They threw
in McAfee and it constantly splashes a stupid window over anything you
are working on. "Your computer needs an update and is in danger
blah...blah...blah". I turned everything off I could, didn't get rid of
it. Next is an un-install I guess.


Same here. Not happy with XP at all. In the end none of these "operating
systems" is as good as DOS.

Regards, Joerg

When I last bought PC's, 3 last summer, they only offered XP. I chose
NONE for OS, and put Win2K on all three ;-)

...Jim Thompson
 
W

Wouter van Ooijen

He specifically suggested orcad and pcad. I just
thought it'd be best to get a second opinion, though I expect he knows
what he's talking about. What do you all think? Thanks,

IIRC Eagle has not been around as long as the ones you mention.
Inertia has a strong relation to the size of a company, so chances are
high that a big company will not even know Eagle exists.

Most newcomers to PCB design seem to prefer Eagle, for whatever
reason.

But what does it matter? If you want to work for a certain class of
companies it makes sense to get yourself at least some experience in
the software they like to see on your resume.


Wouter van Ooijen

-- ------------------------------------
http://www.voti.nl
Webshop for PICs and other electronics
http://www.voti.nl/hvu
Teacher electronics and informatics
 
J

JeffM

When I last bought PC's, 3 last summer, they only offered XP.
I chose NONE for OS, and put Win2K on all three ;-)
Jim Thompson

Vendor?
Price differential?
 
J

John Larkin

When I last bought PC's, 3 last summer, they only offered XP. I chose
NONE for OS, and put Win2K on all three ;-)

...Jim Thompson


Both my new Dells came with XP/SP2 installed. A number of things about
XP are stupid and annoying, but they are very reliable and seem to run
fine for weeks at a time. The Dells themselves are crap, at least as
far as packaging and ergonomics go.

John
 
M

Michael A. Terrell

John said:
Both my new Dells came with XP/SP2 installed. A number of things about
XP are stupid and annoying, but they are very reliable and seem to run
fine for weeks at a time. The Dells themselves are crap, at least as
far as packaging and ergonomics go.

John


Just wait till you need parts. I scrap almost every Dell I get my
hands on because nothing fits other systems and the Dells all have
similar component failures. Only one worked at all, and the on board
IDE ports are bad. Most of them have bad electrolytic capacitors and
blown power supplies.
 
J

John Woodgate

I read in sci.electronics.design that Winfield Hill
about 'best schematic capture/board editor program to learn for
professional', on Tue, 13 Sep 2005:
Interesting factoid, my computer running Win-XP is far less stable
than
my computer running Win-2000. This wasn't true at first, but
degradation
of my Win-XP computer set in rapidly. BTW, it's treated with kid
gloves,
behind a firewall, doesn't even run an email program, full security
progs.

Do you run any app to clear trash out of the machine? I find WinXP SP2
requires the occasional spring-clean, not as often as Win98. I've not
used Win2k.
 
T

Tony Williams

Winfield Hill said:
Interesting factoid, my computer running Win-XP is far less
stable than my computer running Win-2000. This wasn't true at
first, but degradation of my Win-XP computer set in rapidly.
BTW, it's treated with kid gloves, behind a firewall, doesn't
even run an email program, full security progs.

Hello Win. Are you by any chance suffering the XP GDI
Objects bug? This is where various lumps of software
request, and are assigned, GDI handles. The bug allows
some software to acquire thousands of handles, which
drastically slows down the computer.

To look at this: Move to an empty space on the icon bar
along the bottom, right-click, and select 'Task Manager'
from the menu.

From the TM menu select 'processes', then 'view'. In the
view menu, select 'columns', and untick everything except
'user name' and 'GDI Objects'. OK/close the view menu.

The processes window should now show a listing of software
names, who is the user of that software, and the count of
GDI objects assigned to each. Each count should be in the
10's for most software, with just a few 100's.

Make a rough mental record of the counts, and minimise the
TM window. Throughout the day, open up the TM window and
check to see if any software is grossly accumulating handles.

For example. I'm monitoring a particular prog. When loaded
it has 95 GDI Objects assigned to it. When doing a certain
action it gets about 10 more, but when closing the action it
does not release them. In just a few minutes it is up to
about 270, and people have reported 8000-10000 at the end of
the day.... XP running seriously slugged.

I believe that Microsoft have issued a fix for this.
 
T

The Real Andy

Hello Win. Are you by any chance suffering the XP GDI
Objects bug? This is where various lumps of software
request, and are assigned, GDI handles. The bug allows
some software to acquire thousands of handles, which
drastically slows down the computer.

To look at this: Move to an empty space on the icon bar
along the bottom, right-click, and select 'Task Manager'
from the menu.

From the TM menu select 'processes', then 'view'. In the
view menu, select 'columns', and untick everything except
'user name' and 'GDI Objects'. OK/close the view menu.

The processes window should now show a listing of software
names, who is the user of that software, and the count of
GDI objects assigned to each. Each count should be in the
10's for most software, with just a few 100's.

Make a rough mental record of the counts, and minimise the
TM window. Throughout the day, open up the TM window and
check to see if any software is grossly accumulating handles.

For example. I'm monitoring a particular prog. When loaded
it has 95 GDI Objects assigned to it. When doing a certain
action it gets about 10 more, but when closing the action it
does not release them. In just a few minutes it is up to
about 270, and people have reported 8000-10000 at the end of
the day.... XP running seriously slugged.

I believe that Microsoft have issued a fix for this.

Disable themes, problem gone. I have tried to reproduce this behaviour
with no success. According to MS it only affects MFC child windows, so
the problem is limited. There is a hotfix available.
 
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