Use generic threadpool for Windows environment (#1120)

Conditionally retrofit thread_posix for use with std::thread
  and reuse the same logic. Posix users continue using Posix interfaces.
  Enable XPRESS compression in test runs.
  Fix master introduced signed/unsigned mismatch.
This commit is contained in:
Dmitri Smirnov 2016-05-12 18:34:04 -07:00 committed by Andrew Kryczka
parent a400336398
commit aab91b8d8f
7 changed files with 182 additions and 292 deletions

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@ -237,6 +237,7 @@ set(SOURCES
util/testharness.cc util/testharness.cc
util/testutil.cc util/testutil.cc
util/thread_local.cc util/thread_local.cc
util/threadpool.cc
util/thread_status_impl.cc util/thread_status_impl.cc
util/thread_status_updater.cc util/thread_status_updater.cc
util/thread_status_util.cc util/thread_status_util.cc

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@ -2,7 +2,7 @@ version: 1.0.{build}
before_build: before_build:
- md %APPVEYOR_BUILD_FOLDER%\build - md %APPVEYOR_BUILD_FOLDER%\build
- cd %APPVEYOR_BUILD_FOLDER%\build - cd %APPVEYOR_BUILD_FOLDER%\build
- cmake -G "Visual Studio 12 Win64" -DOPTDBG=1 .. - cmake -G "Visual Studio 12 Win64" -DOPTDBG=1 -DXPRESS=1 ..
- cd .. - cd ..
build: build:
project: build\rocksdb.sln project: build\rocksdb.sln
@ -10,6 +10,6 @@ build:
verbosity: minimal verbosity: minimal
test: test:
test_script: test_script:
- ps: build_tools\run_ci_db_test.ps1 -EnableRerun -Run db_test -Exclude DBTest.Randomized,DBTest.FileCreationRandomFailure -Concurrency 18 - ps: build_tools\run_ci_db_test.ps1 -EnableRerun -Run db_test -Concurrency 10
- ps: build_tools\run_ci_db_test.ps1 -Run env_test -Concurrency 1 - ps: build_tools\run_ci_db_test.ps1 -Run env_test -Concurrency 1

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@ -32,6 +32,7 @@
#include "util/sync_point.h" #include "util/sync_point.h"
#include "util/aligned_buffer.h" #include "util/aligned_buffer.h"
#include "util/threadpool.h"
#include "util/thread_status_updater.h" #include "util/thread_status_updater.h"
#include "util/thread_status_util.h" #include "util/thread_status_util.h"
@ -1834,257 +1835,6 @@ class WinEnv : public Env {
bool SupportsFastAllocate(const std::string& /* path */) { return false; } bool SupportsFastAllocate(const std::string& /* path */) { return false; }
class ThreadPool {
public:
ThreadPool()
: total_threads_limit_(1),
bgthreads_(0),
queue_(),
queue_len_(0U),
exit_all_threads_(false),
low_io_priority_(false),
env_(nullptr) {}
~ThreadPool() { assert(bgthreads_.size() == 0U); }
void JoinAllThreads() {
{
std::lock_guard<std::mutex> lock(mu_);
assert(!exit_all_threads_);
exit_all_threads_ = true;
bgsignal_.notify_all();
}
for (std::thread& th : bgthreads_) {
th.join();
}
// Subject to assert in the __dtor
bgthreads_.clear();
}
void SetHostEnv(Env* env) { env_ = env; }
// Return true if there is at least one thread needs to terminate.
bool HasExcessiveThread() const {
return bgthreads_.size() > total_threads_limit_;
}
// Return true iff the current thread is the excessive thread to terminate.
// Always terminate the running thread that is added last, even if there are
// more than one thread to terminate.
bool IsLastExcessiveThread(size_t thread_id) const {
return HasExcessiveThread() && thread_id == bgthreads_.size() - 1;
}
// Is one of the threads to terminate.
bool IsExcessiveThread(size_t thread_id) const {
return thread_id >= total_threads_limit_;
}
// Return the thread priority.
// This would allow its member-thread to know its priority.
