garbage-collection

问题 I am using Emgu OpenCV to grab images from a webcam and want to visualize them with WPF Image Control. So I need to convert the image from Mat to something compatible with Image control. So I took this class from the Emgu examples: public static class BitmapSourceConvert { /// <summary> /// Delete a GDI object /// </summary> /// <param name="o">The poniter to the GDI object to be deleted</param> /// <returns></returns> [DllImport("gdi32")] private static extern int DeleteObject(IntPtr o); ///

问题 I'm trying to write a unit test for testing a memory leak. Steps to Reproduce: TestClass test = new TestClass(); WeakReference reference = new WeakReference(test, true); test = null; GC.Collect(); GC.WaitForPendingFinalizers(); GC.Collect(); Debug.Assert(reference.Target == null, "Memory Leak"); // This works //Replacing the above line with following, I see "Memory Leak" being printed. if (reference.Target != null) { Console.WriteLine("Memory Leak"); } I added a finalizer: ~TestClass() {

问题 People like flash builder profile tool very much.But recently, a problem came to me when I tried to find a memory leak. Here is the simplified sample. package { import flash.display.Sprite; import flash.sampler.pauseSampling; import flash.system.System; import org.robotlegs.base.ContextBase; import org.robotlegs.mvcs.Context; public class MemoryLeak extends Sprite { public function MemoryLeak() { makeAndDrop(); } public function makeAndDrop():void{ var _context : Context = new Context(this);

问题 I have this code in my app: var newImage = // ... if (imageView.Image != null && imageView.Image != newImage) imageView.Image.Dispose (); imageView.Image = newImage; I have three related questions: Does it immediately release the memory occupied by the previous imageView.Image ? If it does, is there a cleaner solution? Does this have anything to do with NSAutoreleasePool ? 回答1: Does it immediately release the memory occupied by the previous imageView.Image? Not immediately but it should be

问题 Java has daemon thread to monitor memory usage and do the gc task. From jstack I see "main" #1 prio=5 os_prio=0 tid=0x00007f34b000e000 nid=0x808 waiting on condition [0x00007f34b6f02000] java.lang.Thread.State: TIMED_WAITING (sleeping) at java.lang.Thread.sleep(Native Method) .... "GC task thread#0 (ParallelGC)" os_prio=0 tid=0x00007f34b0023000 nid=0x809 runnable "GC task thread#1 (ParallelGC)" os_prio=0 tid=0x00007f34b0024800 nid=0x80a runnable "GC task thread#2 (ParallelGC)" os_prio=0 tid

问题 Java has daemon thread to monitor memory usage and do the gc task. From jstack I see "main" #1 prio=5 os_prio=0 tid=0x00007f34b000e000 nid=0x808 waiting on condition [0x00007f34b6f02000] java.lang.Thread.State: TIMED_WAITING (sleeping) at java.lang.Thread.sleep(Native Method) .... "GC task thread#0 (ParallelGC)" os_prio=0 tid=0x00007f34b0023000 nid=0x809 runnable "GC task thread#1 (ParallelGC)" os_prio=0 tid=0x00007f34b0024800 nid=0x80a runnable "GC task thread#2 (ParallelGC)" os_prio=0 tid

问题 Maybe it's a silly question but I'm not sure about the garbage collection process. Consider this code: private HashMap<String, Parameter> configuration = new HashMap<String, Parameter>(); ... //add some items to configuration ... //now get another configuration HashMap<String, Parameter> parameters = new HashMap<String, Parameter>(); for (String parameterName : configurationParameterNameList) { parameters.put(parameterName, reader.readParameter(parameterName)); } //and reassign the variable

问题 What is the best way howto monitor usage of Eden and Survivor heap spaces? I have all the GC logging options on but I can see only YoungGen occupation: -XX:+PrintTenuringDistribution -XX:+UnlockDiagnosticVMOptions -XX:+LogVMOutput -XX:LogFile=jvm.log -server -XX:+HeapDumpOnOutOfMemoryError -XX:+DisableExplicitGC -Xloggc:gc.log -XX:+PrintGCTimeStamps -XX:+PrintGCDetails -showversion -XX:+PrintClassHistogramBeforeFullGC -XX:+PrintClassHistogramAfterFullGC -XX:+UseParallelOldGC -XX

问题 Based on the discussion about getting substring of String Java String.split memory leak? , I have been analyzing two sample substring examples of usage. It is said that objects don't get garbage collected if the caller stores a substring of a field in the object. When I run the code I get and OutofMemory Exception, and see the incresing of char[] allocated size while monitoring it via VisualVM public class TestGC { private String largeString = new String(new byte[100000]); String getString()

问题 void Foo() { System.Windows.Forms.Form f = new System.Windows.Forms.Form(); f.Show(); } To my understanding f holds the reference to the Form. But f is a local variable and it will go out of scope when the control leaves the curly braces. But the Form is still open. I tried calling GC.Collect(), but the Form is still open. One more scenario. private void button2_Click(object sender, EventArgs e) { Timer t = new Timer(); t.Enabled = true; t.Interval = 1000; t.Tick += new EventHandler(t_Tick);