How can I protect a Variable to be Garbage Collected

[msv1022]

Hi guys,

Been searching all over the net on how to protect a variable from garbage collected. I need some variables (tables) to be present and not be garbage collected since the application is running 24/7. I have tested that sometimes, the variable or tables that i have created was FREED (GCed).

Thanks in advance.

Regards,
msv1022

[JosAH]

Been searching all over the net on how to protect a variable from garbage collected. I need some variables (tables) to be present and not be garbage collected since the application is running 24/7. I have tested that sometimes, the variable or tables that i have created was FREED (GCed).

As long as there is a reference to the object in scope, the object won't be garbage collected. There is a transitive relation here: if 'a' refers to 'b' and (some part of) 'b' refers to an object and 'a' is in scope, the object won't be garbage collected.

kind regards,

Jos

[msv1022]

HI JosAH,

Thanks for your quick reply. But if the application is running for sometime let's say 7 days and there's no activity there will be a time that a vector of table or an object will be GCed. That table is needed and should not be collected at anytime. Is there such as as thing as:

class Test {
string b;
int c;
};

PROTECT_FROM_GC Test test = new Test();
//new object test should not be GCed even not used for 7 or 30 days

Thanks in advance

[JosAH]

HI JosAH,

Thanks for your quick reply. But if the application is running for sometime let's say 7 days and there's no activity there will be a time that a vector of table or an object will be GCed. That table is needed and should not be collected at anytime. Is there such as as thing as:

class Test {
string b;
int c;
};

PROTECT_FROM_GC Test test = new Test();
//new object test should not be GCed even not used for 7 or 30 days

Thanks in advance

As I wrote: as long as you refer to your object Test somewhere it won't be garbage collected. A blunt method is to keep a static reference to your Test object if it is just a singleton object:

private static Test test= new Test(); // will never be GC'd

kind regards,

Jos

[msv1022]

Thanks again. Just to put a little detailed example:

class IncNodeList inl {
String node;
int n;
}

protected Vector <IncNodeList> v;
public static NodeList nodes= new NodeList();
IncNodeList inl = new IncNodeList();
inl.node = "TestNode";
inl.n = 10;
v.addElement(inl);
IncNodeList inl2 = new IncNodeList();
inl2.node = "Node";
inl2.n = 20;
v.addElement(inl2);
---
---
---
in this example, is vector will not be GCed, and its members inl and inl2? Do i need to make the Vector static not protected?

[JosAH]

Thanks again. Just to put a little detailed example:

class IncNodeList inl {
String node;
int n;
}

protected Vector <IncNodeList> v;
public static NodeList nodes= new NodeList();
IncNodeList inl = new IncNodeList();
inl.node = "TestNode";
inl.n = 10;
v.addElement(inl);
IncNodeList inl2 = new IncNodeList();
inl2.node = "Node";
inl2.n = 20;
v.addElement(inl2);
---
---
---
in this example, is vector will not be GCed, and its members inl and inl2? Do i need to make the Vector static not protected?

For the third time: keep a reference to that object in scope and the object will not be garbage collected; your example is too convoluted; note that the reference doesn't need to be static but then again, the reference is an element of another object and you have to keep a reference to that other object in scope to prevent garbage collection. Static references are class members and classes are never unloaded/collected. Nor does the reference need to be protected or private or whatever; it's up to you.

kind regards,

Jos

[msv1022]

ok thanks so much Jos for your advise.

[Toll]

EDIT: Ignore, please. Accursed habit of opening up tabs and not looking at them for a long while.