/*
 * Copyright (c) 2014 Justus Winter <4winter@informatik.uni-hamburg.de>
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

#define _GNU_SOURCE
#include <argp.h>
#include <error.h>
#include <hurd.h>
#include <mach.h>
#include <maptime.h>
#include <pthread.h>
#include <stdio.h>
#include <stdlib.h>
#include <sys/time.h>

#include "machometer.h"

volatile struct mapped_time_value *mtime;

struct producer_args
{
  mach_port_t port;
  size_t count;
  struct timeval runtime;
};

void *
producer (void *args_)
{
  error_t err = 0;
  struct producer_args *args = args_;

  struct timeval start_time;
  maptime_read (mtime, &start_time);

  for (size_t i = 0; i < args->count; i++)
    {
      err = send_empty (args->port);
      if (err)
	goto out;
    }

  struct timeval end_time;
  maptime_read (mtime, &end_time);
  timersub (&end_time, &start_time, &args->runtime);

 out:
  return (void *) err;
}

struct consumer_args
{
  mach_port_t port;
  size_t count;
  struct timeval runtime;
};

error_t
consumer (void *args_)
{
  error_t err;
  struct consumer_args *args = args_;

  struct timeval start_time;
  maptime_read (mtime, &start_time);

  for (size_t i = 0; i < args->count; i++)
    {
      err = receive_empty (args->port);
      if (err)
	return err;
    }

  struct timeval end_time;
  maptime_read (mtime, &end_time);

  timersub (&end_time, &start_time, &args->runtime);

 out:
  return 0;
}

void
print_stats (const char *id, size_t n, struct timeval *tv)
{
  double duration = tv->tv_sec + (tv->tv_usec / 1000000.);
  printf ("% 10s: % 3is%06ius\t%fns\t%9.3f (1/s)\n",
	  id,
	  (int) tv->tv_sec, (int) tv->tv_usec,
	  1000000000. * duration / n,
	  n / duration);
}

/* Options.  */
mach_port_msgcount_t qlimit = MACH_PORT_QLIMIT_DEFAULT;
size_t iterations = 1l<<25;

const char *argp_program_version = "machometer-0.0";

static const struct argp_option options[] =
{
  {"iterations", 'n', "N", 0, "Repeat tests N times"},
  {"qlimit", 'Q', "LIMIT", NULL, "Set qlimit"},
  {NULL}
};

/* Parse a command line option.	 */
error_t parse_opt (int key, char *arg, struct argp_state *state)
{
  char *arg_end;
  unsigned long *ptr = NULL;
  switch (key)
    {
    case 'n':
      ptr = ptr ?: &iterations;
    case 'Q':
      ptr = ptr ?: &qlimit;

      *ptr = strtoul (arg, &arg_end, 10);
      if (*arg == '\0' || *arg_end != '\0')
	argp_error (state, "invalid integer: %s", arg);
      break;

    case ARGP_KEY_ARG:
      argp_usage (state);
      return EINVAL;

    case ARGP_KEY_NO_ARGS:
      break;

    default:
      return ARGP_ERR_UNKNOWN;
    }
  return 0;
}

static struct argp argp =
  {
    options,
    parse_opt,
    "YYY",
    "XXX",
  };

/* mach_print performance test.	 */

void mach_print(const char *);

#ifndef EXTERNAL_MACH_PRINT
asm (".global mach_print;"
     " mach_print:;"
     " mov $0xffffffe2, %eax;"
     " lcall $0x7, $0x0;"
     " ret;");
#endif /* EXTERNAL_MACH_PRINT */

error_t
test_mach_print (const size_t n)
{
  error_t err = 0;
  struct timeval start_time;
  maptime_read (mtime, &start_time);

  for (size_t i = 0; i < n; i++)
    mach_print ("");

  struct timeval end_time;
  maptime_read (mtime, &end_time);

  struct timeval runtime;
  timersub (&end_time, &start_time, &runtime);
  print_stats ("mach_print", n, &runtime);

  return err;
}

/* Measure the trap overhead of mach_msg.  */
error_t
test_null_msg (const size_t n)
{
  error_t err = 0;
  struct timeval start_time;
  maptime_read (mtime, &start_time);

  for (size_t i = 0; i < n; i++)
    {
      err = mach_msg (NULL, MACH_MSG_OPTION_NONE, 0, 0,
		      MACH_PORT_NULL, MACH_MSG_TIMEOUT_NONE, MACH_PORT_NULL);
      if (err)
	goto out;
    }

  struct timeval end_time;
  maptime_read (mtime, &end_time);

  struct timeval runtime;
  timersub (&end_time, &start_time, &runtime);
  print_stats ("nullmsg", n, &runtime);

 out:
  return err;
}

int
main (int argc, char **argv)
{
  error_t err;
  mach_port_t port;

  /* Parse our arguments.  */
  argp_parse (&argp, argc, argv, ARGP_IN_ORDER, 0, 0);

  fprintf (stderr, "N: %u (1<<%d), qlimit: %d\n",
	   iterations, __builtin_ffs (iterations) - 1, qlimit);

  err = maptime_map (0, NULL, &mtime);
  if (err)
    error (1, err, "maptime_map");

  err = test_mach_print (iterations);
  if (err)
    error (1, err, "test_mach_print");

  err = test_null_msg (iterations);
  if (err)
    error (1, err, "test_null_msg");

  err = mach_port_allocate (mach_task_self(),
			    MACH_PORT_RIGHT_RECEIVE,
			    &port);
  if (err)
    error (1, err, "mach_port_allocate");

  err = mach_port_set_qlimit (mach_task_self(),
			      port,
			      qlimit);
  if (err)
    error (1, err, "mach_port_set_qlimit");

  struct producer_args pargs = { .port=port, .count=iterations };

  pthread_t producer_thread;
  err = pthread_create (&producer_thread, NULL, &producer, &pargs);
  if (err)
    error (2, err, "pthread_create");

  struct consumer_args cargs = { .port=port, .count=iterations };

  err = consumer (&cargs);

  error_t producer_err;
  err = pthread_join (producer_thread, (void **)&producer_err);
  if (err)
    error (3, err, "pthread_join");

  if (producer_err)
    error (4, producer_err, "producer");

  print_stats ("producer", iterations, &pargs.runtime);
  print_stats ("consumer", iterations, &cargs.runtime);

  return EXIT_SUCCESS;
}