| /* |
| * Copyright (C) 2016 The Android Open Source Project |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| #include <algorithm> |
| #include <chrono> |
| #include <thread> |
| #include <vector> |
| |
| #include <sys/capability.h> |
| |
| #include <cutils/sched_policy.h> |
| |
| #include <gtest/gtest.h> |
| |
| bool hasCapSysNice() { |
| __user_cap_header_struct header; |
| memset(&header, 0, sizeof(header)); |
| header.version = _LINUX_CAPABILITY_VERSION_3; |
| |
| __user_cap_data_struct caps[_LINUX_CAPABILITY_U32S_3]; |
| if (capget(&header, &caps[0])) { |
| GTEST_LOG_(WARNING) << "failed to get process capabilities"; |
| return false; |
| } |
| |
| auto nice_idx = CAP_TO_INDEX(CAP_SYS_NICE); |
| auto nice_mask = CAP_TO_MASK(CAP_SYS_NICE); |
| return caps[nice_idx].effective & nice_mask; |
| } |
| |
| long long medianSleepTime() { |
| std::vector<long long> sleepTimes; |
| constexpr size_t numSamples = 100; |
| |
| for (size_t i = 0; i < numSamples; i++) { |
| auto start = std::chrono::steady_clock::now(); |
| std::this_thread::sleep_for(std::chrono::nanoseconds(1)); |
| auto end = std::chrono::steady_clock::now(); |
| |
| auto diff = end - start; |
| sleepTimes.push_back(diff.count()); |
| } |
| |
| constexpr auto median = numSamples / 2; |
| std::nth_element(sleepTimes.begin(), sleepTimes.begin() + median, |
| sleepTimes.end()); |
| return sleepTimes[median]; |
| } |
| |
| static void AssertPolicy(SchedPolicy expected_policy) { |
| SchedPolicy current_policy; |
| ASSERT_EQ(0, get_sched_policy(0, ¤t_policy)); |
| EXPECT_EQ(expected_policy, current_policy); |
| } |
| |
| TEST(SchedPolicy, set_sched_policy) { |
| ASSERT_EQ(0, set_sched_policy(0, SP_BACKGROUND)); |
| ASSERT_EQ(0, set_cpuset_policy(0, SP_BACKGROUND)); |
| AssertPolicy(SP_BACKGROUND); |
| |
| ASSERT_EQ(0, set_sched_policy(0, SP_FOREGROUND)); |
| ASSERT_EQ(0, set_cpuset_policy(0, SP_FOREGROUND)); |
| AssertPolicy(SP_FOREGROUND); |
| } |
| |
| TEST(SchedPolicy, set_sched_policy_timerslack) { |
| if (!hasCapSysNice()) { |
| GTEST_LOG_(INFO) << "skipping test that requires CAP_SYS_NICE"; |
| return; |
| } |
| |
| // A measureable effect of scheduling policy is that the kernel has 800x |
| // greater slack time in waking up a sleeping background thread. |
| // |
| // Look for 10x difference in how long FB and BG threads actually sleep |
| // when trying to sleep for 1 ns. This difference is large enough not |
| // to happen by chance, but small enough (compared to 800x) to keep inherent |
| // fuzziness in scheduler behavior from causing false negatives. |
| const unsigned int BG_FG_SLACK_FACTOR = 10; |
| |
| ASSERT_EQ(0, set_sched_policy(0, SP_BACKGROUND)); |
| auto bgSleepTime = medianSleepTime(); |
| |
| ASSERT_EQ(0, set_sched_policy(0, SP_FOREGROUND)); |
| auto fgSleepTime = medianSleepTime(); |
| |
| ASSERT_GT(bgSleepTime, fgSleepTime * BG_FG_SLACK_FACTOR); |
| } |
| |
| TEST(SchedPolicy, get_sched_policy_name) { |
| EXPECT_STREQ("bg", get_sched_policy_name(SP_BACKGROUND)); |
| EXPECT_EQ(nullptr, get_sched_policy_name(SchedPolicy(-2))); |
| EXPECT_EQ(nullptr, get_sched_policy_name(SP_CNT)); |
| } |
| |
| TEST(SchedPolicy, get_cpuset_policy_profile_name) { |
| EXPECT_STREQ("CPUSET_SP_BACKGROUND", get_cpuset_policy_profile_name(SP_BACKGROUND)); |
| EXPECT_EQ(nullptr, get_cpuset_policy_profile_name(SchedPolicy(-2))); |
| EXPECT_EQ(nullptr, get_cpuset_policy_profile_name(SP_CNT)); |
| } |
| |
| TEST(SchedPolicy, get_sched_policy_profile_name) { |
| EXPECT_STREQ("SCHED_SP_BACKGROUND", get_sched_policy_profile_name(SP_BACKGROUND)); |
| EXPECT_EQ(nullptr, get_sched_policy_profile_name(SchedPolicy(-2))); |
| EXPECT_EQ(nullptr, get_sched_policy_profile_name(SP_CNT)); |
| } |