lib/timevar.h

   1 /* Timing variables for measuring application performance.
   2
   3    Copyright (C) 2000, 2002, 2004, 2009-2015, 2018-2024 Free Software
   4    Foundation, Inc.
   5
   6    Contributed by Alex Samuel <samuel@codesourcery.com>
   7
   8    This program is free software: you can redistribute it and/or modify
   9    it under the terms of the GNU General Public License as published by
  10    the Free Software Foundation, either version 3 of the License, or
  11    (at your option) any later version.
  12
  13    This program is distributed in the hope that it will be useful,
  14    but WITHOUT ANY WARRANTY; without even the implied warranty of
  15    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16    GNU General Public License for more details.
  17
  18    You should have received a copy of the GNU General Public License
  19    along with this program.  If not, see <https://www.gnu.org/licenses/>.  */
  20
  21 #ifndef _TIMEVAR_H
  22 # define _TIMEVAR_H 1
  23
  24 # include <stdio.h>
  25
  26 # include "xtime.h"
  27
  28 # ifdef  __cplusplus
  29 extern "C" {
  30 # endif
  31
  32 /* Timing variables are used to measure elapsed time in various
  33    portions of the application.  Each measures elapsed user, system, and
  34    wall-clock time, as appropriate to and supported by the host
  35    system.
  36
  37    Timing variables are defined using the DEFTIMEVAR macro in
  38    timevar.def.  Each has an identifier of type timevar_id_t, used to refer
  39    to the timing variable in code, and a character string name.
  40
  41    Timing variables can be used in two ways:
  42
  43      - On the timing stack, using timevar_push and timevar_pop.
  44        Timing variables may be pushed onto the stack; elapsed time is
  45        attributed to the topmost timing variable on the stack.  When
  46        another variable is pushed on, the previous topmost variable is
  47        'paused' until the pushed variable is popped back off.
  48
  49      - As a standalone timer, using timevar_start and timevar_stop.
  50        All time elapsed between the two calls is attributed to the
  51        variable.
  52 */
  53
  54 /* This structure stores the various varieties of time that can be
  55    measured.  Times are stored in seconds.  The time may be an
  56    absolute time or a time difference; in the former case, the time
  57    base is undefined, except that the difference between two times
  58    produces a valid time difference.  */
  59
  60 struct timevar_time_def
  61 {
  62   /* User time in this process.  */
  63   xtime_t user;
  64
  65   /* System time (if applicable for this host platform) in this
  66      process.  */
  67   xtime_t sys;
  68
  69   /* Wall clock time.  */
  70   xtime_t wall;
  71 };
  72
  73 /* An enumeration of timing variable identifiers.  Constructed from
  74    the contents of timevar.def.  */
  75
  76 #define DEFTIMEVAR(identifier__, name__) \
  77     identifier__,
  78 typedef enum
  79 {
  80 #include "timevar.def"
  81   TIMEVAR_LAST
  82 }
  83 timevar_id_t;
  84 #undef DEFTIMEVAR
  85
  86 /* Initialize timing variables.  */
  87
  88 void timevar_init (void);
  89
  90 /* Push TIMEVAR onto the timing stack.  No further elapsed time is
  91    attributed to the previous topmost timing variable on the stack;
  92    subsequent elapsed time is attributed to TIMEVAR, until it is
  93    popped or another element is pushed on top.
  94
  95    TIMEVAR cannot be running as a standalone timer.  */
  96
  97 void timevar_push (timevar_id_t timevar);
  98
  99 /* Pop the topmost timing variable element off the timing stack.  The
 100    popped variable must be TIMEVAR.  Elapsed time since the that
 101    element was pushed on, or since it was last exposed on top of the
 102    stack when the element above it was popped off, is credited to that
 103    timing variable.  */
 104
 105 void timevar_pop (timevar_id_t timevar);
 106
 107 /* Start timing TIMEVAR independently of the timing stack.  Elapsed
 108    time until timevar_stop is called for the same timing variable is
 109    attributed to TIMEVAR.  */
 110
 111 void timevar_start (timevar_id_t timevar);
 112
 113 /* Stop timing TIMEVAR.  Time elapsed since timevar_start was called
 114    is attributed to it.  */
 115
 116 void timevar_stop (timevar_id_t timevar);
 117
 118 /* Fill the elapsed time for TIMEVAR into ELAPSED.  Returns
 119    update-to-date information even if TIMEVAR is currently running.  */
 120
 121 void timevar_get (timevar_id_t timevar, struct timevar_time_def *elapsed);
 122
 123 /* Summarize timing variables to FP.  The timing variable TV_TOTAL has
 124    a special meaning -- it's considered to be the total elapsed time,
 125    for normalizing the others, and is displayed last.  */
 126
 127 void timevar_print (FILE *fp);
 128
 129 /* Set to to nonzero to enable timing variables.  All the timevar
 130    functions make an early exit if timevar is disabled.  */
 131
 132 extern int timevar_enabled;
 133
 134 # ifdef  __cplusplus
 135 }
 136 # endif
 137
 138 #endif /* ! _TIMEVAR_H */