finalizer

问题 We're running a Jersey (1.x) based service in Tomcat on AWS in an array of ~20 instances Periodically an instance "goes bad": over the course of about 4 hours its heap and CPU usage increase until the heap is exhausted and the CPU is pinned. At that point it gets automatically removed from the load balancer and eventually killed. Examining heap dumps from these instances, ~95% of the memory has been used up by an instance of java.lang.ref.Finalizer which is holding onto all sorts of stuff,

问题 I've got the following code : public class A { ~A() { Console.WriteLine("destructor"); } } public static A Aref; static void Main(string[] args) { Aref = new A(); int gen = GC.GetGeneration(Aref); Aref = null; GC.Collect(gen, GCCollectionMode.Forced); Console.WriteLine("GC done"); } I thought my Finalizer method would be called upon my call to GC.Collect, which is not the case. Can anyone explain me why ? 回答1: Finalizers aren't called before GC.Collect() returns. The finalizers are run in a

问题 As I learned from online and my personal experiment, the finalizer of a form (System.Windows.Forms.Form) never gets called by GC. It is said that inside the Dispose() of Form GC.SuppressFinalize() is called so that finalizer wouldn't gets called again. Exapmle: public partial class UpdateForm : Form { public UpdateForm() { InitializeComponent(); // Listen to the event of some model Database.OnDataUpdated += new EventHandler(DataBase_OnDataUpdated); } ~UpdateForm() { // Never gets called. }

问题 Is it not safe to call: component.Dispose(); (if i check null) from the Finalizer if i alter the code to this: ~MyResource() { Dispose(); } public void Dispose() { // Check to see if Dispose has already been called. if(!this.disposed) { if(component != null) component.Dispose(); // !!! // CloseHandle(handle); handle = IntPtr.Zero; disposed = true; } GC.SuppressFinalize(this); } I know this works - but is it safe? (from the example below?) Code example: (before alter code) http://msdn

问题 What would happen if an exception is thrown during the execution of finalize()? Is the stack unwind like normally? Does it continue finalize() and ignore the exception? Does it stop finalize() and continue GC the object? Or something else? I'm not looking for guidelines of using finalize() there are plently of pages explaining that. 回答1: From the Object#finalize() javadoc: Any exception thrown by the finalize method causes the finalization of this object to be halted, but is otherwise ignored

问题 I have an application that experiences a slow memory leak from the word go. Using ANTS Memory Profiler I can see that all of the leaked memory is being held by the finalizer queue's GC root. I suspect what may have happened is that the finalizer is deadlocked waiting on a lock to become available. None of our classes implement explicit finalizers, we avoid them as a rule, this makes me think the lock might related to a system or library class. I've used SOS.dll to take a look at the contents

问题 EDIT See edit note at the bottom of the question for additional detail. Original question I have a CacheWrapper class which creates and holds onto an instance of the .NET MemoryCache class internally. MemoryCache hooks itself into AppDomain events, so it will never be garbage-collected unless it is explicitly disposed. You can verify this with the following code: Func<bool, WeakReference> create = disposed => { var cache = new MemoryCache("my cache"); if (disposed) { cache.Dispose(); } return

问题 As always, a lengthy problem description. We are currently stress testing our product - and we now we face a strange problem. After one to two hours, heap space begins to grow, the application dies sometime later. Profiling the application shows a very large amount of Finalizer objects, filling the heap. Well, we thought "might be the weird finalizer thread to slow" issue and reviewed for reducing the amount of objects that need to be finalized (JNA native handles in this case). Good idea

问题 Is it possible to add a Finalizer to a CodeDom generated class (other than using CodeSnippetTypeMember)? I couldn't find any information about it on MSDN. 回答1: This was a known bug in .NET Framework and was reported some time back at http://lab.msdn.microsoft.com/ProductFeedback/viewFeedback.aspx?feedbackId=FDBK48431 But the link above is currently not working. You can view it using internet archive on the following link http://web.archive.org/web/20080224200911rn_2/connect.microsoft.com

问题 Here's some sample code: using System; namespace UnloadFromFinalizer { class Program { static void Main(string[] args) { Program p = new Program(); } AppDomain domain; Program() { this.domain = AppDomain.CreateDomain("MyDomain"); } ~Program() { AppDomain.Unload(this.domain);//<-- Exception thrown here } } } I have a class that creates an AppDomain in the constructor to be used over the lifetime of the object. I'd like to properly cleanup the AppDomain, so I thought I would call Unload in the