Question about memory management.

[Renji Panicker]

Hi everyone,

When developing a C++ application which requires creation/deletion of
small classes multiple times, can we rely on the memory management in
the standard libraries, or is it smarter to develop our own (perhaps
by overloading new/delete)?

I realize the answer to this question is compiler dependent (I am
using gcc 4.1.3 on Linux). However, can someone provide a general
answer, since the application I have in mind is expected to be cross
platform to work at the least with msvc and XCode as well.

Thanks!
-/renji

 

[Ian Collins]

Hi everyone,

When developing a C++ application which requires creation/deletion of
small classes multiple times, can we rely on the memory management in
the standard libraries, or is it smarter to develop our own (perhaps
by overloading new/delete)?

I realize the answer to this question is compiler dependent (I am
using gcc 4.1.3 on Linux). However, can someone provide a general
answer, since the application I have in mind is expected to be cross
platform to work at the least with msvc and XCode as well.

A custom allocator may help, but the only way to know for sure is to
measure. Object creation and deletion may not even be bottlenecks in
your system

 

[Renji Panicker]

Thanks for the quick response, Ian.
Regards,
-/renji

 

[Lance Diduck]

Hi everyone,

When developing a C++ application which requires creation/deletion of
small classes multiple times, can we rely on the memory management in
the standard libraries, or is it smarter to develop our own (perhaps
by overloading new/delete)?

I realize the answer to this question is compiler dependent (I am
using gcc 4.1.3 on Linux). However, can someone provide a general
answer, since the application I have in mind is expected to be cross
platform to work at the least with msvc and XCode as well.

Thanks!
-/renj

After profiling does indeed find a bottleneck (and on your system the
worst is creating a small object in one thread and deleting it in
another) then yes create a small object allocator. new /delete
bottlenecks like this are fairly platform independent, other than the
tuning parameters (like pagesize and alignments). These are very easy
to build, and an example is found in Stroustrups C++TPL.

Lance