// Licensed to the Apache Software Foundation (ASF) under one

// or more contributor license agreements.  See the NOTICE file

// 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

// with the License.  You may obtain a copy of the License at

//

//   http://www.apache.org/licenses/LICENSE-2.0

//

// Unless required by applicable law or agreed to in writing,

// software distributed under the License is distributed on an

// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY

// KIND, either express or implied.  See the License for the

// specific language governing permissions and limitations

// under the License.

// bthread - An M:N threading library to make applications more concurrent.

// Date: Tue Jul 10 17:40:58 CST 2012

#ifndef BTHREAD_TASK_CONTROL_H

#define BTHREAD_TASK_CONTROL_H

#ifndef NDEBUG

#include <iostream>                             // std::ostream

#endif

#include <signal.h>

#include <stddef.h>                             // size_t

#include <vector>

#include <array>

#include <memory>

#include "butil/atomicops.h"                     // butil::atomic

#include "bvar/bvar.h"                          // bvar::PassiveStatus

#include "bthread/task_tracer.h"

#include "bthread/task_meta.h"                  // TaskMeta

#include "bthread/work_stealing_queue.h"        // WorkStealingQueue

#include "bthread/parking_lot.h"

DECLARE_int32(task_group_ntags);

namespace bthread {

class TaskGroup;

// Control all task groups

class TaskControl {

friend class TaskGroup;

friend void wait_for_butex(void*);

#ifdef BRPC_BTHREAD_TRACER

friend bthread_t init_for_pthread_stack_trace();

#endif // BRPC_BTHREAD_TRACER

public:

    TaskControl();

    ~TaskControl();

    // Must be called before using. `nconcurrency' is # of worker pthreads.

    int init(int nconcurrency);

    // Create a TaskGroup in this control.

    TaskGroup* create_group(bthread_tag_t tag);

    // Steal a task from a "random" group.

    bool steal_task(bthread_t* tid, size_t* seed, size_t offset);

    // Tell other groups that `n' tasks was just added to caller's runqueue

    void signal_task(int num_task, bthread_tag_t tag);

    // Stop and join worker threads in TaskControl.

    void stop_and_join();

    // Get # of worker threads.

    int concurrency() const 

    { return _concurrency.load(butil::memory_order_acquire); }

    int concurrency(bthread_tag_t tag) const 

    { return _tagged_ngroup[tag].load(butil::memory_order_acquire); }

    void print_rq_sizes(std::ostream& os);

    double get_cumulated_worker_time();

    double get_cumulated_worker_time(bthread_tag_t tag);

    int64_t get_cumulated_switch_count();

    int64_t get_cumulated_signal_count();

    // [Not thread safe] Add more worker threads.

    // Return the number of workers actually added, which may be less than |num|

    int add_workers(int num, bthread_tag_t tag);

    // Choose one TaskGroup (randomly right now).

    // If this method is called after init(), it never returns NULL.

    TaskGroup* choose_one_group(bthread_tag_t tag);

    // Parse FLAGS_cpu_set into _tag_cpus.  Two formats are accepted:

    //   Legacy (all tags share one set): "0-3,5,7"

    //   Per-tag:  "0:0-3,5,7;1:6-9,4"

    // Tags not mentioned get an empty cpu list (= no binding).

    // Returns -1 on parse error.

    int parse_cpuset(const std::string& value);

    static void bind_thread_to_cpu(pthread_t pthread, unsigned cpu_id);

#ifdef BRPC_BTHREAD_TRACER

    // A stacktrace of bthread can be helpful in debugging.

    void stack_trace(std::ostream& os, bthread_t tid);

    std::string stack_trace(bthread_t tid);

#endif // BRPC_BTHREAD_TRACER

    void push_ed_priority_queue(

            bthread_tag_t tag, int priority_index, bthread_t tid) {

        ed_priority_queue(tag, priority_index).push(tid);

    }

    std::vector<bthread_t> get_living_bthreads();

private:

    typedef std::array<TaskGroup*, BTHREAD_MAX_CONCURRENCY> TaggedGroups;

    typedef std::array<ParkingLot, BTHREAD_MAX_PARKINGLOT> TaggedParkingLot;

    // Add/Remove a TaskGroup.

    // Returns 0 on success, -1 otherwise.

    int _add_group(TaskGroup*, bthread_tag_t tag);

    int _destroy_group(TaskGroup*);

    // Tag group

    TaggedGroups& tag_group(bthread_tag_t tag) { return _tagged_groups[tag]; }

    // Tag ngroup

    butil::atomic<size_t>& tag_ngroup(int tag) { return _tagged_ngroup[tag]; }

    // Tag parking slot

    TaggedParkingLot& tag_pl(bthread_tag_t tag) { return _tagged_pl[tag]; }

    // Priority queue for a specific ED within a tag

    WorkStealingQueue<bthread_t>& ed_priority_queue(

            bthread_tag_t tag, int index) {

        return _ed_priority_queues[

            tag * _ed_priority_queue_num_of_each_tag + index];

