[c2] MRUMemoryStore: can this really work?

[Gerhard Froehlich <g-...@gmx.de>]

Hi,
Because of Vadims entitled objections I just overlooked the cleanupthread
in the MRUMemoryStore.
When I developed this store I overtaken this thread from the MemoryStore
of cocoon1 with the believe that it works.

But thinking a little bit about it, I have my doubts that the while
loop below works.
The free() method removes the last element of the cache. But it's
guaranteed that memory is immediately deallocated? The gc()is thread
with minor priority and I have the apprehension that due this case
this algorithm doesn't work right.

What do you think out there?
<snip>
if (this.jvm.totalMemory() - this.jvm.freeMemory() > this.heapsize) {
  this.jvm.runFinalization();
  this.jvm.gc();
  synchronized (this) {
    while ((this.cache.size() > 0) && (this.jvm.freeMemory() <
this.freememory)) {
      this.free();
     }
  }
}
</snip>

Greets
Gerhard


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AW: [c2] MRUMemoryStore: can this really work?

[Gerhard Froehlich <g-...@gmx.de>]

Hmm, now I have a guilty conscience. In the cocoon1
project the gc() is forced in the free() method.
_sorry_ cocoon1ers for blaming you!

I think we can overtake the implementation.

But I have still doubts that memory is deallocated
immediately and that the memory calculation is
exact even if the gc() is forced after freeing
memory.

append a patch with the changes against the
2.1 branch.

Some side questions. Do I have to synchronize
the method in the store?

cheers
gerhard
>-----Ursprüngliche Nachricht-----
>Von: Gerhard Froehlich [mailto:g-froehlich@gmx.de]
>Gesendet: Saturday, August 25, 2001 12:29 AM
>An: cocoon
>Betreff: [c2] MRUMemoryStore: can this really work?
>
>
>Hi,
>Because of Vadims entitled objections I just overlooked the cleanupthread
>in the MRUMemoryStore.
>When I developed this store I overtaken this thread from the MemoryStore
>of cocoon1 with the believe that it works.
>
>But thinking a little bit about it, I have my doubts that the while
>loop below works.
>The free() method removes the last element of the cache. But it's
>guaranteed that memory is immediately deallocated? The gc()is thread
>with minor priority and I have the apprehension that due this case
>this algorithm doesn't work right.
>
>What do you think out there?
><snip>
>if (this.jvm.totalMemory() - this.jvm.freeMemory() > this.heapsize) {
>  this.jvm.runFinalization();
>  this.jvm.gc();
>  synchronized (this) {
>    while ((this.cache.size() > 0) && (this.jvm.freeMemory() <
>this.freememory)) {
>      this.free();
>     }
>  }
>}
></snip>
>
>Greets
>Gerhard
>
>
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