Env::Priority GetThreadPriority() { return priority_; }
// Set the thread priority.
void SetThreadPriority(Env::Priority priority) { priority_ = priority; }
void BGThread(size_t thread_id) {
while (true) {
// Wait until there is an item that is ready to run
std::unique_lock<std::mutex> uniqueLock(mu_);
// Stop waiting if the thread needs to do work or needs to terminate.
while (!exit_all_threads_ && !IsLastExcessiveThread(thread_id) &&
(queue_.empty() || IsExcessiveThread(thread_id))) {
bgsignal_.wait(uniqueLock);
}
if (exit_all_threads_) {
// mechanism to let BG threads exit safely
uniqueLock.unlock();
break;
}
if (IsLastExcessiveThread(thread_id)) {
// Current thread is the last generated one and is excessive.
// We always terminate excessive thread in the reverse order of
// generation time.
std::thread& terminating_thread = bgthreads_.back();
auto tid = terminating_thread.get_id();
// Ensure that this thread is ours
assert(tid == std::this_thread::get_id());
terminating_thread.detach();
bgthreads_.pop_back();
if (HasExcessiveThread()) {
// There is still at least more excessive thread to terminate.
WakeUpAllThreads();
}
uniqueLock.unlock();
PrintThreadInfo(thread_id, gettid());
break;
}
void (*function)(void*) = queue_.front().function;
void* arg = queue_.front().arg;
queue_.pop_front();
queue_len_.store(queue_.size(), std::memory_order_relaxed);
uniqueLock.unlock();
(*function)(arg);
}
}
// Helper struct for passing arguments when creating threads.
struct BGThreadMetadata {
ThreadPool* thread_pool_;
size_t thread_id_; // Thread count in the thread.
BGThreadMetadata(ThreadPool* thread_pool, size_t thread_id)
: thread_pool_(thread_pool), thread_id_(thread_id) {}
};
static void* BGThreadWrapper(void* arg) {
std::unique_ptr<BGThreadMetadata> meta(
reinterpret_cast<BGThreadMetadata*>(arg));
size_t thread_id = meta->thread_id_;
ThreadPool* tp = meta->thread_pool_;
#if ROCKSDB_USING_THREAD_STATUS
// for thread-status
ThreadStatusUtil::RegisterThread(
tp->env_, (tp->GetThreadPriority() == Env::Priority::HIGH
? ThreadStatus::HIGH_PRIORITY
: ThreadStatus::LOW_PRIORITY));
#endif
tp->BGThread(thread_id);
#if ROCKSDB_USING_THREAD_STATUS
ThreadStatusUtil::UnregisterThread();
#endif
return nullptr;
}
void WakeUpAllThreads() { bgsignal_.notify_all(); }
void SetBackgroundThreadsInternal(size_t num, bool allow_reduce) {
std::lock_guard<std::mutex> lg(mu_);
if (exit_all_threads_) {
return;
}
if (num > total_threads_limit_ ||
(num < total_threads_limit_ && allow_reduce)) {
total_threads_limit_ = std::max(size_t(1), num);
WakeUpAllThreads();
StartBGThreads();
}
assert(total_threads_limit_ > 0);
}
void IncBackgroundThreadsIfNeeded(int num) {
SetBackgroundThreadsInternal(num, false);
}
void SetBackgroundThreads(int num) {
SetBackgroundThreadsInternal(num, true);
}
void StartBGThreads() {
// Start background thread if necessary
while (bgthreads_.size() < total_threads_limit_) {
std::thread p_t(&ThreadPool::BGThreadWrapper,
new BGThreadMetadata(this, bgthreads_.size()));
bgthreads_.push_back(std::move(p_t));
}
}
void Schedule(void (*function)(void* arg1), void* arg, void* tag,
void (*unschedFunction)(void* arg)) {
std::lock_guard<std::mutex> lg(mu_);
if (exit_all_threads_) {
return;
}
StartBGThreads();
// Add to priority queue
queue_.push_back(BGItem());
queue_.back().function = function;
queue_.back().arg = arg;
queue_.back().tag = tag;
queue_.back().unschedFunction = unschedFunction;
queue_len_.store(queue_.size(), std::memory_order_relaxed);
if (!HasExcessiveThread()) {
// Wake up at least one waiting thread.
bgsignal_.notify_one();
} else {
// Need to wake up all threads to make sure the one woken
// up is not the one to terminate.
