Refactor the benchmark code.

Changes:
- Modify the benchmarks to derive from a single Benchmark object.
- Rewrite the main iteration code. This includes changing the iteration
  code to use the actual total time calculated by the benchmark as a basis
  for determining whether there are enough iterations instead of using
  the time it takes to run the benchmark.
- Allow benchmarks to take no argument, int, or double.
- Fix the PrettyInt printer for negative integers.
- Modify the max column width name to include the whole name including
  the arg part.
- Reformat property_benchmark.cpp in line with the rest of the code.
- Modify a few of the math benchmarks to take an argument instead of
  separate benchmarks for the same function with different args.
- Create a vector of regex_t structs to represent the args all at
  once instead of when running each benchmark.

This change is in preparation for adding new math based benchmarks.

Tested by running on a nexus flo running at max using the new code
and the old code and comparing. All of the numbers are similar, but
some of the iterations are different due to the slightly different
algorithm used.

Change-Id: I57ad1f3ff083282b9ffeb72e687cab369ce3523a

1 files changed, 154 insertions, 0 deletions

diff --git a/benchmarks/benchmark/Benchmark.h b/benchmarks/benchmark/Benchmark.h
new file mode 100644
index 0000000..7c208e6
--- /dev/null
+++ b/benchmarks/benchmark/Benchmark.h
@@ -0,0 +1,154 @@
+/*
+ * Copyright (C) 2012 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef BENCHMARKS_BENCHMARK_H_
+#define BENCHMARKS_BENCHMARK_H_
+
+#include <regex.h>
+#include <stdint.h>
+
+#include <string>
+#include <vector>
+
+namespace testing {
+
+class Benchmark {
+public:
+  Benchmark() {
+    List().push_back(this);
+  }
+  virtual ~Benchmark() {}
+
+  virtual std::string Name() = 0;
+
+  virtual void RunAll() = 0;
+
+  bool ShouldRun(std::vector<regex_t*>&);
+
+  void SetBenchmarkBytesProcessed(uint64_t bytes) { bytes_processed_ += bytes; }
+  void StopBenchmarkTiming();
+  void StartBenchmarkTiming();
+
+  // Run all of the benchmarks that have registered.
+  static bool RunAll(std::vector<regex_t*>&);
+
+  static std::vector<Benchmark*>& List();
+
+  static size_t MaxNameColumnWidth();
+
+protected:
+  virtual size_t NameColumnWidth() = 0;
+
+  uint64_t bytes_processed_;
+  uint64_t total_time_ns_;
+  uint64_t start_time_ns_;
+};
+
+template <typename T>
+class BenchmarkT : public Benchmark {
+public:
+  BenchmarkT() {}
+  virtual ~BenchmarkT() {}
+
+protected:
+  void RunWithArg(T arg);
+  virtual void RunIterations(int, T) = 0;
+  virtual std::string GetNameStr(T) = 0;
+};
+
+class BenchmarkWithoutArg : public BenchmarkT<void*> {
+public:
+  BenchmarkWithoutArg() {}
+  virtual ~BenchmarkWithoutArg() {}
+
+protected:
+  virtual void RunAll() override {
+    RunWithArg(nullptr);
+  }
+
+  virtual void RunIterations(int iters, void*) override {
+    Run(iters);
+  }
+
+  virtual void Run(int) = 0;
+
+  virtual size_t NameColumnWidth() override {
+    return Name().size();
+  }
+
+  virtual std::string GetNameStr(void *) override;
+};
+
+template<typename T>
+class BenchmarkWithArg : public BenchmarkT<T> {
+public:
+  BenchmarkWithArg() {}
+  virtual ~BenchmarkWithArg() {}
+
+  BenchmarkWithArg* Arg(T arg) {
+    args_.push_back(arg);
+    return this;
+  }
+
+protected:
+  virtual size_t NameColumnWidth() override {
+    size_t max = 0;
+    for (const auto arg : args_) {
+      max = std::max(max, GetNameStr(arg).size());
+    }
+    return max;
+  }
+
+  std::string GetNameStr(T arg) override;
+
+  virtual void RunAll() override {
+    for (T arg : args_) {
+      BenchmarkT<T>::RunWithArg(arg);
+    }
+  }
+
+  virtual void RunIterations(int iters, T arg) override {
+    Run(iters, arg);
+  }
+
+  virtual void Run(int iters, T arg) = 0;
+
+private:
+  std::vector<T> args_;
+};
+
+}  // namespace testing
+
+#define BENCHMARK_START(f, super_class) \
+  class f : public super_class { \
+  public: \
+    f() {} \
+    virtual ~f() {} \
+    virtual std::string Name() override { return #f; } \
+
+#define BENCHMARK_NO_ARG(f) \
+  BENCHMARK_START(f, ::testing::BenchmarkWithoutArg) \
+    virtual void Run(int) override; \
+  }; \
+  static ::testing::Benchmark* __benchmark_##f = new f()
+
+#define BENCHMARK_WITH_ARG(f, arg_type) \
+  BENCHMARK_START(f, ::testing::BenchmarkWithArg<arg_type>) \
+    virtual void Run(int, arg_type) override; \
+  }; \
+  static ::testing::BenchmarkWithArg<arg_type>* __benchmark_##f = (new f())
+
+#endif  // BENCHMARKS_BENCHMARK_H_