/*

 * Copyright (c) 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"

// Included early because the NMT flags don't include it.

#include "utilities/macros.hpp"

#include "runtime/thread.hpp"

#include "services/memTracker.hpp"

#include "services/virtualMemoryTracker.hpp"

#include "utilities/globalDefinitions.hpp"

#include "unittest.hpp"

class CommittedVirtualMemoryTest {

public:

  static void test() {

    Thread* thr = Thread::current();

    address stack_end = thr->stack_end();

    size_t  stack_size = thr->stack_size();

    MemTracker::record_thread_stack(stack_end, stack_size);

    VirtualMemoryTracker::add_reserved_region(stack_end, stack_size, CALLER_PC, mtThreadStack);

    // snapshot current stack usage

    VirtualMemoryTracker::snapshot_thread_stacks();

    ReservedMemoryRegion* rmr = VirtualMemoryTracker::_reserved_regions->find(ReservedMemoryRegion(stack_end, stack_size));

    ASSERT_TRUE(rmr != NULL);

    ASSERT_EQ(rmr->base(), stack_end);

    ASSERT_EQ(rmr->size(), stack_size);

    CommittedRegionIterator iter = rmr->iterate_committed_regions();

    int i = 0;

    address i_addr = (address)&i;

    bool found_i_addr = false;

    // stack grows downward

    address stack_top = stack_end + stack_size;

    bool found_stack_top = false;

    for (const CommittedMemoryRegion* region = iter.next(); region != NULL; region = iter.next()) {

      if (region->base() + region->size() == stack_top) {

        ASSERT_TRUE(region->size() <= stack_size);

        found_stack_top = true;

      }

      if(i_addr < stack_top && i_addr >= region->base()) {

        found_i_addr = true;

      }

      i++;

    }

    // stack and guard pages may be contiguous as one region

    ASSERT_TRUE(i >= 1);

    ASSERT_TRUE(found_stack_top);

    ASSERT_TRUE(found_i_addr);

  }

  static void check_covered_pages(address addr, size_t size, address base, size_t touch_pages, int* page_num) {

    const size_t page_sz = os::vm_page_size();

    size_t index;

    for (index = 0; index < touch_pages; index ++) {

      address page_addr = base + page_num[index] * page_sz;

      // The range covers this page, marks the page

      if (page_addr >= addr && page_addr < addr + size) {

        page_num[index] = -1;

      }

    }

  }

  static void test_committed_region_impl(size_t num_pages, size_t touch_pages, int* page_num) {

    const size_t page_sz = os::vm_page_size();

    const size_t size = num_pages * page_sz;

    char* base = os::reserve_memory(size, NULL, page_sz, mtThreadStack);

    bool result = os::commit_memory(base, size, false);

    size_t index;

    ASSERT_NE(base, (char*)NULL);

    for (index = 0; index < touch_pages; index ++) {

      char* touch_addr = base + page_sz * page_num[index];

      *touch_addr = 'a';

    }

    address frame = (address)0x1235;

    NativeCallStack stack(&frame, 1);

    VirtualMemoryTracker::add_reserved_region((address)base, size, stack, mtThreadStack);

    // trigger the test

    VirtualMemoryTracker::snapshot_thread_stacks();

    ReservedMemoryRegion* rmr = VirtualMemoryTracker::_reserved_regions->find(ReservedMemoryRegion((address)base, size));

    ASSERT_TRUE(rmr != NULL);

    bool precise_tracking_supported = false;

    CommittedRegionIterator iter = rmr->iterate_committed_regions();

    for (const CommittedMemoryRegion* region = iter.next(); region != NULL; region = iter.next()) {

      if (region->size() == size) {

        // platforms that do not support precise tracking.

        ASSERT_TRUE(iter.next() == NULL);

        break;

      } else {

        precise_tracking_supported = true;

        check_covered_pages(region->base(), region->size(), (address)base, touch_pages, page_num);

      }

    }

    if (precise_tracking_supported) {

      // All touched pages should be committed

      for (size_t index = 0; index < touch_pages; index ++) {

        ASSERT_EQ(page_num[index], -1);

      }

    }

    // Cleanup

    os::free_memory(base, size, page_sz);

    VirtualMemoryTracker::remove_released_region((address)base, size);

    rmr = VirtualMemoryTracker::_reserved_regions->find(ReservedMemoryRegion((address)base, size));

    ASSERT_TRUE(rmr == NULL);

  }

  static void test_committed_region() {

    // On Linux, we scan 1024 pages at a time.

    // Here, we test scenario that scans < 1024 pages.

    int small_range[] = {3, 9, 46};

    int mid_range[] = {0, 45, 100, 399, 400, 1000, 1031};

    int large_range[] = {100, 301, 1024, 2047, 2048, 2049, 2050, 3000};

    test_committed_region_impl(47, 3, small_range);

    test_committed_region_impl(1088, 5, mid_range);

    test_committed_region_impl(3074, 8, large_range);

  }

  static void test_partial_region() {

    bool   result;

    size_t committed_size;

    address committed_start;

    size_t index;

    const size_t page_sz = os::vm_page_size();

    const size_t num_pages = 4;

    const size_t size = num_pages * page_sz;

    char* base = os::reserve_memory(size, NULL, page_sz, mtTest);

    ASSERT_NE(base, (char*)NULL);

    result = os::commit_memory(base, size, false);

    ASSERT_TRUE(result);

    // touch all pages

    for (index = 0; index < num_pages; index ++) {

      *(base + index * page_sz) = 'a';

    }

    // Test whole range

    result = os::committed_in_range((address)base, size, committed_start, committed_size);

    ASSERT_TRUE(result);

    ASSERT_EQ(num_pages * page_sz, committed_size);

    ASSERT_EQ(committed_start, (address)base);

    // Test beginning of the range

    result = os::committed_in_range((address)base, 2 * page_sz, committed_start, committed_size);

    ASSERT_TRUE(result);

    ASSERT_EQ(2 * page_sz, committed_size);

    ASSERT_EQ(committed_start, (address)base);

    // Test end of the range

    result = os::committed_in_range((address)(base + page_sz), 3 * page_sz, committed_start, committed_size);

    ASSERT_TRUE(result);

    ASSERT_EQ(3 * page_sz, committed_size);

    ASSERT_EQ(committed_start, (address)(base + page_sz));

    // Test middle of the range

    result = os::committed_in_range((address)(base + page_sz), 2 * page_sz, committed_start, committed_size);

    ASSERT_TRUE(result);

    ASSERT_EQ(2 * page_sz, committed_size);

    ASSERT_EQ(committed_start, (address)(base + page_sz));

  }

};

TEST_VM(CommittedVirtualMemoryTracker, test_committed_virtualmemory_region) {

  VirtualMemoryTracker::initialize(NMT_detail);

  VirtualMemoryTracker::late_initialize(NMT_detail);

  CommittedVirtualMemoryTest::test();

  CommittedVirtualMemoryTest::test_committed_region();

  CommittedVirtualMemoryTest::test_partial_region();

}