l4/pkg/l4util/include/ARCH-x86/thread_time.h

   1 /**
   2  * \file
   3  * \brief  Functions to acquire thread time fast (without kernel entry)
   4  *
   5  * \date   Martin Pohlack  <mp26@os.inf.tu-dresden.de> */
   6
   7 /*
   8  * (c) 2005-2009 Adam Lackorzynski <adam@os.inf.tu-dresden.de>,
   9  *               Martin Pohlack <mp26@os.inf.tu-dresden.de>
  10  *     economic rights: Technische Universität Dresden (Germany)
  11  * This file is part of TUD:OS and distributed under the terms of the
  12  * GNU Lesser General Public License 2.1.
  13  * Please see the COPYING-LGPL-2.1 file for details.
  14  */
  15
  16
  17 #ifndef __L4UTIL__INCLUDE__ARCH_X86__THREAD_TIME_H__
  18 #define __L4UTIL__INCLUDE__ARCH_X86__THREAD_TIME_H__
  19
  20 #include <l4/sys/kip.h>
  21 #include <l4/util/rdtsc.h>
  22
  23 EXTERN_C_BEGIN
  24
  25 /**
  26  * \brief Acquire accumulated runtime  from the kernel info page for currently
  27  *        running thread
  28  *
  29  * @param kinfo pointer to mapped kernel info page
  30  *
  31  * \return Accumulated thread time (cycles)
  32  */
  33 L4_INLINE l4_cpu_time_t l4util_thread_time(const l4_kernel_info_t * kinfo);
  34 L4_INLINE l4_cpu_time_t l4util_thread_time(const l4_kernel_info_t * kinfo)
  35 {
  36     l4_cpu_time_t switch_time, thread_time, now;
  37
  38     do
  39       {
  40         now          = l4_rdtsc();
  41         /* fixme: make 64 bit reads atomic ??? */
  42         thread_time  = kinfo->thread_time;
  43         switch_time  = kinfo->switch_time;
  44       }
  45     while (now < switch_time);
  46
  47     return now - switch_time + thread_time;
  48 }
  49
  50 EXTERN_C_END
  51
  52
  53 #endif /* ! __L4UTIL__INCLUDE__ARCH_X86__THREAD_TIME_H__ */