    }

    int init_ed_priority_queues();

    static void delete_task_group(void* arg);

    static void* worker_thread(void* task_control);

    template <typename F>

    void for_each_task_group(F const& f);

    bvar::LatencyRecorder& exposed_pending_time();

    bvar::LatencyRecorder* create_exposed_pending_time();

    bvar::Adder<int64_t>& tag_nworkers(bthread_tag_t tag);

    bvar::Adder<int64_t>& tag_nbthreads(bthread_tag_t tag);

    std::vector<butil::atomic<size_t>> _tagged_ngroup;

    std::vector<TaggedGroups> _tagged_groups;

    butil::Mutex _modify_group_mutex;

    butil::atomic<bool> _init;  // if not init, bvar will case coredump

    bool _stop;

    butil::atomic<int> _concurrency;

    std::vector<pthread_t> _workers;

    bvar::Adder<int64_t> _nworkers;

    butil::Mutex _pending_time_mutex;

    butil::atomic<bvar::LatencyRecorder*> _pending_time;

    bvar::PassiveStatus<double> _cumulated_worker_time;

    bvar::PerSecond<bvar::PassiveStatus<double> > _worker_usage_second;

    bvar::PassiveStatus<int64_t> _cumulated_switch_count;

    bvar::PerSecond<bvar::PassiveStatus<int64_t> > _switch_per_second;

    bvar::PassiveStatus<int64_t> _cumulated_signal_count;

    bvar::PerSecond<bvar::PassiveStatus<int64_t> > _signal_per_second;

    bvar::PassiveStatus<std::string> _status;

    bvar::Adder<int64_t> _nbthreads;

    std::vector<bvar::Adder<int64_t>*> _tagged_nworkers;

    std::vector<bvar::PassiveStatus<double>*> _tagged_cumulated_worker_time;

    std::vector<bvar::PerSecond<bvar::PassiveStatus<double>>*> _tagged_worker_usage_second;

    std::vector<bvar::Adder<int64_t>*> _tagged_nbthreads;

    bool _enable_priority_queue;

    int _ed_priority_queue_num_of_each_tag;

    std::vector<WorkStealingQueue<bthread_t>> _ed_priority_queues;

    size_t _pl_num_of_each_tag;

    std::vector<TaggedParkingLot> _tagged_pl;

    // Per-tag CPU binding lists.  _tag_cpus[tag] is the round-robin list of

    // CPU IDs to which workers of that tag are bound.  Empty means no binding.

    std::vector<std::vector<unsigned>> _tag_cpus;

    // Per-tag monotonic counter for round-robin CPU assignment.

    // Incremented once per worker created for that tag (in worker_thread).

    std::vector<butil::atomic<int>> _tag_next_worker_id;

#ifdef BRPC_BTHREAD_TRACER

    TaskTracer _task_tracer;

#endif // BRPC_BTHREAD_TRACER

};

inline bvar::LatencyRecorder& TaskControl::exposed_pending_time() {

    bvar::LatencyRecorder* pt = _pending_time.load(butil::memory_order_consume);

    if (!pt) {

        pt = create_exposed_pending_time();

    }

    return *pt;

}

inline bvar::Adder<int64_t>& TaskControl::tag_nworkers(bthread_tag_t tag) {

    return *_tagged_nworkers[tag];

}

inline bvar::Adder<int64_t>& TaskControl::tag_nbthreads(bthread_tag_t tag) {

    return *_tagged_nbthreads[tag];

}

template <typename F>

inline void TaskControl::for_each_task_group(F const& f) {

    if (_init.load(butil::memory_order_acquire) == false) {

        return;

    }

    for (size_t i = 0; i < _tagged_groups.size(); ++i) {

        auto ngroup = tag_ngroup(i).load(butil::memory_order_relaxed);

        auto& groups = tag_group(i);

        for (size_t j = 0; j < ngroup; ++j) {

            f(groups[j]);

        }

    }

}

Unexecuted instantiation: task_control.cpp:void bthread::TaskControl::for_each_task_group<bthread::TaskControl::print_rq_sizes(std::basic_ostream<char, std::char_traits<char> >&)::$_1>(bthread::TaskControl::print_rq_sizes(std::basic_ostream<char, std::char_traits<char> >&)::$_1 const&)

Unexecuted instantiation: task_control.cpp:void bthread::TaskControl::for_each_task_group<bthread::TaskControl::get_cumulated_worker_time()::$_0>(bthread::TaskControl::get_cumulated_worker_time()::$_0 const&)

Unexecuted instantiation: task_control.cpp:void bthread::TaskControl::for_each_task_group<bthread::TaskControl::get_cumulated_switch_count()::$_0>(bthread::TaskControl::get_cumulated_switch_count()::$_0 const&)

Unexecuted instantiation: task_control.cpp:void bthread::TaskControl::for_each_task_group<bthread::TaskControl::get_cumulated_signal_count()::$_0>(bthread::TaskControl::get_cumulated_signal_count()::$_0 const&)

}  // namespace bthread

#endif  // BTHREAD_TASK_CONTROL_H