kea/src/lib/util/interprocess_sync.h

// Copyright (C) 2012  Internet Systems Consortium, Inc. ("ISC")
//
// Permission to use, copy, modify, and/or distribute this software for any
// purpose with or without fee is hereby granted, provided that the above
// copyright notice and this permission notice appear in all copies.
//
// THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
// REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
// AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
// INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
// LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
// OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
// PERFORMANCE OF THIS SOFTWARE.

#ifndef __INTERPROCESS_SYNC_H__
#define __INTERPROCESS_SYNC_H__

#include <string>

namespace isc {
namespace util {

class InterprocessSyncLocker;

class InterprocessSync {
public:
    /// \brief Constructor
    ///
    /// Creates a interprocess synchronization object
    InterprocessSync(const std::string component_name) :
        component_name_(component_name)
    {}

    /// \brief Destructor
    virtual ~InterprocessSync() {}

    virtual InterprocessSyncLocker* getLocker() = 0;

protected:
    std::string component_name_;
};

class InterprocessSyncLocker {
friend class InterprocessSync;
public:
    virtual bool lock() = 0;
    virtual bool tryLock() = 0;
    virtual bool unlock() = 0;

    /// \brief Destructor
    virtual ~InterprocessSyncLocker() {}

protected:
    InterprocessSyncLocker(InterprocessSync* sync) :
        sync_(sync), is_locked_(false)
    {}
    InterprocessSync* sync_;
    bool is_locked_;
};

} // namespace util
} // namespace isc

#endif // __INTERPROCESS_SYNC_H__