milvus/core/src/scheduler/Scheduler.cpp

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// distributed with this work for additional information
// regarding copyright ownership.  The ASF licenses this file
// to you under the Apache License, Version 2.0 (the
// "License"); you may not use this file except in compliance
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//
//   http://www.apache.org/licenses/LICENSE-2.0
//
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// specific language governing permissions and limitations
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#include "scheduler/Scheduler.h"
#include "Algorithm.h"
#include "action/Action.h"
#include "cache/GpuCacheMgr.h"
#include "event/LoadCompletedEvent.h"

#include <utility>

namespace milvus {
namespace scheduler {

Scheduler::Scheduler(ResourceMgrWPtr res_mgr) : running_(false), res_mgr_(std::move(res_mgr)) {
    if (auto mgr = res_mgr_.lock()) {
        mgr->RegisterSubscriber(std::bind(&Scheduler::PostEvent, this, std::placeholders::_1));
    }
    event_register_.insert(std::make_pair(static_cast<uint64_t>(EventType::START_UP),
                                          std::bind(&Scheduler::OnStartUp, this, std::placeholders::_1)));
    event_register_.insert(std::make_pair(static_cast<uint64_t>(EventType::LOAD_COMPLETED),
                                          std::bind(&Scheduler::OnLoadCompleted, this, std::placeholders::_1)));
    event_register_.insert(std::make_pair(static_cast<uint64_t>(EventType::TASK_TABLE_UPDATED),
                                          std::bind(&Scheduler::OnTaskTableUpdated, this, std::placeholders::_1)));
    event_register_.insert(std::make_pair(static_cast<uint64_t>(EventType::FINISH_TASK),
                                          std::bind(&Scheduler::OnFinishTask, this, std::placeholders::_1)));
}

void
Scheduler::Start() {
    running_ = true;
    worker_thread_ = std::thread(&Scheduler::worker_function, this);
}

void
Scheduler::Stop() {
    {
        std::lock_guard<std::mutex> lock(event_mutex_);
        running_ = false;
        event_queue_.push(nullptr);
        event_cv_.notify_one();
    }
    worker_thread_.join();
}

void
Scheduler::PostEvent(const EventPtr& event) {
    {
        std::lock_guard<std::mutex> lock(event_mutex_);
        event_queue_.push(event);
    }
    event_cv_.notify_one();
}

json
Scheduler::Dump() const {
    json ret{
        {"running", running_},
        {"event_queue_length", event_queue_.size()},
    };
    return ret;
}

void
Scheduler::worker_function() {
    while (running_) {
        std::unique_lock<std::mutex> lock(event_mutex_);
        event_cv_.wait(lock, [this] { return !event_queue_.empty(); });
        auto event = event_queue_.front();
        event_queue_.pop();
        if (event == nullptr) {
            break;
        }

        Process(event);
    }
}

void
Scheduler::Process(const EventPtr& event) {
    auto process_event = event_register_.at(static_cast<int>(event->Type()));
    process_event(event);
}

// TODO(wxyu): refactor the function
void
Scheduler::OnLoadCompleted(const EventPtr& event) {
    auto load_completed_event = std::static_pointer_cast<LoadCompletedEvent>(event);
    if (auto resource = event->resource_.lock()) {
        resource->WakeupExecutor();

        auto task_table_type = load_completed_event->task_table_item_->task->label()->Type();
        switch (task_table_type) {
            case TaskLabelType::DEFAULT: {
                Action::DefaultLabelTaskScheduler(res_mgr_, resource, load_completed_event);
                break;
            }
            case TaskLabelType::SPECIFIED_RESOURCE: {
                Action::SpecifiedResourceLabelTaskScheduler(res_mgr_, resource, load_completed_event);
                break;
            }
            case TaskLabelType::BROADCAST: {
                if (resource->HasExecutor() == false) {
                    load_completed_event->task_table_item_->Move();
                }
                Action::PushTaskToAllNeighbour(load_completed_event->task_table_item_->task, resource);
                break;
            }
            default: { break; }
        }
        resource->WakeupLoader();
    }
}

void
Scheduler::OnStartUp(const EventPtr& event) {
    if (auto resource = event->resource_.lock()) {
        resource->WakeupLoader();
    }
}

void
Scheduler::OnFinishTask(const EventPtr& event) {
    if (auto resource = event->resource_.lock()) {
        resource->WakeupLoader();
    }
}

void
Scheduler::OnTaskTableUpdated(const EventPtr& event) {
    if (auto resource = event->resource_.lock()) {
        resource->WakeupLoader();
    }
}

}  // namespace scheduler
}  // namespace milvus