Skip to content

[Part 6|*] Thread Contexts through payment methods Part 2 #10308

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

Open
wants to merge 8 commits into
base: elle-payment-sql-series-new
Choose a base branch
from
+156 −107
Open

[Part 6|*] Thread Contexts through payment methods Part 2 #10308

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
8 commits
Select commit Hold shift + click to select a range
ae9c31f
routing: Add context to requestRoute
ziggie1984 Oct 21, 2025
d11b762
multi: thread context through payment lifecyle functions
ziggie1984 Oct 21, 2025
91fd00a
routing: Thread context through failPaymentAndAttempt
ziggie1984 Oct 21, 2025
ea33726
routing: add context to failAttempt
ziggie1984 Oct 21, 2025
abcd834
routing: add context to reloadInflightAttempts
ziggie1984 Oct 21, 2025
6aefe5b
routing: add context to reloadPayment method
ziggie1984 Oct 21, 2025
b60e698
multi: thread context through SendPayment
ziggie1984 Nov 17, 2025
aae5a33
docs: add release-notes
ziggie1984 Oct 21, 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
2 changes: 2 additions & 0 deletions docs/release-notes/release-notes-0.21.0.md
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -85,6 +85,8 @@
for SQL backend](https://github.com/lightningnetwork/lnd/pull/10292)
* [Thread context through payment
db functions Part 1](https://github.com/lightningnetwork/lnd/pull/10307)
* [Thread context through payment
db functions Part 2](https://github.com/lightningnetwork/lnd/pull/10308)


## Code Health
Expand Down
4 changes: 2 additions & 2 deletions lnrpc/routerrpc/router_server.go
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -936,11 +936,11 @@ func (s *Server) SendToRouteV2(ctx context.Context,
// db.
if req.SkipTempErr {
attempt, err = s.cfg.Router.SendToRouteSkipTempErr(
hash, route, firstHopRecords,
ctx, hash, route, firstHopRecords,
)
} else {
attempt, err = s.cfg.Router.SendToRoute(
hash, route, firstHopRecords,
ctx, hash, route, firstHopRecords,
)
}
if attempt != nil {
Expand Down
84 changes: 41 additions & 43 deletions routing/payment_lifecycle.go
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -128,7 +128,7 @@ const (
// results is sent back. then process its result here. When there's no need to
// wait for results, the method will exit with `stepExit` such that the payment
// lifecycle loop will terminate.
func (p *paymentLifecycle) decideNextStep(
func (p *paymentLifecycle) decideNextStep(ctx context.Context,
payment paymentsdb.DBMPPayment) (stateStep, error) {

// Check whether we could make new HTLC attempts.
Expand Down Expand Up @@ -168,7 +168,7 @@ func (p *paymentLifecycle) decideNextStep(
// stepSkip and move to the next lifecycle iteration, which will
// refresh the payment and wait for the next attempt result, if
// any.
_, err := p.handleAttemptResult(r.attempt, r.result)
_, err := p.handleAttemptResult(ctx, r.attempt, r.result)

// We would only get a DB-related error here, which will cause
// us to abort the payment flow.
Expand All @@ -192,6 +192,13 @@ func (p *paymentLifecycle) resumePayment(ctx context.Context) ([32]byte,

// We need to make sure we can still do db operations after the context
// is cancelled.
//
// TODO(ziggie): This is a workaround to avoid a greater refactor of the
// payment lifecycle. We can currently not rely on the parent context
// because this method is also collecting the results of inflight HTLCs
// after the context is cancelled. So we need to make sure we only use
// the current context to stop creating new attempts but use this
// cleanupCtx to do all the db operations.
cleanupCtx := context.WithoutCancel(ctx)

// When the payment lifecycle loop exits, we make sure to signal any
Expand All @@ -202,7 +209,7 @@ func (p *paymentLifecycle) resumePayment(ctx context.Context) ([32]byte,
// If we had any existing attempts outstanding, we'll start by spinning
// up goroutines that'll collect their results and deliver them to the
// lifecycle loop below.
payment, err := p.reloadInflightAttempts()
payment, err := p.reloadInflightAttempts(ctx)
if err != nil {
return [32]byte{}, nil, err
}
Expand Down Expand Up @@ -243,7 +250,7 @@ lifecycle:
}

// We update the payment state on every iteration.
currentPayment, ps, err := p.reloadPayment()
currentPayment, ps, err := p.reloadPayment(cleanupCtx)
Copy link
Member

@yyforyongyu yyforyongyu Nov 27, 2025

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

similar to reloadInflightAttempts, we should also use ctx here to cancel the read operation?

