[libvirt] Memory free in libvirt JNA

[Daniel Veillard]

On Sun, Sep 09, 2012 at 02:09:45PM +0000, Benjamin Wang (gendwang) wrote:
> Hi,
>    I wrote a code to verify the memory leak problem as following.
> C code in so:
> void checkJNAMemLeak1(int **head, int *length)
> {
>     long i = 0;
> 
>     *head = (int *)malloc(sizeof(int) * 100000000);
>     for(i=0; i<100000000; i++)
>     {
>         (*head)[i] = 1;
>     }
> 
>     *length = 100000000;
> }
> 
> Java code:
> 	public static void testJNAMemLeak1()
> 	{
> 		PointerByReference head = new PointerByReference();
> 		IntByReference length = new IntByReference();
> 		
> 		while(true)
> 		{
> 			libben.checkJNAMemLeak1(head, length);
> 			System.out.println(length.getValue());
> 			sleep(1);
> 			
> 		}
> 	}
> 
> When we check memory by top command, the virt and res will increase very quickly. When we check with jconsole, there is no memory in Java heap. Even I execute GC manually by jconsole. Nothing happen.
> 
> If I change java code as following:
> 	public static void testJNAMemLeak1()
> 	{
> 		PointerByReference head = new PointerByReference();
> 		IntByReference length = new IntByReference();
> 		
> 		while(true)
> 		{
> 			libben.checkJNAMemLeak1(head, length);
> 			System.out.println(length.getValue());
> 			sleep(1);
> 			
> 			libc.free(head.getValue());
> 		}
> 	}
> 
> 	public static void testJNAMemLeak1()
> 	{
> 		PointerByReference head = new PointerByReference();
> 		IntByReference length = new IntByReference();
> 		
> 		while(true)
> 		{
> 			libben.checkJNAMemLeak1(head, length);
> 			System.out.println(length.getValue());
> 			sleep(1);
> 			
> 			libc.free(head.getValue());
> 		}
> 	}
> 
> Then everything works well. The virt and res will not increase.
> I think we must provide the free functions for all the memory allocated by libvirt.

  Okay, can you work on making a patch ? To be honnest I'm very unlikely
  to have time for this in the short term,

Daniel

-- 
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