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 <stddef.h>
6
7 #include <limits>
8
9 #include "mojo/public/cpp/bindings/lib/fixed_buffer.h"
10 #include "mojo/public/cpp/bindings/lib/serialization_util.h"
11 #include "testing/gtest/include/gtest/gtest.h"
12
13 namespace mojo {
14 namespace test {
15 namespace {
16
IsZero(void * p_buf,size_t size)17 bool IsZero(void* p_buf, size_t size) {
18 char* buf = reinterpret_cast<char*>(p_buf);
19 for (size_t i = 0; i < size; ++i) {
20 if (buf[i] != 0)
21 return false;
22 }
23 return true;
24 }
25
26 // Tests that FixedBuffer allocates memory aligned to 8 byte boundaries.
TEST(FixedBufferTest,Alignment)27 TEST(FixedBufferTest, Alignment) {
28 internal::FixedBufferForTesting buf(internal::Align(10) * 2);
29 ASSERT_EQ(buf.size(), 16u * 2);
30
31 void* a = buf.Allocate(10);
32 ASSERT_TRUE(a);
33 EXPECT_TRUE(IsZero(a, 10));
34 EXPECT_EQ(0, reinterpret_cast<ptrdiff_t>(a) % 8);
35
36 void* b = buf.Allocate(10);
37 ASSERT_TRUE(b);
38 EXPECT_TRUE(IsZero(b, 10));
39 EXPECT_EQ(0, reinterpret_cast<ptrdiff_t>(b) % 8);
40
41 // Any more allocations would result in an assert, but we can't test that.
42 }
43
44 // Tests that FixedBufferForTesting::Leak passes ownership to the caller.
TEST(FixedBufferTest,Leak)45 TEST(FixedBufferTest, Leak) {
46 void* ptr = nullptr;
47 void* buf_ptr = nullptr;
48 {
49 internal::FixedBufferForTesting buf(8);
50 ASSERT_EQ(8u, buf.size());
51
52 ptr = buf.Allocate(8);
53 ASSERT_TRUE(ptr);
54 buf_ptr = buf.Leak();
55
56 // The buffer should point to the first element allocated.
57 // TODO(mpcomplete): Is this a reasonable expectation?
58 EXPECT_EQ(ptr, buf_ptr);
59
60 // The FixedBufferForTesting should be empty now.
61 EXPECT_EQ(0u, buf.size());
62 EXPECT_FALSE(buf.Leak());
63 }
64
65 // Since we called Leak, ptr is still writable after FixedBufferForTesting
66 // went out of scope.
67 memset(ptr, 1, 8);
68 free(buf_ptr);
69 }
70
71 #if defined(NDEBUG) && !defined(DCHECK_ALWAYS_ON)
TEST(FixedBufferTest,TooBig)72 TEST(FixedBufferTest, TooBig) {
73 internal::FixedBufferForTesting buf(24);
74
75 // A little bit too large.
76 EXPECT_EQ(reinterpret_cast<void*>(0), buf.Allocate(32));
77
78 // Move the cursor forward.
79 EXPECT_NE(reinterpret_cast<void*>(0), buf.Allocate(16));
80
81 // A lot too large.
82 EXPECT_EQ(reinterpret_cast<void*>(0),
83 buf.Allocate(std::numeric_limits<size_t>::max() - 1024u));
84
85 // A lot too large, leading to possible integer overflow.
86 EXPECT_EQ(reinterpret_cast<void*>(0),
87 buf.Allocate(std::numeric_limits<size_t>::max() - 8u));
88 }
89 #endif
90
91 } // namespace
92 } // namespace test
93 } // namespace mojo
94