jonv

3 ms·

1.
by jonv 5y ago
But when you enter the loop you have no other "objects" in your program allocated at all, so it doesn't have to do a search for a suitably sized block. Near-identical timings for changing the size to 256 is what I would expec
2.
by jonv 5y ago
With std::shared_ptr each copy has a pointer to the ref count & there is only one ref count, atomically updated with a cmpxchg instruction. Not sure what you mean by "references are updated or moved around"? But I agree that G
3.
by jonv 5y ago
Not sure what you mean here, std::unique_ptr is for when you want to auto destruct a ptr when going out of scope (ref counting limited to one) and std::shared_ptr is normal reference counting, they aren't alternatives to each other but
4.
by jonv 5y ago
Excuse me if I have mis-read your sample program but it looks like you are allocating 16 bytes, then immediately freeing it, again and again in a loop. Since you're not allocating anything else, the allocate and free will happen almost
5.
by jonv 5y ago
> Reference counting including unique_ptr also have to be locked for updates This is not true. The counter itself can have its count updated atomically with a compare & exchange. I think this is what actually happens in most cpp std
6.
by jonv 7y ago
I was simply saying that it's undecideable to do bounds checking at compile time, so it's better to use languages that do bounds checking at run time. But you shouldn't blame C for this.
7.
by jonv 7y ago
We are in agreement, by comment was not saying people should use C. It was saying that a layer of unsafety has to exist somewhere.
8.
by jonv 7y ago
"I'd rather put my bugs in one, more easily verifiable place." We are in agreement, that is why I was saying people shouldn't use C unless they need it.
9.
by jonv 7y ago
Yes, but I am in agreement with you. I was simply saying you shouldn't blame C for being what it is, not that you should use it.
10.
by jonv 7y ago
"How can I avoid being burned by C’s numerous and severe shortcomings?" I think this is where we start bumping up against the limitations of the universe we live in, because the question becomes "where do we put the bugs?&quo