1 // Copyright 2024 The Pigweed Authors
2 //
3 // Licensed under the Apache License, Version 2.0 (the "License"); you may not
4 // use this file except in compliance with the License. You may obtain a copy of
5 // the License at
6 //
7 // https://www.apache.org/licenses/LICENSE-2.0
8 //
9 // Unless required by applicable law or agreed to in writing, software
10 // distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
11 // WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
12 // License for the specific language governing permissions and limitations under
13 // the License.
14
15 #include "pw_multibuf/simple_allocator.h"
16
17 #include "gtest/gtest.h"
18 #include "pw_allocator/null_allocator.h"
19 #include "pw_allocator/testing.h"
20
21 namespace pw::multibuf {
22 namespace {
23
24 using ::pw::allocator::test::AllocatorForTest;
25
26 constexpr size_t kArbitraryBufferSize = 1024;
27 constexpr size_t kArbitraryMetaSize = 1024;
28
TEST(SimpleAllocator,AllocateWholeDataAreaSizeSucceeds)29 TEST(SimpleAllocator, AllocateWholeDataAreaSizeSucceeds) {
30 std::array<std::byte, kArbitraryBufferSize> data_area;
31 AllocatorForTest<kArbitraryMetaSize> meta_alloc;
32 SimpleAllocator simple_allocator(data_area, meta_alloc);
33 std::optional<MultiBuf> buf = simple_allocator.Allocate(kArbitraryBufferSize);
34 ASSERT_TRUE(buf.has_value());
35 EXPECT_EQ(buf->size(), kArbitraryBufferSize);
36 }
37
TEST(SimpleAllocator,AllocateContiguousWholeDataAreaSizeSucceeds)38 TEST(SimpleAllocator, AllocateContiguousWholeDataAreaSizeSucceeds) {
39 std::array<std::byte, kArbitraryBufferSize> data_area;
40 AllocatorForTest<kArbitraryMetaSize> meta_alloc;
41 SimpleAllocator simple_allocator(data_area, meta_alloc);
42 std::optional<MultiBuf> buf =
43 simple_allocator.AllocateContiguous(kArbitraryBufferSize);
44 ASSERT_TRUE(buf.has_value());
45 EXPECT_EQ(buf->Chunks().size(), 1U);
46 EXPECT_EQ(buf->size(), kArbitraryBufferSize);
47 }
48
TEST(SimpleAllocator,AllocateContiguousHalfDataAreaSizeTwiceSucceeds)49 TEST(SimpleAllocator, AllocateContiguousHalfDataAreaSizeTwiceSucceeds) {
50 std::array<std::byte, kArbitraryBufferSize> data_area;
51 AllocatorForTest<kArbitraryMetaSize> meta_alloc;
52 SimpleAllocator simple_allocator(data_area, meta_alloc);
53 std::optional<MultiBuf> buf =
54 simple_allocator.AllocateContiguous(kArbitraryBufferSize / 2);
55 ASSERT_TRUE(buf.has_value());
56 EXPECT_EQ(buf->Chunks().size(), 1U);
57 EXPECT_EQ(buf->size(), kArbitraryBufferSize / 2);
58
59 std::optional<MultiBuf> buf2 =
60 simple_allocator.AllocateContiguous(kArbitraryBufferSize / 2);
61 ASSERT_TRUE(buf2.has_value());
62 EXPECT_EQ(buf2->Chunks().size(), 1U);
63 EXPECT_EQ(buf2->size(), kArbitraryBufferSize / 2);
64 }
65
TEST(SimpleAllocator,AllocateTooLargeReturnsNullopt)66 TEST(SimpleAllocator, AllocateTooLargeReturnsNullopt) {
67 std::array<std::byte, kArbitraryBufferSize> data_area;
68 AllocatorForTest<kArbitraryMetaSize> meta_alloc;
69 SimpleAllocator simple_allocator(data_area, meta_alloc);
70 std::optional<MultiBuf> buf =
71 simple_allocator.Allocate(kArbitraryBufferSize + 1);
72 EXPECT_FALSE(buf.has_value());
73 std::optional<MultiBuf> contiguous_buf =
74 simple_allocator.Allocate(kArbitraryBufferSize + 1);
75 EXPECT_FALSE(contiguous_buf.has_value());
76 }
77
TEST(SimpleAllocator,AllocateZeroWithNoMetadataOrDataReturnsEmptyMultiBuf)78 TEST(SimpleAllocator, AllocateZeroWithNoMetadataOrDataReturnsEmptyMultiBuf) {
