/*

 * Copyright 2012, 2013 SAP AG. All rights reserved.

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.

 *

 * This code is distributed in the hope that it will be useful, but WITHOUT

 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

 * or visit www.oracle.com if you need additional information or have any

 * questions.

 *

 */

#include "runtime/arguments.hpp"

#include "libperfstat_aix.hpp"

// For dlopen and friends

#include <fcntl.h>

// handle to the libperfstat

static void* g_libhandle = NULL;

// whether initialization worked

static bool g_initialized = false;

typedef int (*fun_perfstat_cpu_total_t) (perfstat_id_t *name, perfstat_cpu_total_t* userbuff,

                                         int sizeof_userbuff, int desired_number);

typedef int (*fun_perfstat_memory_total_t) (perfstat_id_t *name, perfstat_memory_total_t* userbuff,

                                            int sizeof_userbuff, int desired_number);

typedef void (*fun_perfstat_reset_t) ();

static fun_perfstat_cpu_total_t     g_fun_perfstat_cpu_total = NULL;

static fun_perfstat_memory_total_t  g_fun_perfstat_memory_total = NULL;

static fun_perfstat_reset_t         g_fun_perfstat_reset = NULL;

bool libperfstat::init() {

  if (g_initialized) {

    return true;

  }

  g_initialized = false;

  // dynamically load the libperfstat porting library.

  g_libhandle = dlopen("/usr/lib/libperfstat.a(shr_64.o)", RTLD_MEMBER | RTLD_NOW);

  if (!g_libhandle) {

    if (Verbose) {

      fprintf(stderr, "Cannot load libperfstat.a (dlerror: %s)", dlerror());

    }

    return false;

  }

  // resolve function pointers

#define RESOLVE_FUN_NO_ERROR(name) \

  g_fun_##name = (fun_##name##_t) dlsym(g_libhandle, #name);

#define RESOLVE_FUN(name) \

  RESOLVE_FUN_NO_ERROR(name) \

  if (!g_fun_##name) { \

    if (Verbose) { \

      fprintf(stderr, "Cannot resolve " #name "() from libperfstat.a\n" \

                      "   (dlerror: %s)", dlerror()); \

      } \

    return false; \

  }

  RESOLVE_FUN(perfstat_cpu_total);

  RESOLVE_FUN(perfstat_memory_total);

  RESOLVE_FUN(perfstat_reset);

  g_initialized = true;

  return true;

}

void libperfstat::cleanup() {

  g_initialized = false;

  if (g_libhandle) {

    dlclose(g_libhandle);

    g_libhandle = NULL;

  }

  g_fun_perfstat_cpu_total = NULL;

  g_fun_perfstat_memory_total = NULL;

  g_fun_perfstat_reset = NULL;

}

int libperfstat::perfstat_memory_total(perfstat_id_t *name,

                                       perfstat_memory_total_t* userbuff,

                                       int sizeof_userbuff, int desired_number) {

  assert(g_initialized, "libperfstat not initialized");

  assert(g_fun_perfstat_memory_total, "");

  return g_fun_perfstat_memory_total(name, userbuff, sizeof_userbuff, desired_number);

}

int libperfstat::perfstat_cpu_total(perfstat_id_t *name, perfstat_cpu_total_t* userbuff,

                                    int sizeof_userbuff, int desired_number) {

  assert(g_initialized, "libperfstat not initialized");

  assert(g_fun_perfstat_cpu_total, "");

  return g_fun_perfstat_cpu_total(name, userbuff, sizeof_userbuff, desired_number);

}

void libperfstat::perfstat_reset() {

  assert(g_initialized, "libperfstat not initialized");

  assert(g_fun_perfstat_reset, "");

  g_fun_perfstat_reset();

}