Re: encapsulating directory operations

On 6/10/2025 6:19 AM, Scott Lurndal wrote:

Muttley@DastardlyHQ.org writes:

On Mon, 09 Jun 2025 18:33:38 GMT
scott@slp53.sl.home (Scott Lurndal) wibbled:

Bonita Montero <Bonita.Montero@gmail.com> writes:

Am 09.06.2025 um 17:53 schrieb Scott Lurndal:

Bonita Montero <Bonita.Montero@gmail.com> writes:

Am 09.06.2025 um 16:01 schrieb Scott Lurndal:
>

Have you ever written real-world production code?    Like an operating
system, where allocation failures should -never- result in an
inability to recover.

>
If you need an allocation to proceed and it fails you can't recover.

>
That's your problem caused by poor design and implementation.

>
That's how 100% of all programs that deal with bad_alloc are designed.
>

Exacerbated by the propensity for you to use C++ features that require
dynamic allocation where other forms of data structures are more suitable.

>
When dynamic allocation is needed it is needed.

>
And there are many ways to handle it that don't include throwing
bad_alloc when the system is unable to provide additional address
space, memory or backing store.
>
Allocating major data structures at application start (perhaps using a
pool allocator) and crafting your algorithms such that they
don't require infinite memory is a good start.

>
Ugh. Then you end up like the Java JVM - grabbing boatloads of memory that
causes huge startup delays and can often cause the machine to do lots of
swapping and/or slow everything else down to treacle.

 That's a problem with host not being suitable for java, if that
is the behavior you are seeing.  I've not seen that in production
java-based applications that are competently developed.
 For C/C++, one generally allocates page-aligned regions with mmap, eschewing
granular allocation methods such as new/delete/malloc.

Humm... However, one can choose to carve out allocations from the region? Actually, this basically reminds me of my older region allocator code. So, this is basically dynamic within our defined region, so to speak. However, back in the day, I would try to recover from dynamic malloc failures... Just for testing the robustness of my system. Fwiw, here is my old region code:
https://groups.google.com/g/comp.lang.c/c/7oaJFWKVCTw/m/sSWYU9BUS_QJ
If it fails to allocate, it simply means the region is exhausted at that time. Then my code can fall back to dumping connections, freeing cache, and try the allocation again? Fair enough? It was a long time ago, and when I was conducting said experiments. Fwiw, here is a direct link to my old region code that is, well, fun to me at least... :^)
https://pastebin.com/raw/f37a23918
Does it still work for anybody? ;^o