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1563 lines (1193 loc) · 37.2 KB
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// MIT License
//
// Copyright (c) 2018 T.-W Huang, C.-X. Lin, G, Guo, and M. Wong
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in all
// copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
// SOFTWARE.
#pragma once
#include <iostream>
#include <mutex>
#include <deque>
#include <vector>
#include <algorithm>
#include <thread>
#include <future>
#include <functional>
#include <unordered_map>
#include <unordered_set>
#include <sstream>
#include <list>
#include <forward_list>
#include <numeric>
#include <iomanip>
#include <cassert>
#include <optional>
#include <exception>
#include <system_error>
#include "threadpool/threadpool.hpp"
// ============================================================================
// Clang mis-interprets variant's get as a non-friend of variant and cannot
// get compiled correctly. We use the patch:
// https://gcc.gnu.org/viewcvs/gcc?view=revision&revision=258854
// to get rid of this.
#if defined(__clang__)
#include "patch/clang_variant.hpp"
#else
#include <variant>
#endif
// ============================================================================
// Error Handling
// ============================================================================
namespace tf {
// The error category that describes the task informaction.
struct Error : public std::error_category {
enum Code : int {
SUCCESS = 0,
EXECUTOR
};
inline const char* name() const noexcept override final;
inline static const std::error_category& get();
inline std::string message(int) const override final;
};
// Function: name
inline const char* Error::name() const noexcept {
return "Taskflow error";
}
// Function: get
inline const std::error_category& Error::get() {
static Error instance;
return instance;
}
// Function: message
inline std::string Error::message(int code) const {
switch(auto ec = static_cast<Error::Code>(code); ec) {
case SUCCESS:
return "success";
break;
case EXECUTOR:
return "executor error";
break;
default:
return "unknown";
break;
};
}
// Function: make_error_code
// Argument dependent lookup.
inline std::error_code make_error_code(Error::Code e) {
return std::error_code(static_cast<int>(e), Error::get());
}
}; // end of namespace tf ----------------------------------------------------
// Register for implicit conversion
namespace std {
template <>
struct is_error_code_enum<tf::Error::Code> : true_type {};
};
// ----------------------------------------------------------------------------
namespace tf {
// Procedure: throw_se
// Throws the system error under a given error code.
template <typename... ArgsT>
void throw_se(const char* fname, const size_t line, Error::Code c, ArgsT&&... args) {
std::ostringstream oss;
oss << "[" << fname << ":" << line << "] ";
(oss << ... << args);
throw std::system_error(c, oss.str());
}
}; // ------------------------------------------------------------------------
#define TF_THROW(...) tf::throw_se(__FILE__, __LINE__, __VA_ARGS__);
namespace tf {
//-----------------------------------------------------------------------------
// Traits
//-----------------------------------------------------------------------------
// Macro to check whether a class has a member function
#define define_has_member(member_name) \
template <typename T> \
class has_member_##member_name \
{ \
typedef char yes_type; \
typedef long no_type; \
template <typename U> static yes_type test(decltype(&U::member_name)); \
template <typename U> static no_type test(...); \
public: \
static constexpr bool value = sizeof(test<T>(0)) == sizeof(yes_type); \
}
#define has_member(class_, member_name) has_member_##member_name<class_>::value
// Struct: dependent_false
template <typename... T>
struct dependent_false {
static constexpr bool value = false;
};
template <typename... T>
constexpr auto dependent_false_v = dependent_false<T...>::value;
// Struct: is_iterator
template <typename T, typename = void>
struct is_iterator {
static constexpr bool value = false;
};
template <typename T>
struct is_iterator<
T,
std::enable_if_t<!std::is_same_v<typename std::iterator_traits<T>::value_type, void>>
> {
static constexpr bool value = true;
};
template <typename T>
inline constexpr bool is_iterator_v = is_iterator<T>::value;
// Struct: is_iterable
template <typename T, typename = void>
struct is_iterable : std::false_type {
};
template <typename T>
struct is_iterable<T, std::void_t<decltype(std::declval<T>().begin()),
decltype(std::declval<T>().end())>>
: std::true_type {
};
template <typename T>
inline constexpr bool is_iterable_v = is_iterable<T>::value;
// Struct: MoC
// Move-on-copy wrapper.