Copy link
Collaborator Author

@ziggie1984 ziggie1984 Nov 27, 2025

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

no we can't use the ctx context here, because we rely on this function recollect all INFLIGHT results, if we do use the other context we will basically abort as soon as we timeout.

Copy link
Collaborator Author

@ziggie1984 ziggie1984 Nov 27, 2025

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

I tried to describe it in the todo where I introduced the new context:

	// TODO(ziggie): This is a workaround to avoid a greater refactor of the
	// payment lifecycle. We can currently not rely on the parent context
	// because this method is also collect the results of inflight HTLCs
	// after the context is cancelled. So we need to make sure we only use
	// the current context to stop creating new attempts but use this
	// cleanupCtx to do all the db operations.

if err != nil {
return exitWithErr(err)
}
Expand All @@ -264,7 +271,7 @@ lifecycle:
//

// Now decide the next step of the current lifecycle.
step, err := p.decideNextStep(payment)
step, err := p.decideNextStep(cleanupCtx, payment)
if err != nil {
return exitWithErr(err)
}
Expand All @@ -288,7 +295,7 @@ lifecycle:
}

// Now request a route to be used to create our HTLC attempt.
rt, err := p.requestRoute(ps)
rt, err := p.requestRoute(cleanupCtx, ps)
Copy link
Member

@yyforyongyu yyforyongyu Nov 27, 2025

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

We still have this downside such that, when the user cancels the operation, the path finding won't be stopped, but this is already a pre-existing issue, tho this will likely come up again when adding ctx to RequestRoute.

Copy link
Collaborator Author

@ziggie1984 ziggie1984 Nov 27, 2025

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

agree, but luckily we are only talking probably of 1 sec waisted time and as described before we cannot fail this call because we depend on this for loop to collect potential inflight attempts for this payment.

if err != nil {
return exitWithErr(err)
}
Expand All @@ -307,13 +314,15 @@ lifecycle:
log.Tracef("Found route: %s", lnutils.SpewLogClosure(rt.Hops))

// We found a route to try, create a new HTLC attempt to try.
attempt, err := p.registerAttempt(rt, ps.RemainingAmt)
attempt, err := p.registerAttempt(
cleanupCtx, rt, ps.RemainingAmt,
)
if err != nil {
return exitWithErr(err)
}

// Once the attempt is created, send it to the htlcswitch.
result, err := p.sendAttempt(attempt)
result, err := p.sendAttempt(cleanupCtx, attempt)
if err != nil {
return exitWithErr(err)
}
Expand Down Expand Up @@ -399,11 +408,9 @@ func (p *paymentLifecycle) checkContext(ctx context.Context) error {

// requestRoute is responsible for finding a route to be used to create an HTLC
// attempt.
func (p *paymentLifecycle) requestRoute(
func (p *paymentLifecycle) requestRoute(ctx context.Context,
ps *paymentsdb.MPPaymentState) (*route.Route, error) {

ctx := context.TODO()

remainingFees := p.calcFeeBudget(ps.FeesPaid)

// Query our payment session to construct a route.
Expand Down Expand Up @@ -598,11 +605,9 @@ func (p *paymentLifecycle) collectResult(
// registerAttempt is responsible for creating and saving an HTLC attempt in db
// by using the route info provided. The `remainingAmt` is used to decide
// whether this is the last attempt.
func (p *paymentLifecycle) registerAttempt(rt *route.Route,
func (p *paymentLifecycle) registerAttempt(ctx context.Context, rt *route.Route,
remainingAmt lnwire.MilliSatoshi) (*paymentsdb.HTLCAttempt, error) {

ctx := context.TODO()

