Dynamic Memory Allocation in Embedded Apps?

shootTheMessenger asks: "My company is porting our C++ Windows app to C in an embedded device and the question of whether to use dynamic memory allocation continues to come up. So far I have resisted malloc/free use but it gets tedious having the same argument with the next set of managers to take an interest in the project. Is there a definitive answer on the subject, especially one to counter the 'we have plenty of RAM - 16MB - so why not use dynamic allocation' argument? A quick google search finds that some sites frown on allocations within embedded applications, while others say it is OK in some contexts and yet others hack around it with pseudo-static allocations. How do you feel about this particular subject?"

Comments

Re:Why?

[try_anything]

I second sticking with C++. The poster may have a good reason for switching to C, but he should have explained it, because the difference between C and C++ is extremely relevant to his question! Thanks to RAII and smart pointers like boost::scoped_ptr (see boost.org) C++ is way ahead of C for using dynamic memory allocation safely and readably. Switching to dynamic allocation will likely involve much greater cost in bugs and readability if C is used instead of C++.

Also, if performance is important, it's important to be able to experiment with allocation methods when you run into problems. In C++, the ability to implement new and delete differently for each class allows you to experiment with custom allocators without rewriting your code, even if you didn't think of it beforehand. If you use C, make sure you wrap your calls to malloc and free in case you need to tinker later!