template <typename T>
struct MoC {
MoC(T&& rhs) : object(std::move(rhs)) {}
MoC(const MoC& other) : object(std::move(other.object)) {}
T& get() { return object; }
mutable T object;
};
//-----------------------------------------------------------------------------
// Taskflow definition
//-----------------------------------------------------------------------------
// Forward declaration
class Node;
class Topology;
class Task;
class FlowBuilder;
class SubflowBuilder;
template <template<typename...> typename E> class BasicTaskflow;
using Graph = std::forward_list<Node>;
// ----------------------------------------------------------------------------
// Class: Node
class Node {
friend class Task;
friend class Topology;
template <template<typename...> typename E>
friend class BasicTaskflow;
using StaticWork = std::function<void()>;
using DynamicWork = std::function<void(SubflowBuilder&)>;
public:
Node();
template <typename C>
Node(C&&);
const std::string& name() const;
void precede(Node&);
void dump(std::ostream&) const;
size_t num_successors() const;
size_t num_dependents() const;
std::string dump() const;
private:
std::string _name;
std::variant<StaticWork, DynamicWork> _work;
std::vector<Node*> _successors;
std::atomic<int> _dependents;
std::optional<Graph> _subgraph;
Topology* _topology;
};
// Constructor
inline Node::Node() {
_dependents.store(0, std::memory_order_relaxed);
_topology = nullptr;
}
// Constructor
template <typename C>
inline Node::Node(C&& c) : _work {std::forward<C>(c)} {
_dependents.store(0, std::memory_order_relaxed);
_topology = nullptr;
}
// Procedure: precede
inline void Node::precede(Node& v) {
_successors.push_back(&v);
v._dependents.fetch_add(1, std::memory_order_relaxed);
}
// Function: num_successors
inline size_t Node::num_successors() const {
return _successors.size();
}
// Function: dependents
inline size_t Node::num_dependents() const {
return _dependents.load(std::memory_order_relaxed);
}
// Function: name
inline const std::string& Node::name() const {
return _name;
}
// Function: dump
inline std::string Node::dump() const {
std::ostringstream os;
dump(os);
return os.str();
}
// Function: dump
inline void Node::dump(std::ostream& os) const {
if(_name.empty()) os << '\"' << this << '\"';
else os << std::quoted(_name);
os << ";\n";
for(const auto s : _successors) {
if(_name.empty()) os << '\"' << this << '\"';
else os << std::quoted(_name);
os << " -> ";
if(s->name().empty()) os << '\"' << s << '\"';
else os << std::quoted(s->name());
os << ";\n";
}
if(_subgraph && !_subgraph->empty()) {
os << "subgraph cluster_";
if(_name.empty()) os << this;
else os << _name;
os << " {\n";
os << "label = \"Subflow_";
if(_name.empty()) os << this;
else os << _name;
os << "\";\n" << "color=blue\n";
for(const auto& n : *_subgraph) {
n.dump(os);
}
os << "}\n";
}
}
// ----------------------------------------------------------------------------
// class: Topology
class Topology {
template <template<typename...> typename E>
friend class BasicTaskflow;
public:
Topology(Graph&&);
template <typename C>
Topology(Graph&&, C&&);
std::string dump() const;
void dump(std::ostream&) const;
private:
Graph _graph;
std::shared_future<void> _future;
Node _source;
Node _target;
};
// TODO: remove duplicate code in the two constructors
// Constructor
inline Topology::Topology(Graph&& t) :
_graph(std::move(t)) {
_source._topology = this;
_target._topology = this;
std::promise<void> promise;
_future = promise.get_future().share();
_target._work = [p=MoC{std::move(promise)}] () mutable {
p.get().set_value();
};
// ensure the topology is connected
_source.precede(_target);
// Build the super source and super target.
for(auto& node : _graph) {
node._topology = this;
if(node.num_dependents() == 0) {
_source.precede(node);
}
if(node.num_successors() == 0) {
node.precede(_target);
}
}
}
// Constructor
template <typename C>
inline Topology::Topology(Graph&& t, C&& c) :
_graph(std::move(t)) {
_source._topology = this;
_target._topology = this;
std::promise<void> promise;
_future = promise.get_future().share();
_target._work = [p=MoC{std::move(promise)}, c{std::forward<C>(c)}] () mutable {
p.get().set_value();
c();
};
// ensure the topology is connected
_source.precede(_target);
// Build the super source and super target.
