{-# LANGUAGE Trustworthy #-} {-# LANGUAGE NoImplicitPrelude #-} {-# LANGUAGE RecordWildCards #-} {-# OPTIONS_GHC -funbox-strict-fields #-} ----------------------------------------------------------------------------- -- | This module provides access to internal garbage collection and -- memory usage statistics. These statistics are not available unless -- a program is run with the @-T@ RTS flag. -- -- This module is GHC-only and should not be considered portable. -- -- @since 4.5.0.0 ----------------------------------------------------------------------------- module GHC.Stats ( -- * Runtime statistics RTSStats(..), GCDetails(..), RtsTime , getRTSStats , getRTSStatsEnabled ) where import Control.Monad import Data.Int import Data.Word import GHC.Base import GHC.Read ( Read ) import GHC.Show ( Show ) import GHC.IO.Exception import Foreign.Marshal.Alloc import Foreign.Storable import Foreign.Ptr #include "Rts.h" foreign import ccall "getRTSStats" getRTSStats_ :: Ptr () -> IO () -- | Returns whether GC stats have been enabled (with @+RTS -T@, for example). -- -- @since 4.10.0.0 foreign import ccall "getRTSStatsEnabled" getRTSStatsEnabled :: IO Bool -- -- | Statistics about runtime activity since the start of the -- program. This is a mirror of the C @struct RTSStats@ in @RtsAPI.h@ -- -- @since 4.10.0.0 -- data RTSStats = RTSStats { -- ----------------------------------- -- Cumulative stats about memory use -- | Total number of GCs gcs :: Word32 -- | Total number of major (oldest generation) GCs , major_gcs :: Word32 -- | Total bytes allocated , allocated_bytes :: Word64 -- | Maximum live data (including large objects + compact regions) in the -- heap. Updated after a major GC. , max_live_bytes :: Word64 -- | Maximum live data in large objects , max_large_objects_bytes :: Word64 -- | Maximum live data in compact regions , max_compact_bytes :: Word64 -- | Maximum slop , max_slop_bytes :: Word64 -- | Maximum memory in use by the RTS , max_mem_in_use_bytes :: Word64 -- | Sum of live bytes across all major GCs. Divided by major_gcs -- gives the average live data over the lifetime of the program. , cumulative_live_bytes :: Word64 -- | Sum of copied_bytes across all GCs , copied_bytes :: Word64 -- | Sum of copied_bytes across all parallel GCs , par_copied_bytes :: Word64 -- | Sum of par_max_copied_bytes across all parallel GCs. Deprecated. , cumulative_par_max_copied_bytes :: Word64 -- | Sum of par_balanced_copied bytes across all parallel GCs , cumulative_par_balanced_copied_bytes :: Word64 -- ----------------------------------- -- Cumulative stats about time use -- (we use signed values here because due to inaccuracies in timers -- the values can occasionally go slightly negative) -- | Total CPU time used by the init phase -- @since 4.12.0.0 , init_cpu_ns :: RtsTime -- | Total elapsed time used by the init phase -- @since 4.12.0.0 , init_elapsed_ns :: RtsTime -- | Total CPU time used by the mutator , mutator_cpu_ns :: RtsTime -- | Total elapsed time used by the mutator , mutator_elapsed_ns :: RtsTime -- | Total CPU time used by the GC , gc_cpu_ns :: RtsTime -- | Total elapsed time used by the GC , gc_elapsed_ns :: RtsTime -- | Total CPU time (at the previous GC) , cpu_ns :: RtsTime -- | Total elapsed time (at the previous GC) , elapsed_ns :: RtsTime -- | Details about the most recent GC , gc :: GCDetails } deriving ( Read -- ^ @since 4.10.0.0 , Show -- ^ @since 4.10.0.0 ) -- -- | Statistics about a single GC. This is a mirror of the C @struct -- GCDetails@ in @RtsAPI.h@, with the field prefixed with @gc_@ to -- avoid collisions with 'RTSStats'. -- data GCDetails = GCDetails { -- | The generation number of this GC gcdetails_gen :: Word32 -- | Number of threads used in this GC , gcdetails_threads :: Word32 -- | Number of bytes allocated since the previous GC , gcdetails_allocated_bytes :: Word64 -- | Total amount of live data in the heap (incliudes large + compact data). -- Updated after every GC. Data in uncollected generations (in minor GCs) -- are considered live. , gcdetails_live_bytes :: Word64 -- | Total amount of live data in large objects , gcdetails_large_objects_bytes :: Word64 -- | Total amount of live data in compact regions , gcdetails_compact_bytes :: Word64 -- | Total amount of slop (wasted memory) , gcdetails_slop_bytes :: Word64 -- | Total amount of memory in use by the RTS , gcdetails_mem_in_use_bytes :: Word64 -- | Total amount of data copied during this GC , gcdetails_copied_bytes :: Word64 -- | In parallel GC, the max amount of data copied by any one thread. -- Deprecated. , gcdetails_par_max_copied_bytes :: Word64 -- | In parallel GC, the amount of balanced data copied by all threads , gcdetails_par_balanced_copied_bytes :: Word64 -- | The time elapsed during synchronisation before GC , gcdetails_sync_elapsed_ns :: RtsTime -- | The CPU time used during GC itself , gcdetails_cpu_ns :: RtsTime -- | The time elapsed during GC itself , gcdetails_elapsed_ns :: RtsTime } deriving ( Read -- ^ @since 4.10.0.0 , Show -- ^ @since 4.10.0.0 ) -- | Time values from the RTS, using a fixed resolution of nanoseconds. type RtsTime = Int64 -- | Get current runtime system statistics. -- -- @since 4.10.0.0 -- getRTSStats :: IO RTSStats getRTSStats = do statsEnabled <- getRTSStatsEnabled unless statsEnabled . ioError $ IOError Nothing UnsupportedOperation "" "GHC.Stats.getRTSStats: GC stats not enabled. Use `+RTS -T -RTS' to enable them." Nothing Nothing allocaBytes (#size RTSStats) $ \p -> do getRTSStats_ p gcs <- (# peek RTSStats, gcs) p major_gcs <- (# peek RTSStats, major_gcs) p allocated_bytes <- (# peek RTSStats, allocated_bytes) p max_live_bytes <- (# peek RTSStats, max_live_bytes) p max_large_objects_bytes <- (# peek RTSStats, max_large_objects_bytes) p max_compact_bytes <- (# peek RTSStats, max_compact_bytes) p max_slop_bytes <- (# peek RTSStats, max_slop_bytes) p max_mem_in_use_bytes <- (# peek RTSStats, max_mem_in_use_bytes) p cumulative_live_bytes <- (# peek RTSStats, cumulative_live_bytes) p copied_bytes <- (# peek RTSStats, copied_bytes) p par_copied_bytes <- (# peek RTSStats, par_copied_bytes) p cumulative_par_max_copied_bytes <- (# peek RTSStats, cumulative_par_max_copied_bytes) p cumulative_par_balanced_copied_bytes <- (# peek RTSStats, cumulative_par_balanced_copied_bytes) p init_cpu_ns <- (# peek RTSStats, init_cpu_ns) p init_elapsed_ns <- (# peek RTSStats, init_elapsed_ns) p mutator_cpu_ns <- (# peek RTSStats, mutator_cpu_ns) p mutator_elapsed_ns <- (# peek RTSStats, mutator_elapsed_ns) p gc_cpu_ns <- (# peek RTSStats, gc_cpu_ns) p gc_elapsed_ns <- (# peek RTSStats, gc_elapsed_ns) p cpu_ns <- (# peek RTSStats, cpu_ns) p elapsed_ns <- (# peek RTSStats, elapsed_ns) p let pgc = (# ptr RTSStats, gc) p gc <- do gcdetails_gen <- (# peek GCDetails, gen) pgc gcdetails_threads <- (# peek GCDetails, threads) pgc gcdetails_allocated_bytes <- (# peek GCDetails, allocated_bytes) pgc gcdetails_live_bytes <- (# peek GCDetails, live_bytes) pgc gcdetails_large_objects_bytes <- (# peek GCDetails, large_objects_bytes) pgc gcdetails_compact_bytes <- (# peek GCDetails, compact_bytes) pgc gcdetails_slop_bytes <- (# peek GCDetails, slop_bytes) pgc gcdetails_mem_in_use_bytes <- (# peek GCDetails, mem_in_use_bytes) pgc gcdetails_copied_bytes <- (# peek GCDetails, copied_bytes) pgc gcdetails_par_max_copied_bytes <- (# peek GCDetails, par_max_copied_bytes) pgc gcdetails_par_balanced_copied_bytes <- (# peek GCDetails, par_balanced_copied_bytes) pgc gcdetails_sync_elapsed_ns <- (# peek GCDetails, sync_elapsed_ns) pgc gcdetails_cpu_ns <- (# peek GCDetails, cpu_ns) pgc gcdetails_elapsed_ns <- (# peek GCDetails, elapsed_ns) pgc return GCDetails{..} return RTSStats{..}