lib-src/profile.c

   1 /* profile.c --- generate periodic events for profiling of Emacs Lisp code.
   2    Copyright (C) 1992, 1994, 1999, 2001-2016 Free Software Foundation,
   3    Inc.
   4
   5 Author: Boaz Ben-Zvi <boaz@lcs.mit.edu>
   6
   7 This file is part of GNU Emacs.
   8
   9 GNU Emacs is free software: you can redistribute it and/or modify
  10 it under the terms of the GNU General Public License as published by
  11 the Free Software Foundation, either version 3 of the License, or
  12 (at your option) any later version.
  13
  14 GNU Emacs is distributed in the hope that it will be useful,
  15 but WITHOUT ANY WARRANTY; without even the implied warranty of
  16 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17 GNU General Public License for more details.
  18
  19 You should have received a copy of the GNU General Public License
  20 along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
  21
  22
  23 /**
  24  **  To be run as an emacs subprocess.  Input string that starts with:
  25  **    'z' -- resets the watch (to zero).
  26  **    'p' -- return time (on stdout) as string with format <sec>.<micro-sec>
  27  **    'q' -- exit.
  28  **
  29  **  abstraction : a stopwatch
  30  **  operations: reset_watch, get_time
  31  */
  32
  33 #define INLINE EXTERN_INLINE
  34 #include <config.h>
  35
  36 #include <inttypes.h>
  37 #include <stdio.h>
  38
  39 #include <intprops.h>
  40 #include <systime.h>
  41
  42 static struct timespec TV1;
  43 static int watch_not_started = 1; /* flag */
  44 static char time_string[INT_STRLEN_BOUND (uintmax_t) + sizeof "."
  45                         + LOG10_TIMESPEC_RESOLUTION];
  46
  47 /* Reset the stopwatch to zero.  */
  48
  49 static void
  50 reset_watch (void)
  51 {
  52   TV1 = current_timespec ();
  53   watch_not_started = 0;
  54 }
  55
  56 /* This call returns the time since the last reset_watch call.  The time
  57    is returned as a string with the format  <seconds>.<nanoseconds>
  58    If reset_watch was not called yet, exit.  */
  59
  60 static char *
  61 get_time (void)
  62 {
  63   struct timespec TV2 = timespec_sub (current_timespec (), TV1);
  64   uintmax_t s = TV2.tv_sec;
  65   int ns = TV2.tv_nsec;
  66   if (watch_not_started)
  67     exit (EXIT_FAILURE);  /* call reset_watch first ! */
  68   sprintf (time_string, "%"PRIuMAX".%0*d", s, LOG10_TIMESPEC_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 */