for(auto& node : _graph) {
node._topology = this;
if(node.num_dependents() == 0) {
_source.precede(node);
}
if(node.num_successors() == 0) {
node.precede(_target);
}
}
}
// Procedure: dump
inline void Topology::dump(std::ostream& os) const {
assert(!(_source._subgraph));
assert(!(_target._subgraph));
os << "digraph Topology {\n"
<< _source.dump()
<< _target.dump();
for(const auto& node : _graph) {
os << node.dump();
}
os << "}\n";
}
// Function: dump
inline std::string Topology::dump() const {
std::ostringstream os;
dump(os);
return os.str();
}
// ----------------------------------------------------------------------------
// Class: Task
class Task {
friend class FlowBuilder;
template <template<typename...> typename E>
friend class BasicTaskflow;
public:
Task() = default;
Task(Node&);
Task(const Task&);
Task(Task&&);
Task& operator = (const Task&);
const std::string& name() const;
size_t num_successors() const;
size_t num_dependents() const;
Task& name(const std::string&);
template <typename C>
Task& work(C&&);
template <typename... Ts>
Task& precede(Ts&&...);
template <typename... Bs>
Task& broadcast(Bs&&...);
Task& broadcast(std::vector<Task>&);
Task& broadcast(std::initializer_list<Task>);
template <typename... Bs>
Task& gather(Bs&&...);
Task& gather(std::vector<Task>&);
Task& gather(std::initializer_list<Task>);
private:
Node* _node {nullptr};
template<typename S>
void _broadcast(S&);
template<typename S>
void _gather(S&);
};
// Constructor
inline Task::Task(Node& t) : _node {&t} {
}
// Constructor
inline Task::Task(const Task& rhs) : _node {rhs._node} {
}
// Function: broadcast
template <typename... Bs>
Task& Task::broadcast(Bs&&... tgts) {
(_node->precede(*(tgts._node)), ...);
return *this;
}
// Procedure: _broadcast
template <typename S>
inline void Task::_broadcast(S& tgts) {
for(auto& to : tgts) {
_node->precede(*(to._node));
}
}
// Function: broadcast
inline Task& Task::broadcast(std::vector<Task>& tgts) {
_broadcast(tgts);
return *this;
}
// Function: broadcast
inline Task& Task::broadcast(std::initializer_list<Task> tgts) {
_broadcast(tgts);
return *this;
}
// Function: precede
template <typename... Ts>
Task& Task::precede(Ts&&... tgts) {
(_node->precede(*(tgts._node)), ...);
return *this;
}
// Function: gather
template <typename... Bs>
Task& Task::gather(Bs&&... tgts) {
(tgts._node->precede(*_node), ...);
return *this;
}
// Procedure: _gather
template <typename S>
void Task::_gather(S& tgts) {
for(auto& from : tgts) {
from._node->precede(*_node);
}
}
// Function: gather
inline Task& Task::gather(std::vector<Task>& tgts) {
_gather(tgts);
return *this;
}
// Function: gather
inline Task& Task::gather(std::initializer_list<Task> tgts) {
_gather(tgts);
return *this;
}
// Operator =
inline Task& Task::operator = (const Task& rhs) {
_node = rhs._node;
return *this;
}
// Constructor
inline Task::Task(Task&& rhs) : _node{rhs._node} {
rhs._node = nullptr;
}
// Function: work
template <typename C>
inline Task& Task::work(C&& c) {
_node->_work = std::forward<C>(c);
return *this;
}
// Function: name
inline Task& Task::name(const std::string& name) {
_node->_name = name;
return *this;
}
// Function: name
inline const std::string& Task::name() const {
return _node->_name;
}
// Function: num_dependents
inline size_t Task::num_dependents() const {
return _node->_dependents.load(std::memory_order_relaxed);
}
// Function: num_successors
inline size_t Task::num_successors() const {
return _node->_successors.size();
}
// ----------------------------------------------------------------------------
// Class: FlowBuilder
class FlowBuilder {
public:
FlowBuilder(Graph&);
FlowBuilder(Graph&, size_t);
template <typename C>
auto emplace(C&&);
template <typename... C, std::enable_if_t<(sizeof...(C)>1), void>* = nullptr>
auto emplace(C&&...);
template <typename C>
auto silent_emplace(C&&);
template <typename... C, std::enable_if_t<(sizeof...(C)>1), void>* = nullptr>
auto silent_emplace(C&&...);
template <typename I, typename C>
