1 files changed, 102 insertions, 0 deletions
diff --git a/src/bench/bench.cpp b/src/bench/bench.cpp
new file mode 100644
index 000000000..3c9df4f71
--- /dev/null
+++ b/src/bench/bench.cpp
@@ -0,0 +1,102 @@
+// 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;
+}