WakeUpAllThreads();
}
}
int UnSchedule(void* arg) {
int count = 0;
std::lock_guard<std::mutex> lg(mu_);
// Remove from priority queue
BGQueue::iterator it = queue_.begin();
while (it != queue_.end()) {
if (arg == (*it).tag) {
void (*unschedFunction)(void*) = (*it).unschedFunction;
void* arg1 = (*it).arg;
if (unschedFunction != nullptr) {
(*unschedFunction)(arg1);
}
it = queue_.erase(it);
count++;
} else {
++it;
}
}
queue_len_.store(queue_.size(), std::memory_order_relaxed);
return count;
}
unsigned int GetQueueLen() const {
return static_cast<unsigned int>(
queue_len_.load(std::memory_order_relaxed));
}
private:
// Entry per Schedule() call
struct BGItem {
void* arg;
void (*function)(void*);
void* tag;
void (*unschedFunction)(void*);
};
typedef std::deque<BGItem> BGQueue;
std::mutex mu_;
std::condition_variable bgsignal_;
size_t total_threads_limit_;
std::vector<std::thread> bgthreads_;
BGQueue queue_;
std::atomic_size_t queue_len_; // Queue length. Used for stats reporting
bool exit_all_threads_;
bool low_io_priority_;
Env::Priority priority_;
Env* env_;
};
bool checkedDiskForMmap_; bool checkedDiskForMmap_;
bool forceMmapOff; // do we override Env options? bool forceMmapOff; // do we override Env options?
size_t page_size_; size_t page_size_;

2
src.mk
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@ -101,7 +101,7 @@ LIB_SOURCES = \
util/env_hdfs.cc \ util/env_hdfs.cc \
util/env_posix.cc \ util/env_posix.cc \
util/io_posix.cc \ util/io_posix.cc \
util/thread_posix.cc \ util/threadpool.cc \
util/transaction_test_util.cc \ util/transaction_test_util.cc \
util/sst_file_manager_impl.cc \ util/sst_file_manager_impl.cc \
util/file_util.cc \ util/file_util.cc \

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@ -42,7 +42,7 @@
#include "rocksdb/slice.h" #include "rocksdb/slice.h"
#include "util/coding.h" #include "util/coding.h"
#include "util/io_posix.h" #include "util/io_posix.h"
#include "util/thread_posix.h" #include "util/threadpool.h"
#include "util/iostats_context_imp.h" #include "util/iostats_context_imp.h"
#include "util/logging.h" #include "util/logging.h"
#include "util/posix_logger.h" #include "util/posix_logger.h"

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@ -7,11 +7,16 @@
// Use of this source code is governed by a BSD-style license that can be // Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file. See the AUTHORS file for names of contributors. // found in the LICENSE file. See the AUTHORS file for names of contributors.
