code.delx.au - gnu-emacs/blob - lib-src/profile.c

   1 /* profile.c --- generate periodic events for profiling of Emacs Lisp code.
   2    Copyright (C) 1992, 1994, 1999, 2001-2012  Free Software Foundation, Inc.
   3
   4 Author: Boaz Ben-Zvi <boaz@lcs.mit.edu>
   5
   6 This file is part of GNU Emacs.
   7
   8 GNU Emacs 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 GNU Emacs 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 GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
  20
  21
  22 /**
  23  **  To be run as an emacs subprocess.  Input string that starts with:
  24  **    'z' -- resets the watch (to zero).
  25  **    'p' -- return time (on stdout) as string with format <sec>.<micro-sec>
  26  **    'q' -- exit.
  27  **
  28  **  abstraction : a stopwatch
  29  **  operations: reset_watch, get_time
  30  */
  31 #include <config.h>
  32
  33 #include <inttypes.h>
  34 #include <stdio.h>
  35
  36 #include <intprops.h>
  37 #include <systime.h>
  38
  39 static EMACS_TIME TV1, TV2;
  40 static int watch_not_started = 1; /* flag */
  41 static char time_string[INT_STRLEN_BOUND (uintmax_t) + sizeof "."
  42                         + LOG10_EMACS_TIME_RESOLUTION];
  43
  44 /* Reset the stopwatch to zero.  */
  45
  46 static void
  47 reset_watch (void)
  48 {
  49   EMACS_GET_TIME (TV1);
  50   watch_not_started = 0;
  51 }
  52
  53 /* This call returns the time since the last reset_watch call.  The time
  54    is returned as a string with the format  <seconds>.<nanoseconds>
  55    If reset_watch was not called yet, exit.  */
  56
  57 static char *
  58 get_time (void)
  59 {
  60   uintmax_t s;
  61   int ns;
  62   if (watch_not_started)
  63     exit (EXIT_FAILURE);  /* call reset_watch first ! */
  64   EMACS_GET_TIME (TV2);
  65   EMACS_SUB_TIME (TV2, TV2, TV1);
  66   s = EMACS_SECS (TV2);
  67   ns = EMACS_NSECS (TV2);
  68   sprintf (time_string, "%"PRIuMAX".%0*d", s, LOG10_EMACS_TIME_RESOLUTION, ns);
  69   return time_string;
  70 }
  71 \f
  72 int
  73 main (void)
  74 {
  75   int c;
  76   while ((c = getchar ()) != EOF)
  77     {
  78       switch (c)
  79         {
  80         case 'z':
  81           reset_watch ();
  82           break;
  83         case 'p':
  84           puts (get_time ());
  85           break;
  86         case 'q':
  87           exit (EXIT_SUCCESS);
  88         }
  89       /* Anything remaining on the line is ignored.  */
  90       while (c != '\n' && c != EOF)
  91         c = getchar ();
  92     }
  93   exit (EXIT_FAILURE);
  94 }
  95
  96
  97 /* profile.c ends here */