dogecoin/src/bench/bench.cpp
Wladimir J. van der Laan 29c53289a9 bench: Fix initialization order in registration
The initialization order of global data structures in different
implementation units is undefined. Making use of this is essentially
gambling on what the linker does, the so-called [Static initialization
order fiasco](https://isocpp.org/wiki/faq/ctors#static-init-order).

In this case it apparently worked on Linux but failed on OpenBSD and
FreeBSD.

To create it on first use, make the registration structure local to
a function.

Fixes #8910.
2017-02-07 19:07:29 +01:00

103 lines
3.4 KiB
C++

// Copyright (c) 2015-2016 The Bitcoin Core developers
// Distributed under the MIT software license, see the accompanying
// file COPYING or http://www.opensource.org/licenses/mit-license.php.
#include "bench.h"
#include "perf.h"
#include <iostream>
#include <iomanip>
#include <sys/time.h>
benchmark::BenchRunner::BenchmarkMap &benchmark::BenchRunner::benchmarks() {
static std::map<std::string, benchmark::BenchFunction> benchmarks_map;
return benchmarks_map;
}
static double gettimedouble(void) {
struct timeval tv;
gettimeofday(&tv, NULL);
return tv.tv_usec * 0.000001 + tv.tv_sec;
}
benchmark::BenchRunner::BenchRunner(std::string name, benchmark::BenchFunction func)
{
benchmarks().insert(std::make_pair(name, func));
}
void
benchmark::BenchRunner::RunAll(double elapsedTimeForOne)
{
perf_init();
std::cout << "#Benchmark" << "," << "count" << "," << "min" << "," << "max" << "," << "average" << ","
<< "min_cycles" << "," << "max_cycles" << "," << "average_cycles" << "\n";
for (const auto &p: benchmarks()) {
State state(p.first, elapsedTimeForOne);
p.second(state);
}
perf_fini();
}
bool benchmark::State::KeepRunning()
{
if (count & countMask) {
++count;
return true;
}
double now;
uint64_t nowCycles;
if (count == 0) {
lastTime = beginTime = now = gettimedouble();
lastCycles = beginCycles = nowCycles = perf_cpucycles();
}
else {
now = gettimedouble();
double elapsed = now - lastTime;
double elapsedOne = elapsed * countMaskInv;
if (elapsedOne < minTime) minTime = elapsedOne;
if (elapsedOne > maxTime) maxTime = elapsedOne;
// We only use relative values, so don't have to handle 64-bit wrap-around specially
nowCycles = perf_cpucycles();
uint64_t elapsedOneCycles = (nowCycles - lastCycles) * countMaskInv;
if (elapsedOneCycles < minCycles) minCycles = elapsedOneCycles;
if (elapsedOneCycles > maxCycles) maxCycles = elapsedOneCycles;
if (elapsed*128 < maxElapsed) {
// If the execution was much too fast (1/128th of maxElapsed), increase the count mask by 8x and restart timing.
// The restart avoids including the overhead of this code in the measurement.
countMask = ((countMask<<3)|7) & ((1LL<<60)-1);
countMaskInv = 1./(countMask+1);
count = 0;
minTime = std::numeric_limits<double>::max();
maxTime = std::numeric_limits<double>::min();
minCycles = std::numeric_limits<uint64_t>::max();
maxCycles = std::numeric_limits<uint64_t>::min();
return true;
}
if (elapsed*16 < maxElapsed) {
uint64_t newCountMask = ((countMask<<1)|1) & ((1LL<<60)-1);
if ((count & newCountMask)==0) {
countMask = newCountMask;
countMaskInv = 1./(countMask+1);
}
}
}
lastTime = now;
lastCycles = nowCycles;
++count;
if (now - beginTime < maxElapsed) return true; // Keep going
--count;
// Output results
double average = (now-beginTime)/count;
int64_t averageCycles = (nowCycles-beginCycles)/count;
std::cout << std::fixed << std::setprecision(15) << name << "," << count << "," << minTime << "," << maxTime << "," << average << ","
<< minCycles << "," << maxCycles << "," << averageCycles << "\n";
return false;
}