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, see 18 <http://www.gnu.org/licenses/>. */ 19 20 #ifndef _HP_TIMING_H 21 #define _HP_TIMING_H 1 22 23 24 /* There are no generic definitions for the times. We could write something 25 using the `gettimeofday' system call where available but the overhead of 26 the system call might be too high. 27 28 In case a platform supports timers in the hardware the following macros 29 and types must be defined: 30 31 - HP_TIMING_AVAIL: test for availability. 32 33 - HP_TIMING_INLINE: this macro is non-zero if the functionality is not 34 implemented using function calls but instead uses some inlined code 35 which might simply consist of a few assembler instructions. We have to 36 know this since we might want to use the macros here in places where we 37 cannot make function calls. 38 39 - hp_timing_t: This is the type for variables used to store the time 40 values. 41 42 - HP_TIMING_ZERO: clear `hp_timing_t' object. 43 44 - HP_TIMING_NOW: place timestamp for current time in variable given as 45 parameter. 46 47 - HP_TIMING_DIFF_INIT: do whatever is necessary to be able to use the 48 HP_TIMING_DIFF macro. 49 50 - HP_TIMING_DIFF: compute difference between two times and store it 51 in a third. Source and destination might overlap. 52 53 - HP_TIMING_ACCUM: add time difference to another variable. This might 54 be a bit more complicated to implement for some platforms as the 55 operation should be thread-safe and 64bit arithmetic on 32bit platforms 56 is not. 57 58 - HP_TIMING_ACCUM_NT: this is the variant for situations where we know 59 there are no threads involved. 60 61 - HP_TIMING_PRINT: write decimal representation of the timing value into 62 the given string. This operation need not be inline even though 63 HP_TIMING_INLINE is specified. 64 65 */ 66 67 /* Provide dummy definitions. */ 68 #define HP_TIMING_AVAIL (0) 69 #define HP_TIMING_INLINE (0) 70 typedef int hp_timing_t; 71 #define HP_TIMING_ZERO(Var) 72 #define HP_TIMING_NOW(var) 73 #define HP_TIMING_DIFF_INIT() 74 #define HP_TIMING_DIFF(Diff, Start, End) 75 #define HP_TIMING_ACCUM(Sum, Diff) 76 #define HP_TIMING_ACCUM_NT(Sum, Diff) 77 #define HP_TIMING_PRINT(Buf, Len, Val) 78 79 /* Since this implementation is not available we tell the user about it. */ 80 #define HP_TIMING_NONAVAIL 1 81 82 #endif /* hp-timing.h */ 83