/*
* Copyright Onix Solutions Limited [OnixS]. All rights reserved.
*
* This software owned by Onix Solutions Limited [OnixS] and is protected by copyright law
* and international copyright treaties.
*
* Access to and use of the software is governed by the terms of the applicable OnixS Software
* Services Agreement (the Agreement) and Customer end user license agreements granting
* a non-assignable, non-transferable and non-exclusive license to use the software
* for it's own data processing purposes under the terms defined in the Agreement.
*
* Except as otherwise granted within the terms of the Agreement, copying or reproduction of any part
* of this source code or associated reference material to any other location for further reproduction
* or redistribution, and any amendments to this copyright notice, are expressly prohibited.
*
* Any reproduction or redistribution for sale or hiring of the Software not in accordance with
* the terms of the Agreement is a violation of copyright law.
*/

#pragma once

#include <OnixS/FIXEngine/ABI.h>
#include <OnixS/FIXEngine/Threading/Definitions.h>

#include <set>
#include <string>

namespace OnixS {
namespace Threading {
/// Logical processors that a thread is allowed to run on (first logical CPU has index 0).
typedef size_t CpuIndex;
typedef std::set < CpuIndex > CpuIndexes;

/// Represents set of CPU indices.
class ONIXS_FIXENGINE_API ThreadAffinity
{
public:

    /// Constructs the thread affinity from the string presentation.
    /// The symbol ',' is used as the CPU index delimiter.
    explicit ThreadAffinity(const std::string & str);

    /// Destructs the instance.
    ~ThreadAffinity();

    /// The read-only access to the index collection.
    const CpuIndexes & cpuIndexes() const;

    /// The collection of CPU indices.
    CpuIndexes & cpuIndexes();

    /// Serializes the thread affinity to the string presentation.
    std::string toString();

private:

    // The copying and assignment are prohibited.
    ThreadAffinity(const ThreadAffinity &);
    ThreadAffinity & operator = (const ThreadAffinity &);

    CpuIndexes * indexes_;
};

/// Exposes manipulations over the current thread.
class ONIXS_FIXENGINE_API ThisThread
{
public:
    /// Suspends the execution of the current thread for
    /// a given amount of time in milliseconds.
    static void sleep(unsigned int milliseconds);

    /// Executes a singular instruction during the given number of microseconds.
    static void spinWait(int microseconds);

    /// Sets the processor affinity mask for the current thread.
    static void affinity(const CpuIndexes & cpuIndexes);

    /// Sets the processor affinity mask for the current thread.
    static void affinity(CpuIndex cpuIndex);

    /// Sets the priority for the current thread.
    static void priority(int priority);

    /// Sets the scheduling policy for the current thread.
    ///
    /// @note This method also sets the priority to the minimal value for the new policy,
    /// therefore, the priority should be set to a necessary value afterwards.
    static void policy(int policy);

    /// Gets the platform identifier for the current thread.
    static ThreadId id();

private:
    // No instances of the current thread are available.
    ThisThread(const ThisThread &);
    ThisThread & operator = (const ThisThread &);
};

/// Manipulates a thread.
/// Custom thread classes should derive from this class and implement the 'run' method.
class ONIXS_FIXENGINE_API Thread
{
public:

    /// Creates the `Thread` object without running a real thread.
    explicit Thread(const std::string & name);

    /// Cleans up internal resources.
    ///
    /// @note Calls the `std::terminate` if the thread is not stopped at the moment.
    virtual ~Thread();

    /// Creates and runs an actual thread.
    /// Can be called only once for the current 'Thread' instance.
    ///
    /// @throw The std::exception if the thread is started or joined already.
    void start();

    /// Sends a stop signal to the thread.
    void stopAsync();

    /// Returns 'true' if a stop signal is sent to the thread
    /// by the `stopAsync` method or in a different way, otherwise 'false'.
    bool stopRequested() const;

    /// Joins the thread completion.
    void join() const;

    /// Returns the platform identifier.
    ThreadId id() const;

private:

    /// The thread procedure.
    virtual void run() = 0;

    /// Implementation details.
    struct Impl;
    Impl * impl_;

    /// The copying and assignment are prohibited.
    Thread(const Thread &);
    Thread & operator = (const Thread &);
};

}
}