1 // Copyright 2017 The Abseil 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 "absl/base/internal/sysinfo.h"
16
17 #ifndef _WIN32
18 #include <sys/types.h>
19 #include <unistd.h>
20 #endif
21
22 #include <thread> // NOLINT(build/c++11)
23 #include <unordered_set>
24 #include <vector>
25
26 #include "gtest/gtest.h"
27 #include "absl/synchronization/barrier.h"
28 #include "absl/synchronization/mutex.h"
29
30 namespace absl {
31 ABSL_NAMESPACE_BEGIN
32 namespace base_internal {
33 namespace {
34
TEST(SysinfoTest,NumCPUs)35 TEST(SysinfoTest, NumCPUs) {
36 EXPECT_NE(NumCPUs(), 0)
37 << "NumCPUs() should not have the default value of 0";
38 }
39
TEST(SysinfoTest,GetTID)40 TEST(SysinfoTest, GetTID) {
41 EXPECT_EQ(GetTID(), GetTID()); // Basic compile and equality test.
42 #ifdef __native_client__
43 // Native Client has a race condition bug that leads to memory
44 // exaustion when repeatedly creating and joining threads.
45 // https://bugs.chromium.org/p/nativeclient/issues/detail?id=1027
46 return;
47 #endif
48 // Test that TIDs are unique to each thread.
49 // Uses a few loops to exercise implementations that reallocate IDs.
50 for (int i = 0; i < 10; ++i) {
51 constexpr int kNumThreads = 10;
52 Barrier all_threads_done(kNumThreads);
53 std::vector<std::thread> threads;
54
55 Mutex mutex;
56 std::unordered_set<pid_t> tids;
57
58 for (int j = 0; j < kNumThreads; ++j) {
59 threads.push_back(std::thread([&]() {
60 pid_t id = GetTID();
61 {
62 MutexLock lock(&mutex);
63 ASSERT_TRUE(tids.find(id) == tids.end());
64 tids.insert(id);
65 }
66 // We can't simply join the threads here. The threads need to
67 // be alive otherwise the TID might have been reallocated to
68 // another live thread.
69 all_threads_done.Block();
70 }));
71 }
72 for (auto& thread : threads) {
73 thread.join();
74 }
75 }
76 }
77
78 #ifdef __linux__
TEST(SysinfoTest,LinuxGetTID)79 TEST(SysinfoTest, LinuxGetTID) {
80 // On Linux, for the main thread, GetTID()==getpid() is guaranteed by the API.
81 EXPECT_EQ(GetTID(), getpid());
82 }
83 #endif
84
85 } // namespace
86 } // namespace base_internal
87 ABSL_NAMESPACE_END
88 } // namespace absl
89