src/mojo/system/raw_shared_buffer_unittest.cc

   1 // Copyright 2014 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "mojo/system/raw_shared_buffer.h"
   6
   7 #include <limits>
   8
   9 #include "base/macros.h"
  10 #include "base/memory/ref_counted.h"
  11 #include "base/memory/scoped_ptr.h"
  12 #include "testing/gtest/include/gtest/gtest.h"
  13
  14 namespace mojo {
  15 namespace system {
  16 namespace {
  17
  18 TEST(RawSharedBufferTest, Basic) {
  19   const size_t kNumInts = 100;
  20   const size_t kNumBytes = kNumInts * sizeof(int);
  21   // A fudge so that we're not just writing zero bytes 75% of the time.
  22   const int kFudge = 1234567890;
  23
  24   // Make some memory.
  25   scoped_refptr<RawSharedBuffer> buffer(RawSharedBuffer::Create(kNumBytes));
  26   ASSERT_TRUE(buffer);
  27
  28   // Map it all, scribble some stuff, and then unmap it.
  29   {
  30     EXPECT_TRUE(buffer->IsValidMap(0, kNumBytes));
  31     scoped_ptr<RawSharedBufferMapping> mapping(buffer->Map(0, kNumBytes));
  32     ASSERT_TRUE(mapping);
  33     ASSERT_TRUE(mapping->base());
  34     int* stuff = static_cast<int*>(mapping->base());
  35     for (size_t i = 0; i < kNumInts; i++)
  36       stuff[i] = static_cast<int>(i) + kFudge;
  37   }
  38
  39   // Map it all again, check that our scribbling is still there, then do a
  40   // partial mapping and scribble on that, check that everything is coherent,
  41   // unmap the first mapping, scribble on some of the second mapping, and then
  42   // unmap it.
  43   {
  44     ASSERT_TRUE(buffer->IsValidMap(0, kNumBytes));
  45     // Use |MapNoCheck()| this time.
  46     scoped_ptr<RawSharedBufferMapping> mapping1(
  47         buffer->MapNoCheck(0, kNumBytes));
  48     ASSERT_TRUE(mapping1);
  49     ASSERT_TRUE(mapping1->base());
  50     int* stuff1 = static_cast<int*>(mapping1->base());
  51     for (size_t i = 0; i < kNumInts; i++)
  52       EXPECT_EQ(static_cast<int>(i) + kFudge, stuff1[i]) << i;
  53
  54     scoped_ptr<RawSharedBufferMapping> mapping2(
  55         buffer->Map((kNumInts / 2) * sizeof(int), 2 * sizeof(int)));
  56     ASSERT_TRUE(mapping2);
  57     ASSERT_TRUE(mapping2->base());
  58     int* stuff2 = static_cast<int*>(mapping2->base());
  59     EXPECT_EQ(static_cast<int>(kNumInts / 2) + kFudge, stuff2[0]);
  60     EXPECT_EQ(static_cast<int>(kNumInts / 2) + 1 + kFudge, stuff2[1]);
  61
  62     stuff2[0] = 123;
  63     stuff2[1] = 456;
  64     EXPECT_EQ(123, stuff1[kNumInts / 2]);
  65     EXPECT_EQ(456, stuff1[kNumInts / 2 + 1]);
  66
  67     mapping1.reset();
  68
  69     EXPECT_EQ(123, stuff2[0]);
  70     EXPECT_EQ(456, stuff2[1]);
  71     stuff2[1] = 789;
  72   }
  73
  74   // Do another partial mapping and check that everything is the way we expect
  75   // it to be.
  76   {
  77     EXPECT_TRUE(buffer->IsValidMap(sizeof(int), kNumBytes - sizeof(int)));
  78     scoped_ptr<RawSharedBufferMapping> mapping(
  79         buffer->Map(sizeof(int), kNumBytes - sizeof(int)));
  80     ASSERT_TRUE(mapping);
  81     ASSERT_TRUE(mapping->base());
  82     int* stuff = static_cast<int*>(mapping->base());
  83
  84     for (size_t j = 0; j < kNumInts - 1; j++) {
  85       int i = static_cast<int>(j) + 1;
  86       if (i == kNumInts / 2) {
  87         EXPECT_EQ(123, stuff[j]);
  88       } else if (i == kNumInts / 2 + 1) {
  89         EXPECT_EQ(789, stuff[j]);
  90       } else {
  91         EXPECT_EQ(i + kFudge, stuff[j]) << i;
  92       }
  93     }
  94   }
  95 }
  96
  97 // TODO(vtl): Bigger buffers.
