Method testDLLCallback

test/com/sun/jna/CallbacksTest.java:1443–1517

()

    }

    public void testDLLCallback() throws Exception {
        if (!Platform.HAS_DLL_CALLBACKS) {
            return;
        }

        final boolean[] called = { false };
        class TestCallback implements TestLibrary.VoidCallback, com.sun.jna.win32.DLLCallback {
            @Override
            public void callback() {
                called[0] = true;
            }
        }

        TestCallback cb = new TestCallback();
        lib.callVoidCallback(cb);
        assertTrue("Callback not called", called[0]);

        // Check module information
        Pointer fp = CallbackReference.getFunctionPointer(cb);
        NativeLibrary kernel32 = NativeLibrary.getInstance("kernel32", W32APIOptions.DEFAULT_OPTIONS);
        Function f = kernel32.getFunction("GetModuleHandleExW");
        final int GET_MODULE_HANDLE_FROM_ADDRESS = 0x4;
        PointerByReference pref = new PointerByReference();
        int result = f.invokeInt(new Object[] { Integer.valueOf(GET_MODULE_HANDLE_FROM_ADDRESS), fp, pref });
        assertTrue("GetModuleHandleEx(fptr) failed: " + Native.getLastError(), result != 0);

        f = kernel32.getFunction("GetModuleFileNameW");
        char[] buf = new char[1024];
        result = f.invokeInt(new Object[] { pref.getValue(), buf, buf.length });
        assertTrue("GetModuleFileName(fptr) failed: " + Native.getLastError(), result != 0);

        f = kernel32.getFunction("GetModuleHandleW");
        Pointer handle = f.invokePointer(new Object[] { Native.jnidispatchPath != null ? Native.jnidispatchPath : "jnidispatch" });
        assertNotNull("GetModuleHandle(\"jnidispatch\") failed: " + Native.getLastError(), handle);
        assertEquals("Wrong module HANDLE for DLL function pointer", handle, pref.getValue());

        // Check slot re-use
        Map<Callback, CallbackReference> refs = new WeakHashMap<>(callbackCache());
        assertTrue("Callback not cached", refs.containsKey(cb));
        CallbackReference ref = refs.get(cb);
        refs = callbackCache();
        Pointer cbstruct = ref.cbstruct;
        Pointer first_fptr = cbstruct.getPointer(0);

        cb = null;
        System.gc();
        for (int i = 0; i < 100 && (ref.get() != null || refs.containsValue(ref)); ++i) {
            Thread.sleep(10); // Give the GC a chance to run
            System.gc();
        }
        assertNull("Callback not GC'd", ref.get());
        assertFalse("Callback still in map", refs.containsValue(ref));

        ref = null;
        System.gc();
        for (int i = 0; i < 100 && (cbstruct.peer != 0 || refs.size() > 0); ++i) {
            // Flush weak hash map
            refs.size();