Semaphore.h

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/*
* Copyright Onix Solutions Limited [OnixS]. All rights reserved.
*
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* and international copyright treaties.
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* Except as otherwise granted within the terms of the Agreement, copying or reproduction of any part
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#pragma once

#include <OnixS/FIXEngine/ABI.h>

namespace OnixS {
namespace Threading {
/// The limits number of threads that can access the shared resource simultaneously.
class ONIXS_FIXENGINE_API Semaphore
{
public:
    /// Initializes the instance with the given value of
    /// the "count". The @param count indicates the initial "count"
    /// for the semaphore. The state of the semaphore is signaled
    /// when its count is greater than zero and
    /// non-signaled when it is zero.
    Semaphore(unsigned int count = 1);

    /// Destructs the object.
    ~Semaphore();

    /// Decrements the semaphore "counter" by one.
    /// If the semaphore "counter" is already zero,
    /// blocks the thread until the semaphore "count"
    /// becomes greater than zero.
    void acquire();

    /// Tries to acquire the semaphore object. If
    /// its "counter" is already zero, returns
    /// @c false. In all cases, it doesn't block
    /// the thread and quites immediately.
    bool tryAcquire();

    /// Increments the semaphore "counter" by one.
    /// If there are other threads waiting for
    /// the object, it blocks one the them.
    void release();

private:
    // Implementation details.
    void * impl_;

    // Copying & assignment is prohibited.

    Semaphore(const Semaphore &);
    Semaphore & operator = (const Semaphore &);
};
}
}