tdlight/tdutils/td/utils/ChainScheduler.h
2022-03-11 21:38:48 +03:00

376 lines
11 KiB
C++

//
// Copyright Aliaksei Levin (levlam@telegram.org), Arseny Smirnov (arseny30@gmail.com) 2014-2022
//
// Distributed under the Boost Software License, Version 1.0. (See accompanying
// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
//
#pragma once
#include "td/utils/algorithm.h"
#include "td/utils/common.h"
#include "td/utils/Container.h"
#include "td/utils/FlatHashSet.h"
#include "td/utils/List.h"
#include "td/utils/logging.h"
#include "td/utils/optional.h"
#include "td/utils/Span.h"
#include "td/utils/StringBuilder.h"
#include "td/utils/VectorQueue.h"
#include <functional>
#include <unordered_map>
namespace td {
struct ChainSchedulerBase {
struct TaskWithParents {
uint64 task_id{};
vector<uint64> parents;
};
};
template <class ExtraT = Unit>
class ChainScheduler final : public ChainSchedulerBase {
public:
using TaskId = uint64;
using ChainId = uint64;
TaskId create_task(Span<ChainId> chains, ExtraT extra = {});
ExtraT *get_task_extra(TaskId task_id);
optional<TaskWithParents> start_next_task();
void pause_task(TaskId task_id);
void finish_task(TaskId task_id);
void reset_task(TaskId task_id);
template <class F>
void for_each(F &&f) {
tasks_.for_each([&f](auto, Task &task) { f(task.extra); });
}
template <class F>
void for_each_dependent(TaskId task_id, F &&f) {
auto *task = tasks_.get(task_id);
CHECK(task != nullptr);
FlatHashSet<TaskId> visited;
bool check_for_collisions = task->chains.size() > 1;
for (TaskChainInfo &task_chain_info : task->chains) {
ChainInfo &chain_info = *task_chain_info.chain_info;
chain_info.chain.foreach_child(&task_chain_info.chain_node, [&](TaskId task_id, uint64) {
if (check_for_collisions && !visited.insert(task_id).second) {
return;
}
f(task_id);
});
}
}
private:
struct ChainNode : ListNode {
TaskId task_id{};
uint64 generation{};
};
class Chain {
public:
void add_task(ChainNode *node) {
head_.put_back(node);
}
optional<TaskId> get_first() {
if (head_.empty()) {
return {};
}
return static_cast<ChainNode &>(*head_.get_next()).task_id;
}
optional<TaskId> get_child(ChainNode *chain_node) {
if (chain_node->get_next() == head_.end()) {
return {};
}
return static_cast<ChainNode &>(*chain_node->get_next()).task_id;
}
optional<ChainNode *> get_parent(ChainNode *chain_node) {
if (chain_node->get_prev() == head_.end()) {
return {};
}
return static_cast<ChainNode *>(chain_node->get_prev());
}
void finish_task(ChainNode *node) {
node->remove();
}
bool empty() const {
return head_.empty();
}
void foreach(std::function<void(TaskId, uint64)> f) const {
for (auto it = head_.begin(); it != head_.end(); it = it->get_next()) {
auto &node = static_cast<const ChainNode &>(*it);
f(node.task_id, node.generation);
}
}
void foreach_child(ListNode *start_node, std::function<void(TaskId, uint64)> f) const {
for (auto it = start_node; it != head_.end(); it = it->get_next()) {
auto &node = static_cast<const ChainNode &>(*it);
f(node.task_id, node.generation);
}
}
private:
ListNode head_;
};
struct ChainInfo {
Chain chain;
uint32 active_tasks{};
uint64 generation{1};
};
struct TaskChainInfo {
ChainNode chain_node;
ChainId chain_id{};
ChainInfo *chain_info{};
};
struct Task {
enum class State { Pending, Active, Paused } state{State::Pending};
vector<TaskChainInfo> chains;
ExtraT extra;
};
std::unordered_map<ChainId, ChainInfo> chains_;
std::unordered_map<ChainId, TaskId> limited_tasks_;
Container<Task> tasks_;
VectorQueue<TaskId> pending_tasks_;
void try_start_task(TaskId task_id) {
auto *task = tasks_.get(task_id);
CHECK(task != nullptr);
if (task->state != Task::State::Pending) {
return;
}
for (TaskChainInfo &task_chain_info : task->chains) {
auto o_parent = task_chain_info.chain_info->chain.get_parent(&task_chain_info.chain_node);
if (o_parent) {
if (o_parent.value()->generation != task_chain_info.chain_info->generation) {
return;
}
}
if (task_chain_info.chain_info->active_tasks >= 10) {
limited_tasks_[task_chain_info.chain_id] = task_id;
return;
}
}
do_start_task(task_id, task);
}
void do_start_task(TaskId task_id, Task *task) {
for (TaskChainInfo &task_chain_info : task->chains) {
ChainInfo &chain_info = chains_[task_chain_info.chain_id];
chain_info.active_tasks++;
task_chain_info.chain_node.generation = chain_info.generation;
}
task->state = Task::State::Active;
pending_tasks_.push(task_id);
for_each_child(task, [&](TaskId task_id) { try_start_task(task_id); });
}
template <class F>
void for_each_child(Task *task, F &&f) {
for (TaskChainInfo &task_chain_info : task->chains) {
ChainInfo &chain_info = *task_chain_info.chain_info;
auto o_child = chain_info.chain.get_child(&task_chain_info.chain_node);
if (o_child) {
f(o_child.value());
}
}
}
void inactivate_task(TaskId task_id, bool failed) {
LOG(DEBUG) << "Inactivate " << task_id << " " << (failed ? "failed" : "finished");
