Merge pull request #9971 from Morph1984/q

bounded_threadsafe_queue: Use simplified impl of bounded queue
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liamwhite 2023-03-23 10:00:31 -04:00 committed by GitHub
commit ac3927074b
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3 changed files with 221 additions and 130 deletions

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@ -1,159 +1,249 @@
// SPDX-FileCopyrightText: Copyright (c) 2020 Erik Rigtorp <erik@rigtorp.se>
// SPDX-License-Identifier: MIT
// SPDX-FileCopyrightText: Copyright 2023 yuzu Emulator Project
// SPDX-License-Identifier: GPL-2.0-or-later
#pragma once
#include <atomic>
#include <bit>
#include <condition_variable>
#include <memory>
#include <cstddef>
#include <mutex>
#include <new>
#include <type_traits>
#include <utility>
#include "common/polyfill_thread.h"
namespace Common {
#if defined(__cpp_lib_hardware_interference_size)
constexpr size_t hardware_interference_size = std::hardware_destructive_interference_size;
#else
constexpr size_t hardware_interference_size = 64;
#endif
namespace detail {
constexpr size_t DefaultCapacity = 0x1000;
} // namespace detail
template <typename T, size_t Capacity = detail::DefaultCapacity>
class SPSCQueue {
static_assert((Capacity & (Capacity - 1)) == 0, "Capacity must be a power of two.");
template <typename T, size_t capacity = 0x400>
class MPSCQueue {
public:
explicit MPSCQueue() : allocator{std::allocator<Slot<T>>()} {
// Allocate one extra slot to prevent false sharing on the last slot
slots = allocator.allocate(capacity + 1);
// Allocators are not required to honor alignment for over-aligned types
// (see http://eel.is/c++draft/allocator.requirements#10) so we verify
// alignment here
if (reinterpret_cast<uintptr_t>(slots) % alignof(Slot<T>) != 0) {
allocator.deallocate(slots, capacity + 1);
throw std::bad_alloc();
}
for (size_t i = 0; i < capacity; ++i) {
std::construct_at(&slots[i]);
}
static_assert(std::has_single_bit(capacity), "capacity must be an integer power of 2");
static_assert(alignof(Slot<T>) == hardware_interference_size,
"Slot must be aligned to cache line boundary to prevent false sharing");
static_assert(sizeof(Slot<T>) % hardware_interference_size == 0,
"Slot size must be a multiple of cache line size to prevent "
"false sharing between adjacent slots");
static_assert(sizeof(MPSCQueue) % hardware_interference_size == 0,
"Queue size must be a multiple of cache line size to "
"prevent false sharing between adjacent queues");
template <typename... Args>
bool TryEmplace(Args&&... args) {
return Emplace<PushMode::Try>(std::forward<Args>(args)...);
}
~MPSCQueue() noexcept {
for (size_t i = 0; i < capacity; ++i) {
std::destroy_at(&slots[i]);
}
allocator.deallocate(slots, capacity + 1);
template <typename... Args>
void EmplaceWait(Args&&... args) {
Emplace<PushMode::Wait>(std::forward<Args>(args)...);
}
// The queue must be both non-copyable and non-movable
MPSCQueue(const MPSCQueue&) = delete;
MPSCQueue& operator=(const MPSCQueue&) = delete;
MPSCQueue(MPSCQueue&&) = delete;
MPSCQueue& operator=(MPSCQueue&&) = delete;
void Push(const T& v) noexcept {
static_assert(std::is_nothrow_copy_constructible_v<T>,
"T must be nothrow copy constructible");
emplace(v);
bool TryPop(T& t) {
return Pop<PopMode::Try>(t);
}
template <typename P, typename = std::enable_if_t<std::is_nothrow_constructible_v<T, P&&>>>
void Push(P&& v) noexcept {
emplace(std::forward<P>(v));
void PopWait(T& t) {
Pop<PopMode::Wait>(t);
}
void Pop(T& v, std::stop_token stop) noexcept {
auto const tail = tail_.fetch_add(1);
auto& slot = slots[idx(tail)];
if (!slot.turn.test()) {
std::unique_lock lock{cv_mutex};
Common::CondvarWait(cv, lock, stop, [&slot] { return slot.turn.test(); });
void PopWait(T& t, std::stop_token stop_token) {
Pop<PopMode::WaitWithStopToken>(t, stop_token);
}
v = slot.move();
slot.destroy();
slot.turn.clear();
slot.turn.notify_one();
T PopWait() {
T t;
Pop<PopMode::Wait>(t);
return t;
}
T PopWait(std::stop_token stop_token) {
T t;
Pop<PopMode::WaitWithStopToken>(t, stop_token);
return t;
}
private:
template <typename U = T>
struct Slot {
~Slot() noexcept {
if (turn.test()) {
destroy();
enum class PushMode {
Try,
Wait,
Count,
};
enum class PopMode {
Try,
Wait,
WaitWithStopToken,
Count,
};
template <PushMode Mode, typename... Args>
bool Emplace(Args&&... args) {
const size_t write_index = m_write_index.load(std::memory_order::relaxed);
if constexpr (Mode == PushMode::Try) {
// Check if we have free slots to write to.