79 std::array<std::byte, 0> data_area;
80 pw::allocator::NullAllocator meta_alloc;
81 SimpleAllocator simple_allocator(data_area, meta_alloc);
82 std::optional<MultiBuf> buf = simple_allocator.Allocate(0);
83 ASSERT_TRUE(buf.has_value());
84 EXPECT_EQ(buf->size(), 0U);
85 }
86
TEST(SimpleAllocator,AllocateWithNoMetadataRoomReturnsNullopt)87 TEST(SimpleAllocator, AllocateWithNoMetadataRoomReturnsNullopt) {
88 std::array<std::byte, kArbitraryBufferSize> data_area;
89 pw::allocator::NullAllocator meta_alloc;
90 SimpleAllocator simple_allocator(data_area, meta_alloc);
91 std::optional<MultiBuf> buf = simple_allocator.Allocate(1);
92 EXPECT_FALSE(buf.has_value());
93 }
94
TEST(SimpleAllocator,SecondLargeAllocationFailsUntilFirstAllocationReleased)95 TEST(SimpleAllocator, SecondLargeAllocationFailsUntilFirstAllocationReleased) {
96 std::array<std::byte, kArbitraryBufferSize> data_area;
97 AllocatorForTest<kArbitraryMetaSize> meta_alloc;
98 SimpleAllocator simple_allocator(data_area, meta_alloc);
99 const size_t alloc_size = kArbitraryBufferSize / 2 + 1;
100 std::optional<MultiBuf> buf = simple_allocator.Allocate(alloc_size);
101 ASSERT_TRUE(buf.has_value());
102 EXPECT_EQ(buf->size(), alloc_size);
103 EXPECT_FALSE(simple_allocator.Allocate(alloc_size).has_value());
104 // Release the first buffer
105 buf = std::nullopt;
106 EXPECT_TRUE(simple_allocator.Allocate(alloc_size).has_value());
107 }
108
TEST(SimpleAllocator,AllocateSkipsMiddleAllocations)109 TEST(SimpleAllocator, AllocateSkipsMiddleAllocations) {
110 std::array<std::byte, kArbitraryBufferSize> data_area;
111 AllocatorForTest<kArbitraryMetaSize> meta_alloc;
112 SimpleAllocator simple_allocator(data_area, meta_alloc);
113 const size_t alloc_size = kArbitraryBufferSize / 3;
114 std::optional<MultiBuf> buf1 = simple_allocator.Allocate(alloc_size);
115 std::optional<MultiBuf> buf2 = simple_allocator.Allocate(alloc_size);
116 std::optional<MultiBuf> buf3 = simple_allocator.Allocate(alloc_size);
117 EXPECT_TRUE(buf1.has_value());
118 EXPECT_TRUE(buf2.has_value());
119 EXPECT_TRUE(buf3.has_value());
120 buf1 = std::nullopt;
121 buf3 = std::nullopt;
122 // Now `buf2` holds the middle third of data_area
123 std::optional<MultiBuf> split = simple_allocator.Allocate(alloc_size * 2);
124 ASSERT_TRUE(split.has_value());
125 EXPECT_EQ(split->size(), alloc_size * 2);
126 EXPECT_EQ(split->Chunks().size(), 2U);
127 }
128
TEST(SimpleAllocator,FailedAllocationDoesNotHoldOntoChunks)129 TEST(SimpleAllocator, FailedAllocationDoesNotHoldOntoChunks) {
130 std::array<std::byte, kArbitraryBufferSize> data_area;
131 AllocatorForTest<kArbitraryMetaSize> meta_alloc;
132 SimpleAllocator simple_allocator(data_area, meta_alloc);
133 const size_t alloc_size = kArbitraryBufferSize / 2;
134 std::optional<MultiBuf> buf1 = simple_allocator.Allocate(alloc_size);
135 std::optional<MultiBuf> buf2 = simple_allocator.Allocate(alloc_size);
136 EXPECT_TRUE(buf1.has_value());
137 EXPECT_TRUE(buf2.has_value());
138 buf1 = std::nullopt;
139 // When this allocation is attempted, it will initially create a chunk for
140 // the first empty region prior to failing.
141 EXPECT_FALSE(simple_allocator.Allocate(kArbitraryBufferSize).has_value());
142 buf2 = std::nullopt;
143 // Ensure that all chunk holds are released by attempting an allocation.
144 EXPECT_TRUE(simple_allocator.Allocate(kArbitraryBufferSize).has_value());
145 }
146
147 } // namespace
148 } // namespace pw::multibuf
149