src/mojo/embedder/simple_platform_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/embedder/simple_platform_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 embedder {
  16 namespace {
  17
  18 TEST(SimplePlatformSharedBufferTest, 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<SimplePlatformSharedBuffer> buffer(
  26       SimplePlatformSharedBuffer::Create(kNumBytes));
  27   ASSERT_TRUE(buffer);
  28
  29   // Map it all, scribble some stuff, and then unmap it.
  30   {
  31     EXPECT_TRUE(buffer->IsValidMap(0, kNumBytes));
  32     scoped_ptr<PlatformSharedBufferMapping> mapping(buffer->Map(0, kNumBytes));
  33     ASSERT_TRUE(mapping);
  34     ASSERT_TRUE(mapping->GetBase());
  35     int* stuff = static_cast<int*>(mapping->GetBase());
  36     for (size_t i = 0; i < kNumInts; i++)
  37       stuff[i] = static_cast<int>(i) + kFudge;
  38   }
  39
  40   // Map it all again, check that our scribbling is still there, then do a
  41   // partial mapping and scribble on that, check that everything is coherent,
  42   // unmap the first mapping, scribble on some of the second mapping, and then
  43   // unmap it.
  44   {
  45     ASSERT_TRUE(buffer->IsValidMap(0, kNumBytes));
  46     // Use |MapNoCheck()| this time.
  47     scoped_ptr<PlatformSharedBufferMapping> mapping1(
  48         buffer->MapNoCheck(0, kNumBytes));
  49     ASSERT_TRUE(mapping1);
  50     ASSERT_TRUE(mapping1->GetBase());
  51     int* stuff1 = static_cast<int*>(mapping1->GetBase());
  52     for (size_t i = 0; i < kNumInts; i++)
  53       EXPECT_EQ(static_cast<int>(i) + kFudge, stuff1[i]) << i;
  54
  55     scoped_ptr<PlatformSharedBufferMapping> mapping2(
  56         buffer->Map((kNumInts / 2) * sizeof(int), 2 * sizeof(int)));
  57     ASSERT_TRUE(mapping2);
  58     ASSERT_TRUE(mapping2->GetBase());
  59     int* stuff2 = static_cast<int*>(mapping2->GetBase());
  60     EXPECT_EQ(static_cast<int>(kNumInts / 2) + kFudge, stuff2[0]);
  61     EXPECT_EQ(static_cast<int>(kNumInts / 2) + 1 + kFudge, stuff2[1]);
  62
  63     stuff2[0] = 123;
  64     stuff2[1] = 456;
  65     EXPECT_EQ(123, stuff1[kNumInts / 2]);
  66     EXPECT_EQ(456, stuff1[kNumInts / 2 + 1]);
  67
  68     mapping1.reset();
  69
  70     EXPECT_EQ(123, stuff2[0]);
  71     EXPECT_EQ(456, stuff2[1]);
  72     stuff2[1] = 789;
  73   }
  74
  75   // Do another partial mapping and check that everything is the way we expect
  76   // it to be.
  77   {
  78     EXPECT_TRUE(buffer->IsValidMap(sizeof(int), kNumBytes - sizeof(int)));
  79     scoped_ptr<PlatformSharedBufferMapping> mapping(
  80         buffer->Map(sizeof(int), kNumBytes - sizeof(int)));
  81     ASSERT_TRUE(mapping);
  82     ASSERT_TRUE(mapping->GetBase());
  83     int* stuff = static_cast<int*>(mapping->GetBase());
  84
  85     for (size_t j = 0; j < kNumInts - 1; j++) {
  86       int i = static_cast<int>(j) + 1;
  87       if (i == kNumInts / 2) {
  88         EXPECT_EQ(123, stuff[j]);
  89       } else if (i == kNumInts / 2 + 1) {
  90         EXPECT_EQ(789, stuff[j]);
  91       } else {
  92         EXPECT_EQ(i + kFudge, stuff[j]) << i;
  93       }
  94     }
  95   }
  96 }
  97
  98 // TODO(vtl): Bigger buffers.
  99
 100 TEST(SimplePlatformSharedBufferTest, InvalidMappings) {
 101   scoped_refptr<SimplePlatformSharedBuffer> buffer(
 102       SimplePlatformSharedBuffer::Create(100));
 103   ASSERT_TRUE(buffer);
 104
 105   // Zero length not allowed.
