/* clock_getcpuclockid -- Get a clockid_t for process CPU time. Linux version. Copyright (C) 2004, 2005 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 <sysdep.h> #include <unistd.h> #include <bits/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; } #endif /* We don't have a timer for that. */ return ENOENT; }