#
# Patch name: @bench
# Patch version: 1
# Author's name: Anonymous Coward
# Author's email: kmoon@geocities.com
# Version of PennMUSH: 1.7.4p8
# Date patch made: Mon Aug 13 23:59:42 EDT 2001
# Author is willing to support (yes/no): yes
# Patch format: context diff
#
#
# This is a contributed PennMUSH patch. Its use is subject to the
# same restrictions found in PennMUSH's hdrs/copyrite.h file.
#
# No warranty is given for this patch. It is not necessarily going
# to work on your system, with any version of PennMUSH other than
# the one above, etc.
#
# If the author given above was willing to support the patch, you
# should write to the author if you have any questions or problems. Do
# *NOT* send email messages to Javelin or any PennMUSH mailing list about
# this patch!
#
# Below this line is the author's description of the patch,
# followed by the patch itself. If the patch is in context diff
# format, you'll probably apply it by typing: patch < patchfile
# in your top-level MUSH directory, unless instructed otherwise
# below.
#

SUMMARY

This patch adds a @BENCH local command to an unmodified cmdlocal.c.  This is
good for things like winning bar bets about whose code really runs faster, and
can help you choose between different alternative ways of coding an expression
by providing benchmark data.


REQUIREMENTS

This patch was originally written for a PennMUSH 1.7.4p8, but was backwritten
for 1.7.2p35 as well (the only actual change was to change the last few lines
to use a snprintf() instead of a notify_format, which is specific to 1.7.4).

This patch require the availability of a function similar to gettimeofday(),
and the snprintf() function.  Neither is in the ANSI C standard libraries.  The
patch currently does not take advantage of PennMUSH's autoconf header, but may
at a later time.  Sorry, this was a quick-and-dirty hack.


INSTALLATION

Simply type

  patch -p0 < benchmark.174p3

in your pennmush directory.  This will patch the cmdlocal.c file in the src
directory.  You'll also need to either add -DPENNMARK to your makefile, or add
#define PENNMARK to your options.h file.  Then make install and restart.


SYNTAX

The syntax for @BENCH is:

  @BENCH <iterations>=<expression>

This command basically benchmarks a softcode expression by running it
<iterations> times.  It returns the total running time as a number of seconds
elapsed (with a precision to 6 decimal places).  This command can only be used
to evaluate expressions, and thus is useless for benchmarking commands.

Since there is a considerable overhead from executing process_expression, the
results from @BENCH are only really meaningful for compound softcode
expressions, and shouldn't be used to directly compare the performance of
hardcode hacks.  However, in practice @BENCH does provide reasonable
information for making relative comparisons.


KNOWN BUGS

This version of the patch does not support the autoconf header file, and so
does not attempt to resolve platform issues like the presence or absence of
gettimeofday() and snprintf().  snprintf() may be replaced by sprintf(), or on
the Win32 platform, _snprintf().  PennMUSH provides an our_gettimeofday() which
provides the functions of gettimeofday() (although with a slightly different
calling syntax).  If you have problems compiling this code, consider making the
appropriate changes.

This patch makes changes to the src/cmdlocal.c file.  If you have made changes
to this file, this patch probably won't work perfectly.  As a work around, you
can try patching a copy of cmdlocal.dst and then manually copying the changes
to your cmdlocal.c.

A glaringly obvious issue which isn't exactly a bug is the fact that the @BENCH
command circumvents PennMUSH's function invocation limit restrictions.  This is
to allow accurate benchmarking with a large number of iterations.  Since this
will completely lock up your game for the duration of the benchmark procedure
with no way to interrupt the benchmark except a hard kill, it is recommended
that this patch not be used on a production game server, or at least not
without additional security restrictions, perhaps restricting the command to
only GOD, rather than to only WIZARDs.


*** src/cmdlocal.dst	Tue Aug 14 00:19:18 2001
--- src/cmdlocal.c	Tue Aug 14 00:20:14 2001
***************
*** 60,65 ****
--- 60,133 ----
  }
  #endif
  
+ #ifdef PENNMARK
+ extern int global_fun_invocations;
+ extern int global_fun_recursions;
+ COMMAND(cmd_bench) {
+   char buff[BUFFER_LEN];
+   char *bp = buff;
+ 
+   const char *str;
+ 
+   struct timeval tvtot = { 0, 0 }, tv1, tv2;
+   int count, limit;
+ 
+   const int local_fun_invocations = global_fun_invocations;
+   const int local_fun_recursions  = global_fun_recursions;
+ 
+   /* a modicum of security */
+   if (!Wizard(player)) {
+     notify(player, "Permission denied.");
+     return;
+   }
+ 
+   /* perform benchmarking */
+   limit = atoi(arg_left);
+   for (count = 0; count < limit; count++) {
+     /* reset state data */
+     bp = buff;
+     str = arg_right;
+     global_fun_invocations = local_fun_invocations;
+     global_fun_recursions  = local_fun_recursions;
+ 
+     /* time the operation */
+     gettimeofday(&tv1, NULL);
+     process_expression(buff, &bp, &str,
+                        player, player, player,
+                        PE_DEFAULT, PT_DEFAULT, NULL);
+     gettimeofday(&tv2, NULL);
+ 
+     /* calculate time difference */
+     if (tv2.tv_usec < tv1.tv_usec) {
+       tvtot.tv_sec  += tv2.tv_sec - 1 - tv1.tv_sec;
+       tvtot.tv_usec += 1000000 + tv2.tv_usec - tv1.tv_usec;
+     } else {
+       tvtot.tv_sec  += tv2.tv_sec - tv1.tv_sec;
+       tvtot.tv_usec += tv2.tv_usec - tv1.tv_usec;
+     }
+ 
+     if (tvtot.tv_usec >= 1000000) {
+       (tvtot.tv_sec)++;
+       tvtot.tv_usec -= 1000000;
+     }
+   }
+   *bp = '\0';
+ 
+   /* display */
+   bp = (char *)malloc(BUFFER_LEN * sizeof(char));
+   if (!bp) {
+     notify(player, "Unable to allocate memory for output.");
+     return;
+   }
+   snprintf(bp, BUFFER_LEN,
+     "run time: %d.%06ds (%d iteration%s)\nlast output:%s",
+     (int)(tvtot.tv_sec), (int)(tvtot.tv_usec),
+     limit, limit == 1 ? "" : "s",
+     buff);
+   notify(player, bp);
+   free(bp);
+ }
+ #endif /* PENNMARK */
  
  /* Called during the command init sequence.
   * This is where you'd put calls to add_command to insert a local
***************
*** 69,74 ****
--- 137,146 ----
  void
  local_commands()
  {
+ #ifdef PENNMARK
+   command_add("BENCH", CMD_T_ANY | CMD_T_EQSPLIT | CMD_T_RS_NOPARSE, 0, 0, 0,
+     NULL, cmd_bench);
+ #endif /* PENNMARK */
  #ifdef EXAMPLE
    command_add("@SILLY", CMD_T_ANY, 0, 0, 0, switchmask("NOISY NOEVAL"),
  	      cmd_local_silly);