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My program crashes when GC perform garbage collection

Answer 1

A:

Edit: Here's what's going on. You have an object instance of some type that contains unmanaged resources as members. That type has a finalizer (looks like a destructor syntax in C#) that calls Dispose(). Some part of your application relies on the unmanaged resource held by this object - perhaps a handle of type IntPtr. As long as the object stays alive (not collected by GC), Dispose() is never called an the handle remains valid. The problem is due to the program holding on to the raw handle (possibly an IntPtr) without keeping a reference to the managed object holding on to the resource. Without keeping that reference, the object becomes eligible for finalization/collection. Solution: Identify the managed type that manages your resource, and make sure you hold on to a copy of it until you no longer need its resource. When you no longer need the resource, call Dispose() on the managed object yourself to clean things up without needing to call GC.Collect().

280Z28 2009-10-24 02:00:48

How is that supposed to cause a crash? Sure, it might make it slow, but it's not going to crash...

bdonlan 2009-10-24 02:02:24

Also, the OP may have added it as debugging. If `GC.Collect()` causes a crash, _don't just remove it_ - you're just moving the crash somewhere else :)

bdonlan 2009-10-24 02:04:54

Calling GC.Collect() can provoke a crash on another thread if that thread contains unmanaged code that references unpinned memory on the managed heap.

Bevan 2009-10-24 02:07:16

My comment was mostly in response to something that made me go "oh dear..." However, I do know what causes this problem and I explained the source, reason calling `GC.Collect()` crashes, and the solution. :)

280Z28 2009-10-24 02:11:08

Answer 2

+2 A:

A crash (not exception) in GC means that unmanaged (ie, C++-CLR, unsafe, or non-.NET) code has corrupted the heap. Check your non-.NET code for potential issues! In particular, are those files in D:\jizg\NSIISys\bin\Debug .NET? If not, they look mighty suspicious to me.

bdonlan 2009-10-24 02:01:49

Answer 3

A:

There are a couple of messages that seem to be of interest:

WARNING: Unable to verify checksum for C:\WINDOWS\assembly\NativeImages_v2.0.50727_32\mscorlib\6d667f19d687361886990f3ca0f49816\mscorlib.ni.dll

You may want to see why this error comes up, as it may be the problem with the unmanaged API.

Do you have any unmanaged C++ dlls that you wrote?

It seems to have a problem with an image name being possibly corrupt, so you may want to remove code that refers to images and see what happens, and then add in one section of code at a time until you find the block that causes a problem.

James Black 2009-10-24 02:13:20

Answer 4

A:

The defect is caused by stack corruption. Here is a technique that we use in my company to find these issues in release code.

First, download and run appverifier. This is a microsoft tool and only works on windows.

AppVerifier will force your unmanaged code to throw an exeption if there is any pointer problems. However, due to the way .NET initializes, .NET executables will also crash during startup with a false crash. What you need to do , is carefully write a test application in native C which will calls the same unmanaged functions as your .NET code.

Run your code in a debugger. The code will crash with the exact address of the pointer which is causing the problem.

Your code will run very slow. This is because AppVerifier will make windows load a series of tests on your test program.

Andrew Keith 2009-10-24 02:26:03

Answer 5

A:

Thanks for your kindly response,but I think the problem must be rooted in the usb 2 serial drivers,I'll paste my test result with hard serial port soon.thanks all again.

2009-11-05 09:41:59

Answer 6

+1 A:

Just don't do it. Find the problem and fix it rather than just quick-patching it. It will just move somewhere else.

erikkallen 2009-11-05 10:05:15

The usb 2 serial port driver I used is provided by 3rd part.The chip model on usb calbe is FTDi.I also tried the driver of prolific 2303 and got the problem.So,the workable way to get rid of this problem is run my program on hard serial port ,if it works,I 'll give up the "soft serial port"-usb 2 serial port.Thank you!Jizhiguo

2009-11-06 12:08:54

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My program crashes when GC perform garbage collection

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