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// Copyright Vespa.ai. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
#include <vespa/vespalib/testkit/test_kit.h>
#include <vespa/vespalib/util/simple_thread_bundle.h>
#include <vespa/vespalib/util/size_literals.h>
#include <vespa/vespalib/util/box.h>
#include <thread>
using namespace vespalib;
uint64_t doWork(uint64_t data) {
uint64_t value = data;
for (size_t i = 0; i < 1_Mi; ++i) {
value = (value << 16) + (value >> 8) + (value << 32);
}
return value;
}
struct Worker : Runnable {
size_t iter;
uint64_t input;
uint64_t output;
Worker() noexcept : iter(1), input(0), output(0) {}
void init(size_t n, uint64_t i) {
iter = n;
input = i;
}
void run() override {
uint64_t value = input;
for (size_t i = 0; i < iter; ++i) {
value = doWork(value);
}
output = value;
}
};
TEST("estimate cost of thread bundle fork/join") {
std::vector<SimpleThreadBundle::Strategy> strategy_value
= make_box(SimpleThreadBundle::USE_SIGNAL_LIST,
SimpleThreadBundle::USE_SIGNAL_TREE,
SimpleThreadBundle::USE_BROADCAST);
std::vector<std::string> strategy_name
= make_box(std::string("USE_SIGNAL_LIST"),
std::string("USE_SIGNAL_TREE"),
std::string("USE_BROADCAST"));
for (size_t strategy = 0; strategy < strategy_value.size(); ++strategy) {
for (size_t threads = 1; threads <= 16; ++threads) {
SimpleThreadBundle threadBundle(threads, strategy_value[strategy]);
std::vector<Worker> workers(threads);
std::vector<Runnable*> targets;
for (size_t i = 0; i < threads; ++i) {
targets.push_back(&workers[i]);
}
size_t iter = 0x4; // work done per fork
size_t fork = 0x1; // number of forks performed
for (; iter > 0; iter >>= 1, fork <<= 1) {
for (size_t i = 0; i < threads; ++i) {
workers[i].init(iter, i);
}
double minTime = 1000000.0;
for (size_t samples = 0; samples < 32; ++samples) {
vespalib::Timer timer;
for (size_t n = 0; n < fork; ++n) {
threadBundle.run(targets);
}
double time = vespalib::count_ms(timer.elapsed());
if (time < minTime) {
minTime = time;
}
std::this_thread::sleep_for(10ms);
}
fprintf(stderr, "strategy: %s, threads: %zu, fork: %zu, iter: %zu, time: %g, unit: %g\n",
strategy_name[strategy].c_str(), threads, fork, iter, minTime,
minTime / (fork * iter));
}
}
}
}
TEST_MAIN() { TEST_RUN_ALL(); }
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