SERVER-33203 add benchmark canary tests

(cherry picked from commit 721846a8b4b64d72338b46f91002d4a601c7dbba)

1 files changed, 83 insertions, 0 deletions

diff --git a/src/mongo/util/clock_source_bm.cpp b/src/mongo/util/clock_source_bm.cpp
new file mode 100644
index 00000000000..67af4407092
--- /dev/null
+++ b/src/mongo/util/clock_source_bm.cpp
@@ -0,0 +1,83 @@
+/**
+ *    Copyright (C) 2018 MongoDB Inc.
+ *
+ *    This program is free software: you can redistribute it and/or  modify
+ *    it under the terms of the GNU Affero General Public License, version 3,
+ *    as published by the Free Software Foundation.
+ *
+ *    This program is distributed in the hope that it will be useful,
+ *    but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *    GNU Affero General Public License for more details.
+ *
+ *    You should have received a copy of the GNU Affero General Public License
+ *    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ *    As a special exception, the copyright holders give permission to link the
+ *    code of portions of this program with the OpenSSL library under certain
+ *    conditions as described in each individual source file and distribute
+ *    linked combinations including the program with the OpenSSL library. You
+ *    must comply with the GNU Affero General Public License in all respects for
+ *    all of the code used other than as permitted herein. If you modify file(s)
+ *    with this exception, you may extend this exception to your version of the
+ *    file(s), but you are not obligated to do so. If you do not wish to do so,
+ *    delete this exception statement from your version. If you delete this
+ *    exception statement from all source files in the program, then also delete
+ *    it in the license file.
+ */
+
+#include "mongo/platform/basic.h"
+
+#include <benchmark/benchmark.h>
+
+#include "mongo/util/clock_source.h"
+#include "mongo/util/fast_clock_source_factory.h"
+#include "mongo/util/processinfo.h"
+#include "mongo/util/system_clock_source.h"
+
+namespace mongo {
+namespace {
+
+/**
+ * Benchmark calls to the now() method of a clock source. With an argument of 0,
+ * tests the system clock source, and with larger values, uses the FastClockSource
+ * with a clock resolution of the specified number of milliseconds.
+ *
+ * All threads executing the benchmark use the same instance of the clock source,
+ * to allow benchmarking to identify synchronization costs inside the now() method.
+ */
+void BM_ClockNow(benchmark::State& state) {
+    static std::unique_ptr<ClockSource> clock;
+    if (state.thread_index == 0) {
+        if (state.range(0) > 0) {
+            clock = FastClockSourceFactory::create(Milliseconds{state.range(0)});
+        } else if (state.range(0) == 0) {
+            clock = std::make_unique<SystemClockSource>();
+        } else {
+            state.SkipWithError("poll period must be non-negative");
+            return;
+        }
+    }
+
+    for (auto keepRunning : state) {
+        benchmark::DoNotOptimize(clock->now());
+    }
+
+    if (state.thread_index == 0) {
+        clock.reset();
+    }
+}
+
+BENCHMARK(BM_ClockNow)
+    ->ThreadRange(1,
+                  [] {
+                      ProcessInfo pi;
+                      return static_cast<int>(pi.getNumAvailableCores().value_or(pi.getNumCores()));
+                  }())
+    ->ArgName("poll period")
+    ->Arg(0)
+    ->Arg(1)
+    ->Arg(10);
+
+}  // namespace
+}  // namespace mongo