|
mmmm ... beer 
Cheers!
|
|
|
|
|
there is a problem with my miniport driver (passthru).when enabling hyperthreading. In normal cases it works correctly but when hyperthreading is enabled. the driver fails. is there any way to upgrade the driver so that it will work in hyperthreading mode
vineesh
|
|
|
|
|
Hello !
I have a function which must be in a "demon" thread because
I want that it still running until I close my program.
in fact this function is doing a polling with the hardware and it retreive any occured information from it.
I didn't work with thread or timer but is it a solution for my problem ?
thanks a lot
chokran
 zizzzz
zizzzzzzzzzzzzzzz
|
|
|
|
|
i think you should document yourself about Windows services...
|
|
|
|
|
|
Hello,
CRICH is derived from CRichEditCtrl
int index=0;
vector<crich*>RichEditBox;
CRICH *p = RichEditBox[index];
p->SetFocus();
How do I go to index=1 box in the above example.
p++ will not help as I tried that
Any ideas
Prithaa
|
|
|
|
|
prithaa wrote: p++ will not help as I tried that
p++ won't workout because its not the base address and also 'p' is just a class pointer..which can point to single instance of that class.
use index++ instead of p++
Do your Duty and Don't expect the Result
|
|
|
|
|
Hello comunity
i use many times in my project "new" to create an object, in my case this is own class derived from
CObject! So, how to cleany the heap properly??
I hope that is my question is easy to understand?! 
What ist different between this two my samples:
CMyClass* pMyClass = new CMyClass();
delete pMyClass;
CMyClass* pMyClass = new CMyClass();
pMyClass = NULL;
delete pMyClass;
thanks in advance
break;
|
|
|
|
|
break; wrote:
CMyClass* pMyClass = new CMyClass();
pMyClass = NULL;
delete pMyClass;
This won't work: you will first set the adress to a NULL pointer and then try to free the memory at this adress, which will fail (logical, because the memory at address 0x0000 was not allocated). You should first delete the pointed memory and then set your pointer to NULL to specify that the pointer doesn't point to a valid memory.
|
|
|
|
|
Thanks very much! 
break;
|
|
|
|
|
Cedric Moonen wrote: This won't work:
As a minor technicality, it will WORK, but it won't work as expected. That is, there is nothing syntatically wrong with the code. deleting a null pointer is perfectly valid (and does nothing), but the code will have a memory leak since the memory allocated will never be deallocated.
If you decide to become a software engineer, you are signing up to have a 1/2" piece of silicon tell you exactly how stupid you really are for 8 hours a day, 5 days a week
Zac
|
|
|
|
|
Yes, that's what I wanted to say. Ok, it wasn't very clear :p. I know that you can delete a NULL pointer but this will simply be ignored (thus leaving a memory leak).
|
|
|
|
|
what were you thinking of when you wrote this ?
delete needs an adress to clean !! (the address which new returned when allocated the memory).
if you assign the pointer variable BEFORE deleteing, delete will try to free the memory at address 0 -> bug
but NULLing after the delete is the thing to do...!
|
|
|
|
|
toxcct wrote: delete will try to free the memory at address 0 -> bug
That part isn't really a bug; the memory leak is, though. There is nothing wrong with deleting a null pointer.
If you decide to become a software engineer, you are signing up to have a 1/2" piece of silicon tell you exactly how stupid you really are for 8 hours a day, 5 days a week
Zac
|
|
|
|
|
i was making it easy for the guy...
|
|
|
|
|
The two lines at the bottom must change places, otherwise you'll get a runtime error when trying to delete the NULL pointer.
The what-about-this-line -line is considered best practice because you will be able to check the pointer if it equals NULL.
Always NULLify pointers that are not used after freeing up their memory to be able to tell if the memory has been freed or not.
--
Roger
"It's supposed to be hard, otherwise anybody could do it!" - selfquote
"No one remembers a coward!" - Jan Elfström 1998
"...but everyone remembers an idiot!" - my lawyer 2005 when heard of Jan's saying above
|
|
|
|
|
Roger Stoltz wrote: The two lines at the bottom must change places, otherwise you'll get a runtime error when trying to delete the NULL pointer.
Incorrect. There will be a memory leak, but there is no runtime exception in the code as written.
delete NULL;
If you decide to become a software engineer, you are signing up to have a 1/2" piece of silicon tell you exactly how stupid you really are for 8 hours a day, 5 days a week
Zac
|
|
|
|
|
Yeah! 
