| yuezonghe | 824eb0c | 2024-06-27 02:32:26 -0700 | [diff] [blame^] | 1 | /* High precision, low overhead timing functions. Generic version. |
| 2 | Copyright (C) 1998, 2000 Free Software Foundation, Inc. |
| 3 | This file is part of the GNU C Library. |
| 4 | Contributed by Ulrich Drepper <drepper@cygnus.com>, 1998. |
| 5 | |
| 6 | The GNU C Library is free software; you can redistribute it and/or |
| 7 | modify it under the terms of the GNU Lesser General Public |
| 8 | License as published by the Free Software Foundation; either |
| 9 | version 2.1 of the License, or (at your option) any later version. |
| 10 | |
| 11 | The GNU C Library is distributed in the hope that it will be useful, |
| 12 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 13 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| 14 | Lesser General Public License for more details. |
| 15 | |
| 16 | You should have received a copy of the GNU Lesser General Public |
| 17 | License along with the GNU C Library; if not, write to the Free |
| 18 | Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA |
| 19 | 02111-1307 USA. */ |
| 20 | |
| 21 | #ifndef _HP_TIMING_H |
| 22 | #define _HP_TIMING_H 1 |
| 23 | |
| 24 | |
| 25 | /* There are no generic definitions for the times. We could write something |
| 26 | using the `gettimeofday' system call where available but the overhead of |
| 27 | the system call might be too high. |
| 28 | |
| 29 | In case a platform supports timers in the hardware the following macros |
| 30 | and types must be defined: |
| 31 | |
| 32 | - HP_TIMING_AVAIL: test for availability. |
| 33 | |
| 34 | - HP_TIMING_INLINE: this macro is non-zero if the functionality is not |
| 35 | implemented using function calls but instead uses some inlined code |
| 36 | which might simply consist of a few assembler instructions. We have to |
| 37 | know this since we might want to use the macros here in places where we |
| 38 | cannot make function calls. |
| 39 | |
| 40 | - hp_timing_t: This is the type for variables used to store the time |
| 41 | values. |
| 42 | |
| 43 | - HP_TIMING_ZERO: clear `hp_timing_t' object. |
| 44 | |
| 45 | - HP_TIMING_NOW: place timestamp for current time in variable given as |
| 46 | parameter. |
| 47 | |
| 48 | - HP_TIMING_DIFF_INIT: do whatever is necessary to be able to use the |
| 49 | HP_TIMING_DIFF macro. |
| 50 | |
| 51 | - HP_TIMING_DIFF: compute difference between two times and store it |
| 52 | in a third. Source and destination might overlap. |
| 53 | |
| 54 | - HP_TIMING_ACCUM: add time difference to another variable. This might |
| 55 | be a bit more complicated to implement for some platforms as the |
| 56 | operation should be thread-safe and 64bit arithmetic on 32bit platforms |
| 57 | is not. |
| 58 | |
| 59 | - HP_TIMING_ACCUM_NT: this is the variant for situations where we know |
| 60 | there are no threads involved. |
| 61 | |
| 62 | - HP_TIMING_PRINT: write decimal representation of the timing value into |
| 63 | the given string. This operation need not be inline even though |
| 64 | HP_TIMING_INLINE is specified. |
| 65 | |
| 66 | */ |
| 67 | |
| 68 | /* Provide dummy definitions. */ |
| 69 | #define HP_TIMING_AVAIL (0) |
| 70 | #define HP_TIMING_INLINE (0) |
| 71 | typedef int hp_timing_t; |
| 72 | #define HP_TIMING_ZERO(Var) |
| 73 | #define HP_TIMING_NOW(var) |
| 74 | #define HP_TIMING_DIFF_INIT() |
| 75 | #define HP_TIMING_DIFF(Diff, Start, End) |
| 76 | #define HP_TIMING_ACCUM(Sum, Diff) |
| 77 | #define HP_TIMING_ACCUM_NT(Sum, Diff) |
| 78 | #define HP_TIMING_PRINT(Buf, Len, Val) |
| 79 | |
| 80 | /* Since this implementation is not available we tell the user about it. */ |
| 81 | #define HP_TIMING_NONAVAIL 1 |
| 82 | |
| 83 | #endif /* hp-timing.h */ |