+/*
+ * This file is part of the GROMACS molecular simulation package.
+ *
+ * Copyright (c) 2016,2017, by the GROMACS development team, led by
+ * Mark Abraham, David van der Spoel, Berk Hess, and Erik Lindahl,
+ * and including many others, as listed in the AUTHORS file in the
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+
+/*! \libinternal \file
+ * \brief Defines the GPU region timer implementation/wrapper classes.
+ * The implementations live in gpuregiontimer.cuh for CUDA and gpuregiontimer_ocl.h for OpenCL.
+ *
+ * \author Aleksei Iupinov <a.yupinov@gmail.com>
+ */
+
+#ifndef GMX_GPU_UTILS_GPUREGIONTIMER_H
+#define GMX_GPU_UTILS_GPUREGIONTIMER_H
+
+#include <string>
+
+#include "gromacs/utility/gmxassert.h"
+
+//! Debug GPU timers in debug builds only
+#if defined(NDEBUG)
+static const bool c_debugTimerState = false;
+#else
+static const bool c_debugTimerState = true;
+#endif
+
+/*! \libinternal \brief
+ * Enumeration of possible GPU build-paths.
+ * \todo Move somewhere general?
+ */
+enum class GpuFramework
+{
+ CUDA,
+ OpenCL
+};
+
+/*! \libinternal \brief
+ * GPU build-path traits such as types.
+ * \todo Move somewhere general?
+ */
+template <GpuFramework> struct GpuTraits
+{
+ using CommandStream = void; //!< GPU command stream
+ using CommandEvent = void; //!< Single command call timing event - used in OpenCL
+};
+
+/*! \libinternal \brief
+ * This is a GPU region timing implementation interface.
+ * It should provide methods for measuring the last timespan.
+ */
+template <GpuFramework framework> class GpuRegionTimerImpl
+{
+ //! Short-hands
+ using CommandStream = typename GpuTraits<framework>::CommandStream;
+ using CommandEvent = typename GpuTraits<framework>::CommandEvent;
+
+ public:
+ GpuRegionTimerImpl() = default;
+ ~GpuRegionTimerImpl() = default;
+
+ /*! \brief Will be called before the region start. */
+ inline void openTimingRegion(CommandStream) = 0;
+ /*! \brief Will be called after the region end. */
+ inline void closeTimingRegion(CommandStream) = 0;
+ /*! \brief Resets any internal state if needed */
+ inline void reset() = 0;
+ /*! \brief Returns the last measured region timespan (in milliseconds) and calls reset() */
+ inline double getLastRangeTime() = 0;
+ /*! \brief Returns a new raw timing event
+ * for passing into individual GPU API calls
+ * within the region if the API requires it (e.g. on OpenCL). */
+ inline CommandEvent *fetchNextEvent() = 0;
+};
+
+/*! \libinternal \brief
+ * This is a GPU region timing wrapper class.
+ * It allows for host-side tracking of the execution timespans in GPU code
+ * (measuring kernel or transfers duration).
+ * It also partially tracks the correctness of the timer state transitions,
+ * as far as current implementation allows (see TODO in getLastRangeTime() for a disabled check).
+ * Internally it uses GpuRegionTimerImpl for measuring regions.
+ */
+template <GpuFramework framework> class GpuRegionTimerWrapper
+{
+ //! Short-hands
+ using CommandStream = typename GpuTraits<framework>::CommandStream;
+ using CommandEvent = typename GpuTraits<framework>::CommandEvent;
+ //! The timer state used for debug-only assertions
+ enum class TimerState
+ {
+ Idle,
+ Recording,
+ Stopped
+ } debugState_;
+
+ //! The underlying region timer implementation
+ GpuRegionTimerImpl<framework> impl_;
+
+ public:
+ GpuRegionTimerWrapper() : impl_()
+ {
+ reset();
+ }
+ ~GpuRegionTimerWrapper() = default;
+ /*! \brief
+ * To be called before the region start.
+ *
+ * \param[in] s The GPU command stream where the event being measured takes place.
+ */
+ void openTimingRegion(CommandStream s)
+ {
+ if (c_debugTimerState)
+ {
+ std::string error = "GPU timer should be idle, but is " + std::string((debugState_ == TimerState::Stopped) ? "stopped" : "recording") + ".";
+ GMX_ASSERT(debugState_ == TimerState::Idle, error.c_str());
+ debugState_ = TimerState::Recording;
+ }
+ impl_.openTimingRegion(s);
+ }
+ /*! \brief
+ * To be called after the region end.
+ *
+ * \param[in] s The GPU command stream where the event being measured takes place.
+ */
+ void closeTimingRegion(CommandStream s)
+ {
+ if (c_debugTimerState)
+ {
+ std::string error = "GPU timer should be recording, but is " + std::string((debugState_ == TimerState::Idle) ? "idle" : "stopped") + ".";
+ GMX_ASSERT(debugState_ == TimerState::Recording, error.c_str());
+ debugState_ = TimerState::Stopped;
+ }
+ impl_.closeTimingRegion(s);
+ }
+ /*! \brief
+ * Returns the last timespan, and resets the internal timer state.
+ * To be called after closeTimingRegion() and the command stream of the event having been synchronized.
+ * \returns The last timespan (in milliseconds).
+ */
+ double getLastRangeTime()
+ {
+ if (c_debugTimerState)
+ {
+ /* The assertion below is commented because it is currently triggered on a special case:
+ * the early return before the local non-bonded kernel launch if there is nothing to do.
+ * This can be reproduced in OpenCL build by running
+ * mdrun-mpi-test -ntmpi 2 --gtest_filter=*Empty*
+ * Similarly, the GpuRegionTimerImpl suffers from non-nullptr
+ * cl_event conditionals which ideally should only be asserts.
+ * TODO: improve internal task scheduling, re-enable the assert, turn conditionals into asserts
+ */
+ /*
+ std::string error = "GPU timer should be stopped, but is " + std::string((debugState_ == TimerState::Idle) ? "idle" : "recording") + ".";
+ GMX_ASSERT(debugState_ == TimerState::Stopped, error.c_str());
+ */
+ debugState_ = TimerState::Idle;
+ }
+ double milliseconds = impl_.getLastRangeTime();
+ return milliseconds;
+ }
+ /*! \brief Resets the implementation and total time/call count to zeroes. */
+ void reset()
+ {
+ if (c_debugTimerState)
+ {
+ debugState_ = TimerState::Idle;
+ }
+ impl_.reset();
+ }
+ /*! \brief
+ * Gets a pointer to a new timing event for passing into individual GPU API calls
+ * within the region if they require it (e.g. on OpenCL).
+ * \returns The pointer to the underlying single command timing event.
+ */
+ CommandEvent *fetchNextEvent()
+ {
+ if (c_debugTimerState)
+ {
+ std::string error = "GPU timer should be recording, but is " + std::string((debugState_ == TimerState::Idle) ? "idle" : "stopped") + ".";
+ GMX_ASSERT(debugState_ == TimerState::Recording, error.c_str());
+ }
+ return impl_.fetchNextEvent();
+ }
+};
+
+#endif