Why have a static weakreference to service object?

Question

I've come across this android code below. Is there ever a use case of creating a static weakreference object in a service to get its reference? I know that static variables are not eligible for Garbage collection. In general, Does creating a weak reference of any static variable change its gc properties?

for example:

private static WeakReference<MyService> mService;
public static MyService getInstance(){
    if(mService != null){
          return mService.get();
    } 
    return null;
}

And in my onCreate

public void onCreate(){
   super.onCreate();
   mService = new WeakReference<MyService>(this);
}

score 6 · Accepted Answer · answered Feb 04 '15 at 01:15

6

The WeakReference is so the service can be garbage collected even if the activity still has a variable referring to it. The static means it will persist after the activity ends. So you get a reference to the Service that persists between calls but still allow the Service to be gced. (The WeakReference itself can't be GCed, but shouldn't take much in the way of memory).

answered Feb 04 '15 at 01:15

Gabe Sechan

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1

But if the variable is static it won't be eligible for gc right? So isn't static WeakReference an oxymoron? – Daniel P Feb 05 '15 at 01:37
2

No the week reference itself isn't gc-able. The reference it holds is – Gabe Sechan Feb 05 '15 at 02:14

Why have a static weakreference to service object?

1 Answers1