  98
  99 TEST(RawSharedBufferTest, InvalidMappings) {
 100   scoped_refptr<RawSharedBuffer> buffer(RawSharedBuffer::Create(100));
 101   ASSERT_TRUE(buffer);
 102
 103   // Zero length not allowed.
 104   EXPECT_FALSE(buffer->Map(0, 0));
 105   EXPECT_FALSE(buffer->IsValidMap(0, 0));
 106
 107   // Okay:
 108   EXPECT_TRUE(buffer->Map(0, 100));
 109   EXPECT_TRUE(buffer->IsValidMap(0, 100));
 110   // Offset + length too big.
 111   EXPECT_FALSE(buffer->Map(0, 101));
 112   EXPECT_FALSE(buffer->IsValidMap(0, 101));
 113   EXPECT_FALSE(buffer->Map(1, 100));
 114   EXPECT_FALSE(buffer->IsValidMap(1, 100));
 115
 116   // Okay:
 117   EXPECT_TRUE(buffer->Map(50, 50));
 118   EXPECT_TRUE(buffer->IsValidMap(50, 50));
 119   // Offset + length too big.
 120   EXPECT_FALSE(buffer->Map(50, 51));
 121   EXPECT_FALSE(buffer->IsValidMap(50, 51));
 122   EXPECT_FALSE(buffer->Map(51, 50));
 123   EXPECT_FALSE(buffer->IsValidMap(51, 50));
 124 }
 125
 126 TEST(RawSharedBufferTest, TooBig) {
 127   // If |size_t| is 32-bit, it's quite possible/likely that |Create()| succeeds
 128   // (since it only involves creating a 4 GB file).
 129   const size_t kMaxSizeT = std::numeric_limits<size_t>::max();
 130   scoped_refptr<RawSharedBuffer> buffer(RawSharedBuffer::Create(kMaxSizeT));
 131   // But, assuming |sizeof(size_t) == sizeof(void*)|, mapping all of it should
 132   // always fail.
 133   if (buffer)
 134     EXPECT_FALSE(buffer->Map(0, kMaxSizeT));
 135 }
 136
 137 // Tests that separate mappings get distinct addresses.
 138 // Note: It's not inconceivable that the OS could ref-count identical mappings
 139 // and reuse the same address, in which case we'd have to be more careful about
 140 // using the address as the key for unmapping.
 141 TEST(RawSharedBufferTest, MappingsDistinct) {
 142   scoped_refptr<RawSharedBuffer> buffer(RawSharedBuffer::Create(100));
 143   scoped_ptr<RawSharedBufferMapping> mapping1(buffer->Map(0, 100));
 144   scoped_ptr<RawSharedBufferMapping> mapping2(buffer->Map(0, 100));
 145   EXPECT_NE(mapping1->base(), mapping2->base());
 146 }
 147
 148 TEST(RawSharedBufferTest, BufferZeroInitialized) {
 149   static const size_t kSizes[] = { 10, 100, 1000, 10000, 100000 };
 150   for (size_t i = 0; i < arraysize(kSizes); i++) {
 151     scoped_refptr<RawSharedBuffer> buffer(RawSharedBuffer::Create(kSizes[i]));
 152     scoped_ptr<RawSharedBufferMapping> mapping(buffer->Map(0, kSizes[i]));
 153     for (size_t j = 0; j < kSizes[i]; j++) {
 154       // "Assert" instead of "expect" so we don't spam the output with thousands
 155       // of failures if we fail.
 156       ASSERT_EQ('\0', static_cast<char*>(mapping->base())[j])
 157           << "size " << kSizes[i] << ", offset " << j;
 158     }
 159   }
 160 }
 161
 162 TEST(RawSharedBufferTest, MappingsOutliveBuffer) {
 163   scoped_ptr<RawSharedBufferMapping> mapping1;
 164   scoped_ptr<RawSharedBufferMapping> mapping2;
 165
 166   {
 167     scoped_refptr<RawSharedBuffer> buffer(RawSharedBuffer::Create(100));
 168     mapping1 = buffer->Map(0, 100).Pass();
 169     mapping2 = buffer->Map(50, 50).Pass();
 170     static_cast<char*>(mapping1->base())[50] = 'x';
 171   }
 172
 173   EXPECT_EQ('x', static_cast<char*>(mapping2->base())[0]);
 174
 175   static_cast<char*>(mapping2->base())[1] = 'y';
 176   EXPECT_EQ('y', static_cast<char*>(mapping1->base())[51]);
 177 }
 178
 179 }  // namespace
 180 }  // namespace system
 181 }  // namespace mojo