Attach native thread to jvm takes much time

Question

Hello everyone,
I attach a native thread to the jvm. It works but it takes about 10 seconds. I do not understand why and I would like to reduce this time to 1 or 2 seconds.
I use a native thread to get keyboard events (a hook) to capture a screen area (with Robot class).
Samples program :
Abstract class used by the thread :
class CATSrvThreadHandler
public:
CATSrvThreadHandler();
enum
enableCode = 1,
updateCode = 2,
disableCode = 3
virtual ~CATSrvThreadHandler();
virtual void doEnable() = 0;
virtual void doUpdate() = 0;
Herited class : class CATSrvScreenIndicator:public CATSrvThreadHandler
CATSrvScreenIndicator CATSrvScreenIndicator::extract(JNIEnv env, jobject object)
// Get field ID
jfieldID l_handlerId = env->GetFieldID(env->GetObjectClass(object), "_handler", "I");
// Get field
CATSrvScreenIndicator l_handler = (CATSrvScreenIndicator )env->GetIntField(object, l_handlerId);
return l_handler;
// This method is called by Java code to activate the thread
void CATSrvScreenIndicator::enable(JNIEnv *env)
g_DesktopIndicatorThread.MakeSureThreadIsUp(env);
// Takes too much time !!!! (about 5 seconds)
while(!PostThreadMessage(g_DesktopIndicatorThread, WM_DESKTOPINDICATOR, enableCode, (LPARAM)this))
Sleep(0);
The thread class :
CATSrvScreenCaptureThread::CATSrvScreenCaptureThread()
m_env = NULL;
m_thread = 0;
m_vm = NULL;
m_handlerCount = 0;
void CATSrvScreenCaptureThread::MakeSureThreadIsUp(JNIEnv *env)
if(!m_thread)
// --> Get VM
env->GetJavaVM(&m_vm);
// --> Start "native" thread
CreateThread(NULL, 0, ThreadProc, this, 0, &m_thread);
DWORD WINAPI CATSrvScreenCaptureThread::ThreadProc(LPVOID lpParameter)
CATSrvScreenCaptureThread l_this=(CATSrvScreenCaptureThread)lpParameter;
// --> Attach the thread to the VM, takes too much time !!!! (about 5 seconds)
l_this->m_vm->AttachCurrentThread((JNIEnv**)&l_this->m_env, NULL);
MSG msg;
while(GetMessage(&msg, NULL, 0, 0))
Thanks for any information !

Answer 1

It's ellapse time with no other application running
between this method call and tray icon appearing int
the taskbar.
Now I am not sure I understand the question.
To time how long a method call takes you must time the method - not just the code that the method runs in. And you need to use a timer and not just guess about it.