Copyright	(C) 2026 Edward Kmett
License	UPL-1.0 AND BSD-3-Clause
Maintainer	Edward Kmett <ekmett@gmail.com>
Stability	experimental
Portability	THC with the pinned Graal integration; native fallback statuses
Safe Haskell	Unsafe
Language	Haskell2010

THC.Internal.JIT

Description

Unstable, potentially hazardous Graal diagnostics. This module is deliberately Unsafe for Safe Haskell and is not re-exported by THC. Enabling callbacks affects compilation behavior and overhead; the Graal integration is version-pinned. No Java handles or forced recompilation are exposed. Counters are context-attributed, not JVM-wide.

Synopsis

data Available a
- = Available a
- | Unsupported
- | Disabled
- | Denied
- | Unavailable
data JitSnapshot = JitSnapshot {
- compilationsStarted :: Available Word64
- compilationsSucceeded :: Available Word64
- compilationsFailed :: Available Word64
- invalidations :: Available Word64
- deoptimizations :: Available Word64
- compilationsQueued :: Available Word64
}
jitTelemetryEnabled :: IO (Available Bool)
setJitTelemetryEnabled :: Bool -> IO (Available ())
jitSnapshot :: IO JitSnapshot

Documentation

data Available a Source #

An absent metric is not zero. Queries never enable JVM-wide monitoring. fmap transforms a genuine value and preserves every non-value status:

>>> fmap (+ 1) (Available (41 :: Int))
Available 42
>>> fmap (+ 1) (Disabled :: Available Int)
Disabled
>>> map (fmap (+ 1)) [Unsupported, Disabled, Denied, Unavailable :: Available Int]
[Unsupported,Disabled,Denied,Unavailable]

Constructors

Available a	A genuine value; its scope is specified by the query.
Unsupported	The runtime or provider does not implement this service.
Disabled	Supported, but its instrumentation or sink is switched off.
Denied	The current context or host security policy forbids access.
Unavailable	Normally supported, but no value is currently available.

Instances

Instances details

Functor Available #
Instance details Defined in THC.Runtime.Types Methods fmap :: (a -> b) -> Available a -> Available b # (<$) :: a -> Available b -> Available a #
Eq a => Eq (Available a) #
Instance details Defined in THC.Runtime.Types Methods (==) :: Available a -> Available a -> Bool # (/=) :: Available a -> Available a -> Bool #
Ord a => Ord (Available a) #
Instance details Defined in THC.Runtime.Types Methods compare :: Available a -> Available a -> Ordering # (<) :: Available a -> Available a -> Bool # (<=) :: Available a -> Available a -> Bool # (>) :: Available a -> Available a -> Bool # (>=) :: Available a -> Available a -> Bool # max :: Available a -> Available a -> Available a # min :: Available a -> Available a -> Available a #
Show a => Show (Available a) #
Instance details Defined in THC.Runtime.Types Methods showsPrec :: Int -> Available a -> ShowS # show :: Available a -> String # showList :: [Available a] -> ShowS #

data JitSnapshot Source #

Independently sampled cumulative event counts during enabled periods. Disabling does not reset counters. These are callbacks, not a count of currently installed call targets or proof that a particular entry compiled. All tiers/recompilations count. An enabled-period boundary can separate a start from its completion, so matching totals are not guaranteed. Counts saturate at 2^63-1.

Constructors

JitSnapshot
Fields compilationsStarted :: Available Word64 compilationsSucceeded :: Available Word64 compilationsFailed :: Available Word64 invalidations :: Available Word64 deoptimizations :: Available Word64 compilationsQueued :: Available Word64

Instances

Instances details

Eq JitSnapshot #
Instance details Defined in THC.Internal.JIT Methods (==) :: JitSnapshot -> JitSnapshot -> Bool # (/=) :: JitSnapshot -> JitSnapshot -> Bool #
Show JitSnapshot #
Instance details Defined in THC.Internal.JIT Methods showsPrec :: Int -> JitSnapshot -> ShowS # show :: JitSnapshot -> String # showList :: [JitSnapshot] -> ShowS #

jitTelemetryEnabled :: IO (Available Bool) Source #

Query whether this context has opted into telemetry callbacks.

setJitTelemetryEnabled :: Bool -> IO (Available ()) Source #

Explicitly opt this context into or out of telemetry. Does not force compilation or enable process-wide monitoring; counters survive toggling.

jitSnapshot :: IO JitSnapshot Source #

Sample the context-attributed counters without enabling telemetry or requesting compilation. Each counter retains its own availability status.