SERVER-55056 benchmark for Status

Also try variations of boost::intrusive_ptr behavior relevant to Status.

2 files changed, 136 insertions, 0 deletions

diff --git a/src/mongo/base/SConscript b/src/mongo/base/SConscript
index 7909ef0c396..fff7782f2a2 100644
--- a/src/mongo/base/SConscript
+++ b/src/mongo/base/SConscript
@@ -103,3 +103,14 @@ env.CppUnitTest(
         'system_error',
     ],
 )
+
+env.Benchmark(
+    target='status_bm',
+    source=[
+        'status_bm.cpp',
+    ],
+    LIBDEPS=[
+        '$BUILD_DIR/mongo/util/processinfo',
+    ],
+)
+
diff --git a/src/mongo/base/status_bm.cpp b/src/mongo/base/status_bm.cpp
new file mode 100644
index 00000000000..c59cc5b20d0
--- /dev/null
+++ b/src/mongo/base/status_bm.cpp
@@ -0,0 +1,125 @@
+/**
+ *    Copyright (C) 2021-present MongoDB, Inc.
+ *
+ *    This program is free software: you can redistribute it and/or modify
+ *    it under the terms of the Server Side Public License, version 1,
+ *    as published by MongoDB, Inc.
+ *
+ *    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
+ *    Server Side Public License for more details.
+ *
+ *    You should have received a copy of the Server Side Public License
+ *    along with this program. If not, see
+ *    <http://www.mongodb.com/licensing/server-side-public-license>.
+ *
+ *    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 Server Side 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 <benchmark/benchmark.h>
+
+#include <algorithm>
+#include <string>
+#include <vector>
+
+#include <boost/intrusive_ptr.hpp>
+
+#include "mongo/base/status.h"
+#include "mongo/base/string_data.h"
+#include "mongo/util/processinfo.h"
+
+namespace mongo {
+namespace {
+
+/**
+ * Construct and destroy OK
+ */
+void BM_StatusCtorDtorOK(benchmark::State& state) {
+    for (auto _ : state) {
+        benchmark::DoNotOptimize(Status::OK());
+    }
+}
+
+BENCHMARK(BM_StatusCtorDtorOK);
+
+/**
+ * Construct and destroy
+ */
+void BM_StatusCtorDtor(benchmark::State& state) {
+    for (auto _ : state) {
+        benchmark::DoNotOptimize(
+            Status(ErrorCodes::Error::InternalError, "A reasonably long reason"));
+    }
+}
+
+BENCHMARK(BM_StatusCtorDtor);
+
+
+/**
+ * Copying an uncontended Status object once.
+ */
+void BM_StatusRefUnref(benchmark::State& state) {
+    static Status s(ErrorCodes::Error::InternalError, "A reasonably long reason");
+    for (auto _ : state) {
+        benchmark::DoNotOptimize(Status(s));
+    }
+}
+
+BENCHMARK(BM_StatusRefUnref)->ThreadRange(1, 4);
+
+template <typename D>
+struct TestRefCountable {
+    friend void intrusive_ptr_add_ref(const TestRefCountable* ptr) {
+        ptr->_count.fetch_add(1, std::memory_order_relaxed);
+    };
+
+    friend void intrusive_ptr_release(const TestRefCountable* ptr) {
+        if (ptr->_count.fetch_sub(1, std::memory_order_acq_rel) == 1)
+            delete static_cast<const D*>(ptr);
+    };
+
+    mutable std::atomic<uint32_t> _count;  // NOLINT
+};
+
+struct Nonpolymorphic : TestRefCountable<Nonpolymorphic> {};
+
+struct Polymorphic : TestRefCountable<Polymorphic> {
+    virtual ~Polymorphic() = default;
+};
+
+void BM_NonpolymorphicRefUnref(benchmark::State& state) {
+    static boost::intrusive_ptr<Nonpolymorphic> s{new Nonpolymorphic{}};
+    for (auto _ : state) {
+        benchmark::DoNotOptimize(boost::intrusive_ptr<Nonpolymorphic>{s});
+    }
+}
+
+BENCHMARK(BM_NonpolymorphicRefUnref)->ThreadRange(1, 4);
+
+/**
+ * Curious: Does a virtual dtor mean a slower ref/unref cycle?
+ * The count is then at offset 8 rather than 0, so maybe!
+ */
+void BM_PolymorphicRefUnref(benchmark::State& state) {
+    static boost::intrusive_ptr<Polymorphic> s{new Polymorphic{}};
+    for (auto _ : state) {
+        benchmark::DoNotOptimize(boost::intrusive_ptr<Polymorphic>{s});
+    }
+}
+
+BENCHMARK(BM_PolymorphicRefUnref)->ThreadRange(1, 4);
+
+
+}  // namespace
+}  // namespace mongo