/* -*- Mode: C++; c-basic-offset: 2; indent-tabs-mode: t; tab-width: 4 -*- */
/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

#include "VMPI.h"

// Note, this is not supported in configurations with more than one AvmCore
// running in the same process.

#ifdef WIN32
#  include "util/Windows.h"
#else
#  define __cdecl
#  include <stdarg.h>
#  include <string.h>
#endif

#include "vprof.h"

#ifndef MIN
#  define MIN(x, y) ((x) <= (y) ? x : y)
#endif
#ifndef MAX
#  define MAX(x, y) ((x) >= (y) ? x : y)
#endif

#ifndef MAXINT
#  define MAXINT int(unsigned(-1) >> 1)
#endif

#ifndef MAXINT64
#  define MAXINT64 int64_t(uint64_t(-1) >> 1)
#endif

#ifndef __STDC_WANT_SECURE_LIB__
#  define sprintf_s(b, size, fmt, ...) sprintf((b), (fmt), __VA_ARGS__)
#endif

#if THREADED
#  define DO_LOCK(lock) \
    Lock(lock);         \
    {
#  define DO_UNLOCK(lock) \
    }                     \
    ;                     \
    Unlock(lock)
#else
#  define DO_LOCK(lock) \
    {                   \
      (void)(lock);
#  define DO_UNLOCK(lock) }
#endif

#if THREAD_SAFE
#  define LOCK(lock) DO_LOCK(lock)
#  define UNLOCK(lock) DO_UNLOCK(lock)
#else
#  define LOCK(lock) \
    {                \
      (void)(lock);
#  define UNLOCK(lock) }
#endif

static entry* entries = nullptr;
static bool notInitialized = true;
static long glock = LOCK_IS_FREE;

#define Lock(lock)                                                         \
  while (_InterlockedCompareExchange(lock, LOCK_IS_TAKEN, LOCK_IS_FREE) == \
         LOCK_IS_TAKEN) {                                                  \
  };
#define Unlock(lock) \
  _InterlockedCompareExchange(lock, LOCK_IS_FREE, LOCK_IS_TAKEN);

#if defined(WIN32)
static void vprof_printf(const char* format, ...) {
  va_list args;
  va_start(args, format);

  char buf[1024];
  vsnprintf(buf, sizeof(buf), format, args);

  va_end(args);

  printf(buf);
  ::OutputDebugStringA(buf);
}
#else
#  define vprof_printf printf
#endif

static inline entry* reverse(entry* s) {
  entry_t e, n, p;

  p = nullptr;
  for (e = s; e; e = n) {
    n = e->next;
    e->next = p;
    p = e;
  }

  return p;
}

static char* f(double d) {
  static char s[80];
  char* p;
  sprintf_s(s, sizeof(s), "%lf", d);
  p = s + VMPI_strlen(s) - 1;
  while (*p == '0') {
    *p = '\0';
    p--;
    if (p == s) break;
  }
  if (*p == '.') *p = '\0';
  return s;
}

static void dumpProfile(void) {
  entry_t e;

  entries = reverse(entries);
  vprof_printf("event avg [min : max] total count\n");
  for (e = entries; e; e = e->next) {
    if (e->count == 0) continue;  // ignore entries with zero count.
    vprof_printf("%s", e->file);
    if (e->line >= 0) {
      vprof_printf(":%d", e->line);
    }
    vprof_printf(" %s [%lld : %lld] %lld %lld ",
                 f(((double)e->sum) / ((double)e->count)),
                 (long long int)e->min, (long long int)e->max,
                 (long long int)e->sum, (long long int)e->count);
    if (e->h) {
      int j = MAXINT;
      for (j = 0; j < e->h->nbins; j++) {
        vprof_printf("(%lld < %lld) ", (long long int)e->h->count[j],
                     (long long int)e->h->lb[j]);
      }
      vprof_printf("(%lld >= %lld) ", (long long int)e->h->count[e->h->nbins],
                   (long long int)e->h->lb[e->h->nbins - 1]);
    }
    if (e->func) {
      int j;
      for (j = 0; j < NUM_EVARS; j++) {
        if (e->ivar[j] != 0) {
          vprof_printf("IVAR%d %d ", j, e->ivar[j]);
        }
      }
      for (j = 0; j < NUM_EVARS; j++) {
        if (e->i64var[j] != 0) {
          vprof_printf("I64VAR%d %lld ", j, (long long int)e->i64var[j]);
        }
      }
      for (j = 0; j < NUM_EVARS; j++) {
        if (e->dvar[j] != 0) {
          vprof_printf("DVAR%d %lf ", j, e->dvar[j]);
        }
      }
    }
    vprof_printf("\n");
  }
  entries = reverse(entries);
}

static inline entry_t findEntry(char* file, int line) {
  for (entry_t e = entries; e; e = e->next) {
    if ((e->line == line) && (VMPI_strcmp(e->file, file) == 0)) {
      return e;
    }
  }
  return nullptr;
}

// Initialize the location pointed to by 'id' to a new value profile entry
// associated with 'file' and 'line', or do nothing if already initialized.
// An optional final argument provides a user-defined probe function.

