test/hotspot/gtest/runtime/test_os.cpp
changeset 47216 71c04702a3d5
parent 46587 6c97f34cb194
child 49177 eebf559c9e0d
equal deleted inserted replaced
47215:4ebc2e2fb97c 47216:71c04702a3d5
       
     1 /*
       
     2  * Copyright (c) 2016, 2017, Oracle and/or its affiliates. All rights reserved.
       
     3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
       
     4  *
       
     5  * This code is free software; you can redistribute it and/or modify it
       
     6  * under the terms of the GNU General Public License version 2 only, as
       
     7  * published by the Free Software Foundation.
       
     8  *
       
     9  * This code is distributed in the hope that it will be useful, but WITHOUT
       
    10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
       
    11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
       
    12  * version 2 for more details (a copy is included in the LICENSE file that
       
    13  * accompanied this code).
       
    14  *
       
    15  * You should have received a copy of the GNU General Public License version
       
    16  * 2 along with this work; if not, write to the Free Software Foundation,
       
    17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
       
    18  *
       
    19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
       
    20  * or visit www.oracle.com if you need additional information or have any
       
    21  * questions.
       
    22  */
       
    23 
       
    24 #include "precompiled.hpp"
       
    25 #include "runtime/os.hpp"
       
    26 #include "unittest.hpp"
       
    27 
       
    28 static size_t small_page_size() {
       
    29   return os::vm_page_size();
       
    30 }
       
    31 
       
    32 static size_t large_page_size() {
       
    33   const size_t large_page_size_example = 4 * M;
       
    34   return os::page_size_for_region_aligned(large_page_size_example, 1);
       
    35 }
       
    36 
       
    37 TEST_VM(os, page_size_for_region) {
       
    38   size_t large_page_example = 4 * M;
       
    39   size_t large_page = os::page_size_for_region_aligned(large_page_example, 1);
       
    40 
       
    41   size_t small_page = os::vm_page_size();
       
    42   if (large_page > small_page) {
       
    43     size_t num_small_in_large = large_page / small_page;
       
    44     size_t page = os::page_size_for_region_aligned(large_page, num_small_in_large);
       
    45     ASSERT_EQ(page, small_page) << "Did not get a small page";
       
    46   }
       
    47 }
       
    48 
       
    49 TEST_VM(os, page_size_for_region_aligned) {
       
    50   if (UseLargePages) {
       
    51     const size_t small_page = small_page_size();
       
    52     const size_t large_page = large_page_size();
       
    53 
       
    54     if (large_page > small_page) {
       
    55       size_t num_small_pages_in_large = large_page / small_page;
       
    56       size_t page = os::page_size_for_region_aligned(large_page, num_small_pages_in_large);
       
    57 
       
    58       ASSERT_EQ(page, small_page);
       
    59     }
       
    60   }
       
    61 }
       
    62 
       
    63 TEST_VM(os, page_size_for_region_alignment) {
       
    64   if (UseLargePages) {
       
    65     const size_t small_page = small_page_size();
       
    66     const size_t large_page = large_page_size();
       
    67     if (large_page > small_page) {
       
    68       const size_t unaligned_region = large_page + 17;
       
    69       size_t page = os::page_size_for_region_aligned(unaligned_region, 1);
       
    70       ASSERT_EQ(page, small_page);
       
    71 
       
    72       const size_t num_pages = 5;
       
    73       const size_t aligned_region = large_page * num_pages;
       
    74       page = os::page_size_for_region_aligned(aligned_region, num_pages);
       
    75       ASSERT_EQ(page, large_page);
       
    76     }
       
    77   }
       
    78 }
       
    79 
       
    80 TEST_VM(os, page_size_for_region_unaligned) {
       
    81   if (UseLargePages) {
       
    82     // Given exact page size, should return that page size.
       
    83     for (size_t i = 0; os::_page_sizes[i] != 0; i++) {
       
    84       size_t expected = os::_page_sizes[i];
       
    85       size_t actual = os::page_size_for_region_unaligned(expected, 1);
       
    86       ASSERT_EQ(expected, actual);
       
    87     }
       
    88 
       
    89     // Given slightly larger size than a page size, return the page size.
       
    90     for (size_t i = 0; os::_page_sizes[i] != 0; i++) {
       
    91       size_t expected = os::_page_sizes[i];
       
    92       size_t actual = os::page_size_for_region_unaligned(expected + 17, 1);
       
    93       ASSERT_EQ(expected, actual);
       
    94     }
       
    95 
       
    96     // Given a slightly smaller size than a page size,
       
    97     // return the next smaller page size.
       
    98     if (os::_page_sizes[1] > os::_page_sizes[0]) {
       
    99       size_t expected = os::_page_sizes[0];
       
   100       size_t actual = os::page_size_for_region_unaligned(os::_page_sizes[1] - 17, 1);
       
   101       ASSERT_EQ(actual, expected);
       
   102     }
       
   103 
       
   104     // Return small page size for values less than a small page.
       
   105     size_t small_page = small_page_size();
       
   106     size_t actual = os::page_size_for_region_unaligned(small_page - 17, 1);
       
   107     ASSERT_EQ(small_page, actual);
       
   108   }
       
   109 }
       
   110 
       
   111 TEST(os, test_random) {
       
   112   const double m = 2147483647;
       
   113   double mean = 0.0, variance = 0.0, t;
       
   114   const int reps = 10000;
       
   115   unsigned int seed = 1;
       
   116 
       
   117   // tty->print_cr("seed %ld for %ld repeats...", seed, reps);
       
   118   os::init_random(seed);
       
   119   int num;
       
   120   for (int k = 0; k < reps; k++) {
       
   121     num = os::random();
       
   122     double u = (double)num / m;
       
   123     ASSERT_TRUE(u >= 0.0 && u <= 1.0) << "bad random number!";
       
   124 
       
   125     // calculate mean and variance of the random sequence
       
   126     mean += u;
       
   127     variance += (u*u);
       
   128   }
       
   129   mean /= reps;
       
   130   variance /= (reps - 1);
       
   131 
       
   132   ASSERT_EQ(num, 1043618065) << "bad seed";
       
   133   // tty->print_cr("mean of the 1st 10000 numbers: %f", mean);
       
   134   int intmean = mean*100;
       
   135   ASSERT_EQ(intmean, 50);
       
   136   // tty->print_cr("variance of the 1st 10000 numbers: %f", variance);
       
   137   int intvariance = variance*100;
       
   138   ASSERT_EQ(intvariance, 33);
       
   139   const double eps = 0.0001;
       
   140   t = fabsd(mean - 0.5018);
       
   141   ASSERT_LT(t, eps) << "bad mean";
       
   142   t = (variance - 0.3355) < 0.0 ? -(variance - 0.3355) : variance - 0.3355;
       
   143   ASSERT_LT(t, eps) << "bad variance";
       
   144 }
       
   145 
       
   146 
       
   147 #ifdef ASSERT
       
   148 TEST_VM_ASSERT_MSG(os, page_size_for_region_with_zero_min_pages, "sanity") {
       
   149   size_t region_size = 16 * os::vm_page_size();
       
   150   os::page_size_for_region_aligned(region_size, 0); // should assert
       
   151 }
       
   152 #endif