lib/timevar.h

   1 /* Timing variables for measuring application performance.
   2
   3    Copyright (C) 2000, 2002, 2004, 2009-2015, 2018 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 <http://www.gnu.org/licenses/>.  */
  20
  21 #ifndef _TIMEVAR_H
  22 # define _TIMEVAR_H 1
  23
  24 # include <stdio.h>
  25
  26 # ifdef  __cplusplus
  27 extern "C" {
  28 # endif
  29
  30 /* Timing variables are used to measure elapsed time in various
  31    portions of the application.  Each measures elapsed user, system, and
  32    wall-clock time, as appropriate to and supported by the host
  33    system.
  34
  35    Timing variables are defined using the DEFTIMEVAR macro in
  36    timevar.def.  Each has an enumeral identifier, used when referring
  37    to the timing variable in code, and a character string name.
  38
  39    Timing variables can be used in two ways:
  40
  41      - On the timing stack, using timevar_push and timevar_pop.
  42        Timing variables may be pushed onto the stack; elapsed time is
  43        attributed to the topmost timing variable on the stack.  When
  44        another variable is pushed on, the previous topmost variable is
  45        'paused' until the pushed variable is popped back off.
  46
  47      - As a standalone timer, using timevar_start and timevar_stop.
  48        All time elapsed between the two calls is attributed to the
  49        variable.
  50 */
  51
  52 /* This structure stores the various varieties of time that can be
  53    measured.  Times are stored in seconds.  The time may be an
  54    absolute time or a time difference; in the former case, the time
  55    base is undefined, except that the difference between two times
  56    produces a valid time difference.  */
  57
  58 struct timevar_time_def
  59 {
  60   /* User time in this process.  */
  61   float user;
  62
  63   /* System time (if applicable for this host platform) in this
  64      process.  */
  65   float sys;
  66
  67   /* Wall clock time.  */
  68   float wall;
  69 };
  70
  71 /* An enumeration of timing variable identifiers.  Constructed from
  72    the contents of timevar.def.  */
  73
  74 #define DEFTIMEVAR(identifier__, name__) \
  75     identifier__,
  76 typedef enum
  77 {
  78 #include "timevar.def"
  79   TIMEVAR_LAST
  80 }
  81 timevar_id_t;
  82 #undef DEFTIMEVAR
  83
  84 /* Initialize timing variables.  */
  85
  86 void timevar_init (void);
  87
  88 /* Push TIMEVAR onto the timing stack.  No further elapsed time is
  89    attributed to the previous topmost timing variable on the stack;
  90    subsequent elapsed time is attributed to TIMEVAR, until it is
  91    popped or another element is pushed on top.
  92
  93    TIMEVAR cannot be running as a standalone timer.  */
  94
  95 void timevar_push (timevar_id_t timevar);
  96
  97 /* Pop the topmost timing variable element off the timing stack.  The
  98    popped variable must be TIMEVAR.  Elapsed time since the that
  99    element was pushed on, or since it was last exposed on top of the
 100    stack when the element above it was popped off, is credited to that
 101    timing variable.  */
 102
 103 void timevar_pop (timevar_id_t timevar);
 104
 105 /* Start timing TIMEVAR independently of the timing stack.  Elapsed
 106    time until timevar_stop is called for the same timing variable is
 107    attributed to TIMEVAR.  */
 108
 109 void timevar_start (timevar_id_t timevar);
 110
 111 /* Stop timing TIMEVAR.  Time elapsed since timevar_start was called
 112    is attributed to it.  */
 113
 114 void timevar_stop (timevar_id_t timevar);
 115
 116 /* Fill the elapsed time for TIMEVAR into ELAPSED.  Returns
 117    update-to-date information even if TIMEVAR is currently running.  */
 118
 119 void timevar_get (timevar_id_t timevar, struct timevar_time_def *elapsed);
 120
 121 /* Summarize timing variables to FP.  The timing variable TV_TOTAL has
 122    a special meaning -- it's considered to be the total elapsed time,
 123    for normalizing the others, and is displayed last.  */
 124
 125 void timevar_print (FILE *fp);
 126
 127 /* Set to to nonzero to enable timing variables.  All the timevar
 128    functions make an early exit if timevar is disabled.  */
 129
 130 extern int timevar_enabled;
 131
 132 # ifdef  __cplusplus
 133 }
 134 # endif
 135
 136 #endif /* ! _TIMEVAR_H */