This is not very precise. You are referring to garbage collection in
general. Reference counting as it used to be defined in the original COM
specification for DLL and statically linked objects specifically states that
the object will be destroyed as soon as the last reference to it is lost.
The non deterministic garbage collector is the exact reason we don't have
stable Java programs, and they al tend to leak, and crash the systems. There
is no Garbage collection per say for resources, and there is no function
enclosement either. .NET has number of ugly language extensions "patches" to
work around that in C#, but this is a whole different story. To be able to
work with resources we have to have a tight control over their lifespan.
otherwise we are in a grave danger of crashes. We can surely revert to the
old days of doing that with functional programming, as Java developers tend
to do, but that has all the disadvantages and dangers of functional
programming. OOP is supposed to assist us in writing safe code, not endanger
us.
With best regards,
Boian Mitov
--------------------------------------------------------------------
Mitov Software
http://www.mitov.com
--------------------------------------------------------------------
----- Original Message -----
From: "Jonas Maebe" <[EMAIL PROTECTED]>
To: "FPC developers' list" <fpc-devel@lists.freepascal.org>
Sent: Thursday, June 19, 2008 5:55 AM
Subject: Re: [fpc-devel] Need patch for bugs : 0011503 / 0009472
Reference counting only guarantees that
a) an instance will not be freed as long as any references to it exist
b) an instance will be freed automatically after the last reference
disappears
It does not guarantee/define
a) at which point in the code exactly an instance will be freed
b) the actual mechanism used for reclaiming the memory (a simple free
when the reference count hits zero, mark and sweep, ...)
It is therefore not a substitute for managing other kinds of resources
which require predictable freeing points. The above example is
conceptually identical to several of the examples given in the comments
to http://bugs.freepascal.org/view.php?id=9472
It's similar to how you cannot use the Finalize method in Java to perform
resource management, because it will only be called when the garbage
collector reaps your instance and not necessarily immediately when the
last reference to an instance is gone.
Jonas
_______________________________________________
fpc-devel maillist - fpc-devel@lists.freepascal.org
http://lists.freepascal.org/mailman/listinfo/fpc-devel
_______________________________________________
fpc-devel maillist - fpc-devel@lists.freepascal.org
http://lists.freepascal.org/mailman/listinfo/fpc-devel
