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rocksdb/util/benchharness.h

407 lines
13 KiB

// Copyright (c) 2013, Facebook, Inc. All rights reserved.
// This source code is licensed under the BSD-style license found in the
// LICENSE file in the root directory of this source tree. An additional grant
// of patent rights can be found in the PATENTS file in the same directory.
//
// This code is derived from Benchmark.h implemented in Folly, the opensourced
// Facebook C++ library available at https://github.com/facebook/folly
// The code has removed any dependence on other folly and boost libraries
#pragma once
#include <gflags/gflags.h>
#include <cassert>
#include <ctime>
#include <functional>
#include <limits>
#include "util/testharness.h"
namespace rocksdb {
namespace benchmark {
/**
* Runs all benchmarks defined. Usually put in main().
*/
void RunBenchmarks();
namespace detail {
/**
* This is the clock ID used for measuring time. On older kernels, the
* resolution of this clock will be very coarse, which will cause the
* benchmarks to fail.
*/
enum Clock { DEFAULT_CLOCK_ID = CLOCK_REALTIME };
/**
* Adds a benchmark wrapped in a std::function. Only used
* internally. Pass by value is intentional.
*/
void AddBenchmarkImpl(const char* file,
const char* name,
std::function<uint64_t(unsigned int)>);
/**
* Takes the difference between two timespec values. end is assumed to
* occur after start.
*/
inline uint64_t TimespecDiff(timespec end, timespec start) {
if (end.tv_sec == start.tv_sec) {
assert(end.tv_nsec >= start.tv_nsec);
return end.tv_nsec - start.tv_nsec;
}
assert(end.tv_sec > start.tv_sec &&
end.tv_sec - start.tv_sec <
std::numeric_limits<uint64_t>::max() / 1000000000UL);
return (end.tv_sec - start.tv_sec) * 1000000000UL
+ end.tv_nsec - start.tv_nsec;
}
/**
* Takes the difference between two sets of timespec values. The first
* two come from a high-resolution clock whereas the other two come
* from a low-resolution clock. The crux of the matter is that
* high-res values may be bogus as documented in
* http://linux.die.net/man/3/clock_gettime. The trouble is when the
* running process migrates from one CPU to another, which is more
* likely for long-running processes. Therefore we watch for high
* differences between the two timings.
*
* This function is subject to further improvements.
*/
inline uint64_t TimespecDiff(timespec end, timespec start,
timespec endCoarse, timespec startCoarse) {
auto fine = TimespecDiff(end, start);
auto coarse = TimespecDiff(endCoarse, startCoarse);
if (coarse - fine >= 1000000) {
// The fine time is in all likelihood bogus
return coarse;
}
return fine;
}
} // namespace detail
/**
* Supporting type for BENCHMARK_SUSPEND defined below.
*/
struct BenchmarkSuspender {
BenchmarkSuspender() {
ASSERT_EQ(0, clock_gettime(detail::DEFAULT_CLOCK_ID, &start_));
}
BenchmarkSuspender(const BenchmarkSuspender &) = delete;
BenchmarkSuspender(BenchmarkSuspender && rhs) {
start_ = rhs.start_;
rhs.start_.tv_nsec = rhs.start_.tv_sec = 0;
}
BenchmarkSuspender& operator=(const BenchmarkSuspender &) = delete;
BenchmarkSuspender& operator=(BenchmarkSuspender && rhs) {
if (start_.tv_nsec > 0 || start_.tv_sec > 0) {
tally();
}
start_ = rhs.start_;
rhs.start_.tv_nsec = rhs.start_.tv_sec = 0;
return *this;
}
~BenchmarkSuspender() {
if (start_.tv_nsec > 0 || start_.tv_sec > 0) {
tally();
}
}
void Dismiss() {
assert(start_.tv_nsec > 0 || start_.tv_sec > 0);
tally();
start_.tv_nsec = start_.tv_sec = 0;
}
void Rehire() {
assert(start_.tv_nsec == 0 || start_.tv_sec == 0);
ASSERT_EQ(0, clock_gettime(detail::DEFAULT_CLOCK_ID, &start_));
}
/**
* This helps the macro definition. To get around the dangers of
* operator bool, returns a pointer to member (which allows no
* arithmetic).
*/
/* implicit */
operator int BenchmarkSuspender::*() const {
return nullptr;
}
/**
* Accumulates nanoseconds spent outside benchmark.