if ((write_index - m_read_index.load(std::memory_order::acquire)) == Capacity) {
return false;
}
} else if constexpr (Mode == PushMode::Wait) {
// Wait until we have free slots to write to.
std::unique_lock lock{producer_cv_mutex};
producer_cv.wait(lock, [this, write_index] {
return (write_index - m_read_index.load(std::memory_order::acquire)) < Capacity;
});
} else {
static_assert(Mode < PushMode::Count, "Invalid PushMode.");
}
// Determine the position to write to.
const size_t pos = write_index % Capacity;
// Emplace into the queue.
std::construct_at(std::addressof(m_data[pos]), std::forward<Args>(args)...);
// Increment the write index.
++m_write_index;
// Notify the consumer that we have pushed into the queue.
std::scoped_lock lock{consumer_cv_mutex};
consumer_cv.notify_one();
return true;
}
template <PopMode Mode>
bool Pop(T& t, [[maybe_unused]] std::stop_token stop_token = {}) {
const size_t read_index = m_read_index.load(std::memory_order::relaxed);
if constexpr (Mode == PopMode::Try) {
// Check if the queue is empty.
if (read_index == m_write_index.load(std::memory_order::acquire)) {
return false;
}
} else if constexpr (Mode == PopMode::Wait) {
// Wait until the queue is not empty.
std::unique_lock lock{consumer_cv_mutex};
consumer_cv.wait(lock, [this, read_index] {
return read_index != m_write_index.load(std::memory_order::acquire);
});
} else if constexpr (Mode == PopMode::WaitWithStopToken) {
// Wait until the queue is not empty.
std::unique_lock lock{consumer_cv_mutex};
Common::CondvarWait(consumer_cv, lock, stop_token, [this, read_index] {
return read_index != m_write_index.load(std::memory_order::acquire);
});
if (stop_token.stop_requested()) {
return false;
}
} else {
static_assert(Mode < PopMode::Count, "Invalid PopMode.");
}
// Determine the position to read from.
const size_t pos = read_index % Capacity;
// Pop the data off the queue, moving it.
t = std::move(m_data[pos]);
// Increment the read index.
++m_read_index;
// Notify the producer that we have popped off the queue.
std::scoped_lock lock{producer_cv_mutex};
producer_cv.notify_one();
return true;
}
alignas(128) std::atomic_size_t m_read_index{0};
alignas(128) std::atomic_size_t m_write_index{0};
std::array<T, Capacity> m_data;
std::condition_variable_any producer_cv;
std::mutex producer_cv_mutex;
std::condition_variable_any consumer_cv;
std::mutex consumer_cv_mutex;
};
template <typename T, size_t Capacity = detail::DefaultCapacity>
class MPSCQueue {
public:
template <typename... Args>
bool TryEmplace(Args&&... args) {
std::scoped_lock lock{write_mutex};
return spsc_queue.TryEmplace(std::forward<Args>(args)...);
}
template <typename... Args>
void construct(Args&&... args) noexcept {
static_assert(std::is_nothrow_constructible_v<U, Args&&...>,
"T must be nothrow constructible with Args&&...");
std::construct_at(reinterpret_cast<U*>(&storage), std::forward<Args>(args)...);
void EmplaceWait(Args&&... args) {
std::scoped_lock lock{write_mutex};
spsc_queue.EmplaceWait(std::forward<Args>(args)...);
}
void destroy() noexcept {
static_assert(std::is_nothrow_destructible_v<U>, "T must be nothrow destructible");
std::destroy_at(reinterpret_cast<U*>(&storage));
bool TryPop(T& t) {
return spsc_queue.TryPop(t);
}
U&& move() noexcept {
return reinterpret_cast<U&&>(storage);
void PopWait(T& t) {
spsc_queue.PopWait(t);
}
// Align to avoid false sharing between adjacent slots
alignas(hardware_interference_size) std::atomic_flag turn{};
struct aligned_store {
struct type {
alignas(U) unsigned char data[sizeof(U)];
};
};
typename aligned_store::type storage;
};
void PopWait(T& t, std::stop_token stop_token) {
spsc_queue.PopWait(t, stop_token);
}
T PopWait() {
return spsc_queue.PopWait();
}
T PopWait(std::stop_token stop_token) {
return spsc_queue.PopWait(stop_token);
}
private:
SPSCQueue<T, Capacity> spsc_queue;
std::mutex write_mutex;
};
template <typename T, size_t Capacity = detail::DefaultCapacity>
class MPMCQueue {
public:
template <typename... Args>
bool TryEmplace(Args&&... args) {
std::scoped_lock lock{write_mutex};
return spsc_queue.TryEmplace(std::forward<Args>(args)...);
}
template <typename... Args>
void emplace(Args&&... args) noexcept {
static_assert(std::is_nothrow_constructible_v<T, Args&&...>,