 106   EXPECT_FALSE(buffer->Map(0, 0));
 107   EXPECT_FALSE(buffer->IsValidMap(0, 0));
 108
 109   // Okay:
 110   EXPECT_TRUE(buffer->Map(0, 100));
 111   EXPECT_TRUE(buffer->IsValidMap(0, 100));
 112   // Offset + length too big.
 113   EXPECT_FALSE(buffer->Map(0, 101));
 114   EXPECT_FALSE(buffer->IsValidMap(0, 101));
 115   EXPECT_FALSE(buffer->Map(1, 100));
 116   EXPECT_FALSE(buffer->IsValidMap(1, 100));
 117
 118   // Okay:
 119   EXPECT_TRUE(buffer->Map(50, 50));
 120   EXPECT_TRUE(buffer->IsValidMap(50, 50));
 121   // Offset + length too big.
 122   EXPECT_FALSE(buffer->Map(50, 51));
 123   EXPECT_FALSE(buffer->IsValidMap(50, 51));
 124   EXPECT_FALSE(buffer->Map(51, 50));
 125   EXPECT_FALSE(buffer->IsValidMap(51, 50));
 126 }
 127
 128 TEST(SimplePlatformSharedBufferTest, TooBig) {
 129   // If |size_t| is 32-bit, it's quite possible/likely that |Create()| succeeds
 130   // (since it only involves creating a 4 GB file).
 131   const size_t kMaxSizeT = std::numeric_limits<size_t>::max();
 132   scoped_refptr<SimplePlatformSharedBuffer> buffer(
 133       SimplePlatformSharedBuffer::Create(kMaxSizeT));
 134   // But, assuming |sizeof(size_t) == sizeof(void*)|, mapping all of it should
 135   // always fail.
 136   if (buffer)
 137     EXPECT_FALSE(buffer->Map(0, kMaxSizeT));
 138 }
 139
 140 // Tests that separate mappings get distinct addresses.
 141 // Note: It's not inconceivable that the OS could ref-count identical mappings
 142 // and reuse the same address, in which case we'd have to be more careful about
 143 // using the address as the key for unmapping.
 144 TEST(SimplePlatformSharedBufferTest, MappingsDistinct) {
 145   scoped_refptr<SimplePlatformSharedBuffer> buffer(
 146       SimplePlatformSharedBuffer::Create(100));
 147   scoped_ptr<PlatformSharedBufferMapping> mapping1(buffer->Map(0, 100));
 148   scoped_ptr<PlatformSharedBufferMapping> mapping2(buffer->Map(0, 100));
 149   EXPECT_NE(mapping1->GetBase(), mapping2->GetBase());
 150 }
 151
 152 TEST(SimplePlatformSharedBufferTest, BufferZeroInitialized) {
 153   static const size_t kSizes[] = {10, 100, 1000, 10000, 100000};
 154   for (size_t i = 0; i < arraysize(kSizes); i++) {
 155     scoped_refptr<SimplePlatformSharedBuffer> buffer(
 156         SimplePlatformSharedBuffer::Create(kSizes[i]));
 157     scoped_ptr<PlatformSharedBufferMapping> mapping(buffer->Map(0, kSizes[i]));
 158     for (size_t j = 0; j < kSizes[i]; j++) {
 159       // "Assert" instead of "expect" so we don't spam the output with thousands
 160       // of failures if we fail.
 161       ASSERT_EQ('\0', static_cast<char*>(mapping->GetBase())[j])
 162           << "size " << kSizes[i] << ", offset " << j;
 163     }
 164   }
 165 }
 166
 167 TEST(SimplePlatformSharedBufferTest, MappingsOutliveBuffer) {
 168   scoped_ptr<PlatformSharedBufferMapping> mapping1;
 169   scoped_ptr<PlatformSharedBufferMapping> mapping2;
 170
 171   {
 172     scoped_refptr<SimplePlatformSharedBuffer> buffer(
 173         SimplePlatformSharedBuffer::Create(100));
 174     mapping1 = buffer->Map(0, 100).Pass();
 175     mapping2 = buffer->Map(50, 50).Pass();
 176     static_cast<char*>(mapping1->GetBase())[50] = 'x';
 177   }
 178
 179   EXPECT_EQ('x', static_cast<char*>(mapping2->GetBase())[0]);
 180
 181   static_cast<char*>(mapping2->GetBase())[1] = 'y';
 182   EXPECT_EQ('y', static_cast<char*>(mapping1->GetBase())[51]);
 183 }
 184
 185 }  // namespace
 186 }  // namespace embedder
 187 }  // namespace mojo