int initValueProfile(void** id, char* file, int line, ...) {
  DO_LOCK(&glock);
  entry_t e = (entry_t)*id;
  if (notInitialized) {
    atexit(dumpProfile);
    notInitialized = false;
  }

  if (e == nullptr) {
    e = findEntry(file, line);
    if (e) {
      *id = e;
    }
  }

  if (e == nullptr) {
    va_list va;
    e = (entry_t)malloc(sizeof(entry));
    e->lock = LOCK_IS_FREE;
    e->file = file;
    e->line = line;
    e->value = 0;
    e->sum = 0;
    e->count = 0;
    e->min = 0;
    e->max = 0;
    // optional probe function argument
    va_start(va, line);
    e->func = (void(__cdecl*)(void*))va_arg(va, void*);
    va_end(va);
    e->h = nullptr;
    e->genptr = nullptr;
    VMPI_memset(&e->ivar, 0, sizeof(e->ivar));
    VMPI_memset(&e->i64var, 0, sizeof(e->i64var));
    VMPI_memset(&e->dvar, 0, sizeof(e->dvar));
    e->next = entries;
    entries = e;
    *id = e;
  }
  DO_UNLOCK(&glock);

  return 0;
}

// Record a value profile event.

int profileValue(void* id, int64_t value) {
  entry_t e = (entry_t)id;
  long* lock = &(e->lock);
  LOCK(lock);
  e->value = value;
  if (e->count == 0) {
    e->sum = value;
    e->count = 1;
    e->min = value;
    e->max = value;
  } else {
    e->sum += value;
    e->count++;
    e->min = MIN(e->min, value);
    e->max = MAX(e->max, value);
  }
  if (e->func) e->func(e);
  UNLOCK(lock);

  return 0;
}

// Initialize the location pointed to by 'id' to a new histogram profile entry
// associated with 'file' and 'line', or do nothing if already initialized.

int initHistProfile(void** id, char* file, int line, int nbins, ...) {
  DO_LOCK(&glock);
  entry_t e = (entry_t)*id;
  if (notInitialized) {
    atexit(dumpProfile);
    notInitialized = false;
  }

  if (e == nullptr) {
    e = findEntry(file, line);
    if (e) {
      *id = e;
    }
  }

  if (e == nullptr) {
    va_list va;
    hist_t h;
    int b, n, s;
    int64_t* lb;

    e = (entry_t)malloc(sizeof(entry));
    e->lock = LOCK_IS_FREE;
    e->file = file;
    e->line = line;
    e->value = 0;
    e->sum = 0;
    e->count = 0;
    e->min = 0;
    e->max = 0;
    e->func = nullptr;
    e->h = h = (hist_t)malloc(sizeof(hist));
    n = 1 + MAX(nbins, 0);
    h->nbins = n - 1;
    s = n * sizeof(int64_t);
    lb = (int64_t*)malloc(s);
    h->lb = lb;
    VMPI_memset(h->lb, 0, s);
    h->count = (int64_t*)malloc(s);
    VMPI_memset(h->count, 0, s);

    va_start(va, nbins);
    for (b = 0; b < nbins; b++) {
      // lb[b] = va_arg (va, int64_t);
      lb[b] = va_arg(va, int);
    }
    lb[b] = MAXINT64;
    va_end(va);

    e->genptr = nullptr;
    VMPI_memset(&e->ivar, 0, sizeof(e->ivar));
    VMPI_memset(&e->i64var, 0, sizeof(e->i64var));
    VMPI_memset(&e->dvar, 0, sizeof(e->dvar));
    e->next = entries;
    entries = e;
    *id = e;
  }
  DO_UNLOCK(&glock);

  return 0;
}

// Record a histogram profile event.

int histValue(void* id, int64_t value) {
  entry_t e = (entry_t)id;
  long* lock = &(e->lock);
  hist_t h = e->h;
  int nbins = h->nbins;
  int64_t* lb = h->lb;
  int b;

  LOCK(lock);
  e->value = value;
  if (e->count == 0) {
    e->sum = value;
    e->count = 1;
    e->min = value;
    e->max = value;
  } else {
    e->sum += value;
    e->count++;
    e->min = MIN(e->min, value);
    e->max = MAX(e->max, value);
  }
  for (b = 0; b < nbins; b++) {
    if (value < lb[b]) break;
  }
  h->count[b]++;
  UNLOCK(lock);

  return 0;
}

#if defined(_MSC_VER) && defined(_M_IX86)
uint64_t readTimestampCounter() {
  // read the cpu cycle counter.  1 tick = 1 cycle on IA32
  _asm rdtsc;
}
#elif defined(__GNUC__) && (__i386__ || __x86_64__)
uint64_t readTimestampCounter() {
  uint32_t lo, hi;
  __asm__ __volatile__("rdtsc" : "=a"(lo), "=d"(hi));
  return (uint64_t(hi) << 32) | lo;
}
#else
// add stub for platforms without it, so fat builds don't fail
uint64_t readTimestampCounter() { return 0; }
#endif