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| -rw-r--r-- | libc/sysdeps/linux/common/hp-timing.h | 83 |
1 files changed, 83 insertions, 0 deletions
diff --git a/libc/sysdeps/linux/common/hp-timing.h b/libc/sysdeps/linux/common/hp-timing.h new file mode 100644 index 000000000..099342db8 --- /dev/null +++ b/libc/sysdeps/linux/common/hp-timing.h @@ -0,0 +1,83 @@ +/* High precision, low overhead timing functions. Generic version. + Copyright (C) 1998, 2000 Free Software Foundation, Inc. + This file is part of the GNU C Library. + Contributed by Ulrich Drepper <drepper@cygnus.com>, 1998. + + 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. */ + +#ifndef _HP_TIMING_H +#define _HP_TIMING_H 1 + + +/* There are no generic definitions for the times. We could write something + using the `gettimeofday' system call where available but the overhead of + the system call might be too high. + + In case a platform supports timers in the hardware the following macros + and types must be defined: + + - HP_TIMING_AVAIL: test for availability. + + - HP_TIMING_INLINE: this macro is non-zero if the functionality is not + implemented using function calls but instead uses some inlined code + which might simply consist of a few assembler instructions. We have to + know this since we might want to use the macros here in places where we + cannot make function calls. + + - hp_timing_t: This is the type for variables used to store the time + values. + + - HP_TIMING_ZERO: clear `hp_timing_t' object. + + - HP_TIMING_NOW: place timestamp for current time in variable given as + parameter. + + - HP_TIMING_DIFF_INIT: do whatever is necessary to be able to use the + HP_TIMING_DIFF macro. + + - HP_TIMING_DIFF: compute difference between two times and store it + in a third. Source and destination might overlap. + + - HP_TIMING_ACCUM: add time difference to another variable. This might + be a bit more complicated to implement for some platforms as the + operation should be thread-safe and 64bit arithmetic on 32bit platforms + is not. + + - HP_TIMING_ACCUM_NT: this is the variant for situations where we know + there are no threads involved. + + - HP_TIMING_PRINT: write decimal representation of the timing value into + the given string. This operation need not be inline even though + HP_TIMING_INLINE is specified. + +*/ + +/* Provide dummy definitions. */ +#define HP_TIMING_AVAIL (0) +#define HP_TIMING_INLINE (0) +typedef int hp_timing_t; +#define HP_TIMING_ZERO(Var) +#define HP_TIMING_NOW(var) +#define HP_TIMING_DIFF_INIT() +#define HP_TIMING_DIFF(Diff, Start, End) +#define HP_TIMING_ACCUM(Sum, Diff) +#define HP_TIMING_ACCUM_NT(Sum, Diff) +#define HP_TIMING_PRINT(Buf, Len, Val) + +/* Since this implementation is not available we tell the user about it. */ +#define HP_TIMING_NONAVAIL 1 + +#endif /* hp-timing.h */ |