// If this route will consume the last remaining amount to send
// to the receiver, this will be our last shard (for now).
isLastAttempt := rt.ReceiverAmt() == remainingAmt
Expand Down Expand Up @@ -676,7 +681,7 @@ func (p *paymentLifecycle) createNewPaymentAttempt(rt *route.Route,
// sendAttempt attempts to send the current attempt to the switch to complete
// the payment. If this attempt fails, then we'll continue on to the next
// available route.
func (p *paymentLifecycle) sendAttempt(
func (p *paymentLifecycle) sendAttempt(ctx context.Context,
attempt *paymentsdb.HTLCAttempt) (*attemptResult, error) {

log.Debugf("Sending HTLC attempt(id=%v, total_amt=%v, first_hop_amt=%d"+
Expand Down Expand Up @@ -708,7 +713,7 @@ func (p *paymentLifecycle) sendAttempt(
"payment=%v, err:%v", attempt.AttemptID,
p.identifier, err)

return p.failAttempt(attempt.AttemptID, err)
return p.failAttempt(ctx, attempt.AttemptID, err)
}

htlcAdd.OnionBlob = onionBlob
Expand All @@ -722,7 +727,7 @@ func (p *paymentLifecycle) sendAttempt(
log.Errorf("Failed sending attempt %d for payment %v to "+
"switch: %v", attempt.AttemptID, p.identifier, err)

return p.handleSwitchErr(attempt, err)
return p.handleSwitchErr(ctx, attempt, err)
}

log.Debugf("Attempt %v for payment %v successfully sent to switch, "+
Expand Down Expand Up @@ -813,12 +818,10 @@ func (p *paymentLifecycle) amendFirstHopData(rt *route.Route) error {

// failAttemptAndPayment fails both the payment and its attempt via the
// router's control tower, which marks the payment as failed in db.
func (p *paymentLifecycle) failPaymentAndAttempt(
func (p *paymentLifecycle) failPaymentAndAttempt(ctx context.Context,
attemptID uint64, reason *paymentsdb.FailureReason,
sendErr error) (*attemptResult, error) {

ctx := context.TODO()

log.Errorf("Payment %v failed: final_outcome=%v, raw_err=%v",
p.identifier, *reason, sendErr)

Expand All @@ -836,7 +839,7 @@ func (p *paymentLifecycle) failPaymentAndAttempt(
}

// Fail the attempt.
return p.failAttempt(attemptID, sendErr)
return p.failAttempt(ctx, attemptID, sendErr)
}

// handleSwitchErr inspects the given error from the Switch and determines
Expand All @@ -847,7 +850,8 @@ func (p *paymentLifecycle) failPaymentAndAttempt(
// the error type, the error is either the final outcome of the payment or we
// need to continue with an alternative route. A final outcome is indicated by
// a non-nil reason value.
func (p *paymentLifecycle) handleSwitchErr(attempt *paymentsdb.HTLCAttempt,
func (p *paymentLifecycle) handleSwitchErr(ctx context.Context,
attempt *paymentsdb.HTLCAttempt,
sendErr error) (*attemptResult, error) {

internalErrorReason := paymentsdb.FailureReasonError
Expand All @@ -874,11 +878,11 @@ func (p *paymentLifecycle) handleSwitchErr(attempt *paymentsdb.HTLCAttempt,
// Fail the attempt only if there's no reason.
if reason == nil {
// Fail the attempt.
return p.failAttempt(attemptID, sendErr)
return p.failAttempt(ctx, attemptID, sendErr)
}

// Otherwise fail both the payment and the attempt.
return p.failPaymentAndAttempt(attemptID, reason, sendErr)
return p.failPaymentAndAttempt(ctx, attemptID, reason, sendErr)
}

// If this attempt ID is unknown to the Switch, it means it was never
Expand All @@ -889,7 +893,7 @@ func (p *paymentLifecycle) handleSwitchErr(attempt *paymentsdb.HTLCAttempt,
log.Warnf("Failing attempt=%v for payment=%v as it's not "+
"found in the Switch", attempt.AttemptID, p.identifier)

return p.failAttempt(attemptID, sendErr)
return p.failAttempt(ctx, attemptID, sendErr)
}

if errors.Is(sendErr, htlcswitch.ErrUnreadableFailureMessage) {
Expand All @@ -911,7 +915,7 @@ func (p *paymentLifecycle) handleSwitchErr(attempt *paymentsdb.HTLCAttempt,
ok := errors.As(sendErr, &rtErr)
if !ok {
return p.failPaymentAndAttempt(
attemptID, &internalErrorReason, sendErr,
ctx, attemptID, &internalErrorReason, sendErr,
)
}