auto *task = tasks_.get(task_id);
CHECK(task != nullptr);
bool was_active = task->state == Task::State::Active;
task->state = Task::State::Pending;
for (TaskChainInfo &task_chain_info : task->chains) {
ChainInfo &chain_info = *task_chain_info.chain_info;
if (was_active) {
chain_info.active_tasks--;
}
if (was_active && failed) {
chain_info.generation = td::max(chain_info.generation, task_chain_info.chain_node.generation + 1);
}
auto it = limited_tasks_.find(task_chain_info.chain_id);
if (it != limited_tasks_.end()) {
auto limited_task_id = it->second;
limited_tasks_.erase(it);
if (limited_task_id != task_id) {
try_start_task_later(limited_task_id);
}
}
auto o_first = chain_info.chain.get_first();
if (o_first) {
auto first_task_id = o_first.unwrap();
if (first_task_id != task_id) {
try_start_task_later(first_task_id);
}
}
}
}
void finish_chain_task(TaskChainInfo &task_chain_info) {
auto &chain = task_chain_info.chain_info->chain;
chain.finish_task(&task_chain_info.chain_node);
if (chain.empty()) {
chains_.erase(task_chain_info.chain_id);
}
}
vector<TaskId> to_start_;
void try_start_task_later(TaskId task_id) {
LOG(DEBUG) << "Start later " << task_id;
to_start_.push_back(task_id);
}
void flush_try_start_task() {
auto moved_to_start = std::move(to_start_);
for (auto task_id : moved_to_start) {
try_start_task(task_id);
}
CHECK(to_start_.empty());
}
template <class ExtraTT>
friend StringBuilder &operator<<(StringBuilder &sb, ChainScheduler<ExtraTT> &scheduler);
};
template <class ExtraT>
typename ChainScheduler<ExtraT>::TaskId ChainScheduler<ExtraT>::create_task(Span<ChainScheduler::ChainId> chains,
ExtraT extra) {
auto task_id = tasks_.create();
Task &task = *tasks_.get(task_id);
task.extra = std::move(extra);
task.chains = transform(chains, [&](auto chain_id) {
TaskChainInfo task_chain_info;
ChainInfo &chain_info = chains_[chain_id];
task_chain_info.chain_id = chain_id;
task_chain_info.chain_info = &chain_info;
task_chain_info.chain_node.task_id = task_id;
task_chain_info.chain_node.generation = 0;
return task_chain_info;
});
for (TaskChainInfo &task_chain_info : task.chains) {
ChainInfo &chain_info = *task_chain_info.chain_info;
chain_info.chain.add_task(&task_chain_info.chain_node);
}
try_start_task(task_id);
return task_id;
}
// TODO: return reference
template <class ExtraT>
ExtraT *ChainScheduler<ExtraT>::get_task_extra(ChainScheduler::TaskId task_id) { // may return nullptr
auto *task = tasks_.get(task_id);
if (task == nullptr) {
return nullptr;
}
return &task->extra;
}
template <class ExtraT>
optional<ChainSchedulerBase::TaskWithParents> ChainScheduler<ExtraT>::start_next_task() {
if (pending_tasks_.empty()) {
return {};
}
auto task_id = pending_tasks_.pop();
TaskWithParents res;
res.task_id = task_id;
auto *task = tasks_.get(task_id);
CHECK(task != nullptr);
for (TaskChainInfo &task_chain_info : task->chains) {
Chain &chain = task_chain_info.chain_info->chain;
auto o_parent = chain.get_parent(&task_chain_info.chain_node);
if (o_parent) {
res.parents.push_back(o_parent.value()->task_id);
}
}
return res;
}
template <class ExtraT>
void ChainScheduler<ExtraT>::finish_task(ChainScheduler::TaskId task_id) {
auto *task = tasks_.get(task_id);
CHECK(task != nullptr);
CHECK(to_start_.empty());
inactivate_task(task_id, false);
for_each_child(task, [&](TaskId task_id) { try_start_task_later(task_id); });
for (TaskChainInfo &task_chain_info : task->chains) {
finish_chain_task(task_chain_info);
}
tasks_.erase(task_id);
flush_try_start_task();
}
template <class ExtraT>
void ChainScheduler<ExtraT>::reset_task(ChainScheduler::TaskId task_id) {
CHECK(to_start_.empty());
auto *task = tasks_.get(task_id);
CHECK(task != nullptr);
inactivate_task(task_id, true);
try_start_task_later(task_id);
flush_try_start_task();
}
template <class ExtraT>
void ChainScheduler<ExtraT>::pause_task(TaskId task_id) {
auto *task = tasks_.get(task_id);
CHECK(task != nullptr);
inactivate_task(task_id, true);
task->state = Task::State::Paused;
flush_try_start_task();
}
template <class ExtraT>
StringBuilder &operator<<(StringBuilder &sb, ChainScheduler<ExtraT> &scheduler) {
// 1 print chains
sb << '\n';
for (auto &it : scheduler.chains_) {
sb << "ChainId{" << it.first << "}";
sb << " active_cnt = " << it.second.active_tasks;
sb << " g = " << it.second.generation;
sb << ':';
it.second.chain.foreach(
[&](auto task_id, auto generation) { sb << ' ' << *scheduler.get_task_extra(task_id) << ':' << generation; });
sb << '\n';
}
scheduler.tasks_.for_each([&](auto id, auto &task) {
sb << "Task: " << task.extra;
sb << " state = " << static_cast<int>(task.state);
for (auto &task_chain_info : task.chains) {
sb << " g = " << task_chain_info.chain_node.generation;
if (task_chain_info.chain_info->generation != task_chain_info.chain_node.generation) {
sb << " chain_g = " << task_chain_info.chain_info->generation;
}
}
sb << '\n';
});
return sb;
}
} // namespace td