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author | Adhemerval Zanella <adhemerval.zanella@linaro.org> | 2019-12-16 09:58:32 -0300 |
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committer | Adhemerval Zanella <adhemerval.zanella@linaro.org> | 2020-01-03 11:22:04 -0300 |
commit | e760874ee3315ca3a8a2978b5f8e4dba1e336197 (patch) | |
tree | 07c69a08dede6e2d58d24d78e2891406aadaf3c3 /sysdeps/unix/sysv/linux/time.c | |
parent | c701bcc6f4b0077e544ac100338343ac6cc4cb8a (diff) | |
download | glibc-e760874ee3315ca3a8a2978b5f8e4dba1e336197.tar.gz glibc-e760874ee3315ca3a8a2978b5f8e4dba1e336197.tar.xz glibc-e760874ee3315ca3a8a2978b5f8e4dba1e336197.zip |
linux: Consolidate time implementation
The IFUNC bypass to vDSO is used when USE_IFUNC_TIME is set. Currently powerpc and x86 defines it. Otherwise the generic implementation is used, which calls clock_gettime. Checked on powerpc64le-linux-gnu, powerpc64-linux-gnu, powerpc-linux-gnu-power4, x86_64-linux-gnu, and i686-linux-gnu. Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
Diffstat (limited to 'sysdeps/unix/sysv/linux/time.c')
-rw-r--r-- | sysdeps/unix/sysv/linux/time.c | 50 |
1 files changed, 50 insertions, 0 deletions
diff --git a/sysdeps/unix/sysv/linux/time.c b/sysdeps/unix/sysv/linux/time.c new file mode 100644 index 0000000000..2dc4cbe786 --- /dev/null +++ b/sysdeps/unix/sysv/linux/time.c @@ -0,0 +1,50 @@ +/* time -- Get number of seconds since Epoch. Linux version. + Copyright (C) 2020 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, see + <https://www.gnu.org/licenses/>. */ + +/* Optimize the function call by setting the PLT directly to vDSO symbol. */ +#ifdef USE_IFUNC_TIME +# include <time.h> +# include <sysdep.h> +# include <sysdep-vdso.h> + +#ifdef SHARED +# include <dl-vdso.h> + +static time_t +time_syscall (time_t *t) +{ + return INLINE_SYSCALL_CALL (time, t); +} + +# undef INIT_ARCH +# define INIT_ARCH() \ + void *vdso_time = get_vdso_symbol (HAVE_TIME_VSYSCALL); +libc_ifunc (time, + vdso_time ? VDSO_IFUNC_RET (vdso_time) + : (void *) time_syscall); + +# else +time_t +time (time_t *t) +{ + return INLINE_VSYSCALL (time, 1, t); +} +# endif /* !SHARED */ +#else /* USE_IFUNC_TIME */ +# include <time/time.c> +#endif |