Re: Jawin failing after large number of object creations/uses

Sun 1.5.0_04

Josh Passenger wrote:

> What JVM are you using?
>
> Josh
>
>>
>> Hi
>>
>> I've been testing Jawin with the view to using it in some applications
>> that run in app-servers.
>> The key point for me is that the applications will run for a very long
>> time, without being restarted.
>>
>> I've run a few tests with various common COM components where objects
>> are repeatedly created, used and released.
>> All of the tests I've run eventually fail after a large number of
>> executions (depending on the particular COM object this can be 200,000
>> -> 50,000,000).
>>
>> In all cases when the programme fails, the JVM locks.
>> Dumping the threads for the process reveals that the JVM is stuck in a
>> native method trying to print an exception stack trace, although any
>> attempts to print anything at this point fail (even String constants).
>> Running in a debugger reveals that a ComError is the error being thrown
>> - after which the running Thread gets deadlocked in
>> ClassLoader.findBootstrapClass( "java.util.Arrays" ) <native>.
>> My guess is that this is some kind of native resource exhaustion for the
>> process, which is why the JVM native methods are blocking.
>> The memory and virtual memory for the JVM process is pretty much static
>> throughout the run, and the Threads, Handles, GDI Object and User Object
>> counts are also static.
>> The Access Violation address (0x6D64A9DE) is inside the jvm.dll range
>> (0x6D640000)  (i.e. not in jawin.dll).
>>
>> Has anyone seen this behaviour before, or have any ideas as to the
>> cause?
>>
>> Some other (fairly unsubstantiated) observations:
>> - failure seems to happen earlier when an STA thread is used (object is
>> Both threaded).
>> - failure seems to happen later when the thread is
>> CoInitialize/CoUnitialized for each object creation, and later still if
>> a single object is allocated and used repeatedly.
>>
>> tim
>>
>>
>> ComError:
>> -----------
>> detailMessage= "Access Violation at 0x6D64A9DE, thread attempts to write
>> at 0x830bec (description: The thread attempted to read from or write to
>> a virtual address for which it does not have the appropriate access)"
>> hresult= -2147418113
>>
>> Test method:
>> --------------
>>    public static void main(String[] args) throws Exception {
>>        Ole32.CoInitialize(COINIT.MULTITHREADED);
>>        try {
>>
>>            int i = 0;
>>            while (true) {
>>                DispatchPtr xr = new
>> DispatchPtr("Msxml2.DOMDocument.5.0");
>>
>>                Boolean load = (Boolean)xr.invoke( "loadXML",
>> "<foo>stuff</foo>" );
>>
>> //                System.out.println( load );
>> //                System.out.println( xr.get( "xml" ) );
>>
>>                if (i % 100000 == 0) {
>>                    System.out.println(i);
>>                }
>>                i++;
>>                xr.close();
>>            }
>>        } catch (Error e) {
>>            e.printStackTrace();
>>        }
>>        Ole32.CoUninitialize();
>>    }
>