[PATCH 1/2] Add pthread_getname_np and pthread_setname_np

[Jon Turney]

On 28/07/2016 20:21, Corinna Vinschen wrote:
> Hi Jon,
>
> On Jul 28 12:43, Jon Turney wrote:
>> This patch adds pthread_getname_np and pthread_setname_np.
>>
>> These were added to glibc in 2.12[1] and are also present in some form on
>> NetBSD and several UNIXes.
>>
>> The code is based on NetBSD's implementation with changes to better match
>> Linux behaviour.
>>
>> Implementation quirks:
>>
>> * pthread_setname_np with a NULL pointer segfaults (as linux)
>>
>> * pthread_setname_np accepts names longer than 16 characters (linux returns
>> ERANGE)
>
> Given the behaviour of pthread_getname_np we should do the same, I think.

Ok.

>
>> * pthread_getname_np with a NULL pointer returns EFAULT (as linux)
>>
>> * pthread_getname_np with a buffer length of less than 16 returns ERANGE (as
>> linux)
>>
>> * pthread_getname_np truncates the thread name to fit the buffer length.
>> This guarantees success even when the default thread name is longer than 16
>> characters, but means there is no way to discover the actual length of the
>> thread name. (Linux always truncates the thread name to 16 characters)
>>
>> * Changing program_invocation_short_name changes the default thread name.
>>
>> I'll leave it up to you to decide any of these matter.
>>
>> This is implemented via class pthread_attr to make it easier to add
>> pthread_attr_[gs]etname_np (present in NetBSD and some UNIXes) should it
>> ever be added to Linux (or we decide we want it anyway).
>
> Good thinking.

Yaakov's idea, not mine :)