auto parallel_for(I, I, C&&, size_t = 0);
template <typename T, typename C, std::enable_if_t<is_iterable_v<T>, void>* = nullptr>
auto parallel_for(T&, C&&, size_t = 0);
template <typename I, typename T, typename B>
auto reduce(I, I, T&, B&&);
template <typename I, typename T>
auto reduce_min(I, I, T&);
template <typename I, typename T>
auto reduce_max(I, I, T&);
template <typename I, typename T, typename B, typename U>
auto transform_reduce(I, I, T&, B&&, U&&);
template <typename I, typename T, typename B, typename P, typename U>
auto transform_reduce(I, I, T&, B&&, P&&, U&&);
auto placeholder();
void precede(Task, Task);
void linearize(std::vector<Task>&);
void linearize(std::initializer_list<Task>);
void broadcast(Task, std::vector<Task>&);
void broadcast(Task, std::initializer_list<Task>);
void gather(std::vector<Task>&, Task);
void gather(std::initializer_list<Task>, Task);
void partition_factor(size_t);
size_t size() const;
bool empty() const;
protected:
Graph& _graph;
size_t _partition_factor {std::thread::hardware_concurrency()};
template <typename L>
void _linearize(L&);
};
// Constructor
inline FlowBuilder::FlowBuilder(Graph& graph) :
_graph {graph} {
}
inline FlowBuilder::FlowBuilder(Graph& graph, size_t f) :
_graph {graph},
_partition_factor {f} {
}
// Procedure: partition_factor
inline void FlowBuilder::partition_factor(size_t f) {
_partition_factor = f;
}
// Procedure: size
inline size_t FlowBuilder::size() const {
return std::distance(_graph.begin(), _graph.end());
}
// Function: empty
inline bool FlowBuilder::empty() const {
return _graph.empty();
}
// Procedure: precede
inline void FlowBuilder::precede(Task from, Task to) {
from._node->precede(*(to._node));
}
// Procedure: broadcast
inline void FlowBuilder::broadcast(Task from, std::vector<Task>& keys) {
from.broadcast(keys);
}
// Procedure: broadcast
inline void FlowBuilder::broadcast(Task from, std::initializer_list<Task> keys) {
from.broadcast(keys);
}
// Function: gather
inline void FlowBuilder::gather(std::vector<Task>& keys, Task to) {
to.gather(keys);
}
// Function: gather
inline void FlowBuilder::gather(std::initializer_list<Task> keys, Task to) {
to.gather(keys);
}
// Function: placeholder
inline auto FlowBuilder::placeholder() {
auto& node = _graph.emplace_front();
return Task(node);
}
// Function: silent_emplace
template <typename... C, std::enable_if_t<(sizeof...(C)>1), void>*>
auto FlowBuilder::silent_emplace(C&&... cs) {
return std::make_tuple(silent_emplace(std::forward<C>(cs))...);
}
// Function: parallel_for
template <typename I, typename C>
auto FlowBuilder::parallel_for(I beg, I end, C&& c, size_t g) {
using category = typename std::iterator_traits<I>::iterator_category;
if(g == 0) {
auto d = std::distance(beg, end);
auto w = std::max(size_t{1}, _partition_factor);
g = (d + w - 1) / w;
}
auto source = placeholder();
auto target = placeholder();
while(beg != end) {
auto e = beg;
// Case 1: random access iterator
if constexpr(std::is_same_v<category, std::random_access_iterator_tag>) {
size_t r = std::distance(beg, end);
std::advance(e, std::min(r, g));
}
// Case 2: non-random access iterator
else {
for(size_t i=0; i<g && e != end; ++e, ++i);
}
// Create a task
auto task = silent_emplace([beg, e, c] () mutable {
std::for_each(beg, e, c);
});
source.precede(task);
task.precede(target);
// adjust the pointer
beg = e;
}
return std::make_pair(source, target);
}
// Function: parallel_for
template <typename T, typename C, std::enable_if_t<is_iterable_v<T>, void>*>
auto FlowBuilder::parallel_for(T& t, C&& c, size_t group) {
return parallel_for(t.begin(), t.end(), std::forward<C>(c), group);
}
// Function: reduce_min
// Find the minimum element over a range of items.
template <typename I, typename T>
auto FlowBuilder::reduce_min(I beg, I end, T& result) {
return reduce(beg, end, result, [] (const auto& l, const auto& r) {
return std::min(l, r);
});
}
// Function: reduce_max
// Find the maximum element over a range of items.
