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I would like to know the amount of heap space used by my android application in two ways: - programmatically - through DDMS.

I have referred to this post, prior to posting here. In that post, it is mentioned that, Debug.getNativeHeapSize() returns the heapsize. Is this the exact method I should use, in order to programmatically detect the heap size? If so, where should I log it in order to get the correct heapsize usage of my application?

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user264953
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    In this post http://stackoverflow.com/questions/2298208/how-to-discover-memory-usage-of-my-application-in-android Dianne provides a ton of information that may help. – Charlie Collins Jan 27 '11 at 19:52

2 Answers2

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here's what I use:

public static void logHeap() {
        Double allocated = new Double(Debug.getNativeHeapAllocatedSize())/new Double((1048576));
        Double available = new Double(Debug.getNativeHeapSize())/1048576.0;
        Double free = new Double(Debug.getNativeHeapFreeSize())/1048576.0;
        DecimalFormat df = new DecimalFormat();
        df.setMaximumFractionDigits(2);
        df.setMinimumFractionDigits(2);

        Log.d("tag", "debug. =================================");
        Log.d("tag", "debug.heap native: allocated " + df.format(allocated) + "MB of " + df.format(available) + "MB (" + df.format(free) + "MB free)");
        Log.d("tag", "debug.memory: allocated: " + df.format(new Double(Runtime.getRuntime().totalMemory()/1048576)) + "MB of " + df.format(new Double(Runtime.getRuntime().maxMemory()/1048576))+ "MB (" + df.format(new Double(Runtime.getRuntime().freeMemory()/1048576)) +"MB free)");
    }
zrgiu
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Yes. Please note that also there are heap view in DDMS and you can use MAT Eclipse which is more than helpful especially in memory leaks tracking BUT and this is a huge but the numbers you see are reference only memory that is managed by VM. There are a lot of subsystems in android that are implemented underneath VM - native. The simplest example Bitmap class. You will not see the whole memory allocated to a Bitmap in DDMS and garbage collector is not very good/fast at recovering this memory. so be careful.

Boris Daich
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