Skip to content

Allow nil-ing out arenas to break the GC link between nodes and the arena they came from #4024

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
weswigham wants to merge 2 commits into
base: main
Choose a base branch
from
Open

Allow nil-ing out arenas to break the GC link between nodes and the arena they came from #4024

Show file tree
Hide file tree
Changes from 1 commit
Commits
Show all changes
2 commits
Select commit Hold shift + click to select a range
9203e4a
Allow nil-ing out arenas to break the GC link between nodes and the a…
weswigham May 13, 2026
9b37bd6
Format
weswigham May 21, 2026
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
9 changes: 9 additions & 0 deletions _scripts/generate-go-ast.ts
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -117,6 +117,15 @@ function generateNodeFactoryStruct(w: CodeWriter) {
w.pop();
w.write("}");
w.write("");

w.write("func (f *NodeFactory) ReleaseArenas() {")
w.push();
for (const { fieldName } of arenaFields) {
w.write(`f.${fieldName}.Release()`);
}
w.pop();
w.write("}");
w.write("");
}

function generateHeader(w: CodeWriter) {
Expand Down
51 changes: 51 additions & 0 deletions internal/ast/ast_generated.go
View file
Open in desktop

Some generated files are not rendered by default. Learn more about how customized files appear on GitHub.

9 changes: 6 additions & 3 deletions internal/checker/nodebuilder.go
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -285,12 +285,15 @@ func NewNodeBuilderEx(ch *Checker, e *printer.EmitContext, idToSymbol map[*ast.I
return &NodeBuilder{impl: impl, ctxStack: make([]*NodeBuilderContext, 0, 1), host: ch.program}
}

func (c *Checker) getNodeBuilder() *NodeBuilder {
func (c *Checker) getNodeBuilder() (*NodeBuilder, func()) {
releaseNodes := func() {
c.typeToStringNodebuilder.EmitContext().Factory.ReleaseArenas() // Allow any allocated nodes to be freed if they're no longer in a cache
}
if c.typeToStringNodebuilder != nil {
return c.typeToStringNodebuilder
return c.typeToStringNodebuilder, releaseNodes
}
c.typeToStringNodebuilder = c.getNodeBuilderEx(nil /*idToSymbol*/)
return c.typeToStringNodebuilder
return c.typeToStringNodebuilder, releaseNodes
}

func (c *Checker) getNodeBuilderEx(idToSymbol map[*ast.IdentifierNode]*ast.Symbol) *NodeBuilder {
Expand Down
25 changes: 18 additions & 7 deletions internal/checker/printer.go
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -197,7 +197,8 @@ func (c *Checker) typeToStringEx(t *Type, enclosingDeclaration *ast.Node, flags
if noTruncation {
combinedFlags = combinedFlags | nodebuilder.FlagsNoTruncation
}
nodeBuilder := c.getNodeBuilder()
nodeBuilder, release := c.getNodeBuilder()
defer release()
if vc != nil {
nodeBuilder.verbosity = vc
}
Comment on lines 202 to 204
Copy link
Copy Markdown
Member Author

@weswigham weswigham May 21, 2026

Choose a reason for hiding this comment

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

@gabritto @RyanCavanaugh I'm pretty sure this copilot comment just picked up on the fix for #4010 (unrelated to this PR though)

Expand Down Expand Up @@ -270,7 +271,8 @@ func (c *Checker) symbolToStringEx(symbol *ast.Symbol, enclosingDeclaration *ast
internalNodeFlags |= nodebuilder.InternalFlagsWriteComputedProps
}

nodeBuilder := c.getNodeBuilder()
nodeBuilder, release := c.getNodeBuilder()
defer release()
var sourceFile *ast.SourceFile
if enclosingDeclaration != nil {
sourceFile = ast.GetSourceFileOfNode(enclosingDeclaration)
Expand Down Expand Up @@ -319,7 +321,8 @@ func (c *Checker) signatureToStringEx(signature *Signature, enclosingDeclaration
}
}