template <typename I, typename T>
auto FlowBuilder::reduce_max(I beg, I end, T& result) {
return reduce(beg, end, result, [] (const auto& l, const auto& r) {
return std::max(l, r);
});
}
// Function: transform_reduce
template <typename I, typename T, typename B, typename U>
auto FlowBuilder::transform_reduce(I beg, I end, T& result, B&& bop, U&& uop) {
using category = typename std::iterator_traits<I>::iterator_category;
// Even partition
size_t d = std::distance(beg, end);
size_t w = std::max(size_t{1}, _partition_factor);
size_t g = std::max((d + w - 1) / w, size_t{2});
auto source = placeholder();
auto target = placeholder();
std::vector<std::future<T>> futures;
while(beg != end) {
auto e = beg;
// Case 1: random access iterator
if constexpr(std::is_same_v<category, std::random_access_iterator_tag>) {
size_t r = std::distance(beg, end);
std::advance(e, std::min(r, g));
}
// Case 2: non-random access iterator
else {
for(size_t i=0; i<g && e != end; ++e, ++i);
}
// Create a task
auto [task, future] = emplace([beg, e, bop, uop] () mutable {
auto init = uop(*beg);
for(++beg; beg != e; ++beg) {
init = bop(std::move(init), uop(*beg));
}
return init;
});
source.precede(task);
task.precede(target);
futures.push_back(std::move(future));
// adjust the pointer
beg = e;
}
// target synchronizer
target.work([&result, futures=MoC{std::move(futures)}, bop] () {
for(auto& fu : futures.object) {
result = bop(std::move(result), fu.get());
}
});
return std::make_pair(source, target);
}
// Function: transform_reduce
template <typename I, typename T, typename B, typename P, typename U>
auto FlowBuilder::transform_reduce(I beg, I end, T& result, B&& bop, P&& pop, U&& uop) {
using category = typename std::iterator_traits<I>::iterator_category;
// Even partition
size_t d = std::distance(beg, end);
size_t w = std::max(size_t{1}, _partition_factor);
size_t g = std::max((d + w - 1) / w, size_t{2});
auto source = placeholder();
auto target = placeholder();
std::vector<std::future<T>> futures;
while(beg != end) {
auto e = beg;
// Case 1: random access iterator
if constexpr(std::is_same_v<category, std::random_access_iterator_tag>) {
size_t r = std::distance(beg, end);
std::advance(e, std::min(r, g));
}
// Case 2: non-random access iterator
else {
for(size_t i=0; i<g && e != end; ++e, ++i);
}
// Create a task
auto [task, future] = emplace([beg, e, uop, pop] () mutable {
auto init = uop(*beg);
for(++beg; beg != e; ++beg) {
init = pop(std::move(init), *beg);
}
return init;
});
source.precede(task);
task.precede(target);
futures.push_back(std::move(future));
// adjust the pointer
beg = e;
}
// target synchronizer
target.work([&result, futures=MoC{std::move(futures)}, bop] () {
for(auto& fu : futures.object) {
result = bop(std::move(result), fu.get());
}
});
return std::make_pair(source, target);
}
// Procedure: _linearize
template <typename L>
void FlowBuilder::_linearize(L& keys) {
std::adjacent_find(keys.begin(), keys.end(), [] (auto& from, auto& to) {
from._node->precede(*(to._node));
return false;
});
}
// Procedure: linearize
inline void FlowBuilder::linearize(std::vector<Task>& keys) {
_linearize(keys);
}
// Procedure: linearize
inline void FlowBuilder::linearize(std::initializer_list<Task> keys) {
_linearize(keys);
}
// Proceduer: reduce
template <typename I, typename T, typename B>
auto FlowBuilder::reduce(I beg, I end, T& result, B&& op) {
using category = typename std::iterator_traits<I>::iterator_category;
size_t d = std::distance(beg, end);
size_t w = std::max(size_t{1}, _partition_factor);
size_t g = std::max((d + w - 1) / w, size_t{2});
auto source = placeholder();
auto target = placeholder();
std::vector<std::future<T>> futures;
while(beg != end) {
auto e = beg;
// Case 1: random access iterator
if constexpr(std::is_same_v<category, std::random_access_iterator_tag>) {
size_t r = std::distance(beg, end);
std::advance(e, std::min(r, g));
}
// Case 2: non-random access iterator
else {
for(size_t i=0; i<g && e != end; ++e, ++i);
}
// Create a task
auto [task, future] = emplace([beg, e, op] () mutable {
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