Skip to content

Commit

Permalink
Use a single lane per priority level
Browse files Browse the repository at this point in the history
(Except transitions and retries.)

The idea is that the only priorities that benefit from multiple parallel
updates are the ones that might suspend: transitions and retries. All
other priorities, including the ones that are interruptible like
Continuous and Idle, don't need multiple lanes because it's better to
batch everything together.
  • Loading branch information
acdlite committed Feb 10, 2021
1 parent eee874c commit f9c52bd
Show file tree
Hide file tree
Showing 2 changed files with 200 additions and 190 deletions.
195 changes: 100 additions & 95 deletions packages/react-reconciler/src/ReactFiberLane.new.js
Original file line number Diff line number Diff line change
Expand Up @@ -85,38 +85,49 @@ export const SyncLane: Lane = /* */ 0b0000000000000000000
export const SyncBatchedLane: Lane = /* */ 0b0000000000000000000000000000010;

export const InputDiscreteHydrationLane: Lane = /* */ 0b0000000000000000000000000000100;
const InputDiscreteLanes: Lanes = /* */ 0b0000000000000000000000000011000;
const InputDiscreteLane: Lanes = /* */ 0b0000000000000000000000000001000;

const InputContinuousHydrationLane: Lane = /* */ 0b0000000000000000000000000100000;
const InputContinuousLanes: Lanes = /* */ 0b0000000000000000000000011000000;
const InputContinuousLane: Lanes = /* */ 0b0000000000000000000000001000000;

export const DefaultHydrationLane: Lane = /* */ 0b0000000000000000000000100000000;
export const DefaultLanes: Lanes = /* */ 0b0000000000000000000111000000000;
export const DefaultLane: Lanes = /* */ 0b0000000000000000000001000000000;

const TransitionHydrationLane: Lane = /* */ 0b0000000000000000001000000000000;
const TransitionLanes: Lanes = /* */ 0b0000000001111111110000000000000;
const FirstTransitionLane: Lane = /* */ 0b0000000000000000010000000000000;
const TransitionLane1: Lane = /* */ 0b0000000000000000010000000000000;
const TransitionLane2: Lane = /* */ 0b0000000000000000100000000000000;
const TransitionLane3: Lane = /* */ 0b0000000000000001000000000000000;
const TransitionLane4: Lane = /* */ 0b0000000000000010000000000000000;
const TransitionLane5: Lane = /* */ 0b0000000000000100000000000000000;
const TransitionLane6: Lane = /* */ 0b0000000000001000000000000000000;
const TransitionLane7: Lane = /* */ 0b0000000000010000000000000000000;
const TransitionLane8: Lane = /* */ 0b0000000000100000000000000000000;
const TransitionLane9: Lane = /* */ 0b0000000001000000000000000000000;

const RetryLanes: Lanes = /* */ 0b0000011110000000000000000000000;
const RetryLane1: Lane = /* */ 0b0000000010000000000000000000000;
const RetryLane2: Lane = /* */ 0b0000000100000000000000000000000;
const RetryLane3: Lane = /* */ 0b0000001000000000000000000000000;
const RetryLane4: Lane = /* */ 0b0000010000000000000000000000000;

const FirstRetryLane: Lanes = /* */ 0b0000000010000000000000000000000;
export const SomeRetryLane: Lane = FirstRetryLane;
export const SomeRetryLane: Lane = RetryLane1;

export const SelectiveHydrationLane: Lane = /* */ 0b0000100000000000000000000000000;

const NonIdleLanes = /* */ 0b0000111111111111111111111111111;

export const IdleHydrationLane: Lane = /* */ 0b0001000000000000000000000000000;
const IdleLanes: Lanes = /* */ 0b0110000000000000000000000000000;
const IdleLane: Lanes = /* */ 0b0010000000000000000000000000000;

export const OffscreenLane: Lane = /* */ 0b1000000000000000000000000000000;

export const NoTimestamp = -1;

let currentUpdateLanePriority: LanePriority = NoLanePriority;

let nextTransitionLane: Lane = FirstTransitionLane;
let nextRetryLane: Lane = FirstRetryLane;
let nextTransitionLane: Lane = TransitionLane1;
let nextRetryLane: Lane = RetryLane1;

