diff options
Diffstat (limited to 'libpthread/linuxthreads/sysdeps/pthread/getcpuclockid.c')
| -rw-r--r-- | libpthread/linuxthreads/sysdeps/pthread/getcpuclockid.c | 117 |
1 files changed, 117 insertions, 0 deletions
diff --git a/libpthread/linuxthreads/sysdeps/pthread/getcpuclockid.c b/libpthread/linuxthreads/sysdeps/pthread/getcpuclockid.c new file mode 100644 index 000000000..1c64e6c2b --- /dev/null +++ b/libpthread/linuxthreads/sysdeps/pthread/getcpuclockid.c @@ -0,0 +1,117 @@ +/* pthread_getcpuclockid -- Get POSIX clockid_t for a pthread_t. Linux version + Copyright (C) 2000, 2001, 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; see the file COPYING.LIB. If not, + write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330, + Boston, MA 02111-1307, USA. */ + +#include <errno.h> +#include <pthread.h> +#include <sys/time.h> +#include <time.h> +#include <internals.h> +#include <spinlock.h> +#include <kernel-features.h> +#include <kernel-posix-cpu-timers.h> + + +#if !(__ASSUME_POSIX_CPU_TIMERS > 0) +int __libc_missing_posix_cpu_timers attribute_hidden; +#endif +#if !(__ASSUME_POSIX_TIMERS > 0) +int __libc_missing_posix_timers attribute_hidden; +#endif + +int +pthread_getcpuclockid (pthread_t thread_id, clockid_t *clock_id) +{ +#ifdef __NR_clock_getres + pthread_handle handle = thread_handle(thread_id); + int pid; + + __pthread_lock (&handle->h_lock, NULL); + if (nonexisting_handle (handle, thread_id)) + { + __pthread_unlock (&handle->h_lock); + return ESRCH; + } + pid = handle->h_descr->p_pid; + __pthread_unlock (&handle->h_lock); + + /* The clockid_t value is a simple computation from the PID. + But we do a clock_getres call to validate it if we aren't + yet sure we have the kernel support. */ + + const clockid_t pidclock = MAKE_PROCESS_CPUCLOCK (pid, CPUCLOCK_SCHED); + +# if !(__ASSUME_POSIX_CPU_TIMERS > 0) +# if !(__ASSUME_POSIX_TIMERS > 0) + if (__libc_missing_posix_timers && !__libc_missing_posix_cpu_timers) + __libc_missing_posix_cpu_timers = 1; +# endif + if (!__libc_missing_posix_cpu_timers) + { + INTERNAL_SYSCALL_DECL (err); + int r = INTERNAL_SYSCALL (clock_getres, err, 2, pidclock, NULL); + if (!INTERNAL_SYSCALL_ERROR_P (r, err)) +# endif + { + *clock_id = pidclock; + return 0; + } + +# if !(__ASSUME_POSIX_CPU_TIMERS > 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) + { + /* The kernel doesn't support these clocks at all. */ + __libc_missing_posix_cpu_timers = 1; + } + else + return INTERNAL_SYSCALL_ERRNO (r, err); + } +# endif +#endif + +#ifdef CLOCK_THREAD_CPUTIME_ID + /* We need to store the thread ID in the CLOCKID variable together + with a number identifying the clock. We reserve the low 3 bits + for the clock ID and the rest for the thread ID. This is + problematic if the thread ID is too large. But 29 bits should be + fine. + + If some day more clock IDs are needed the ID part can be + enlarged. The IDs are entirely internal. */ + if (2 * PTHREAD_THREADS_MAX + >= 1 << (8 * sizeof (*clock_id) - CLOCK_IDFIELD_SIZE)) + return ERANGE; + + /* Store the number. */ + *clock_id = CLOCK_THREAD_CPUTIME_ID | (thread_id << CLOCK_IDFIELD_SIZE); + + return 0; +#else + /* We don't have a timer for that. */ + return ENOENT; +#endif +} |