diff options
Diffstat (limited to 'sysdeps/unix/sysv/linux/clock_getcpuclockid.c')
| -rw-r--r-- | sysdeps/unix/sysv/linux/clock_getcpuclockid.c | 103 |
1 files changed, 103 insertions, 0 deletions
diff --git a/sysdeps/unix/sysv/linux/clock_getcpuclockid.c b/sysdeps/unix/sysv/linux/clock_getcpuclockid.c new file mode 100644 index 0000000000..ac893c0a77 --- /dev/null +++ b/sysdeps/unix/sysv/linux/clock_getcpuclockid.c @@ -0,0 +1,103 @@ +/* clock_getcpuclockid -- Get a clockid_t for process CPU time. Linux version. + Copyright (C) 2004 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, write to the Free + Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA + 02111-1307 USA. */ + +#include <errno.h> +#include <time.h> +#include <unistd.h> +#include "kernel-features.h" +#include "kernel-posix-cpu-timers.h" + +#ifndef HAS_CPUCLOCK +# define HAS_CPUCLOCK 1 +#endif + +int +clock_getcpuclockid (pid_t pid, clockid_t *clock_id) +{ +#ifdef __NR_clock_getres + /* The clockid_t value is a simple computation from the PID. + But we do a clock_getres call to validate it. */ + + const clockid_t pidclock = MAKE_PROCESS_CPUCLOCK (pid, CPUCLOCK_SCHED); + +# if !(__ASSUME_POSIX_CPU_TIMERS > 0) + extern int __libc_missing_posix_cpu_timers attribute_hidden; +# if !(__ASSUME_POSIX_TIMERS > 0) + extern int __libc_missing_posix_timers attribute_hidden; + if (__libc_missing_posix_timers && !__libc_missing_posix_cpu_timers) + __libc_missing_posix_cpu_timers = 1; +# endif + if (!__libc_missing_posix_cpu_timers) +# endif + { + INTERNAL_SYSCALL_DECL (err); + int r = INTERNAL_SYSCALL (clock_getres, err, 2, pidclock, NULL); + if (!INTERNAL_SYSCALL_ERROR_P (r, err)) + { + *clock_id = pidclock; + return 0; + } + +# if !(__ASSUME_POSIX_TIMERS > 0) + if (INTERNAL_SYSCALL_ERRNO (r, err) == ENOSYS) + { + /* The kernel doesn't support these calls at all. */ + __libc_missing_posix_timers = 1; + __libc_missing_posix_cpu_timers = 1; + } + else +# endif + if (INTERNAL_SYSCALL_ERRNO (r, err) == EINVAL) + { +# if !(__ASSUME_POSIX_CPU_TIMERS > 0) + if (pidclock == MAKE_PROCESS_CPUCLOCK (0, CPUCLOCK_SCHED) + || INTERNAL_SYSCALL_ERROR_P (INTERNAL_SYSCALL + (clock_getres, err, 2, + MAKE_PROCESS_CPUCLOCK + (0, CPUCLOCK_SCHED), NULL), + err)) + /* The kernel doesn't support these clocks at all. */ + __libc_missing_posix_cpu_timers = 1; + else +# endif + /* The clock_getres system call checked the PID for us. */ + return ESRCH; + } + else + return INTERNAL_SYSCALL_ERRNO (r, err); + } +# endif + + /* We don't allow any process ID but our own. */ + if (pid != 0 && pid != getpid ()) + return EPERM; + +#ifdef CLOCK_PROCESS_CPUTIME_ID + if (HAS_CPUCLOCK) + { + /* Store the number. */ + *clock_id = CLOCK_PROCESS_CPUTIME_ID; + + return 0; + } +#else + /* We don't have a timer for that. */ + return ENOENT; +#endif +} |