Java PhantomReference.clear方法代碼示例

import java.lang.ref.PhantomReference; //導入方法依賴的package包/類
/**
 * @tests java.lang.ref.Reference#clear()
 */
@TestTargetNew(
    level = TestLevel.COMPLETE,
    notes = "",
    method = "clear",
    args = {}
)
public void test_clear() {
    tmpA = new Object();
    tmpB = new Object();
    tmpC = new Object();
    SoftReference sr = new SoftReference(tmpA, new ReferenceQueue());
    WeakReference wr = new WeakReference(tmpB, new ReferenceQueue());
    PhantomReference pr = new PhantomReference(tmpC, new ReferenceQueue());
    assertTrue("Start: Object not cleared.", (sr.get() != null)
            && (wr.get() != null));
    assertNull("Referent is not null.", pr.get());
    sr.clear();
    wr.clear();
    pr.clear();
    assertTrue("End: Object cleared.", (sr.get() == null)
            && (wr.get() == null));
    assertNull("Referent is not null.", pr.get());
    // Must reference tmpA and tmpB so the jit does not optimize them away
    assertTrue("should always pass", tmpA != sr.get() && tmpB != wr.get());
}
 

import java.lang.ref.PhantomReference; //導入方法依賴的package包/類
/**
 * @tests java.lang.ref.PhantomReference#get()
 */
@TestTargetNew(
    level = TestLevel.COMPLETE,
    notes = "",
    method = "get",
    args = {}
)
public void test_get() {
    ReferenceQueue rq = new ReferenceQueue();
    bool = new Boolean(false);
    PhantomReference pr = new PhantomReference(bool, rq);
    assertNull("get() should return null.", pr.get());
    pr.enqueue();
    assertNull("get() should return null.", pr.get());
    pr.clear();
    assertNull("get() should return null.", pr.get());
}
 

import java.lang.ref.PhantomReference; //導入方法依賴的package包/類
private void processDeadParsedQueries() throws IOException {
    PhantomReference deadQuery;
    while ((deadQuery = (PhantomReference)parsedQueryCleanupQueue.poll()) != null)
    {
        String statementName = (String)parsedQueryMap.remove(deadQuery);
        sendCloseStatement(statementName);
        deadQuery.clear();
    }
}
 

import java.lang.ref.PhantomReference; //導入方法依賴的package包/類
private void processDeadPortals() throws IOException {
    PhantomReference deadPortal;
    while ((deadPortal = (PhantomReference)openPortalCleanupQueue.poll()) != null)
    {
        String portalName = (String)openPortalMap.remove(deadPortal);
        sendClosePortal(portalName);
        deadPortal.clear();
    }
}
 

import java.lang.ref.PhantomReference; //導入方法依賴的package包/類
public static void removeCleanupReference(PhantomReference<Object> ref) {
	if (ref == null) {
		return;
	}
	REFERENCES.remove(ref);
	ref.clear();
}
 

import java.lang.ref.PhantomReference; //導入方法依賴的package包/類
/**
 * See <a href="http://opensource.atlassian.com/projects/spring/browse/RCP-492">RCP-492<a/>
 * for details on this test and related bug.
 *
 * @throws Exception
 */
public void testRegressionOverlayHelperLeak() throws Exception {
    // Basically, this test will simulate adding a component to a
    // JRootPane, then attach an overlay to it.  The overlay will be
    // installed into the layered pane of the JRootPane at the
    // PALETTE_LAYER.  This test will then remove the component from the
    // JRootPane, ensure the overlay is removed from the layered pane,
    // and then further ensure that nothing else holds a strong reference
    // to the component (by waiting for the component to be garbage
    // collected).
    JComponent component = createTestComponent();
    JComponent overlay = createTestOverlay();
    final ReferenceQueue rq = new ReferenceQueue();
    final PhantomReference componentRef = new PhantomReference(component, rq);

    final JRootPane rootPane = new JRootPane() {
        public boolean isVisible() {
            return true;
        }
        public boolean isShowing() {
            return true;
        }
        protected JLayeredPane createLayeredPane() {
            return new JLayeredPane() {
                public boolean isVisible() {
                    return true;
                }
                public boolean isShowing() {
                    return true;
                }
            };
        }
    };
    
    final int lpcount = rootPane.getLayeredPane().getComponentCountInLayer(JLayeredPane.PALETTE_LAYER.intValue());
    
    OverlayHelper.attachOverlay(overlay, component, 0, 0, 0);
    
    assertEquals(lpcount, rootPane.getLayeredPane().getComponentCountInLayer(JLayeredPane.PALETTE_LAYER.intValue()));
    rootPane.getContentPane().add(component);
    // updateOverlay is "invokedLater", so wait for it...
    waitUntilEventQueueIsEmpty();
    assertEquals(lpcount + 1, rootPane.getLayeredPane().getComponentCountInLayer(JLayeredPane.PALETTE_LAYER.intValue()));
    
    rootPane.getContentPane().remove(component);
    
    // the remove operation make be invoked later, so wait for it...
    waitUntilEventQueueIsEmpty();
    
    // Clear out our strong references so it gets garbage collected.
    component = null;
    overlay = null;
    
    // Make sure the overlay was removed from the layered pane.
    assertEquals("It appears the overlay was not removed from the layered pane when its component was removed from the content pane", lpcount, rootPane.getLayeredPane().getComponentCountInLayer(JLayeredPane.PALETTE_LAYER.intValue()));
    
    // Make sure no other references are held... wait up to 15 seconds for
    // the object to be garbage collected.
    // Note: we may want to remove this section from the test as it
    // presumes the VM will garbage collect the reference fairly quickly
    // once a System.gc() is invoked.
    // There is no guarantee this will happen, so the assumption may be
    // faulty.  If it ends up being a problem, or starts yielding
    // inconsistent test results, then feel free to yank it.
    PhantomReference pr;
    final long end = System.currentTimeMillis() + 15000;
    do {
        System.gc();
    } while((pr = (PhantomReference)rq.remove(100)) == null && System.currentTimeMillis() < end);
    if(pr != null) {
        pr.clear();
    }
    assertSame("Either something else is still holding a strong reference to the component, or the VM is not garbage collecting it.  See comments in OverlayHelperTests.testRegressionOverlayHelperLeak() for more detail", pr, componentRef);
}
 

import java.lang.ref.PhantomReference; //導入方法依賴的package包/類
/**
 * Removes the released collection from the garbage collection reference tracker, since this
 * connection is being release via a normal close method.
 *
 * @param interceptor    ignored
 * @param connectionInfo the connection that was released
 * @param action         ignored
 */
public void handleReleased(final ConnectionTrackingInterceptor interceptor, final ConnectionInfo connectionInfo, final ConnectionReturnAction action) {
    final PhantomReference phantomReference = references.remove(connectionInfo.getManagedConnectionInfo());
    if (phantomReference != null) {
        phantomReference.clear();
    }
}