Expand All @@ -937,7 +941,7 @@ func (p *paymentLifecycle) handleSwitchErr(attempt *paymentsdb.HTLCAttempt,
)
if err != nil {
return p.failPaymentAndAttempt(
attemptID, &internalErrorReason, sendErr,
ctx, attemptID, &internalErrorReason, sendErr,
)
}

Expand Down Expand Up @@ -1021,11 +1025,9 @@ func (p *paymentLifecycle) handleFailureMessage(rt *route.Route,
}

// failAttempt calls control tower to fail the current payment attempt.
func (p *paymentLifecycle) failAttempt(attemptID uint64,
func (p *paymentLifecycle) failAttempt(ctx context.Context, attemptID uint64,
sendError error) (*attemptResult, error) {

ctx := context.TODO()

log.Warnf("Attempt %v for payment %v failed: %v", attemptID,
p.identifier, sendError)

Expand Down Expand Up @@ -1136,10 +1138,8 @@ func (p *paymentLifecycle) patchLegacyPaymentHash(
// reloadInflightAttempts is called when the payment lifecycle is resumed after
// a restart. It reloads all inflight attempts from the control tower and
// collects the results of the attempts that have been sent before.
func (p *paymentLifecycle) reloadInflightAttempts() (paymentsdb.DBMPPayment,
error) {

ctx := context.TODO()
func (p *paymentLifecycle) reloadInflightAttempts(
ctx context.Context) (paymentsdb.DBMPPayment, error) {

payment, err := p.router.cfg.Control.FetchPayment(ctx, p.identifier)
if err != nil {
Expand All @@ -1163,11 +1163,10 @@ func (p *paymentLifecycle) reloadInflightAttempts() (paymentsdb.DBMPPayment,
}

// reloadPayment returns the latest payment found in the db (control tower).
func (p *paymentLifecycle) reloadPayment() (paymentsdb.DBMPPayment,
func (p *paymentLifecycle) reloadPayment(
ctx context.Context) (paymentsdb.DBMPPayment,
*paymentsdb.MPPaymentState, error) {

ctx := context.TODO()

// Read the db to get the latest state of the payment.
payment, err := p.router.cfg.Control.FetchPayment(ctx, p.identifier)
if err != nil {
Expand All @@ -1186,15 +1185,14 @@ func (p *paymentLifecycle) reloadPayment() (paymentsdb.DBMPPayment,

// handleAttemptResult processes the result of an HTLC attempt returned from
// the htlcswitch.
func (p *paymentLifecycle) handleAttemptResult(attempt *paymentsdb.HTLCAttempt,
func (p *paymentLifecycle) handleAttemptResult(ctx context.Context,
attempt *paymentsdb.HTLCAttempt,
result *htlcswitch.PaymentResult) (*attemptResult, error) {

ctx := context.TODO()

// If the result has an error, we need to further process it by failing
// the attempt and maybe fail the payment.
if result.Error != nil {
return p.handleSwitchErr(attempt, result.Error)
return p.handleSwitchErr(ctx, attempt, result.Error)
}

// We got an attempt settled result back from the switch.
Expand Down Expand Up @@ -1237,13 +1235,13 @@ func (p *paymentLifecycle) handleAttemptResult(attempt *paymentsdb.HTLCAttempt,
// available from the Switch, then records the attempt outcome with the control
// tower. An attemptResult is returned, indicating the final outcome of this
// HTLC attempt.
func (p *paymentLifecycle) collectAndHandleResult(
func (p *paymentLifecycle) collectAndHandleResult(ctx context.Context,
attempt *paymentsdb.HTLCAttempt) (*attemptResult, error) {

result, err := p.collectResult(attempt)
if err != nil {
return nil, err
}

return p.handleAttemptResult(attempt, result)
return p.handleAttemptResult(ctx, attempt, result)
}
Loading
Loading