TcpDirectStack.h

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/*
* 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/FIX/ISessionReactor.h>
#include <OnixS/FIXEngine/FIX/TcpDirectAttr.h>
#include <OnixS/FIXEngine/Threading/Thread.h>

#include <cassert>

namespace OnixS {
namespace FIX {
class ReactorOperator;
namespace TCPDirect {

/**
 * A high-level wrapper over the TCPDirect stack.
 */
class ONIXS_FIXENGINE_API Stack : public ISessionReactor
{
public:
    /** Allocates a stack with the supplied attributes.
    *
    * \param attr A set of properties to apply to the stack.
    *
    * A stack binds to a single network interface, specified by the `interface` attribute in @p attr.    *
    *
    * Relevant attributes to set in @p attr are those in the `zf_stack`,
    * `zf_pool` and `zf_vi` categories described in the attributes documentation.
    *
    * \throws The std::bad_alloc is thrown in case of out of memory. N.B. Huge pages are required.
    * \throws The std::runtime_error is thrown if the TCPDirect library reported an error.
    * \throws The std::exception is thrown if a system call reported an error.
    */
    explicit Stack(const Attributes & attr);

#ifdef ONIXS_FIXENGINE_CXX11
    Stack(const Stack &) = delete;
    Stack(Stack &&) = delete;

    Stack & operator=(const Stack &) = delete;
    Stack & operator=(Stack &&) = delete;
#endif

    ~Stack();

    /**
     * Processes events on a stack and performs the necessary handling.
     *
     * These events include transmit and receive events raised by the hardware,
     * and also software events such as TCP and FIX protocol timers.
     *
     * Please see the "Stack polling" section in the TCPDirect User Guide for further information.
     *
     * \warning The event dispatching should be performed from the same thread that created the stack.
     */
    void dispatchEvents() ONIXS_FIXENGINE_OVERRIDE {
        // The TCPDirect middleware is NOT thread-safe.
        // Therefore, the event dispatching should be performed from the same thread that created the stack.

        assert(threadId() == Threading::ThisThread::id() && "should be performed from the same thread that created the stack");

        dispatchEventsImpl();
    }

    /**
    * \return a boolean value indicating whether a stack is quiescent.
     *
     * This can be used to ensure that all connections have been closed gracefully before the destroying of a stack
     * (or exiting the application). The destroying of a stack while it is not quiescent is permitted by the API,
     * but when doing so there is no guarantee that sent data has been acknowledged by the peer or even transmitted,
     * and there is the possibility that peers' connections will be reset.
     */
    bool isQuiescent() const ONIXS_FIXENGINE_OVERRIDE {
        assert(threadId() == Threading::ThisThread::id() && "should be performed from the same thread that created the stack");

        return isQuiescentImpl();
    }

    /**
     * Returns the ID of the thread that created the stack.
     *
     * \return the ID of the thread that created the stack.
     */
    Threading::ThreadId threadId() const ONIXS_FIXENGINE_OVERRIDE {
        return threadId_;
    }

    ReactorType::Enum type() const ONIXS_FIXENGINE_OVERRIDE {
        return ReactorType::TcpDirect;
    }

private:
    void dispatchEventsImpl();

    bool isQuiescentImpl() const;

    class Impl;
    Impl * const impl_;

    Threading::ThreadId const threadId_;

#ifndef ONIXS_FIXENGINE_CXX11
    Stack(const Stack &);
    Stack & operator=(const Stack &);
#endif

    friend class FIX::ReactorOperator;
};

}}}