In glibc 2.17, the functions clock_getcpuclockid, clock_getres,
clock_gettime, clock_nanosleep, and clock_settime were moved from
librt.so to libc.so, leaving compatibility stubs behind. Now that the
dynamic linker no longer insists on finding versioned symbols in the
same library that originally defined them, we do not need the stubs
anymore, and this means we don't need GLIBC_PRIVATE __-prefix aliases
for most of the functions anymore either. (clock_gettime still needs
one.) For ports added before 2.17, libc.so needs to provide two
symbol versions for each, the default at GLIBC_2.17 plus a compat
version matching what librt had.
While I'm at it, move the clock_*.c files and their tests from rt/ to
time/.
This patch removes CLOCK_THREAD_CPUTIME_ID and CLOCK_PROCESS_CPUTIME_ID support
from clock_gettime and clock_settime generic implementation. For Linux, kernel
already provides supports through the syscall and Hurd HTL lacks
__pthread_clock_gettime and __pthread_clock_settime internal implementation.
As described in clock_gettime man-page [1] on 'Historical note for SMP
system', implementing CLOCK_{THREAD,PROCESS}_CPUTIME_ID with timer registers
is error-prone and susceptible to timing and accurary issues that the libc
can not deal without kernel support.
This allows removes unused code which, however, still incur in some runtime
overhead in thread creation (the struct pthread cpuclock_offset
initialization).
If hurd eventually wants to support them it should either either implement as
a kernel facility (or something related due its architecture) or in system
specific implementation.
Checked on aarch64-linux-gnu, x86_64-linux-gnu, and i686-linux-gnu. I also
checked on a i686-gnu build.
* nptl/Makefile (libpthread-routines): Remove pthread_clock_gettime and
pthread_clock_settime.
* nptl/pthreadP.h (__find_thread_by_id): Remove prototype.
* elf/dl-support.c [!HP_TIMING_NOAVAIL] (_dl_cpuclock_offset): Remove.
(_dl_non_dynamic_init): Remove _dl_cpuclock_offset setting.
* elf/rtld.c (_dl_start_final): Likewise.
* nptl/allocatestack.c (__find_thread_by_id): Remove function.
* sysdeps/generic/ldsodefs.h [!HP_TIMING_NOAVAIL] (_dl_cpuclock_offset):
Remove.
* sysdeps/mach/hurd/dl-sysdep.c [!HP_TIMING_NOAVAIL]
(_dl_cpuclock_offset): Remove.
* nptl/descr.h (struct pthread): Rename cpuclock_offset to
cpuclock_offset_ununsed.
* nptl/nptl-init.c (__pthread_initialize_minimal_internal): Remove
cpuclock_offset set.
* nptl/pthread_create.c (START_THREAD_DEFN): Likewise.
* sysdeps/nptl/fork.c (__libc_fork): Likewise.
* nptl/pthread_clock_gettime.c: Remove file.
* nptl/pthread_clock_settime.c: Likewise.
* sysdeps/unix/clock_gettime.c (hp_timing_gettime): Remove function.
[HP_TIMING_AVAIL] (realtime_gettime): Remove CLOCK_THREAD_CPUTIME_ID
and CLOCK_PROCESS_CPUTIME_ID support.
* sysdeps/unix/clock_settime.c (hp_timing_gettime): Likewise.
[HP_TIMING_AVAIL] (realtime_gettime): Likewise.
* sysdeps/posix/clock_getres.c (hp_timing_getres): Likewise.
[HP_TIMING_AVAIL] (__clock_getres): Likewise.
* sysdeps/unix/clock_nanosleep.c (CPUCLOCK_P, INVALID_CLOCK_P):
Likewise.
(__clock_nanosleep): Remove CPUCLOCK_P and INVALID_CLOCK_P usage.
[1] http://man7.org/linux/man-pages/man2/clock_gettime.2.html
Clock_gettime, settime and getres implementations are unncessarily
complex due to using defines and C file inclusion. Simplify the
code by replacing the redundant defines and removing the inclusion,
making it much easier to understand. No functional changes.
* sysdeps/posix/clock_getres.c (__clock_getres): Cleanup.
