    {-# LANGUAGE Trustworthy #-}
    {-# LANGUAGE NoImplicitPrelude #-}

    -- | @since base-4.7.0.0
    module GHC.Internal.Profiling ( -- * Cost Centre Profiling
                           startProfTimer
                         , stopProfTimer
                           -- * Heap Profiling
                         , startHeapProfTimer
                         , stopHeapProfTimer
                         , requestHeapCensus
                           -- * Ticky counters (eventlog)
                         , requestTickyCounterSamples
                         )where

    import GHC.Internal.Base

    -- | Stop attributing ticks to cost centres. Allocations will still be
    -- attributed.
    --
    -- @since base-4.7.0.0
    foreign import ccall stopProfTimer :: IO ()

    -- | Start attributing ticks to cost centres. This is called by the RTS on
    -- startup but can be disabled using the rts flag @--no-automatic-time-samples@.
    --
    -- @since base-4.7.0.0
    foreign import ccall startProfTimer :: IO ()

    -- | Request a heap census on the next context switch. The census can be
    -- requested whether or not the heap profiling timer is running.
    --
    -- Note: This won't do anything unless you also specify a profiling mode on the
    -- command line using the normal RTS options.
    --
    -- @since base-4.16.0.0
    foreign import ccall requestHeapCensus :: IO ()

    -- | Start heap profiling. This is called normally by the RTS on start-up,
    -- but can be disabled using the rts flag @--no-automatic-heap-samples@.
    --
    -- Note: This won't do anything unless you also specify a profiling mode on the
    -- command line using the normal RTS options.
    --
    -- @since base-4.16.0.0
    foreign import ccall startHeapProfTimer :: IO ()

    -- | Stop heap profiling.
    --
    -- Note: This won't do anything unless you also specify a profiling mode on the
    -- command line using the normal RTS options.
    --
    -- @since base-4.16.0.0
    foreign import ccall stopHeapProfTimer :: IO ()

    -- | Request ticky counter samples to be written to the eventlog.
    --
    -- Note: This won't do anything unless you have specified RTS options on
    -- the command line to log ticky samples to the eventlog.
    --
    -- @since base-4.20.0.0

    foreign import ccall requestTickyCounterSamples :: IO ()