export function getCurrentUpdateLanePriority(): LanePriority {
return currentUpdateLanePriority;
Expand All @@ -131,78 +142,73 @@ export function setCurrentUpdateLanePriority(newLanePriority: LanePriority) {
let return_highestLanePriority: LanePriority = DefaultLanePriority;

function getHighestPriorityLanes(lanes: Lanes | Lane): Lanes {
if ((SyncLane & lanes) !== NoLanes) {
return_highestLanePriority = SyncLanePriority;
return SyncLane;
}
if ((SyncBatchedLane & lanes) !== NoLanes) {
return_highestLanePriority = SyncBatchedLanePriority;
return SyncBatchedLane;
}
if ((InputDiscreteHydrationLane & lanes) !== NoLanes) {
return_highestLanePriority = InputDiscreteHydrationLanePriority;
return InputDiscreteHydrationLane;
}
const inputDiscreteLanes = InputDiscreteLanes & lanes;
if (inputDiscreteLanes !== NoLanes) {
return_highestLanePriority = InputDiscreteLanePriority;
return inputDiscreteLanes;
}
if ((lanes & InputContinuousHydrationLane) !== NoLanes) {
return_highestLanePriority = InputContinuousHydrationLanePriority;
return InputContinuousHydrationLane;
}
const inputContinuousLanes = InputContinuousLanes & lanes;
if (inputContinuousLanes !== NoLanes) {
return_highestLanePriority = InputContinuousLanePriority;
return inputContinuousLanes;
}
if ((lanes & DefaultHydrationLane) !== NoLanes) {
return_highestLanePriority = DefaultHydrationLanePriority;
return DefaultHydrationLane;
}
const defaultLanes = DefaultLanes & lanes;
if (defaultLanes !== NoLanes) {
return_highestLanePriority = DefaultLanePriority;
return defaultLanes;
}
if ((lanes & TransitionHydrationLane) !== NoLanes) {
return_highestLanePriority = TransitionHydrationPriority;
return TransitionHydrationLane;
}
const transitionLanes = TransitionLanes & lanes;
if (transitionLanes !== NoLanes) {
return_highestLanePriority = TransitionPriority;
return transitionLanes;
}
const retryLanes = RetryLanes & lanes;
if (retryLanes !== NoLanes) {
return_highestLanePriority = RetryLanePriority;
return retryLanes;
}
if (lanes & SelectiveHydrationLane) {
return_highestLanePriority = SelectiveHydrationLanePriority;
return SelectiveHydrationLane;
}
if ((lanes & IdleHydrationLane) !== NoLanes) {
return_highestLanePriority = IdleHydrationLanePriority;
return IdleHydrationLane;
}
const idleLanes = IdleLanes & lanes;
if (idleLanes !== NoLanes) {
return_highestLanePriority = IdleLanePriority;
return idleLanes;
}
if ((OffscreenLane & lanes) !== NoLanes) {
return_highestLanePriority = OffscreenLanePriority;
return OffscreenLane;
}
if (__DEV__) {
console.error('Should have found matching lanes. This is a bug in React.');
switch (getHighestPriorityLane(lanes)) {
case SyncLane:
return_highestLanePriority = SyncLanePriority;
return SyncLane;
case SyncBatchedLane:
return_highestLanePriority = SyncBatchedLanePriority;
return SyncBatchedLane;
case InputDiscreteHydrationLane:
return_highestLanePriority = InputDiscreteHydrationLanePriority;
return InputDiscreteHydrationLane;
case InputDiscreteLane:
return_highestLanePriority = InputDiscreteLanePriority;
return InputDiscreteLane;
case InputContinuousHydrationLane:
return_highestLanePriority = InputContinuousHydrationLanePriority;
return InputContinuousHydrationLane;
case InputContinuousLane:
return_highestLanePriority = InputContinuousLanePriority;
return InputContinuousLane;
case DefaultHydrationLane:
return_highestLanePriority = DefaultHydrationLanePriority;
return DefaultHydrationLane;
case DefaultLane:
return_highestLanePriority = DefaultLanePriority;
return DefaultLane;
case TransitionHydrationLane:
return_highestLanePriority = TransitionHydrationPriority;
return TransitionHydrationLane;
case TransitionLane1:
case TransitionLane2:
case TransitionLane3:
case TransitionLane4:
case TransitionLane5:
case TransitionLane6:
case TransitionLane7:
case TransitionLane8:
case TransitionLane9:
return_highestLanePriority = TransitionPriority;
return lanes & TransitionLanes;
case RetryLane1:
case RetryLane2:
case RetryLane3:
case RetryLane4:
return_highestLanePriority = RetryLanePriority;
return lanes & RetryLanes;
case SelectiveHydrationLane:
return_highestLanePriority = SelectiveHydrationLanePriority;
return SelectiveHydrationLane;
case IdleHydrationLane:
return_highestLanePriority = IdleHydrationLanePriority;
return IdleHydrationLane;
case IdleLane:
return_highestLanePriority = IdleLanePriority;
return IdleLane;
case OffscreenLane:
return_highestLanePriority = OffscreenLanePriority;
return OffscreenLane;
default:
if (__DEV__) {
console.error(
'Should have found matching lanes. This is a bug in React.',
);
}
// This shouldn't be reachable, but as a fallback, return the entire bitmask.
return_highestLanePriority = DefaultLanePriority;
return lanes;
}
// This shouldn't be reachable, but as a fallback, return the entire bitmask.
return_highestLanePriority = DefaultLanePriority;
return lanes;
}

