[PATCH v6] time: Add TIME_MONOTONIC, TIME_ACTIVE, and TIME_THREAD_ACTIVE

[Adhemerval Zanella Netto]

On 04/12/25 10:56, 罗勇刚(Yonggang Luo) wrote:
> On Wed, Dec 3, 2025 at 2:51 AM Adhemerval Zanella
> <adhemerval.zanella@linaro.org> wrote:
>>
>> The TIME_MONOTONIC maps to POSIX's CLOCK_MONOTONIC, TIME_ACTIVE to
>> CLOCK_PROCESS_CPUTIME_ID, and TIME_THREAD_ACTIVE to
>> CLOCK_THREAD_CPUTIME_ID.
>>
>> No Linux specific timer are added as extension.
>>
>> Co-authored-by: Yonggang Luo <luoyonggang@gmail.com>
>> --
>> Change from v5:
>> * Changed _Static_assert to use verify.
>> * Added Paul Eggert manual suggestions.
>>
>> Changes from v4:
>> * Fixed _Static_assert naming in clock_from_timebase (hopefully
>>   this time).
>>
>> Changes from v3:
>> * Fixed _Static_assert naming in clock_from_timebase.
>>
>> Changes from v2:
>> * Added manual entries for the new symbols.
>> * Optimized C TIME to POSIX clockid_t mapping.
>>
>> Changes from v1:
>> * Fixed new timers on ABIs with 32 bit time_t support.
>> * Dropped support for the Linux specific timers.
>> ---
>>  NEWS                                      |  3 ++
>>  include/time.h                            | 12 +++++++
>>  manual/time.texi                          | 13 ++++++++
>>  sysdeps/unix/sysv/linux/timespec_get.c    |  9 ++---
>>  sysdeps/unix/sysv/linux/timespec_getres.c | 10 ++----
>>  time/time.h                               |  5 +++
>>  time/timespec_get.c                       |  7 +---
>>  time/timespec_getres.c                    |  7 +---
>>  time/tst-timespec_get.c                   | 24 +++++++-------
>>  time/tst-timespec_getres.c                | 40 ++++++++++++++---------
>>  10 files changed, 76 insertions(+), 54 deletions(-)
>>
>> diff --git a/NEWS b/NEWS
>> index 81c7e04293..c420b67676 100644
>> --- a/NEWS
>> +++ b/NEWS
>> @@ -46,6 +46,9 @@ Major new features:
>>    lgammaf/lgammaf_r, log10f, sinhf, sqrtf, tgammaf, y0/j0, y1/j1, and yn/jn
>>    were moved to compat symbols, allowing improvements in performance.
>>
>> +* The ISO C23 optional time base TIME_MONOTONIC, TIME_ACTIVE, and
>> +  TIME_THREAD_ACTIVE have been added.
>> +
>>  Deprecated and removed features, and other changes affecting compatibility:
>>
>>  * Support for dumped heaps has been removed - malloc_set_state() now always
>> diff --git a/include/time.h b/include/time.h
>> index f599eeed4e..518215a2f9 100644
>> --- a/include/time.h
>> +++ b/include/time.h
>> @@ -12,6 +12,7 @@
>>  # include <time-clockid.h>
>>  # include <sys/time.h>
>>  # include <stdint.h>
>> +# include <verify.h>
>>
>>  extern __typeof (strftime_l) __strftime_l;
>>  libc_hidden_proto (__strftime_l)
>> @@ -536,6 +537,17 @@ time64_now (void)
>>    return ts.tv_sec;
>>  }
>>
>> +/* Helper that converts from C timebase to POSIX clockid_t.  */
>> +static inline clockid_t
>> +clock_from_timebase (int timebase)
> 
> Please rename clock_from_timebase to __clock_from_timebase
> or   __glibc_clock_from_timebase, as this function is in header that
> be used by so much code, use __glibc_clock_from_timebase will reduce
> potential conflict

This is an internal-only header and the function is marked as inline,
so there is no need to use a double underscore to avoid namespace
polution in staitc linking, neither to prepend to with a __glibc
namespace.