Bug #1398

hdestroy(3) restricts hash key to point to malloc'ed space

Added by Anonymous over 5 years ago. Updated over 5 years ago.

Status:NewStart date:
Priority:NormalDue date:
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Description

Salute.

hdestroy(3) frees the memory pointed to by the hash key. In other words it
expects the user to always have malloc()'ed rather than used static allocation
for the hash key. This doesn't apply to the data associated with the key.

Although POSIX standard doesn't say much on this particular topic:

1) This is unnecessarily restrictive. If the user wants static allocation, we
should allow this. If she wants dynamic then let *her* free the memory she
malloc()'ed.

2) It is in conflict with the example code in the POSIX page. The code
segfaults if you add an hdestroy() call in the end of it.

3) Programs that target other implementations may segfault in DragonFly (that's
how I discovered it). AFAIK sunOS 5.10 and a recent glibc work fine, whereas
{Net, Free, DragonFly}BSD all are affected because they share the same code.
(One could argue that all programs written with the *BSD version in mind would
result in a memory leak. But still I think these programs (if any) should be fixed.)

Any thoughts ?

Cheers,
Stathis

hdestroy-3-Don-t-call-free-3-for-each-hash-key.patch Magnifier (2.27 KB) Anonymous, 06/10/2009 07:08 PM

History

#1 Updated by Anonymous over 5 years ago

> hdestroy(3) frees the memory pointed to by the hash key. In other words it
> expects the user to always have malloc()'ed rather than used static allocation
> for the hash key. This doesn't apply to the data associated with the key.

Any thoughts about this one ?
If no objections are raised, I'm going to push it in ~1 week.

Cheers,
Stathis

#2 Updated by Anonymous over 5 years ago

>> hdestroy(3) frees the memory pointed to by the hash key. In other words it
>> expects the user to always have malloc()'ed rather than used static allocation
>> for the hash key. This doesn't apply to the data associated with the key.

> Any thoughts about this one ?
> If no objections are raised, I'm going to push it in ~1 week.

I'll tweak the example in the man page, add a few words in the text and commit it.

Reviewed by dillon@ and hasso@.

Cheers,
Stathis

#3 Updated by dillon over 5 years ago

:Stathis Kamperis <> added the comment:
:
:> hdestroy(3) frees the memory pointed to by the hash key. In other words i=
:t
:> expects the user to always have malloc()'ed rather than used static alloc=
:ation
:> for the hash key. This doesn't apply to the data associated with the key.
:
:Any thoughts about this one ?
:If no objections are raised, I'm going to push it in ~1 week.
:
:Cheers,
:Stathis

Sure. Does anyone even use those functions any more? They
aren't threadable.

-Matt

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