[ajug-members] java object allocation and memory

[Wilson, Jeff]

Also note that calling GC explicitly doesn't guarantee anything in the
JSE VM. It is only a hint to the garbage collector; the VM may or may
not run GC in response.

+jeff (MJW)
---

"History will be kind to me for I intend to write it."
 -W. Churchill 

---------------------------------------------
M. Jeff Wilson, Lead Member Technical Staff
AT&T Services, Inc.
Operations & Service Dev
jw9615 at att.com 
+1 404.499.7235

-----Original Message-----
From: Wilson, Jeff 
Sent: Wednesday, September 10, 2008 9:29 AM
To: ajug-members at ajug.org
Subject: Re: [ajug-members] java object allocation and memory

Unless you are doing Real-Time programming, you shouldn't be calling GC
anyways. It runs whenever the VM wants to run it.

Predicting memory allocation is tricky in Java. The VM reserves all
kinds of memory areas [eden area, permanent area, others] and uses those
to allocate objects. In general the VM uses those pre-allocated memory
areas until it needs more, and then allocates more memory from the OS. 

Also, objects are typically very small.

+jeff (MJW)
---

"History will be kind to me for I intend to write it."
 -W. Churchill 

---------------------------------------------
M. Jeff Wilson, Lead Member Technical Staff
AT&T Services, Inc.
Operations & Service Dev
jw9615 at att.com 
+1 404.499.7235

-----Original Message-----
From: mcdaniel [mailto:521 at ofig.org] 
Sent: Tuesday, September 09, 2008 8:20 PM
To: ajug-members at ajug.org
Subject: Re: [ajug-members] java object allocation and memory

this makes it look like i was calling on the gc call to free memory but 
i was not; i did this w/ zero/none of them too- what keeps the 
freeMemory call's value close like those are?  why does it not go up
more?

barclay

mcdaniel wrote:
> why does the free-memory not change much with object allocation? - i 
> keep playing with this and don't see it...
> -attached-
>
> barclay
>
>
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>

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