nodeBuilder := c.getNodeBuilder()
nodeBuilder, release := c.getNodeBuilder()
defer release()
if vc != nil {
nodeBuilder.verbosity = vc
}
Comment on lines 326 to 328
Expand Down Expand Up @@ -348,7 +351,8 @@ func (c *Checker) typePredicateToString(typePredicate *TypePredicate) string {
func (c *Checker) typePredicateToStringEx(typePredicate *TypePredicate, enclosingDeclaration *ast.Node, flags TypeFormatFlags) string {
writer, putWriter := printer.GetSingleLineStringWriter()
defer putWriter()
nodeBuilder := c.getNodeBuilder()
nodeBuilder, release := c.getNodeBuilder()
defer release()
combinedFlags := toNodeBuilderFlags(flags) | nodebuilder.FlagsIgnoreErrors | nodebuilder.FlagsWriteTypeParametersInQualifiedName
predicate := nodeBuilder.TypePredicateToTypePredicateNode(typePredicate, enclosingDeclaration, combinedFlags, nodebuilder.InternalFlagsNone, nil) // TODO: GH#18217
printer_ := createPrinterWithRemoveComments(nodeBuilder.EmitContext())
Expand Down Expand Up @@ -405,13 +409,17 @@ func (c *Checker) TypeToTypeNode(t *Type, enclosingDeclaration *ast.Node, flags
}

func (c *Checker) SignatureToSignatureDeclaration(signature *Signature, kind ast.Kind, enclosingDeclaration *ast.Node, flags nodebuilder.Flags) *ast.Node {
nodeBuilder := c.getNodeBuilder()
nodeBuilder, release := c.getNodeBuilder()
defer release()
return nodeBuilder.SignatureToSignatureDeclaration(signature, kind, enclosingDeclaration, flags, nodebuilder.InternalFlagsNone, nil)
}

// ExpandSymbolForHover produces declaration strings for a symbol with verbosity support for expandable hover.
func (c *Checker) ExpandSymbolForHover(symbol *ast.Symbol, meaning ast.SymbolFlags, vc *VerbosityContext) string {
nodeBuilder := c.getNodeBuilder()
nodeBuilder, release := c.getNodeBuilder()
defer release()
oldVerbosity := nodeBuilder.verbosity
defer func() { nodeBuilder.verbosity = oldVerbosity }()
nodeBuilder.verbosity = vc
nodes := nodeBuilder.ExpandSymbolForHover(symbol, meaning)
if len(nodes) == 0 {
Expand All @@ -434,7 +442,10 @@ func (c *Checker) ExpandSymbolForHover(symbol *ast.Symbol, meaning ast.SymbolFla

// TypeParameterToStringEx renders a type parameter declaration (e.g. "T extends Foo") with optional verbosity support.
func (c *Checker) TypeParameterToStringEx(t *Type, enclosingDeclaration *ast.Node, vc *VerbosityContext) string {
nodeBuilder := c.getNodeBuilder()
nodeBuilder, release := c.getNodeBuilder()
defer release()
oldVerbosity := nodeBuilder.verbosity
defer func() { nodeBuilder.verbosity = oldVerbosity }()
nodeBuilder.verbosity = vc
typeParamNode := nodeBuilder.TypeParameterToDeclaration(t, enclosingDeclaration, nodebuilder.FlagsIgnoreErrors, nodebuilder.InternalFlagsNone, nil)
if typeParamNode == nil {
Expand Down
5 changes: 5 additions & 0 deletions internal/core/arena.go
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -58,6 +58,11 @@ func (a *Arena[T]) Clone(t []T) []T {
return slice
}

// Reset arena back to zero, removing GC refs between the arena and any objects in the arena, allowing them to be freed
func (a *Arena[T]) Release() {
a.data = nil
}

func nextArenaSize(size int) int {
// This compiles down branch-free.
size = max(size, 1)
Expand Down
Loading