#include "util/thread_posix.h" #include "util/threadpool.h"
#include <atomic> #include <atomic>
#include <unistd.h> #include <algorithm>
#ifndef OS_WIN
# include <unistd.h>
#endif
#ifdef OS_LINUX #ifdef OS_LINUX
#include <sys/syscall.h> # include <sys/syscall.h>
#endif #endif
namespace rocksdb { namespace rocksdb {
@ -23,29 +28,128 @@ void ThreadPool::PthreadCall(const char* label, int result) {
} }
} }
namespace {
#ifdef ROCKSDB_STD_THREADPOOL
struct Lock {
std::unique_lock<std::mutex> ul_;
Lock(std::mutex& m) : ul_(m, std::defer_lock) {}
};
using Condition = std::condition_variable;
inline
int MutexLock(Lock& mutex) {
mutex.ul_.lock();
return 0;
}
inline
int ConditionWait(Condition& condition, Lock& lock) {
condition.wait(lock.ul_);
return 0;
}
inline
int ConditionSignalAll(Condition& condition) {
condition.notify_all();
return 0;
}
inline
int ConditionSignal(Condition& condition) {
condition.notify_one();
return 0;
}
inline
int MutexUnlock(Lock& mutex) {
mutex.ul_.unlock();
return 0;
}
inline
void ThreadJoin(std::thread& thread) {
thread.join();
}
inline
int ThreadDetach(std::thread& thread) {
thread.detach();
return 0;
}
#else
using Lock = pthread_mutex_t&;
using Condition = pthread_cond_t&;
inline
int MutexLock(Lock mutex) {
return pthread_mutex_lock(&mutex);
}
inline
int ConditionWait(Condition condition, Lock lock) {
return pthread_cond_wait(&condition, &lock);
}
inline
int ConditionSignalAll(Condition condition) {
return pthread_cond_broadcast(&condition);
}
inline
int ConditionSignal(Condition condition) {
return pthread_cond_signal(&condition);
}
inline
int MutexUnlock(Lock mutex) {
return pthread_mutex_unlock(&mutex);
}
inline
void ThreadJoin(pthread_t& thread) {
pthread_join(thread, nullptr);
}
inline
int ThreadDetach(pthread_t& thread) {
return pthread_detach(thread);
}
#endif
}
ThreadPool::ThreadPool() ThreadPool::ThreadPool()
: total_threads_limit_(1), : total_threads_limit_(1),
bgthreads_(0), bgthreads_(0),
queue_(), queue_(),
queue_len_(0), queue_len_(),
exit_all_threads_(false), exit_all_threads_(false),
low_io_priority_(false), low_io_priority_(false),
env_(nullptr) { env_(nullptr) {
#ifndef ROCKSDB_STD_THREADPOOL
PthreadCall("mutex_init", pthread_mutex_init(&mu_, nullptr)); PthreadCall("mutex_init", pthread_mutex_init(&mu_, nullptr));
PthreadCall("cvar_init", pthread_cond_init(&bgsignal_, nullptr)); PthreadCall("cvar_init", pthread_cond_init(&bgsignal_, nullptr));
#endif
} }
ThreadPool::~ThreadPool() { assert(bgthreads_.size() == 0U); } ThreadPool::~ThreadPool() { assert(bgthreads_.size() == 0U); }
void ThreadPool::JoinAllThreads() { void ThreadPool::JoinAllThreads() {
PthreadCall("lock", pthread_mutex_lock(&mu_));
Lock lock(mu_);
PthreadCall("lock", MutexLock(lock));
assert(!exit_all_threads_); assert(!exit_all_threads_);
exit_all_threads_ = true; exit_all_threads_ = true;
PthreadCall("signalall", pthread_cond_broadcast(&bgsignal_)); PthreadCall("signalall", ConditionSignalAll(bgsignal_));
PthreadCall("unlock", pthread_mutex_unlock(&mu_)); PthreadCall("unlock", MutexUnlock(lock));
for (const auto tid : bgthreads_) {
pthread_join(tid, nullptr); for (auto& th : bgthreads_) {
ThreadJoin(th);
} }
bgthreads_.clear(); bgthreads_.clear();
} }
@ -60,31 +164,35 @@ void ThreadPool::LowerIOPriority() {
void ThreadPool::BGThread(size_t thread_id) { void ThreadPool::BGThread(size_t thread_id) {
bool low_io_priority = false; bool low_io_priority = false;
while (true) { while (true) {
// Wait until there is an item that is ready to run // Wait until there is an item that is ready to run
PthreadCall("lock", pthread_mutex_lock(&mu_)); Lock uniqueLock(mu_);
PthreadCall("lock", MutexLock(uniqueLock));
// Stop waiting if the thread needs to do work or needs to terminate. // Stop waiting if the thread needs to do work or needs to terminate.
