/*

 * Copyright (c) 2016, 2018, 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.

 *

 * 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 "precompiled.hpp"

#include "gc/z/zPage.inline.hpp"

#include "gc/z/zPhysicalMemory.inline.hpp"

#include "gc/z/zPreMappedMemory.inline.hpp"

#include "gc/z/zVirtualMemory.inline.hpp"

#include "logging/log.hpp"

ZPreMappedMemory::ZPreMappedMemory(ZVirtualMemoryManager &vmm, ZPhysicalMemoryManager &pmm, size_t size) :

    _vmem(),

    _pmem(),

    _initialized(false) {

  if (!vmm.is_initialized() || !pmm.is_initialized()) {

    // Not initialized

    return;

  }

  // Pre-mapping and pre-touching memory can take a long time. Log a message

  // to help the user understand why the JVM might seem slow to start.

  log_info(gc, init)("Pre-touching: %s", AlwaysPreTouch ? "Enabled" : "Disabled");

  log_info(gc, init)("Pre-mapping: " SIZE_FORMAT "M", size / M);

  if (size > 0) {

    _pmem = pmm.alloc(size);

    if (_pmem.is_null()) {

      // Out of memory

      log_error(gc, init)("Failed to pre-map Java heap (Cannot allocate physical memory)");

      return;

    }

    _vmem = vmm.alloc(size, true /* alloc_from_front */);

    if (_vmem.is_null()) {

      // Out of address space

      log_error(gc, init)("Failed to pre-map Java heap (Cannot allocate virtual memory)");

      pmm.free(_pmem);

      return;

    }

    // Map physical memory

    pmm.map(_pmem, _vmem.start());

  }

  _initialized = true;

}

ZPage* ZPreMappedMemory::alloc_page(uint8_t type, size_t size) {

  if (size > available()) {

    // Not enough pre-mapped memory

    return NULL;

  }

  // Take a chunk of the pre-mapped memory

  const ZPhysicalMemory pmem = _pmem.split(size);

  const ZVirtualMemory  vmem = _vmem.split(size);

  ZPage* const page = new ZPage(type, vmem, pmem);

  page->set_pre_mapped();

  return page;

}

void ZPreMappedMemory::clear() {

  assert(_pmem.is_null(), "Should be detached");

  _vmem.clear();

}