Do Small Memory Leaks Matter Anymore?

Question

With RAM typically in the Gigabytes on all PC\'s now, should I be spending time hunting down all the small (non-growing) memory leaks that may be in my program? I\'m talking abo

Answer 1

This is completely a personal decision.

However, if:

So the question I am really asking is, if I know I have a program that leaks, say 40 bytes every time it is run, does that matter?

In this case, I'd say no. The memory will be reclaimed when the program terminates, so if it's only leaking 40 bytes one time during the operation of an executable, that's practically meaningless.

If, however, it's leaking 40 bytes repeatedly, each time you do some operation, that might be more meaningful. The longer running the application, the more significant that becomes.

I would say, though, that fixing memory leaks often is worthwhile, even if the leak is a "meaningless" leak. Memory leaks are typically indicators of some underlying problem, so understanding and correcting the leak will often make your program more reliable over time.

Answer 2

Memory leaks are very important in 32 bit applications because the application is limited to 2^32 bytes of memory which is approximately 4 GB. Once a 32 bit application attempts to allocate more than 2^32 bytes of memory the application may crash or hang.

Memory leaks are not as important in 64 bit applications because the application is limited to 2^64 bytes of memory which is approximately 16 EB; so with a 64 bit application you are more-so limited by hardware, but the OS will still likely impose an artificial limit at some time.

Bottom line is that having a memory leak in your code is bad programming; so fix it and be a better programmer.

Answer 3

I am in the same boat as you. I have small memory leaks that don't grow ever. Most of the leaks are caused by improperly tearing down COM objects. I have studied the leaks and come to realize the time and money to fix them is disproportional to the damage the leaks do. Windows cleans up most of the time so the true damage is only realized if the user runs his computer for years without rebooting.

I think it's acceptable to leave in the leaks. It sounds so taboo, but if the leaks never ever ever grow and they are small, it's pretty insignificant in the larger scheme of things.

Answer 4

Are memory leaks ever ok?

Sure, if it's a short-lived process.

Memory leaks over a long period of time are, as the 85-point answer implies, problematic. Take a simple desktop app, for example -- prior to versions 3.x, did you ever notice how you needed it reboot Firefox after a while to recover it from sluggishness?

As for the short term, no, it doesn't matter. Take CGI or PHP scripts for example, or the little Perl three-liner in your ~/bin directory. Nobody's going to call the memory police if you write a 30-line non-looping application in C with 5 lines of malloc() and not a single call to free().

Answer 5

Yes, it matters. Every little leak adds up.

For one, if your leaky code is used in a context where it is repeatedly used, and it leaks a little bit each time, those little bits add up. Even if the leak is small, and infrequent, those things can add up to significant quantities over long periods of time.

Secondarily... if you're writing code that has memory leaks, then that code has problems. I'm not saying that good code doesn't from time to time have memory leaks, but the fact of their existence means that there are some serious problems going on. Many, many security holes are due to just this sort of oversight (unbounded string copy, anyone?).

Bottom line is, if you know about it, and don't do all you can to track it down and fix it, then you're causing problems.