* sysdeps/unix/clock_gettime.c (__clock_gettime): Cleanup.
* sysdeps/unix/clock_settime.c (__clock_settime): Cleanup.
* sysdeps/unix/sysv/linux/clock_getres.c (__clock_getres): Cleanup.
* sysdeps/unix/sysv/linux/clock_gettime.c (__clock_gettime): Cleanup.
* sysdeps/unix/sysv/linux/clock_settime.c (__clock_settime): Cleanup.
__clock_gettime and other __clock_* functions could result in an extra
PLT reference within libc.so if it actually gets used. None of the
code currently uses them, which is why this probably went unnoticed.
* sysdeps/unix/sysv/linux/kernel-posix-cpu-timers.h: New file.
* sysdeps/unix/sysv/linux/clock_getcpuclockid.c: New file.
* sysdeps/unix/sysv/linux/ia64/clock_getcpuclockid.c
(HAS_CPUCLOCK): New macro.
(clock_getcpuclockid): Function removed.
#include the new linux file to define it instead.
* sysdeps/unix/clock_gettime.c [HP_TIMING_AVAIL] (hp_timing_gettime):
New function, broken out of ...
(clock_gettime) [HP_TIMING_AVAIL]: ... here. Call it.
(realtime_gettime): New function, broken out of ...
(clock_gettime) [! HANDLED_REALTIME]: ... here. Call it.
(clock_gettime) [SYSDEP_GETTIME_CPU]: Use new macro in default case.
* sysdeps/unix/sysv/linux/clock_gettime.c (SYSCALL_GETTIME): New macro.
(SYSDEP_GETTIME_CPUTIME): New macro.
(SYSDEP_GETTIME): Use both.
[! __ASSUME_POSIX_TIMERS] (maybe_syscall_gettime): New function, broken
out of ...
(SYSDEP_GETTIME): ... here. Use it.
[__NR_clock_gettime] (HANDLED_CPUTIME): Define it.
(SYSDEP_GETTIME_CPUTIME): New macro. Handle CPU timers by trying
kernel support and falling back to hp-timing code.
* sysdeps/posix/clock_getres.c
[HP_TIMING_AVAIL] (hp_timing_getres): New function, broken out of ...
(clock_getres) [HP_TIMING_AVAIL]: ... here. Call it.
(realtime_getres): New function, broken out of ...
(clock_getres) [! HANDLED_REALTIME]: ... here. Call it.
(clock_getres) [SYSDEP_GETRES_CPU]: Use new macro in default case.
* sysdeps/unix/sysv/linux/clock_getres.c (SYSCALL_GETRES): New macro.
(SYSDEP_GETRES_CPUTIME): New macro.
(SYSDEP_GETRES): Use both.
[! __ASSUME_POSIX_TIMERS] (maybe_syscall_getres): New function, broken
out of ...
(SYSDEP_GETRES): ... here. Use it.
[__NR_clock_getres] (HANDLED_CPUTIME): Define it.
(SYSDEP_GETRES_CPUTIME): New macro. Handle CPU timers by trying
kernel support and falling back to hp-timing code.
* sysdeps/unix/sysv/linux/clock_nanosleep.c: Handle
CLOCK_PROCESS_CPUTIME_ID and CLOCK_PROCESS_THREAD_ID specially,
translating to the kernel clockid_t for our own process/thread clock.
* include/time.h: Define CLOCK_IDFIELD_SIZE.
* sysdeps/posix/clock_getres.c: Recognize thread CPU clock IDs.
* sysdeps/unix/clock_gettime.c: Likewise.
* sysdeps/unix/clock_settime.c: Likewise.
* sysdeps/unix/clock_nanosleep.c (CPUCLOCK_P): Adjust for new
clock id for thread CPU clocks.
2001-07-06 Paul Eggert <eggert@twinsun.com>
* manual/argp.texi: Remove ignored LGPL copyright notice; it's
not appropriate for documentation anyway.
* manual/libc-texinfo.sh: "Library General Public License" ->
"Lesser General Public License".
2001-07-06 Andreas Jaeger <aj@suse.de>
* All files under GPL/LGPL version 2: Place under LGPL version
2.1.