while (!exit_all_threads_ && !IsLastExcessiveThread(thread_id) && while (!exit_all_threads_ && !IsLastExcessiveThread(thread_id) &&
(queue_.empty() || IsExcessiveThread(thread_id))) { (queue_.empty() || IsExcessiveThread(thread_id))) {
PthreadCall("wait", pthread_cond_wait(&bgsignal_, &mu_)); PthreadCall("wait", ConditionWait(bgsignal_, uniqueLock));
} }
if (exit_all_threads_) { // mechanism to let BG threads exit safely if (exit_all_threads_) { // mechanism to let BG threads exit safely
PthreadCall("unlock", pthread_mutex_unlock(&mu_)); PthreadCall("unlock", MutexUnlock(uniqueLock));
break; break;
} }
if (IsLastExcessiveThread(thread_id)) { if (IsLastExcessiveThread(thread_id)) {
// Current thread is the last generated one and is excessive. // Current thread is the last generated one and is excessive.
// We always terminate excessive thread in the reverse order of // We always terminate excessive thread in the reverse order of
// generation time. // generation time.
auto terminating_thread = bgthreads_.back(); auto& terminating_thread = bgthreads_.back();
pthread_detach(terminating_thread); PthreadCall("detach", ThreadDetach(terminating_thread));
bgthreads_.pop_back(); bgthreads_.pop_back();
if (HasExcessiveThread()) { if (HasExcessiveThread()) {
// There is still at least more excessive thread to terminate. // There is still at least more excessive thread to terminate.
WakeUpAllThreads(); WakeUpAllThreads();
} }
PthreadCall("unlock", pthread_mutex_unlock(&mu_)); PthreadCall("unlock", MutexUnlock(uniqueLock));
break; break;
} }
void (*function)(void*) = queue_.front().function; void (*function)(void*) = queue_.front().function;
void* arg = queue_.front().arg; void* arg = queue_.front().arg;
queue_.pop_front(); queue_.pop_front();
@ -92,7 +200,7 @@ void ThreadPool::BGThread(size_t thread_id) {
std::memory_order_relaxed); std::memory_order_relaxed);
bool decrease_io_priority = (low_io_priority != low_io_priority_); bool decrease_io_priority = (low_io_priority != low_io_priority_);
PthreadCall("unlock", pthread_mutex_unlock(&mu_)); PthreadCall("unlock", MutexUnlock(uniqueLock));
#ifdef OS_LINUX #ifdef OS_LINUX
if (decrease_io_priority) { if (decrease_io_priority) {
@ -124,7 +232,7 @@ void ThreadPool::BGThread(size_t thread_id) {
struct BGThreadMetadata { struct BGThreadMetadata {
ThreadPool* thread_pool_; ThreadPool* thread_pool_;
size_t thread_id_; // Thread count in the thread. size_t thread_id_; // Thread count in the thread.
explicit BGThreadMetadata(ThreadPool* thread_pool, size_t thread_id) BGThreadMetadata(ThreadPool* thread_pool, size_t thread_id)
: thread_pool_(thread_pool), thread_id_(thread_id) {} : thread_pool_(thread_pool), thread_id_(thread_id) {}
}; };
@ -148,13 +256,14 @@ static void* BGThreadWrapper(void* arg) {
} }
void ThreadPool::WakeUpAllThreads() { void ThreadPool::WakeUpAllThreads() {
PthreadCall("signalall", pthread_cond_broadcast(&bgsignal_)); PthreadCall("signalall", ConditionSignalAll(bgsignal_));
} }
void ThreadPool::SetBackgroundThreadsInternal(int num, bool allow_reduce) { void ThreadPool::SetBackgroundThreadsInternal(int num, bool allow_reduce) {
PthreadCall("lock", pthread_mutex_lock(&mu_)); Lock lock(mu_);
PthreadCall("lock", MutexLock(lock));
if (exit_all_threads_) { if (exit_all_threads_) {
PthreadCall("unlock", pthread_mutex_unlock(&mu_)); PthreadCall("unlock", MutexUnlock(lock));
return; return;
} }
if (num > total_threads_limit_ || if (num > total_threads_limit_ ||
@ -163,7 +272,7 @@ void ThreadPool::SetBackgroundThreadsInternal(int num, bool allow_reduce) {
WakeUpAllThreads(); WakeUpAllThreads();
StartBGThreads(); StartBGThreads();
} }
PthreadCall("unlock", pthread_mutex_unlock(&mu_)); PthreadCall("unlock", MutexUnlock(lock));
