I have a whole list of C wrappers for OpenCV C++ functions like the one below. And all of them return a "new". I can't change them because they are becoming part of OpenCV and it would make my library perfect to have a consistently updated skeleton to wrap around. My question is in this case how would one of you free these "new" memory allocators...When I run them in any kind of loop. It just eats up my ram, I end up having to restart my pc. Should I make a "delete" wrapper and use that.
I've tried using foreign-free but I still have the same issue of having to restart. Any help is appreciated.
Mat* cv_create_Mat() { return new Mat(); }
On Sat, 22 Mar 2014, Joeish W wrote:
I have a whole list of C wrappers for OpenCV C++ functions like the one below. And all of them return a "new". I can't change them because they are becoming part of OpenCV and it would make my library perfect to have a consistently updated skeleton to wrap around. My question is in this case how would one of you free these "new" memory allocators...When I run them in any kind of loop. It just eats up my ram, I end up having to restart my pc. Should I make a "delete" wrapper and use that. I've tried using foreign-free but I still have the same issue of having to restart. Any help is appreciated.
Mat* cv_create_Mat() { return new Mat(); }
Hi Joeish,
Long story short, you need to follow new() with delete().
C++ new() and delete() extend C's malloc() and free() in roughly the following way.
T * new(args) { T *x=(T *)malloc(sizeof(T)); x->T(args); // constructor (aka ctor) return x; }
void delete(T *x) { if(x) { x->~T(); // destructor (aka dtor) free(x); } }
Note that both the constructor and destructor are fairly arbitrary functions, and it is common for them to do additional memory management.
- Daniel
Thanks for your reply..I can't rewrite the C wrapper for the C++ function so I wrote a delete wrapper like the below because I was getting a warning when it didn't have the char* and I heard you could also use char* explicitly to remove warning. My defcfun is standard it accepts a :pointer and returns void....I use it in my programs wherever memory need to get deleted ...I'm pretty good at knowing where to put the memory freeing functions but I still am getting memory leaks that make me have to restart.The memory I'm trying to free is a Mat*, Mat is an OpenCV c++ class...any help is appreciated
void delete_ptr(void* ptr) { delete (char*)ptr; }
On Saturday, March 22, 2014 2:31 PM, Daniel Herring dherring@tentpost.com wrote:
On Sat, 22 Mar 2014, Joeish W wrote:
I have a whole list of C wrappers for OpenCV C++ functions like the one below. And all of them return a "new". I can't change them because they are becoming part of OpenCV and it would make my library perfect to have a consistently updated skeleton to wrap around. My question is in this case how would one of you free these "new" memory allocators...When I run them in any kind of
loop. It just eats up my ram, I end up having to restart my pc. Should I make a
"delete" wrapper and use that. I've tried using foreign-free but I still have the same issue of having to restart. Any help is appreciated.
Mat* cv_create_Mat() { return new Mat(); }
Hi Joeish,
Long story short, you need to follow new() with delete().
C++ new() and delete() extend C's malloc() and free() in roughly the following way.
T * new(args) { T *x=(T *)malloc(sizeof(T)); x->T(args); // constructor (aka ctor) return x; }
void delete(T *x) {
if(x) {
x->~T(); // destructor (aka dtor) free(x); } }
Note that both the constructor and destructor are fairly arbitrary functions, and it is common for them to do additional memory management.
- Daniel
Pls ignore last post from me - here is new info
have a whole list of C wrappers for OpenCV C++ functions like the one below. And all of them return a "new". I can't change them because they are becoming part of OpenCV and it would make my library perfect to have a consistently updated skeleton to wrap around.
Mat* cv_create_Mat() { return new Mat(); }
I can't rewrite the C wrapper for the C++ function so I wrote a delete wrapper like the below,The memory I'm trying to free is a Mat*, Mat is an OpenCV c++ class...and the delete wrapper works There is absolutely no memory leakage at all, but I have a lot of other C wrappers for OpenCV C++ functions that return a new pointer...there is at least 10 of 15 and my intention is to not have to write a separate delete wrapper for all of them. If you can show me how to write one delete wrapper that would free any pointer I give to it that would be great...I have CvSVMParams*, Brisk*, RotatedRect*, CVANN_MLP* pointers there are a few others as well...Any help at this is greatly valued.
void delete_ptr(void* ptr) { delete (Mat*)ptr; }
;; void operator delete ( void* ptr ); (defcfun ("delete" del) :void (ptr :pointer))
On Saturday, March 22, 2014 3:37 PM, Joeish W joeish80829@yahoo.com wrote:
Thanks for your reply..I can't rewrite the C wrapper for the C++ function so I wrote a delete wrapper like the below because I was getting a warning when it didn't have the char* and I heard you could also use char* explicitly to remove warning. My defcfun is standard it accepts a :pointer and returns void....I use it in my programs wherever memory need to get deleted ...I'm pretty good at knowing where to put the memory freeing functions but I still am getting memory leaks that make me have to restart.The memory I'm trying to free is a Mat*, Mat is an OpenCV c++ class...any help is appreciated
void delete_ptr(void* ptr) { delete (char*)ptr; }
On Saturday, March 22, 2014 2:31 PM, Daniel Herring dherring@tentpost.com wrote:
On Sat, 22 Mar 2014, Joeish W wrote:
I have a whole list of C wrappers for OpenCV C++ functions like the one below. And all of them return a "new". I can't change them because they are becoming part of OpenCV and it would make my library perfect to have a consistently updated skeleton to wrap around. My question is in this case how would one of you free these "new" memory allocators...When I run them in any kind of
loop. It just eats up my ram, I end up having to restart my pc. Should I make a
"delete" wrapper and use that. I've tried using foreign-free but I still have the same issue of having to restart. Any help is appreciated.
Mat* cv_create_Mat() { return new Mat(); }
Hi Joeish,
Long story short, you need to follow new() with delete().
C++ new() and delete() extend C's malloc() and free() in roughly the following way.
T * new(args) { T *x=(T *)malloc(sizeof(T)); x->T(args); // constructor (aka ctor) return x; }
void delete(T *x) {
if(x) {
x->~T(); // destructor (aka dtor) free(x); } }
Note that both the constructor and destructor are fairly arbitrary functions, and it is common for them to do additional memory management.
- Daniel
Hi Joeish,
The best path is probably to write a small script that generates the C wrappers and CFFI bindings for a list of class names.
There is a way to skip the C wrappers entirely, but it is generally more fragile and harder to implement. It turns out that most C++ functions are nothing more than carefully named C functions. However, there are a number of subtleties in their calling convention (in particular casting derived classes, calling virtual functions, and filling in default parameters). It is also intentionally difficult to find the right function names to use. Thus very few people go down this path.
- Daniel
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Daniel Herring -
Joeish W