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35 /*! \libinternal \file
36 * \brief Implements a GpuEventSynchronizer class for CUDA.
38 * \author Aleksei Iupinov <a.yupinov@gmail.com>
41 #ifndef GMX_GPU_UTILS_GPUEVENTSYNCHRONIZER_CUH
42 #define GMX_GPU_UTILS_GPUEVENTSYNCHRONIZER_CUH
44 #include "gromacs/gpu_utils/cudautils.cuh"
45 #include "gromacs/gpu_utils/device_stream.h"
46 #include "gromacs/gpu_utils/gputraits.cuh"
47 #include "gromacs/utility/gmxassert.h"
51 /*! \libinternal \brief
52 * A class which allows for CPU thread to mark and wait for certain GPU stream execution point.
53 * The event can be put into the stream with markEvent() and then later waited on with waitForEvent().
54 * This can be repeated as necessary, but the current implementation does not allow waiting on
55 * completed event more than once, expecting only exact pairs of markEvent(stream); waitForEvent().
56 * The class generally attempts to track the correctness of its state transitions, but
57 * please note that calling waitForEvent() right after the construction will succeed with CUDA but fail with OpenCL.
59 * Another possible mode of operation can be implemented if needed:
60 * multiple calls to waitForEvent() after a single markEvent().
61 * For this, only some small alterations to gpueventsynchronizer_ocl.h need to be made.
62 * This was tested to work both with CUDA and NVidia OpenCL, but not with AMD/Intel OpenCL.
64 class GpuEventSynchronizer
67 GpuEventSynchronizer()
69 cudaError_t gmx_used_in_debug stat = cudaEventCreateWithFlags(&event_, cudaEventDisableTiming);
70 GMX_RELEASE_ASSERT(stat == cudaSuccess,
71 ("cudaEventCreate failed. " + gmx::getDeviceErrorString(stat)).c_str());
73 ~GpuEventSynchronizer()
75 cudaError_t gmx_used_in_debug stat = cudaEventDestroy(event_);
76 GMX_RELEASE_ASSERT(stat == cudaSuccess,
77 ("cudaEventDestroy failed. " + gmx::getDeviceErrorString(stat)).c_str());
80 GpuEventSynchronizer(const GpuEventSynchronizer&) = delete;
82 GpuEventSynchronizer& operator=(GpuEventSynchronizer&&) = delete;
83 //! Moving is disabled but can be considered in the future if needed
84 GpuEventSynchronizer(GpuEventSynchronizer&&) = delete;
86 /*! \brief Marks the synchronization point in the \p stream.
87 * Should be followed by waitForEvent().
89 inline void markEvent(const DeviceStream& deviceStream)
91 cudaError_t gmx_used_in_debug stat = cudaEventRecord(event_, deviceStream.stream());
92 GMX_ASSERT(stat == cudaSuccess,
93 ("cudaEventRecord failed. " + gmx::getDeviceErrorString(stat)).c_str());
95 /*! \brief Synchronizes the host thread on the marked event. */
96 inline void waitForEvent()
98 cudaError_t gmx_used_in_debug stat = cudaEventSynchronize(event_);
99 GMX_ASSERT(stat == cudaSuccess,
100 ("cudaEventSynchronize failed. " + gmx::getDeviceErrorString(stat)).c_str());
102 /*! \brief Enqueues a wait for the recorded event in stream \p stream */
103 inline void enqueueWaitEvent(const DeviceStream& deviceStream)
105 cudaError_t gmx_used_in_debug stat = cudaStreamWaitEvent(deviceStream.stream(), event_, 0);
106 GMX_ASSERT(stat == cudaSuccess,
107 ("cudaStreamWaitEvent failed. " + gmx::getDeviceErrorString(stat)).c_str());