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
40 // Ensure that NominalCPUFrequency returns a reasonable value, or 1.00 on
41 // platforms where the CPU frequency is not available through sysfs.
42 //
43 // POWER is particularly problematic here; some Linux kernels expose the CPU
44 // frequency, while others do not. Since we can't predict a priori what a given
45 // machine is going to do, just disable this test on POWER on Linux.
46 #if !(defined(__linux) && (defined(__ppc64__) || defined(__PPC64__)))
TEST(SysinfoTest,NominalCPUFrequency)47 TEST(SysinfoTest, NominalCPUFrequency) {
48 // Linux only exposes the CPU frequency on certain architectures, and
49 // Emscripten doesn't expose it at all.
50 #if defined(__linux__) && \
51 (defined(__aarch64__) || defined(__hppa__) || defined(__mips__) || \
52 defined(__riscv) || defined(__s390x__)) || \
53 defined(__EMSCRIPTEN__)
54 EXPECT_EQ(NominalCPUFrequency(), 1.0)
55 << "CPU frequency detection was fixed! Please update unittest.";
56 #else
57 EXPECT_GE(NominalCPUFrequency(), 1000.0)
58 << "NominalCPUFrequency() did not return a reasonable value";
59 #endif
60 }
61 #endif
62
TEST(SysinfoTest,GetTID)63 TEST(SysinfoTest, GetTID) {
64 EXPECT_EQ(GetTID(), GetTID()); // Basic compile and equality test.
65 #ifdef __native_client__
66 // Native Client has a race condition bug that leads to memory
67 // exaustion when repeatedly creating and joining threads.
68 // https://bugs.chromium.org/p/nativeclient/issues/detail?id=1027
69 return;
70 #endif
71 // Test that TIDs are unique to each thread.
72 // Uses a few loops to exercise implementations that reallocate IDs.
73 for (int i = 0; i < 10; ++i) {
74 constexpr int kNumThreads = 10;
75 Barrier all_threads_done(kNumThreads);
76 std::vector<std::thread> threads;
77
78 Mutex mutex;
79 std::unordered_set<pid_t> tids;
80
81 for (int j = 0; j < kNumThreads; ++j) {
82 threads.push_back(std::thread([&]() {
83 pid_t id = GetTID();
84 {
85 MutexLock lock(&mutex);
86 ASSERT_TRUE(tids.find(id) == tids.end());
87 tids.insert(id);
88 }
89 // We can't simply join the threads here. The threads need to
90 // be alive otherwise the TID might have been reallocated to
91 // another live thread.
92 all_threads_done.Block();
93 }));
94 }
95 for (auto& thread : threads) {
96 thread.join();
97 }
98 }
99 }
100
101 #ifdef __linux__
TEST(SysinfoTest,LinuxGetTID)102 TEST(SysinfoTest, LinuxGetTID) {
103 // On Linux, for the main thread, GetTID()==getpid() is guaranteed by the API.
104 EXPECT_EQ(GetTID(), getpid());
105 }
106 #endif
107
108 } // namespace
109 } // namespace base_internal
110 ABSL_NAMESPACE_END
111 } // namespace absl
112