@startuml

'Copyright (c) 2021 Via Technology Ltd. All Rights Reserved.

'title OpenCL Application Sequence

actor "OpenCL Application" as user

participant "OpenCL\nplatforms" as platforms

participant "OpenCL\ndevices" as devices

participant "OpenCL\nContext" as opencl_context

participant "OpenCL\nCommandQueue" as opencl_queue

participant "OpenCL\nProgram" as opencl_program

participant "OpenCL\nKernel" as opencl_kernel

participant "OpenCL\nMemory" as opencl_memory

group Query
  user -> platforms : Query OpenCL platforms.
  user <- platforms : available OpenCL platforms

  user -> devices : Query OpenCL devices.
  user <- devices : available OpenCL devices
end

group Initialisation
  user -> user : Choose most appropriate\nplatform and device(s)

  user -> opencl_context : Construct OpenCL Context for platform and device(s)

  devices -> opencl_context : Context devices

  opencl_context -> opencl_queue : Create device\ncommand_queue(s)

  user -> opencl_context : Construct and build programs: source, binary and/or IL
  opencl_context -> opencl_program : Build program
  opencl_context -> opencl_kernel : Construct kernels for program

  user -> opencl_context : Create OpenCL memory
  opencl_context -> opencl_memory : Create: buffers, images, samplers, pipes, svm, etc.
end

group Compute Data
  user -> opencl_context : get kernel(s)

  group loop
    user -> opencl_memory : Write input data to OpenCL memory
    user -> opencl_queue : execute kernel(s)
    user <- opencl_memory : Read output data from OpenCL memory
    user <- opencl_queue : wait for events or queue finished
  end
end

group Clean Up
  user -> opencl_context : drop context

  opencl_context -> opencl_memory : release: buffers, images, samplers, pipes, svm, etc.
  opencl_context -> opencl_kernel : release kernels
  opencl_context -> opencl_program : release programs
  opencl_context -> opencl_queue : release command_queues
  opencl_context -> opencl_context : release context
end

@enduml