*/
typedef uint64_t NanosecondsSpent;
static NanosecondsSpent nsSpent;
private:
void tally() {
timespec end;
ASSERT_EQ(0, clock_gettime(detail::DEFAULT_CLOCK_ID, &end));
nsSpent += detail::TimespecDiff(end, start_);
start_ = end;
}
timespec start_;
};
/**
* Adds a benchmark. Usually not called directly but instead through
* the macro BENCHMARK defined below. The lambda function involved
* must take exactly one parameter of type unsigned, and the benchmark
* uses it with counter semantics (iteration occurs inside the
* function).
*/
template <typename Lambda>
void
AddBenchmark_n(const char* file, const char* name, Lambda&& lambda) {
auto execute = [=](unsigned int times) -> uint64_t {
BenchmarkSuspender::nsSpent = 0;
timespec start, end;
// CORE MEASUREMENT STARTS
auto const r1 = clock_gettime(detail::DEFAULT_CLOCK_ID, &start);
lambda(times);
auto const r2 = clock_gettime(detail::DEFAULT_CLOCK_ID, &end);
// CORE MEASUREMENT ENDS
ASSERT_EQ(0, r1);
ASSERT_EQ(0, r2);
return detail::TimespecDiff(end, start) - BenchmarkSuspender::nsSpent;
};
detail::AddBenchmarkImpl(file, name,
std::function<uint64_t(unsigned int)>(execute));
}
/**
* Adds a benchmark. Usually not called directly but instead through
* the macro BENCHMARK defined below. The lambda function involved
* must take zero parameters, and the benchmark calls it repeatedly
* (iteration occurs outside the function).
*/
template <typename Lambda>
void
AddBenchmark(const char* file, const char* name, Lambda&& lambda) {
AddBenchmark_n(file, name, [=](unsigned int times) {
while (times-- > 0) {
lambda();
}
});
}
} // namespace benchmark
} // namespace rocksdb
/**
* FB_ONE_OR_NONE(hello, world) expands to hello and
* FB_ONE_OR_NONE(hello) expands to nothing. This macro is used to
* insert or eliminate text based on the presence of another argument.
*/
#define FB_ONE_OR_NONE(a, ...) FB_THIRD(a, ## __VA_ARGS__, a)
#define FB_THIRD(a, b, ...) __VA_ARGS__
#define FB_CONCATENATE_IMPL(s1, s2) s1##s2
#define FB_CONCATENATE(s1, s2) FB_CONCATENATE_IMPL(s1, s2)
#define FB_ANONYMOUS_VARIABLE(str) FB_CONCATENATE(str, __LINE__)
#define FB_STRINGIZE(x) #x
/**
* Introduces a benchmark function. Used internally, see BENCHMARK and
* friends below.
*/
#define BENCHMARK_IMPL_N(funName, stringName, paramType, paramName) \
static void funName(paramType); \
static bool FB_ANONYMOUS_VARIABLE(rocksdbBenchmarkUnused) = ( \
::rocksdb::benchmark::AddBenchmark_n(__FILE__, stringName, \
[](paramType paramName) { funName(paramName); }), \
true); \
static void funName(paramType paramName)
#define BENCHMARK_IMPL(funName, stringName) \
static void funName(); \
static bool FB_ANONYMOUS_VARIABLE(rocksdbBenchmarkUnused) = ( \
::rocksdb::benchmark::AddBenchmark(__FILE__, stringName, \
[]() { funName(); }), \
true); \
static void funName()
/**
* Introduces a benchmark function. Use with either one one or two
* arguments. The first is the name of the benchmark. Use something
* descriptive, such as insertVectorBegin. The second argument may be
* missing, or could be a symbolic counter. The counter dictates how
* many internal iteration the benchmark does. Example:
*
* BENCHMARK(vectorPushBack) {
* vector<int> v;
* v.push_back(42);
* }
*
* BENCHMARK_N(insertVectorBegin, n) {
* vector<int> v;
* FOR_EACH_RANGE (i, 0, n) {
* v.insert(v.begin(), 42);
* }
* }
*/
#define BENCHMARK_N(name, ...) \
BENCHMARK_IMPL_N( \
name, \
FB_STRINGIZE(name), \
FB_ONE_OR_NONE(unsigned, ## __VA_ARGS__), \
__VA_ARGS__)
#define BENCHMARK(name) \
BENCHMARK_IMPL( \
name, \
FB_STRINGIZE(name))
/**
* Defines a benchmark that passes a parameter to another one. This is
* common for benchmarks that need a "problem size" in addition to
* "number of iterations". Consider:
*
* void pushBack(uint n, size_t initialSize) {
* vector<int> v;
* BENCHMARK_SUSPEND {
* v.resize(initialSize);
* }
* FOR_EACH_RANGE (i, 0, n) {
* v.push_back(i);
* }
* }
* BENCHMARK_PARAM(pushBack, 0)
* BENCHMARK_PARAM(pushBack, 1000)
* BENCHMARK_PARAM(pushBack, 1000000)
*
* The benchmark above estimates the speed of push_back at different
* initial sizes of the vector. The framework will pass 0, 1000, and
* 1000000 for initialSize, and the iteration count for n.
