/*

 * Copyright (c) 1998, 2011, Oracle and/or its affiliates. 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.  Oracle designates this

 * particular file as subject to the "Classpath" exception as provided

 * by Oracle in the LICENSE file that accompanied this code.

 *

 * 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.

 */

/* This file houses the common methods for VM ergonomics the platforms

 * are split into ergo_sparc and ergo_x86, and they could be split more

 * in the future if required. The following comments are not entirely

 * true after bifurcation of the platform specific files.

 */

/*

 * The following methods (down to ServerClassMachine()) answer

 * the question about whether a machine is a "server-class"

 * machine.  A server-class machine is loosely defined as one

 * with 2 or more processors and 2 gigabytes or more physical

 * memory.  The definition of a processor is a physical package,

 * not a hyperthreaded chip masquerading as a multi-processor.

 * The definition of memory is also somewhat fuzzy, since x86

 * machines seem not to report all the memory in their DIMMs, we

 * think because of memory mapping of graphics cards, etc.

 *

 * This code is somewhat more confused with #ifdef's than we'd

 * like because this file is used by both Solaris and Linux

 * platforms, and so needs to be parameterized for SPARC and

 * i586 hardware.  The other Linux platforms (amd64 and ia64)

 * don't even ask this question, because they only come with

 * server JVMs.

 */

#include "ergo.h"

/* Dispatch to the platform-specific definition of "server-class" */

jboolean

ServerClassMachine(void) {

  jboolean result;

  switch(GetErgoPolicy()) {

    case NEVER_SERVER_CLASS:

      return JNI_FALSE;

    case ALWAYS_SERVER_CLASS:

      return JNI_TRUE;

    default:

      result = ServerClassMachineImpl();

      JLI_TraceLauncher("ServerClassMachine: returns default value of %s\n",

           (result == JNI_TRUE ? "true" : "false"));

      return result;

  }

}

#ifdef USE_GENERIC_ERGO

/* Ask the OS how many processors there are. */

static unsigned long

physical_processors(void) {

  const unsigned long sys_processors = sysconf(_SC_NPROCESSORS_CONF);

  JLI_TraceLauncher("sysconf(_SC_NPROCESSORS_CONF): %lu\n", sys_processors);

  return sys_processors;

}

jboolean

ServerClassMachineImpl(void) {

  jboolean            result            = JNI_FALSE;

  /* How big is a server class machine? */

  const unsigned long server_processors = 2UL;

  const uint64_t      server_memory     = 2UL * GB;

  const uint64_t      actual_memory     = physical_memory();

  /* Is this a server class machine? */

  if (actual_memory >= server_memory) {

    const unsigned long actual_processors = physical_processors();

    if (actual_processors >= server_processors) {

      result = JNI_TRUE;

    }

  }

  JLI_TraceLauncher("unix_" LIBARCHNAME "_ServerClassMachine: %s\n",

           (result == JNI_TRUE ? "JNI_TRUE" : "JNI_FALSE"));

  return result;

}

#endif

/* Compute physical memory by asking the OS */

uint64_t

physical_memory(void) {

  const uint64_t pages     = (uint64_t) sysconf(_SC_PHYS_PAGES);

  const uint64_t page_size = (uint64_t) sysconf(_SC_PAGESIZE);

  const uint64_t result    = pages * page_size;

# define UINT64_FORMAT "%" PRIu64

  JLI_TraceLauncher("pages: " UINT64_FORMAT

          "  page_size: " UINT64_FORMAT

          "  physical memory: " UINT64_FORMAT " (%.3fGB)\n",

           pages, page_size, result, result / (double) GB);

  return result;

}