| > how frequent is memory allocation failure nowadays I'd guess that it varies a lot by domain and project but from what I've seen, pretty common. > I'd think that if allocs began to fail, there was no recovery anyhow I think this is what both high-level languages and the Linux "over-commit-by-default" policy have convinced people is the normal behavior. However in my experience it's not that hard to make OOM simply bubble up the stack and have all the callers up the stack free their resources, then let the rest of the program keep running. It doesn't have to be a catastrophic event. You just have to be consistent about handling it, and write code expecting it. > Are there lots of ways allocation can fail besides low memory conditions? To think of a few, there's running out of memory, but there's also running out of address space. The latter is not so hard to accomplish on a 32-bit system. You could ask for a chunk of memory where, if you could coalesce all the free space throughout the heap, you may have enough space, but you can't make it into a contiguous allocation. On Windows I've also seen the kernel run out of nonpaged pool, which is more space constrained than the rest of memory. I've seen this when a lot of I/O is going on. You get things like WriteFile failing with ERROR_NOT_ENOUGH_MEMORY. |