*/
#define BENCHMARK_PARAM(name, param) \
BENCHMARK_NAMED_PARAM(name, param, param)
/*
* Like BENCHMARK_PARAM(), but allows a custom name to be specified for each
* parameter, rather than using the parameter value.
*
* Useful when the parameter value is not a valid token for string pasting,
* of when you want to specify multiple parameter arguments.
*
* For example:
*
* void addValue(uint n, int64_t bucketSize, int64_t min, int64_t max) {
* Histogram<int64_t> hist(bucketSize, min, max);
* int64_t num = min;
* FOR_EACH_RANGE (i, 0, n) {
* hist.addValue(num);
* ++num;
* if (num > max) { num = min; }
* }
* }
*
* BENCHMARK_NAMED_PARAM(addValue, 0_to_100, 1, 0, 100)
* BENCHMARK_NAMED_PARAM(addValue, 0_to_1000, 10, 0, 1000)
* BENCHMARK_NAMED_PARAM(addValue, 5k_to_20k, 250, 5000, 20000)
*/
#define BENCHMARK_NAMED_PARAM(name, param_name, ...) \
BENCHMARK_IMPL( \
FB_CONCATENATE(name, FB_CONCATENATE(_, param_name)), \
FB_STRINGIZE(name) "(" FB_STRINGIZE(param_name) ")", \
unsigned, \
iters) { \
name(iters, ## __VA_ARGS__); \
}
/**
* Just like BENCHMARK, but prints the time relative to a
* baseline. The baseline is the most recent BENCHMARK() seen in
* lexical order. Example:
*
* // This is the baseline
* BENCHMARK_N(insertVectorBegin, n) {
* vector<int> v;
* FOR_EACH_RANGE (i, 0, n) {
* v.insert(v.begin(), 42);
* }
* }
*
* BENCHMARK_RELATIVE_N(insertListBegin, n) {
* list<int> s;
* FOR_EACH_RANGE (i, 0, n) {
* s.insert(s.begin(), 42);
* }
* }
*
* Any number of relative benchmark can be associated with a
* baseline. Another BENCHMARK() occurrence effectively establishes a
* new baseline.
*/
#define BENCHMARK_RELATIVE_N(name, ...) \
BENCHMARK_IMPL_N( \
name, \
"%" FB_STRINGIZE(name), \
FB_ONE_OR_NONE(unsigned, ## __VA_ARGS__), \
__VA_ARGS__)
#define BENCHMARK_RELATIVE(name) \
BENCHMARK_IMPL( \
name, \
"%" FB_STRINGIZE(name))
/**
* A combination of BENCHMARK_RELATIVE and BENCHMARK_PARAM.
*/
#define BENCHMARK_RELATIVE_PARAM(name, param) \
BENCHMARK_RELATIVE_NAMED_PARAM(name, param, param)
/**
* A combination of BENCHMARK_RELATIVE and BENCHMARK_NAMED_PARAM.
*/
#define BENCHMARK_RELATIVE_NAMED_PARAM(name, param_name, ...) \
BENCHMARK_IMPL( \
FB_CONCATENATE(name, FB_CONCATENATE(_, param_name)), \
"%" FB_STRINGIZE(name) "(" FB_STRINGIZE(param_name) ")", \
unsigned, \
iters) { \
name(iters, ## __VA_ARGS__); \
}
/**
* Draws a line of dashes.
*/
#define BENCHMARK_DRAW_LINE() \
static bool FB_ANONYMOUS_VARIABLE(rocksdbBenchmarkUnused) = ( \
::rocksdb::benchmark::AddBenchmark(__FILE__, "-", []() { }), \
true);
/**
* Allows execution of code that doesn't count torward the benchmark's
* time budget. Example:
*
* BENCHMARK_START_GROUP(insertVectorBegin, n) {
* vector<int> v;
* BENCHMARK_SUSPEND {
* v.reserve(n);
* }
* FOR_EACH_RANGE (i, 0, n) {
* v.insert(v.begin(), 42);
* }
* }
*/
#define BENCHMARK_SUSPEND \
if (auto FB_ANONYMOUS_VARIABLE(BENCHMARK_SUSPEND) = \
::rocksdb::benchmark::BenchmarkSuspender()) {} \
else