rocksdb/monitoring/iostats_context_imp.h
Yanqin Jin fd00f39f97 Disable IOStatsContext/PerfContext if no thread local (#8117)
Summary:
Before this PR, `get_iostats_context()` will silently return a nullptr if no thread_local support is detected.
This can be the result of build_detect_platform's failure to compile the simple code snippet on certain platforms, as
reported in https://github.com/facebook/mysql-5.6/issues/904.
To be safe, we should fail the compilation if user does not opt out IOStatsContext and
ROCKSDB_SUPPORT_THREAD_LOCAL is not defined.

If RocksDB relies on c++11, can we just always use thread_local? It turns out there might be
performance concerns (https://github.com/facebook/rocksdb/issues/5774),
which is beyond the scope of this PR. We can revisit this later. Here, we stick to the original impl.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8117

Reviewed By: ajkr

Differential Revision: D27356847

Pulled By: riversand963

fbshipit-source-id: f7d5776842277598d8341b955febb601946801ae
2021-04-13 07:56:59 -07:00

61 lines
2.2 KiB
C++

// Copyright (c) 2011-present, Facebook, Inc. All rights reserved.
// This source code is licensed under both the GPLv2 (found in the
// COPYING file in the root directory) and Apache 2.0 License
// (found in the LICENSE.Apache file in the root directory).
//
#pragma once
#include "monitoring/perf_step_timer.h"
#include "rocksdb/iostats_context.h"
#if defined(ROCKSDB_SUPPORT_THREAD_LOCAL) && !defined(NIOSTATS_CONTEXT)
namespace ROCKSDB_NAMESPACE {
extern __thread IOStatsContext iostats_context;
} // namespace ROCKSDB_NAMESPACE
// increment a specific counter by the specified value
#define IOSTATS_ADD(metric, value) (iostats_context.metric += value)
// Increase metric value only when it is positive
#define IOSTATS_ADD_IF_POSITIVE(metric, value) \
if (value > 0) { IOSTATS_ADD(metric, value); }
// reset a specific counter to zero
#define IOSTATS_RESET(metric) (iostats_context.metric = 0)
// reset all counters to zero
#define IOSTATS_RESET_ALL() (iostats_context.Reset())
#define IOSTATS_SET_THREAD_POOL_ID(value) \
(iostats_context.thread_pool_id = value)
#define IOSTATS_THREAD_POOL_ID() (iostats_context.thread_pool_id)
#define IOSTATS(metric) (iostats_context.metric)
// Declare and set start time of the timer
#define IOSTATS_TIMER_GUARD(metric) \
PerfStepTimer iostats_step_timer_##metric(&(iostats_context.metric)); \
iostats_step_timer_##metric.Start();
// Declare and set start time of the timer
#define IOSTATS_CPU_TIMER_GUARD(metric, clock) \
PerfStepTimer iostats_step_timer_##metric( \
&(iostats_context.metric), clock, true, \
PerfLevel::kEnableTimeAndCPUTimeExceptForMutex); \
iostats_step_timer_##metric.Start();
#else // ROCKSDB_SUPPORT_THREAD_LOCAL && !NIOSTATS_CONTEXT
#define IOSTATS_ADD(metric, value)
#define IOSTATS_ADD_IF_POSITIVE(metric, value)
#define IOSTATS_RESET(metric)
#define IOSTATS_RESET_ALL()
#define IOSTATS_SET_THREAD_POOL_ID(value)
#define IOSTATS_THREAD_POOL_ID()
#define IOSTATS(metric) 0
#define IOSTATS_TIMER_GUARD(metric)
#define IOSTATS_CPU_TIMER_GUARD(metric, clock) static_cast<void>(clock)
#endif // ROCKSDB_SUPPORT_THREAD_LOCAL && !NIOSTATS_CONTEXT