src/api/cpp/context-impl.h

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  35 #ifndef GMXAPI_CONTEXT_IMPL_H
  36 #define GMXAPI_CONTEXT_IMPL_H
  37 /*! \file
  38  * \brief Declare gmxapi::ContextImpl
  39  *
  40  * \author M. Eric Irrgang <ericirrgang@gmail.com>
  41  * \ingroup gmxapi
  42  */
  43
  44 #include <memory>
  45 #include <string>
  46
  47 #include "gromacs/mdrun/mdfilenames.h"
  48
  49 #include "gmxapi/context.h"
  50 #include "gmxapi/session.h"
  51
  52 namespace gmxapi
  53 {
  54
  55 /*!
  56  * \brief Context implementation base class.
  57  *
  58  * Execution contexts have a uniform interface specified by the API. Implementations for
  59  * particular execution environments can specialize / derive from this base.
  60  *
  61  * \todo Separate interface and implementation.
  62  * \ingroup gmxapi
  63  */
  64 class ContextImpl final : public std::enable_shared_from_this<ContextImpl>
  65 {
  66     public:
  67         /*!
  68          * \brief Default constructor.
  69          *
  70          * Don't use this. Use create() to get a shared pointer right away.
  71          * Otherwise, shared_from_this() is potentially dangerous.
  72          *
  73          * \todo Make default constructor private or otherwise reduce brittleness of construction.
  74          */
  75         ContextImpl();
  76
  77         /*!
  78          * \brief Factory function
  79          *
  80          * Since this class provides `shared_from_this`, we need to make sure
  81          * that it never exists without a shared_ptr owning it.
  82          *
  83          * If we can confirm `shared_from_this` is no longer necessary, implementation may change.
  84          *
  85          * \return ownership of a new object
  86          */
  87         static std::shared_ptr<gmxapi::ContextImpl> create();
  88
  89         /*!
  90          * \brief Copy disallowed because Session state would become ambiguous.
  91          *
  92          * The API implementation needs to unambiguously determine
  93          * which Sessions and Contexts are associated with each other.
  94          * \{
  95          */
  96         ContextImpl(const ContextImpl&) = delete;
  97         ContextImpl                  &operator=(const ContextImpl &) = delete;
  98         //! \}
  99
 100         /*!
 101          * \brief Objects are not trivial to move.
 102          *
 103          * \todo Implement move semantics.
 104          * \{
 105          */
 106         ContextImpl(ContextImpl &&)            = delete;
 107         ContextImpl &operator=(ContextImpl &&) = delete;
 108         //! \}
 109
 110         /*!
 111          * \brief Translate the workflow to the execution context and launch.
 112          *
 113          * \param work workflow graph
 114          * \return ownership of a new session
 115          *
 116          * \todo This probably makes more sense as a free function, but we need to determine access policies.
 117          *
 118          * Session is returned with shared_ptr ownership so that Context
 119          * can hold a weak_ptr and because Session Resources handles
 120          * are still evolving.
 121          * \todo Hide lifetime management and ownership from handle object.
 122          * We can achieve the necessary aspects of this shared_ptr at a lower level of implementation.
 123          */
 124         std::shared_ptr<Session> launch(const Workflow &work);
 125
 126         /*!
 127          * \brief Retain the ability to find a launched session while it exists.
 128          *
 129          * The client owns the Session launched by a Context, but it is helpful
 130          * for the Context to know if it has an active Session associated with it.
 131          */
 132         std::weak_ptr<Session>  session_;
 133
 134         /*!
 135          * \brief mdrun command line arguments.
 136          *
 137          * Store arguments provided by the client and pass them when launching
 138          * a simulation runner. This allows client code to access the same
 139          * options as are available to mdrun on the command line while the API
 140          * evolves.
 141          */
 142         MDArgs                  mdArgs_;
 143
 144         /*!
 145          * \brief Ensure lifetime of MD filenames options object exceeds that of session.
 146          */
 147         gmx::MdFilenames mdFilenames_;
 148 };
 149
 150 }      // end namespace gmxapi
 151 #endif //GMXAPI_CONTEXT_IMPL_H