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;
  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   TV1 = current_emacs_time ();
  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   EMACS_TIME TV2 = sub_emacs_time (current_emacs_time (), TV1);
  61   uintmax_t s = EMACS_SECS (TV2);
  62   int ns = EMACS_NSECS (TV2);
  63   if (watch_not_started)
  64     exit (EXIT_FAILURE);  /* call reset_watch first ! */
  65   sprintf (time_string, "%"PRIuMAX".%0*d", s, LOG10_EMACS_TIME_RESOLUTION, ns);
  66   return time_string;
  67 }
  68 \f
  69 int
  70 main (void)
  71 {
  72   int c;
  73   while ((c = getchar ()) != EOF)
  74     {
  75       switch (c)
  76         {
  77         case 'z':
  78           reset_watch ();
  79           break;
  80         case 'p':
  81           puts (get_time ());
  82           break;
  83         case 'q':
  84           exit (EXIT_SUCCESS);
  85         }
  86       /* Anything remaining on the line is ignored.  */
  87       while (c != '\n' && c != EOF)
  88         c = getchar ();
  89     }
  90   exit (EXIT_FAILURE);
  91 }
  92
  93
  94 /* profile.c ends here */