| sadmac | Keybuk: how was your flight? | 14:05 |
|---|---|---|
| Keybuk | sadmac: short and uneventful | 14:49 |
| Keybuk | just the way I like them ;) | 14:49 |
| sadmac | Keybuk: sweet | 14:49 |
| sadmac | Keybuk: so after hacking n-ary event operators together, I'm getting a segfault inside nih_ref | 14:49 |
| sadmac | Keybuk: specifically in a call to nih_list_add_after | 14:50 |
| Keybuk | is the pointer freed? | 14:51 |
| sadmac | Keybuk: I don't believe so. If so its an error outside my code. | 14:52 |
| sadmac | or maybe not... yeah it could be in the parse_job changes | 14:52 |
| Keybuk | one of the obvious issues with nih_alloc | 14:55 |
| Keybuk | x = nih_alloc (NULL, ...) | 14:55 |
| Keybuk | nih_ref (y, x) | 14:56 |
| Keybuk | nih_unref (y, x) | 14:56 |
| Keybuk | // x is now free | 14:56 |
| sadmac | Keybuk: it also bugs me that you have to declare nih_local in a certain place or you get a leak | 14:56 |
| sadmac | nih_local int *foo; while {} vs while {nih_local int *foo } | 14:57 |
| sadmac | Keybuk: I have a solution for that. I would propose a macro that would create a local /parent/ rather than a local object. So when you did locally scoped allocations, you'd just give them that parent and they'd all go away at once. | 14:58 |
| sadmac | its a bit harder to screw up, and its not mutually exclusive with nih_local so we can keep bot. | 14:58 |
| sadmac | *both | 14:58 |
| Keybuk | not sure I follow | 15:01 |
| sadmac | Keybuk: so where you had this: | 15:01 |
| sadmac | nih_local obj *foo = nih_alloc (null, sizeof obj); | 15:02 |
| sadmac | Keybuk: you'd have this | 15:02 |
| Keybuk | yes, you can do that ;) | 15:02 |
| sadmac | NIH_DECLARE_LOCAL_ANCHOR (anchor) | 15:02 |
| Keybuk | nih_local void *foo = nih_alloc (NULL, 0); | 15:02 |
| sadmac | obj *foo = nih_alloc (anchor, sizeof obj); | 15:03 |
| sadmac | Keybuk: nih_alloc doesn't assert there? | 15:03 |
| sadmac | Keybuk: because otherwise yes, that'd pretty much be it | 15:03 |
| sadmac | Keybuk: though I'd recommend the type be struct dummy * so it screams a bit if you try to use it as an object. | 15:04 |
| Keybuk | not that I know of | 15:10 |
| sadmac | Keybuk: well that works out nicely then | 15:11 |
| Keybuk | though I don't see that that helps you | 15:14 |
| sadmac | Keybuk: it makes it a bit harder to lose objects | 15:17 |
| sadmac | Keybuk: anything that has that as a parent at the end of the function /will/ get an unref | 15:18 |
| sadmac | Keybuk: regardless of whether its address is stored at a particular local pointer. | 15:18 |
| sadmac | Keybuk: it also offers a performance advantage | 15:21 |
| sadmac | NIH_DECLARE_LOCAL_ANCHOR (anchor) | 15:21 |
| sadmac | while (...) { /* use anchor for allocating */ } | 15:21 |
| sadmac | return; | 15:22 |
| sadmac | the stuff the loop created isn't freed til return. The loop now never passes through allocation code. The program gets faster. | 15:22 |
| sadmac | *never passes through free code | 15:23 |
| Keybuk | why is that different than the alternative? | 15:25 |
| Keybuk | the loop can instead consume large amounts of memory | 15:25 |
| sadmac | Keybuk: unlikely for most use patterns. Deferring garbage collection should be a big win in 99.9% of cases. The other way is still there. Furthermore, the old C maxim that variable declarations belong at the top of the function (and that's not a crazy assertion whether you agree or not) is no longer punished with a memory leak. | 15:27 |
| sadmac | Keybuk: and what's more, you no longer treat objects specially based on what variables they're held in. Less semantic confusion | 15:28 |
| Keybuk | but why can't you put them in the while loop? | 15:29 |
| sadmac | Keybuk: you can, its just gross. | 15:30 |
| Keybuk | sure | 15:32 |
| Keybuk | which is why I tend to attach them to something else outside it | 15:32 |
| sadmac | not following | 15:37 |
| Keybuk | well, I do what you do in those situations | 15:37 |
| Keybuk | have something at the top-level of the function and attach things to it | 15:38 |
| sadmac | makes sense | 15:38 |
| Milan-BV | Keybuk: hi! | 19:10 |
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