mirror of
https://github.com/facebook/rocksdb
synced 2026-05-24 09:29:21 +00:00
6614a48418
This eliminates the need to remember to call PERF_TIMER_STOP when a section has
been timed. This allows more useful design with the perf timers and enables
possible return value optimizations. Simplistic example:
class Foo {
public:
Foo(int v) : m_v(v);
private:
int m_v;
}
Foo makeFrobbedFoo(int *errno)
{
*errno = 0;
return Foo();
}
Foo bar(int *errno)
{
PERF_TIMER_GUARD(some_timer);
return makeFrobbedFoo(errno);
}
int main(int argc, char[] argv)
{
Foo f;
int errno;
f = bar(&errno);
if (errno)
return -1;
return 0;
}
After bar() is called, perf_context.some_timer would be incremented as if
Stop(&perf_context.some_timer) was called at the end, and the compiler is still
able to produce optimizations on the return value from makeFrobbedFoo() through
to main().
88 lines
2 KiB
C++
88 lines
2 KiB
C++
// 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.
|
|
//
|
|
#pragma once
|
|
#include "rocksdb/perf_context.h"
|
|
#include "util/stop_watch.h"
|
|
|
|
namespace rocksdb {
|
|
|
|
#if defined(NPERF_CONTEXT) || defined(IOS_CROSS_COMPILE)
|
|
|
|
#define PERF_TIMER_GUARD(metric)
|
|
#define PERF_TIMER_MEASURE(metric)
|
|
#define PERF_TIMER_STOP(metric)
|
|
#define PERF_TIMER_START(metric)
|
|
#define PERF_COUNTER_ADD(metric, value)
|
|
|
|
#else
|
|
|
|
extern __thread PerfLevel perf_level;
|
|
|
|
class PerfStepTimer {
|
|
public:
|
|
PerfStepTimer(uint64_t* metric)
|
|
: enabled_(perf_level >= PerfLevel::kEnableTime),
|
|
env_(enabled_ ? Env::Default() : nullptr),
|
|
start_(0),
|
|
metric_(metric) {
|
|
}
|
|
|
|
~PerfStepTimer() {
|
|
Stop();
|
|
}
|
|
|
|
void Start() {
|
|
if (enabled_) {
|
|
start_ = env_->NowNanos();
|
|
}
|
|
}
|
|
|
|
void Measure() {
|
|
if (start_) {
|
|
uint64_t now = env_->NowNanos();
|
|
*metric_ += now - start_;
|
|
start_ = now;
|
|
}
|
|
}
|
|
|
|
void Stop() {
|
|
if (start_) {
|
|
*metric_ += env_->NowNanos() - start_;
|
|
start_ = 0;
|
|
}
|
|
}
|
|
|
|
private:
|
|
const bool enabled_;
|
|
Env* const env_;
|
|
uint64_t start_;
|
|
uint64_t* metric_;
|
|
};
|
|
|
|
// Stop the timer and update the metric
|
|
#define PERF_TIMER_STOP(metric) \
|
|
perf_step_timer_ ## metric.Stop();
|
|
|
|
#define PERF_TIMER_START(metric) \
|
|
perf_step_timer_ ## metric.Start();
|
|
|
|
// Declare and set start time of the timer
|
|
#define PERF_TIMER_GUARD(metric) \
|
|
PerfStepTimer perf_step_timer_ ## metric(&(perf_context.metric)); \
|
|
perf_step_timer_ ## metric.Start();
|
|
|
|
// Update metric with time elapsed since last START. start time is reset
|
|
// to current timestamp.
|
|
#define PERF_TIMER_MEASURE(metric) \
|
|
perf_step_timer_ ## metric.Measure();
|
|
|
|
// Increase metric value
|
|
#define PERF_COUNTER_ADD(metric, value) \
|
|
perf_context.metric += value;
|
|
|
|
#endif
|
|
|
|
}
|