From a84f8da136a4f2f4c4a08bc4c25237f2f3b7b141 Mon Sep 17 00:00:00 2001
From: "Wladimir J. van der Laan" <laanwj@gmail.com>
Date: Thu, 19 Jan 2017 15:21:27 +0100
Subject: [PATCH] Merge #9498: Basic CCheckQueue Benchmarks

aad4cb5 Address ryanofsky feedback on CCheckQueue benchmarks. Eliminated magic numbers, fixed scoping of vectors (and memory movement component of benchmark). (Jeremy Rubin)
9f03110 Add Basic CheckQueue Benchmark (Jeremy Rubin)
---
 src/Makefile.bench.include |   1 +
 src/bench/checkqueue.cpp   | 103 +++++++++++++++++++++++++++++++++++++
 2 files changed, 104 insertions(+)
 create mode 100644 src/bench/checkqueue.cpp

diff --git a/src/Makefile.bench.include b/src/Makefile.bench.include
index ae27f58a4b..e23a81c96e 100644
--- a/src/Makefile.bench.include
+++ b/src/Makefile.bench.include
@@ -16,6 +16,7 @@ bench_bench_dash_SOURCES = \
   bench/bench.cpp \
   bench/bench.h \
   bench/checkblock.cpp \
+  bench/checkqueue.cpp \
   bench/Examples.cpp \
   bench/rollingbloom.cpp \
   bench/crypto_hash.cpp \
diff --git a/src/bench/checkqueue.cpp b/src/bench/checkqueue.cpp
new file mode 100644
index 0000000000..6fa9fe4fe8
--- /dev/null
+++ b/src/bench/checkqueue.cpp
@@ -0,0 +1,103 @@
+// Copyright (c) 2015 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 "util.h"
+#include "validation.h"
+#include "checkqueue.h"
+#include "prevector.h"
+#include <vector>
+#include <boost/thread/thread.hpp>
+#include "random.h"
+
+
+// This Benchmark tests the CheckQueue with the lightest
+// weight Checks, so it should make any lock contention
+// particularly visible
+static const int MIN_CORES = 2;
+static const size_t BATCHES = 101;
+static const size_t BATCH_SIZE = 30;
+static const int PREVECTOR_SIZE = 28;
+static const int QUEUE_BATCH_SIZE = 128;
+static void CCheckQueueSpeed(benchmark::State& state)
+{
+    struct FakeJobNoWork {
+        bool operator()()
+        {
+            return true;
+        }
+        void swap(FakeJobNoWork& x){};
+    };
+    CCheckQueue<FakeJobNoWork> queue {QUEUE_BATCH_SIZE};
+    boost::thread_group tg;
+    for (auto x = 0; x < std::max(MIN_CORES, GetNumCores()); ++x) {
+       tg.create_thread([&]{queue.Thread();});
+    }
+    while (state.KeepRunning()) {
+        CCheckQueueControl<FakeJobNoWork> control(&queue);
+
+        // We call Add a number of times to simulate the behavior of adding
+        // a block of transactions at once.
+
+        std::vector<std::vector<FakeJobNoWork>> vBatches(BATCHES);
+        for (auto& vChecks : vBatches) {
+            vChecks.resize(BATCH_SIZE);
+        }
+        for (auto& vChecks : vBatches) {
+            // We can't make vChecks in the inner loop because we want to measure
+            // the cost of getting the memory to each thread and we might get the same
+            // memory
+            control.Add(vChecks);
+        }
+        // control waits for completion by RAII, but
+        // it is done explicitly here for clarity
+        control.Wait();
+    }
+    tg.interrupt_all();
+    tg.join_all();
+}
+
+// This Benchmark tests the CheckQueue with a slightly realistic workload,
+// where checks all contain a prevector that is indirect 50% of the time
+// and there is a little bit of work done between calls to Add.
+static void CCheckQueueSpeedPrevectorJob(benchmark::State& state)
+{
+    struct PrevectorJob {
+        prevector<PREVECTOR_SIZE, uint8_t> p;
+        PrevectorJob(){
+        }
+        PrevectorJob(FastRandomContext& insecure_rand){
+            p.resize(insecure_rand.rand32() % (PREVECTOR_SIZE*2));
+        }
+        bool operator()()
+        {
+            return true;
+        }
+        void swap(PrevectorJob& x){p.swap(x.p);};
+    };
+    CCheckQueue<PrevectorJob> queue {QUEUE_BATCH_SIZE};
+    boost::thread_group tg;
+    for (auto x = 0; x < std::max(MIN_CORES, GetNumCores()); ++x) {
+       tg.create_thread([&]{queue.Thread();});
+    }
+    while (state.KeepRunning()) {
+        // Make insecure_rand here so that each iteration is identical.
+        FastRandomContext insecure_rand(true);
+        CCheckQueueControl<PrevectorJob> control(&queue);
+        std::vector<std::vector<PrevectorJob>> vBatches(BATCHES);
+        for (auto& vChecks : vBatches) {
+            vChecks.reserve(BATCH_SIZE);
+            for (size_t x = 0; x < BATCH_SIZE; ++x)
+                vChecks.emplace_back(insecure_rand);
+            control.Add(vChecks);
+        }
+        // control waits for completion by RAII, but
+        // it is done explicitly here for clarity
+        control.Wait();
+    }
+    tg.interrupt_all();
+    tg.join_all();
+}
+BENCHMARK(CCheckQueueSpeed);
+BENCHMARK(CCheckQueueSpeedPrevectorJob);