| /* |
| * Copyright (C) 2019 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 <getopt.h> |
| #include <stdint.h> |
| #include <unistd.h> |
| |
| #include <thread> |
| |
| #include "perfetto/base/logging.h" |
| #include "perfetto/base/time.h" |
| |
| // Spawns the requested number threads that alternate between busy-waiting and |
| // sleeping. |
| |
| namespace perfetto { |
| namespace { |
| |
| __attribute__((noreturn)) void BusyWait(long busy_us, long sleep_us) { |
| while (1) { |
| base::TimeNanos start = base::GetWallTimeNs(); |
| while ((base::GetWallTimeNs() - start).count() < busy_us * 1000) { |
| for (int i = 0; i < 10000; i++) { |
| asm volatile("" ::: "memory"); |
| } |
| } |
| if (sleep_us > 0) |
| base::SleepMicroseconds(static_cast<unsigned>(sleep_us)); |
| else |
| std::this_thread::yield(); |
| } |
| } |
| |
| int BusyThreadsMain(int argc, char** argv) { |
| long num_threads = -1; |
| long period_us = -1; |
| long duty_cycle = -1; |
| |
| static struct option long_options[] = { |
| {"threads", required_argument, nullptr, 't'}, |
| {"period_us", required_argument, nullptr, 'p'}, |
| {"duty_cycle", required_argument, nullptr, 'd'}, |
| {nullptr, 0, nullptr, 0}}; |
| int option_index; |
| int c; |
| while ((c = getopt_long(argc, argv, "", long_options, &option_index)) != -1) { |
| switch (c) { |
| case 't': |
| num_threads = atol(optarg); |
| break; |
| case 'p': |
| period_us = atol(optarg); |
| break; |
| case 'd': |
| duty_cycle = atol(optarg); |
| break; |
| default: |
| break; |
| } |
| } |
| if (num_threads < 1 || period_us < 0 || duty_cycle < 1 || duty_cycle > 100) { |
| PERFETTO_ELOG("Usage: %s --threads=N --period_us=N --duty_cycle=[1-100]", |
| argv[0]); |
| return 1; |
| } |
| |
| long busy_us = period_us * duty_cycle / 100; |
| long sleep_us = period_us - busy_us; |
| |
| PERFETTO_LOG( |
| "Spawning %ld threads; wait duration: %ldus; sleep duration: %ldus.", |
| num_threads, busy_us, sleep_us); |
| for (int i = 0; i < num_threads; i++) { |
| std::thread th(BusyWait, busy_us, sleep_us); |
| th.detach(); |
| } |
| PERFETTO_LOG("Threads spawned, Ctrl-C to stop."); |
| while (sleep(600)) |
| ; |
| |
| return 0; |
| } |
| |
| } // namespace |
| } // namespace perfetto |
| |
| int main(int argc, char** argv) { |
| return perfetto::BusyThreadsMain(argc, argv); |
| } |