1 // Copyright 2019 The Marl Authors.
2 //
3 // Licensed under the Apache License, Version 2.0 (the "License");
4 // you may not use this file except in compliance with the License.
5 // You may obtain a copy of 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,
11 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12 // See the License for the specific language governing permissions and
13 // limitations under the License.
14
15 #include "osfiber.h"
16
17 #include "marl_test.h"
18
19 namespace {
20
21 // A custom, small stack size for the fibers in these tests.
22 // Note: Stack sizes less than 16KB may cause issues on some platforms.
23 // See: https://github.com/google/marl/issues/201
24 constexpr size_t fiberStackSize = 16 * 1024;
25
26 } // anonymous namespace
27
TEST_F(WithoutBoundScheduler,OSFiber)28 TEST_F(WithoutBoundScheduler, OSFiber) {
29 std::string str;
30 auto main = marl::OSFiber::createFiberFromCurrentThread(allocator);
31 marl::Allocator::unique_ptr<marl::OSFiber> fiberA, fiberB, fiberC;
32 fiberC = marl::OSFiber::createFiber(allocator, fiberStackSize, [&] {
33 str += "C";
34 fiberC->switchTo(fiberB.get());
35 });
36 fiberB = marl::OSFiber::createFiber(allocator, fiberStackSize, [&] {
37 str += "B";
38 fiberB->switchTo(fiberA.get());
39 });
40 fiberA = marl::OSFiber::createFiber(allocator, fiberStackSize, [&] {
41 str += "A";
42 fiberA->switchTo(main.get());
43 });
44
45 main->switchTo(fiberC.get());
46
47 ASSERT_EQ(str, "CBA");
48 }
49
TEST_F(WithoutBoundScheduler,StackAlignment)50 TEST_F(WithoutBoundScheduler, StackAlignment) {
51 uintptr_t address = 0;
52
53 struct alignas(16) AlignTo16Bytes {
54 uint64_t a, b;
55 };
56
57 auto main = marl::OSFiber::createFiberFromCurrentThread(allocator);
58 marl::Allocator::unique_ptr<marl::OSFiber> fiber;
59 fiber = marl::OSFiber::createFiber(allocator, fiberStackSize, [&] {
60 AlignTo16Bytes stack_var;
61
62 address = reinterpret_cast<uintptr_t>(&stack_var);
63
64 fiber->switchTo(main.get());
65 });
66
67 main->switchTo(fiber.get());
68
69 ASSERT_TRUE((address & 15) == 0)
70 << "Stack variable had unaligned address: 0x" << std::hex << address;
71 }
72