export function schedulerPriorityToLanePriority(
Expand Down Expand Up @@ -516,20 +522,17 @@ export function findUpdateLane(lanePriority: LanePriority): Lane {
return SyncLane;
case SyncBatchedLanePriority:
return SyncBatchedLane;
case InputDiscreteLanePriority: {
return pickArbitraryLane(InputDiscreteLanes);
}
case InputContinuousLanePriority: {
return pickArbitraryLane(InputContinuousLanes);
}
case DefaultLanePriority: {
return pickArbitraryLane(DefaultLanes);
}
case InputDiscreteLanePriority:
return InputDiscreteLane;
case InputContinuousLanePriority:
return InputContinuousLane;
case DefaultLanePriority:
return DefaultLane;
case TransitionPriority: // Should be handled by findTransitionLane instead
case RetryLanePriority: // Should be handled by findRetryLane instead
break;
case IdleLanePriority:
return pickArbitraryLane(IdleLanes);
return IdleLane;
default:
// The remaining priorities are not valid for updates
break;
Expand All @@ -549,7 +552,7 @@ export function claimNextTransitionLane(): Lane {
const lane = nextTransitionLane;
nextTransitionLane <<= 1;
if ((nextTransitionLane & TransitionLanes) === 0) {
nextTransitionLane = FirstTransitionLane;
nextTransitionLane = TransitionLane1;
}
return lane;
}
Expand All @@ -558,7 +561,7 @@ export function claimNextRetryLane(): Lane {
const lane = nextRetryLane;
nextRetryLane <<= 1;
if ((nextRetryLane & RetryLanes) === 0) {
nextRetryLane = FirstRetryLane;
nextRetryLane = RetryLane1;
}
return lane;
}
Expand Down Expand Up @@ -650,7 +653,7 @@ export function markRootUpdated(
// We don't do this if the incoming update is idle, because we never process
// idle updates until after all the regular updates have finished; there's no
// way it could unblock a transition.
if ((updateLane & IdleLanes) === NoLanes) {
if (updateLane !== IdleLane) {
root.suspendedLanes = NoLanes;
root.pingedLanes = NoLanes;
}
Expand Down Expand Up @@ -692,11 +695,13 @@ export function markRootExpired(root: FiberRoot, expiredLanes: Lanes) {
}

export function markDiscreteUpdatesExpired(root: FiberRoot) {
root.expiredLanes |= InputDiscreteLanes & root.pendingLanes;
if (root.pendingLanes & InputDiscreteLane) {
root.expiredLanes |= InputDiscreteLane;
}
}

export function hasDiscreteLanes(lanes: Lanes) {
return (lanes & InputDiscreteLanes) !== NoLanes;
return (lanes & InputDiscreteLane) !== NoLanes;
}

export function markRootMutableRead(root: FiberRoot, updateLane: Lane) {
Expand Down
Loading

0 comments on commit f9c52bd

Please sign in to comment.