I was waiting for your post since I saw you lecturing crusade.
Seriously Zac, where can that be found in the C/C++ specs?
Isn't this an unspecified behaviour?
--
Roger
"It's supposed to be hard, otherwise anybody could do it!" - selfquote
"No one remembers a coward!" - Jan Elfström 1998
"...but everyone remembers an idiot!" - my lawyer 2005 when heard of Jan's saying above
|
|
|
|
|
Roger Stoltz wrote: Seriously Zac, where can that be found in the C/C++ specs?
Isn't this an unspecified behaviour?
I gave you a link to the CPP FAQ. If you want the spec, you'd have to buy it (~$30US) so I obviously can't provide you a direct link to the line in the spec. You can either google it yourself, read "Effective C++" by Scott Meyers, buy the standard, read the FAQ, or take my word for it that the standard states that deleting a NULL pointer is both defined and does nothing.
Sorry, I forgot the link I provided was from a site using frames. Here is the link to directly answer your question:
http://www.parashift.com/c++-faq-lite/freestore-mgmt.html#faq-16.8
If you decide to become a software engineer, you are signing up to have a 1/2" piece of silicon tell you exactly how stupid you really are for 8 hours a day, 5 days a week
Zac
|
|
|
|
|
Roger Stoltz wrote: Seriously Zac, where can that be found in the C/C++ specs?
Isn't this an unspecified behaviour?
Per Stroustrup's book:
The effect of applying delete to a pointer not obtained from the new operator without a placement specification is undefined and usually harmful. Deleting a pointer with the value zero, however, is guaranteed to be harmless.
"Approved Workmen Are Not Ashamed" - 2 Timothy 2:15
"Judge not by the eye but by the heart." - Native American Proverb
|
|
|
|
|
In my opinion, in the second case:
pMyClass = NULL;
delete pMyClass;
you will not receive any run-time error, since deleting of null pointer is not an error (delete simply does nothing).
But in this case your object, allocated with new, will remain unused in the heap memory, producing "memory leak".
Therefore, the correct way is:
delete pMyClass;
pMyClass = NULL;
If you are familiar with STL, you can also consider this approach:
std::auto_ptr< CMyClass > pMyClass(new CMyClass);
I this case the de-allocation will be performed automatically.
I hope this helps.
|
|
|
|
|
Hello,
thank you for answer, i try to use auto_ptr, but im not familiar with this!! 
regards
break;
|
|
|
|
|
break; wrote: i try to use auto_ptr, but im not familiar with this!!
Make sure you read up on auto_ptr if you plan to use it. The assignment of auto_ptr's can cause problems if you don't realize what it is actually doing.
If you decide to become a software engineer, you are signing up to have a 1/2" piece of silicon tell you exactly how stupid you really are for 8 hours a day, 5 days a week
Zac
|
|
|
|
|
break; wrote: CMyClass* pMyClass = new CMyClass();
// and later
//
delete pMyClass;
As a general rule, only use the ()'s when you have an argument to pass the constructor. There are cases where using empty ()'s will actually call a function and you will get very different results from what you expect.
CMyClass* pMyClass = new CMyClass;
delete pMyClass;
pMyClass = NULL;
or better yet:
</code>std::tr1::shared_ptr<CMyClass> pMyClass = std::tr1::shared_ptr<CMyClass>(new CMyClass);</code>
Calling delete on a NULL pointer will do nothing to it, but setting the pointer to NULL prior to deleting it will cause a memory leak (bad!).
If you decide to become a software engineer, you are signing up to have a 1/2" piece of silicon tell you exactly how stupid you really are for 8 hours a day, 5 days a week
Zac
|
|
|
|
|
Hi everyone,
i made already my own WM and it works nice
i made it like this:
In the Grid :
GetParent()->PostMessage(WM_COMMAND, WM_GRID_DOWN);
with a define for this kind of mesage :
#define WM_GRID_DOWN (WM_USER + 1)
and in my View :
ON_COMMAND(WM_GRID_DOWN,On_Grid_Down)
with a function :
afx_msg void On_Grid_Down();
Now, i need to send a message from the Grid to the View with a parameter.
Is there another kind of message?
Thanks a lot !
|
|
|
|
General 
News 
Suggestion 
Question 
Bug 
Answer 
Joke 
Praise 
Rant 
Admin 
Submit an article or tip
