Skip to content

Enable safe recursion with trampoline #54

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Draft
majocha wants to merge 15 commits into
base: master
Choose a base branch
from
Draft

Enable safe recursion with trampoline #54

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
15 commits
Select commit Hold shift + click to select a range
45ef556
cold tasks only
majocha Aug 23, 2025
428a7cb
some cleanup
majocha Aug 23, 2025
4294dc3
vibe code more tests
majocha Aug 23, 2025
c2cdd07
cleanup
majocha Aug 24, 2025
fa5473c
currently broken mut rec
majocha Aug 27, 2025
74bf071
mut rec tests do pass now
majocha Aug 28, 2025
e72d11d
check just once for each task and use it both ways
majocha Aug 28, 2025
dbcd50f
fix nasty bug - stale ref to wrong instance
majocha Aug 28, 2025
019ec44
restore check on each possible yield
majocha Sep 1, 2025
0a0c85f
bindLimit 100
majocha Sep 1, 2025
7ac5b55
missed this one
majocha Sep 3, 2025
cff23a1
format
majocha Sep 3, 2025
ae56870
Merge branch 'master' into trampoline
majocha Sep 28, 2025
e3d2023
Merge remote-tracking branch 'origin/master' into trampoline
majocha Nov 30, 2025
39cd1ca
update
majocha Dec 1, 2025
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
145 changes: 103 additions & 42 deletions src/IcedTasks/CancellablePoolingValueTask.fs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -60,35 +60,75 @@ module CancellablePoolingValueTasks =
let initialResumptionFunc =
CancellableTaskBaseResumptionFunc<'T, _>(fun sm -> code.Invoke(&sm))

let resumptionInfo =
{ new CancellableTaskBaseResumptionDynamicInfo<'T, _>(initialResumptionFunc) with
member info.MoveNext(sm) =
let mutable savedExn = null
let bounceAllowed = Trampoline.Current.IsAwaited()

let maybeBounce state =
if
bounceAllowed
&& Trampoline.Current.ShouldBounce
then
Bounce state
else
Immediate state

try
sm.ResumptionDynamicInfo.ResumptionData <- null
let step = info.ResumptionFunc.Invoke(&sm)
let resumptionInfo =
let initialState = maybeBounce Running

if step then
MethodBuilder.SetResult(&sm.Data.MethodBuilder, sm.Data.Result)
else
match sm.ResumptionDynamicInfo.ResumptionData with
| :? ICriticalNotifyCompletion as awaiter ->
let mutable awaiter = awaiter
// assert not (isNull awaiter)
MethodBuilder.AwaitOnCompleted(
&sm.Data.MethodBuilder,
&awaiter,
&sm
)
| awaiter -> assert not (isNull awaiter)
{ new CancellableTaskBaseResumptionDynamicInfo<'T, _>(initialResumptionFunc,
ResumptionData = initialState) with
member info.MoveNext(sm) =

with exn ->
savedExn <- exn
// Run SetException outside the stack unwind, see https://github.com/dotnet/roslyn/issues/26567
match savedExn with
| null -> ()
| exn -> MethodBuilder.SetException(&sm.Data.MethodBuilder, exn)
let getCurrent () =
match info.ResumptionData with
| :? DynamicState as state -> state
| _ -> failwith "Invalid resumption data"

let setState state = info.ResumptionData <- state

match getCurrent () with
| Immediate state ->
setState state
info.MoveNext &sm
| Running ->
let mutable keepGoing = true

try
if info.ResumptionFunc.Invoke(&sm) then
setState (maybeBounce SetResult)
else
keepGoing <-
match getCurrent () with
| Awaiting _ -> true
| _ -> false
with exn ->
setState (
maybeBounce
<| SetException(ExceptionCache.CaptureOrRetrieve exn)
)

if keepGoing then
info.MoveNext &sm
| Awaiting awaiter ->
setState Running
let mutable awaiter = awaiter

MethodBuilder.AwaitUnsafeOnCompleted(
&sm.Data.MethodBuilder,
&awaiter,
&sm
)
| Bounce next ->
setState next

MethodBuilder.AwaitOnCompleted(
&sm.Data.MethodBuilder,
Trampoline.Current.Ref,
&sm
)
| SetResult ->
MethodBuilder.SetResult(&sm.Data.MethodBuilder, sm.Data.Result)
| SetException edi ->
MethodBuilder.SetException(&sm.Data.MethodBuilder, edi.SourceException)

member _.SetStateMachine(sm, state) =
MethodBuilder.SetStateMachine(&sm.Data.MethodBuilder, state)
Expand All @@ -109,22 +149,43 @@ module CancellablePoolingValueTasks =
if __useResumableCode then
__stateMachine<CancellableTaskBaseStateMachineData<'T, _>, CancellableValueTask<'T>>
(MoveNextMethodImpl<_>(fun sm ->
//-- RESUMABLE CODE START
__resumeAt sm.ResumptionPoint
let mutable __stack_exn = null

try
let __stack_code_fin = code.Invoke(&sm)

if __stack_code_fin then
MethodBuilder.SetResult(&sm.Data.MethodBuilder, sm.Data.Result)
with exn ->
__stack_exn <- exn
// Run SetException outside the stack unwind, see https://github.com/dotnet/roslyn/issues/26567
match __stack_exn with
| null -> ()
| exn -> MethodBuilder.SetException(&sm.Data.MethodBuilder, exn)
//-- RESUMABLE CODE END

let mutable error = ValueNone

let noBounce = not (Trampoline.Current.IsAwaited())

let __stack_go1 =
noBounce
|| yieldOnBindLimit().Invoke(&sm)

if __stack_go1 then
try
let __stack_code_fin = code.Invoke(&sm)

if __stack_code_fin then
let __stack_go2 =
noBounce
|| yieldOnBindLimit().Invoke(&sm)

if __stack_go2 then
MethodBuilder.SetResult(
&sm.Data.MethodBuilder,
sm.Data.Result
)
with exn ->
error <- ValueSome(ExceptionCache.CaptureOrRetrieve exn)

if error.IsSome then
let __stack_go2 =
noBounce
|| yieldOnBindLimit().Invoke(&sm)

if __stack_go2 then
MethodBuilder.SetException(
&sm.Data.MethodBuilder,
error.Value.SourceException
)
))
(SetStateMachineMethodImpl<_>(fun sm state ->
MethodBuilder.SetStateMachine(&sm.Data.MethodBuilder, state)
Expand Down Expand Up @@ -154,7 +215,7 @@ module CancellablePoolingValueTasks =
([<InlineIfLambda>] x: CancellationToken -> ValueTask<_>)
: CancellationToken -> Awaiter<ValueTaskAwaiter<_>, _> =
fun ct ->
(x ct)
Trampoline.Allow x ct
|> Awaitable.GetAwaiter

[<NoEagerConstraintApplication>]
Expand Down
Loading