[libvirt] Libvir JNA report SIGSEGV

[Benjamin Wang (gendwang)]

Hi,
   The problem only occurs in JNA part. The pure c libvirt works well.  Even If I only create a connection outside of the loop, the 
problem can still happen. The following is the easiest problem to reproduce this problem

    public static void testcase1() throws LibvirtException
    {
        Connect conn=null;
        
        //connect to the hypervisor
        conn = new Connect("esx://10.74.125.69:443/?no_verify=1&transport=https", new ConnectAuthDefault(), 0);
        
        while(true)
        {
        	int[] array = new int[100000000];
        	
        	try
        	{
        		Thread.sleep(1000);
        	}
        	catch(Exception e){}
        }
    }

B.R.
Benjamin Wang

-----Original Message-----
From: Daniel Veillard [mailto:veillard at redhat.com] 
Sent: 2012年9月6日 15:49
To: Benjamin Wang (gendwang)
Cc: libvir-list at redhat.com; Yang Zhou (yangzho)
Subject: Re: [libvirt] Libvir JNA report SIGSEGV

On Wed, Sep 05, 2012 at 08:59:07AM +0000, Benjamin Wang (gendwang) wrote:
> Hi,
>   I try to verify the JNA with concurrent situation but meet some problems. The following is my example code:
>     public static void testcase1() throws LibvirtException
>     {
>         Connect conn=null;
>         Connect conn1=null;
> 
>         //connect to the hypervisor
>         conn = new Connect("esx://10.74.125.68:443/?no_verify=1&transport=https", new ConnectAuthDefault(), 0);
>         System.out.println(conn.getVersion());
> 
>         //connect to the hypervisor
>         conn1 = new Connect("esx://10.74.125.90:443/?no_verify=1&transport=https", new ConnectAuthDefault(), 0);
>         System.out.println(conn1.getVersion());
> 
> 
>         while(true)
>         {
>                 int[] array = new int[100000000];
>                 Long version = conn.getVersion();
>                 Long version1 = conn1.getVersion();
> 
>                 try
>                 {
>                          Thread.sleep(1000);
>                 }
>                 catch(Exception e)
>                 {
>                 }
>         }
> }
> 
> When I add line "int[] array = new int[100000000]", then the following error will be generated very quickly:
> # An unexpected error has been detected by Java Runtime Environment:
> #
> #  SIGSEGV (0xb) at pc=0x0000003f9b07046e, pid=30049, tid=1109510464 # 
> # Java VM: OpenJDK 64-Bit Server VM (1.6.0-b09 mixed mode linux-amd64) 
> # Problematic frame:
> # C  [libc.so.6+0x7046e]
> #
> # An error report file with more information is saved as:
> 
> I have tried to write the similar code as following. It works well.
> static void virXenBasic_TC001(void)
> {
>     virConnectPtr conn = NULL;
>     virConnectPtr conn1 = NULL;
>     unsigned long version = 0;
>     unsigned long version1 = 0;
>     char *hostname = NULL;
> 
>     conn = virConnectOpenAuth("esx://10.74.125.21/?no_verify=1", virConnectAuthPtrDefault, 0);
>     if (conn == NULL) {
>         fprintf(stderr, "Failed to open connection to qemu:///system\n");
>         return;
>     }
> 
>     conn1 = virConnectOpenAuth("esx://192.168.119.40/?no_verify=1", virConnectAuthPtrDefault, 0);
>     if (conn1 == NULL) {
>         fprintf(stderr, "Failed to open connection to qemu:///system\n");
>         return;
>     }
> 
>     while(true)
>     {
>         hostname = malloc(sizeof(char) * 100000000);
>         virConnectGetVersion(conn, &version);
>         virConnectGetVersion(conn, &version1);
>         free(hostname);
>         sleep(1);
>     }
>     return;
> }

Maybe you need to increase the stack or memory size of you java process or something, that doesn't look related to libvirt at all in my opinion.
Well maybe the bindings fails somewhere at checking for an allocation error, but is it in JNA ?

Daniel

-- 
Daniel Veillard      | libxml Gnome XML XSLT toolkit  http://xmlsoft.org/
daniel at veillard.com  | Rpmfind RPM search engine http://rpmfind.net/ http://veillard.com/ | virtualization library  http://libvirt.org/