Managed C++/CLI

Garbage collection -- what's the trick?

24-Jul-03 1:43

How about this:

namespace oldCpp
{
 enum { myfirst = 0, mysecond };
}

public __value enum newMCpp { myfirst = oldCpp::myfirst, mysecond = oldCpp::mysecond };

Then you could do something like:

int oc = (int)newMCpp::myfirst;

Untested, but should hopefully get you started.

[edit] wrapped first enum in namespace. Learned this in another post in the VC forum. [/edit]

Hope this helps,
Nathan

---------------------------
Hmmm... what's a signature?

Jeremy Osner22-Jul-03 9:04

22-Jul-03 9:04

I noticed my program was leaking memory at a huge rate -- went in and did some debugging and it seemed pretty clear that managed memory was never being deallocated. After fretting for a while over why this should be so, I added a call System::GC::Collect() under certain circumstances. With this call in, there is no leak. Why shouldn't the gc have been collecting on its own -- isn't this the whole point of garbage collection?

READIN writin rhythmetic

Nathan Blomquist23-Jul-03 5:15

23-Jul-03 5:15

The garbage collector in .NET is a lazy collector. What this means is that it will not collect until it needs to. Only when memory is getting low, will it collect.

Check the MSDN for more info.

-Nathan

---------------------------
Hmmm... what's a signature?

Jeremy Osner23-Jul-03 5:28

23-Jul-03 5:28

Thanks, I guess I just wanted it do happen a bit before it would by default -- are there any caveats I should be aware of afa using GC::Collect()?

READIN writin rhythmetic

Nathan Blomquist23-Jul-03 6:21

23-Jul-03 6:21

Only a possible performance hit. How often are you calling a collect? A collection is very intensive operation since it has to go through all the objects in your process and see if they are to be collected.

-Nathan

---------------------------
Hmmm... what's a signature?

Jeremy Osner23-Jul-03 6:58

23-Jul-03 6:58

Yeah, I figured it was an expensive call -- I am doing it quite infrequently, immediately after a call which I know results in a whole lot of objects being eligible for reclamation -- is that the correct terminology? I want to just say "I deleted a lot of stuff" but obviously I did not delete it, I just removed references.

READIN writin rhythmetic

Nathan Blomquist23-Jul-03 8:30

23-Jul-03 8:30

Jeremy Osner wrote:
eligible for reclamation

I think the phrase would be "eligible for collection", because "reclamation" to me sounds like you are recycling the objects themselves instead of just the memory. But I am sure that anyone you typed with or spoke to would readily understand Smile | :)

.

-Nathan

---------------------------
Hmmm... what's a signature?

Jeremy Osner23-Jul-03 8:41

23-Jul-03 8:41

Thanks for the help, Nathan!

READIN writin rhythmetic

Linker errors

Slaru21-Jul-03 17:20

21-Jul-03 17:20

Hey,
First of all, I would like to say with only being a member of this site for a little while, I have found it very useful. I am pretty much a newbie in programming and don't know much about compiler and linker errors. I get this error when trying to compile.

playSound.obj : error LNK2022: metadata operation failed (8013118D) : Inconsistent layout information in duplicated types (playSound): (0x02000005).

LINK : fatal error LNK1255: link failed because of metadata errors

Anybody know what this is? If you need source code I can give it. I am sure I included all the includes and libraries. Thanks.

Also does anybody know how to convert a String to a LPCWSTR? I hadn't heard of LPCWSTR before but appears to be some other kind of string.
example:

String * str = S"Hello";<br />
// Convert str to a LPCWSTR so I can pass it into a function<br />
<br />
somefunction(MyConvertedString)

Double thanks.

Jeremy Osner22-Jul-03 7:24

22-Jul-03 7:24

I can't answer your linker question but an LPCWSTR is a char pointer -- see the thread lower on this page regarding PtrToStringChars().

READIN writin rhythmetic

Slaru22-Jul-03 7:49

22-Jul-03 7:49

Thanks for answering my second question. Is there anyone who knows what my linker problem is or who can give tips to fix it?

jspano22-Jul-03 15:14

jspano

22-Jul-03 15:14

I believe that your first error is from a type that is defined 2x and differently each time. Check that in your playsound files.

Slaru22-Jul-03 17:10

Serial COM port in Managed C++

22-Jul-03 17:10

I have fixed both problems. Thanks. I made my class all inline and that fixed my linker errors whatever they were. Case closed.

icdma21-Jul-03 6:37

icdma

21-Jul-03 6:37

Has anyone implemented Albert's article, "How to open a serial COM port in Managed C++, By Albert Pascual"

After I boot up my WinXP Pro system, Albert's implementation only works after I start up HyperTerminal. After that, it works fine from then on... Any clues? Has anyone else run into this on XP.

Thanks in Advance!

Re: Serial COM port in Managed C++

icdma26-Jul-03 7:43

icdma

26-Jul-03 7:43

I worked through this. The code provided in the article is not sufficient to make the serial port work properly.

icdma

strange compiler error

Slaru20-Jul-03 13:06