} }
void ThreadPool::IncBackgroundThreadsIfNeeded(int num) { void ThreadPool::IncBackgroundThreadsIfNeeded(int num) {
@ -177,11 +286,15 @@ void ThreadPool::SetBackgroundThreads(int num) {
void ThreadPool::StartBGThreads() { void ThreadPool::StartBGThreads() {
// Start background thread if necessary // Start background thread if necessary
while ((int)bgthreads_.size() < total_threads_limit_) { while ((int)bgthreads_.size() < total_threads_limit_) {
#ifdef ROCKSDB_STD_THREADPOOL
std::thread p_t(&BGThreadWrapper,
new BGThreadMetadata(this, bgthreads_.size()));
bgthreads_.push_back(std::move(p_t));
#else
pthread_t t; pthread_t t;
PthreadCall("create thread", PthreadCall("create thread",
pthread_create(&t, nullptr, &BGThreadWrapper, pthread_create(&t, nullptr, &BGThreadWrapper,
new BGThreadMetadata(this, bgthreads_.size()))); new BGThreadMetadata(this, bgthreads_.size())));
// Set the thread name to aid debugging // Set the thread name to aid debugging
#if defined(_GNU_SOURCE) && defined(__GLIBC_PREREQ) #if defined(_GNU_SOURCE) && defined(__GLIBC_PREREQ)
#if __GLIBC_PREREQ(2, 12) #if __GLIBC_PREREQ(2, 12)
@ -192,17 +305,19 @@ void ThreadPool::StartBGThreads() {
pthread_setname_np(t, name_buf); pthread_setname_np(t, name_buf);
#endif #endif
#endif #endif
bgthreads_.push_back(t); bgthreads_.push_back(t);
#endif
} }
} }
void ThreadPool::Schedule(void (*function)(void* arg1), void* arg, void* tag, void ThreadPool::Schedule(void (*function)(void* arg1), void* arg, void* tag,
void (*unschedFunction)(void* arg)) { void (*unschedFunction)(void* arg)) {
PthreadCall("lock", pthread_mutex_lock(&mu_));
Lock lock(mu_);
PthreadCall("lock", MutexLock(lock));
if (exit_all_threads_) { if (exit_all_threads_) {
PthreadCall("unlock", pthread_mutex_unlock(&mu_)); PthreadCall("unlock", MutexUnlock(lock));
return; return;
} }
@ -219,19 +334,21 @@ void ThreadPool::Schedule(void (*function)(void* arg1), void* arg, void* tag,
if (!HasExcessiveThread()) { if (!HasExcessiveThread()) {
// Wake up at least one waiting thread. // Wake up at least one waiting thread.
PthreadCall("signal", pthread_cond_signal(&bgsignal_)); PthreadCall("signal", ConditionSignal(bgsignal_));
} else { } else {
// Need to wake up all threads to make sure the one woken // Need to wake up all threads to make sure the one woken
// up is not the one to terminate. // up is not the one to terminate.
WakeUpAllThreads(); WakeUpAllThreads();
} }
PthreadCall("unlock", pthread_mutex_unlock(&mu_)); PthreadCall("unlock", MutexUnlock(lock));
} }
int ThreadPool::UnSchedule(void* arg) { int ThreadPool::UnSchedule(void* arg) {
int count = 0; int count = 0;
PthreadCall("lock", pthread_mutex_lock(&mu_));
Lock lock(mu_);
PthreadCall("lock", MutexLock(lock));
// Remove from priority queue // Remove from priority queue
BGQueue::iterator it = queue_.begin(); BGQueue::iterator it = queue_.begin();
@ -245,12 +362,12 @@ int ThreadPool::UnSchedule(void* arg) {
it = queue_.erase(it); it = queue_.erase(it);
count++; count++;
} else { } else {
it++; ++it;
} }
} }
queue_len_.store(static_cast<unsigned int>(queue_.size()), queue_len_.store(static_cast<unsigned int>(queue_.size()),
std::memory_order_relaxed); std::memory_order_relaxed);
PthreadCall("unlock", pthread_mutex_unlock(&mu_)); PthreadCall("unlock", MutexUnlock(lock));
return count; return count;
} }

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@ -7,9 +7,23 @@
// Use of this source code is governed by a BSD-style license that can be // Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file. See the AUTHORS file for names of contributors. // found in the LICENSE file. See the AUTHORS file for names of contributors.
