// file : libbuild2/scheduler.test.cxx -*- C++ -*- // copyright : Copyright (c) 2014-2019 Code Synthesis Ltd // license : MIT; see accompanying LICENSE file #include <chrono> #include <thread> #include <cassert> #include <iostream> #include <libbuild2/types.hxx> #include <libbuild2/utility.hxx> #include <libbuild2/scheduler.hxx> using namespace std; namespace build2 { // Usage argv[0] [-v <volume>] [-d <difficulty>] [-c <concurrency>] // [-q <queue-depth>] // // -v task tree volume (affects both depth and width), for example 100 // -d computational difficulty of each task, for example 10 // -c max active threads, if unspecified or 0, then hardware concurrency // -q task queue depth, if unspecified or 0, then appropriate default used // // Specifying any option also turns on the verbose mode. // // Notes on testing: // // 1. Ideally you would want to test things on an SMP machine. // // 2. When need to compare performance, disable turbo boost since its // availability depends on CPU utilization/temperature: // // # echo '1' >/sys/devices/system/cpu/intel_pstate/no_turbo // // 3. Use turbostat(1) to see per-CPU details (utlization, frequency): // // $ sudo turbostat --interval 1 ./driver -d 8 -v 300 // static bool prime (uint64_t); // Find # of primes in the [x, y) range. // static void inner (uint64_t x, uint64_t y, uint64_t& r) { for (; x != y; ++x) if (prime (x)) r++; }; int main (int argc, char* argv[]) { bool verb (false); // Adjust assert() below if changing these defaults. // size_t volume (100); uint32_t difficulty (10); size_t max_active (0); size_t queue_depth (0); for (int i (1); i != argc; ++i) { string a (argv[i]); if (a == "-v") volume = stoul (argv[++i]); else if (a == "-d") difficulty = stoul (argv[++i]); else if (a == "-c") max_active = stoul (argv[++i]); else if (a == "-q") queue_depth = stoul (argv[++i]); else assert (false); verb = true; } if (max_active == 0) max_active = scheduler::hardware_concurrency (); scheduler s (max_active, 1, 0, queue_depth); // Find # prime counts of primes in [i, d*i*i) ranges for i in (0, n]. // auto outer = [difficulty, &s] (size_t n, vector<uint64_t>& o, uint64_t& r) { scheduler::atomic_count task_count (0); for (size_t i (1); i <= n; ++i) { o[i - 1] = 0; s.async (task_count, inner, i, i * i * difficulty, ref (o[i - 1])); } s.wait (task_count); assert (task_count == 0); for (uint64_t v: o) r += prime (v) ? 1 : 0; }; vector<uint64_t> r (volume, 0); vector<vector<uint64_t>> o (volume, vector<uint64_t> ()); scheduler::atomic_count task_count (0); for (size_t i (0); i != volume; ++i) { o[i].resize (i); s.async (task_count, outer, i, ref (o[i]), ref (r[i])); } s.wait (task_count); assert (task_count == 0); uint64_t n (0); for (uint64_t v: r) n += v; if (volume == 100 && difficulty == 10) assert (n == 580); scheduler::stat st (s.shutdown ()); if (verb) { cerr << "result " << n << endl << endl; cerr << "thread_max_active " << st.thread_max_active << endl << "thread_max_total " << st.thread_max_total << endl << "thread_helpers " << st.thread_helpers << endl << "thread_max_waiting " << st.thread_max_waiting << endl << endl << "task_queue_depth " << st.task_queue_depth << endl << "task_queue_full " << st.task_queue_full << endl << endl << "wait_queue_slots " << st.wait_queue_slots << endl << "wait_queue_collisions " << st.wait_queue_collisions << endl; } return 0; } static bool prime (uint64_t x) { if (x == 2 || x == 3) return true; if (x < 2 || x % 2 == 0 || x % 3 == 0) return false; // Test divisors starting from 5 and incrementing alternatively by 2/4. // for (uint64_t d (5), i (2); d * d <= x; d += i, i = 6 - i) { if (x % d == 0) return false; } return true; } } int main (int argc, char* argv[]) { return build2::main (argc, argv); }