"T must be nothrow constructible with Args&&...");
auto const head = head_.fetch_add(1);
auto& slot = slots[idx(head)];
slot.turn.wait(true);
slot.construct(std::forward<Args>(args)...);
slot.turn.test_and_set();
cv.notify_one();
void EmplaceWait(Args&&... args) {
std::scoped_lock lock{write_mutex};
spsc_queue.EmplaceWait(std::forward<Args>(args)...);
}
constexpr size_t idx(size_t i) const noexcept {
return i & mask;
bool TryPop(T& t) {
std::scoped_lock lock{read_mutex};
return spsc_queue.TryPop(t);
}
static constexpr size_t mask = capacity - 1;
void PopWait(T& t) {
std::scoped_lock lock{read_mutex};
spsc_queue.PopWait(t);
}
// Align to avoid false sharing between head_ and tail_
alignas(hardware_interference_size) std::atomic<size_t> head_{0};
alignas(hardware_interference_size) std::atomic<size_t> tail_{0};
void PopWait(T& t, std::stop_token stop_token) {
std::scoped_lock lock{read_mutex};
spsc_queue.PopWait(t, stop_token);
}
std::mutex cv_mutex;
std::condition_variable_any cv;
T PopWait() {
std::scoped_lock lock{read_mutex};
return spsc_queue.PopWait();
}
Slot<T>* slots;
[[no_unique_address]] std::allocator<Slot<T>> allocator;
T PopWait(std::stop_token stop_token) {
std::scoped_lock lock{read_mutex};
return spsc_queue.PopWait(stop_token);
}
static_assert(std::is_nothrow_copy_assignable_v<T> || std::is_nothrow_move_assignable_v<T>,
"T must be nothrow copy or move assignable");
static_assert(std::is_nothrow_destructible_v<T>, "T must be nothrow destructible");
private:
SPSCQueue<T, Capacity> spsc_queue;
std::mutex write_mutex;
std::mutex read_mutex;
};
} // namespace Common

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@ -28,7 +28,7 @@
#ifdef _WIN32
#include "common/string_util.h"
#endif
#include "common/threadsafe_queue.h"
#include "common/bounded_threadsafe_queue.h"
namespace Common::Log {
@ -204,11 +204,11 @@ public:
void PushEntry(Class log_class, Level log_level, const char* filename, unsigned int line_num,
const char* function, std::string&& message) {
if (!filter.CheckMessage(log_class, log_level))
if (!filter.CheckMessage(log_class, log_level)) {
return;
const Entry& entry =
CreateEntry(log_class, log_level, filename, line_num, function, std::move(message));
message_queue.Push(entry);
}
message_queue.EmplaceWait(
CreateEntry(log_class, log_level, filename, line_num, function, std::move(message)));
}
private:
@ -225,7 +225,7 @@ private:
ForEachBackend([&entry](Backend& backend) { backend.Write(entry); });
};
while (!stop_token.stop_requested()) {
entry = message_queue.PopWait(stop_token);
message_queue.PopWait(entry, stop_token);
if (entry.filename != nullptr) {
write_logs();
}
@ -233,7 +233,7 @@ private:
// Drain the logging queue. Only writes out up to MAX_LOGS_TO_WRITE to prevent a
// case where a system is repeatedly spamming logs even on close.
int max_logs_to_write = filter.IsDebug() ? INT_MAX : 100;
while (max_logs_to_write-- && message_queue.Pop(entry)) {
while (max_logs_to_write-- && message_queue.TryPop(entry)) {
write_logs();
}
});
@ -273,7 +273,7 @@ private:
ColorConsoleBackend color_console_backend{};
FileBackend file_backend;
MPSCQueue<Entry, true> message_queue{};
MPSCQueue<Entry> message_queue{};
std::chrono::steady_clock::time_point time_origin{std::chrono::steady_clock::now()};
std::jthread backend_thread;
};

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@ -31,9 +31,10 @@ static void RunThread(std::stop_token stop_token, Core::System& system,
auto current_context = context.Acquire();
VideoCore::RasterizerInterface* const rasterizer = renderer.ReadRasterizer();
while (!stop_token.stop_requested()) {
CommandDataContainer next;
state.queue.Pop(next, stop_token);
while (!stop_token.stop_requested()) {
state.queue.PopWait(next, stop_token);
if (stop_token.stop_requested()) {
break;
}
@ -117,7 +118,7 @@ u64 ThreadManager::PushCommand(CommandData&& command_data, bool block) {
std::unique_lock lk(state.write_lock);
const u64 fence{++state.last_fence};
state.queue.Push(CommandDataContainer(std::move(command_data), fence, block));
state.queue.EmplaceWait(std::move(command_data), fence, block);
if (block) {
Common::CondvarWait(state.cv, lk, thread.get_stop_token(), [this, fence] {