#pragma once #pragma once
#ifdef OS_WIN
# define ROCKSDB_STD_THREADPOOL
#endif
#include "rocksdb/env.h" #include "rocksdb/env.h"
#include "util/thread_status_util.h" #include "util/thread_status_util.h"
#ifdef ROCKSDB_STD_THREADPOOL
# include <thread>
# include <mutex>
# include <condition_variable>
#endif
#include <atomic>
#include <vector>
namespace rocksdb { namespace rocksdb {
class ThreadPool { class ThreadPool {
@ -33,28 +47,28 @@ class ThreadPool {
} }
void SetHostEnv(Env* env) { env_ = env; } void SetHostEnv(Env* env) { env_ = env; }
Env* GetHostEnv() { return env_; } Env* GetHostEnv() const { return env_; }
// Return true if there is at least one thread needs to terminate. // Return true if there is at least one thread needs to terminate.
bool HasExcessiveThread() { bool HasExcessiveThread() const {
return static_cast<int>(bgthreads_.size()) > total_threads_limit_; return static_cast<int>(bgthreads_.size()) > total_threads_limit_;
} }
// Return true iff the current thread is the excessive thread to terminate. // Return true iff the current thread is the excessive thread to terminate.
// Always terminate the running thread that is added last, even if there are // Always terminate the running thread that is added last, even if there are
// more than one thread to terminate. // more than one thread to terminate.
bool IsLastExcessiveThread(size_t thread_id) { bool IsLastExcessiveThread(size_t thread_id) const {
return HasExcessiveThread() && thread_id == bgthreads_.size() - 1; return HasExcessiveThread() && thread_id == bgthreads_.size() - 1;
} }
// Is one of the threads to terminate. // Is one of the threads to terminate.
bool IsExcessiveThread(size_t thread_id) { bool IsExcessiveThread(size_t thread_id) const {
return static_cast<int>(thread_id) >= total_threads_limit_; return static_cast<int>(thread_id) >= total_threads_limit_;
} }
// Return the thread priority. // Return the thread priority.
// This would allow its member-thread to know its priority. // This would allow its member-thread to know its priority.
Env::Priority GetThreadPriority() { return priority_; } Env::Priority GetThreadPriority() const { return priority_; }
// Set the thread priority. // Set the thread priority.
void SetThreadPriority(Env::Priority priority) { priority_ = priority; } void SetThreadPriority(Env::Priority priority) { priority_ = priority; }
@ -69,12 +83,20 @@ class ThreadPool {
void* tag; void* tag;
void (*unschedFunction)(void*); void (*unschedFunction)(void*);
}; };
typedef std::deque<BGItem> BGQueue; typedef std::deque<BGItem> BGQueue;
int total_threads_limit_;
#ifdef ROCKSDB_STD_THREADPOOL
std::mutex mu_;
std::condition_variable bgsignal_;
std::vector<std::thread> bgthreads_;
#else
pthread_mutex_t mu_; pthread_mutex_t mu_;
pthread_cond_t bgsignal_; pthread_cond_t bgsignal_;
int total_threads_limit_;
std::vector<pthread_t> bgthreads_; std::vector<pthread_t> bgthreads_;
#endif
BGQueue queue_; BGQueue queue_;
std::atomic_uint queue_len_; // Queue length. Used for stats reporting std::atomic_uint queue_len_; // Queue length. Used for stats reporting
bool exit_all_threads_; bool exit_all_threads_;