InstanceLimit.hpublic header

Defines struct fair::mq::tools::InstanceLimiter.

fairmq/tools/InstanceLimit.h54 lines · C++API: InstanceLimiterGitHub ↗

1/********************************************************************************2 *    Copyright (C) 2019 GSI Helmholtzzentrum fuer Schwerionenforschung GmbH    *3 *                                                                              *4 *              This software is distributed under the terms of the             *5 *              GNU Lesser General Public Licence (LGPL) version 3,             *6 *                  copied verbatim in the file "LICENSE"                       *7 ********************************************************************************/8 9#ifndef FAIR_MQ_TOOLS_INSTANCELIMIT_H10#define FAIR_MQ_TOOLS_INSTANCELIMIT_H11 12#include "Strings.h"13 14namespace fair::mq::tools15{16 17template<typename Tag, int Max>18struct InstanceLimiter19{20    InstanceLimiter() { Increment(); }21    explicit InstanceLimiter(const InstanceLimiter&) = delete;22    explicit InstanceLimiter(InstanceLimiter&&) = delete;23    InstanceLimiter& operator=(const InstanceLimiter&) = delete;24    InstanceLimiter& operator=(InstanceLimiter&&) = delete;25    ~InstanceLimiter() { Decrement(); }26    auto GetCount() -> int { return fCount; }27 28  private:29    auto Increment() -> void30    {31        if (fCount < Max) {32            ++fCount;33        } else {34            throw std::runtime_error(35                ToString("More than ", Max, " instances of ", Tag(), " in parallel not supported"));36        }37    }38 39    auto Decrement() -> void40    {41        if (fCount > 0) {42            --fCount;43        }44    }45 46    static int fCount; // NOLINT(cppcoreguidelines-avoid-non-const-global-variables)47};48 49template<typename Tag, int Max>50int InstanceLimiter<Tag, Max>::fCount(0); // NOLINT(cppcoreguidelines-avoid-non-const-global-variables)51 52} // namespace fair::mq::tools53 54#endif /* FAIR_MQ_TOOLS_INSTANCELIMIT_H */