tls: add gc-aware pthread slots

runtime/internal/clite/bdwgc/bdwgc.go

@@ -40,6 +40,12 @@ func Realloc(ptr c.Pointer, size uintptr) c.Pointer
 //go:linkname Free C.GC_free
 func Free(ptr c.Pointer)
 
+//go:linkname AddRoots C.GC_add_roots
+func AddRoots(start, end c.Pointer)
+
+//go:linkname RemoveRoots C.GC_remove_roots
+func RemoveRoots(start, end c.Pointer)
+
 // -----------------------------------------------------------------------------
 
 //go:linkname RegisterFinalizer C.GC_register_finalizer

runtime/internal/clite/tls/tls_common.go

@@ -0,0 +1,88 @@
+//go:build llgo
+
+package tls
+
+import (
+	"unsafe"
+
+	c "github.com/goplus/llgo/runtime/internal/clite"
+	"github.com/goplus/llgo/runtime/internal/clite/pthread"
+)
+
+type Handle[T any] struct {
+	key        pthread.Key
+	destructor func(*T)
+}
+
+// Alloc creates a TLS handle backed by pthread TLS.
+func Alloc[T any](destructor func(*T)) Handle[T] {
+	var key pthread.Key
+	if ret := key.Create(slotDestructor[T]); ret != 0 {
+		c.Fprintf(c.Stderr, c.Str("tls: pthread_key_create failed (errno=%d)\n"), ret)
+		panic("tls: failed to create thread local storage key")
+	}
+	return Handle[T]{key: key, destructor: destructor}
+}
+
+// Get returns the value stored in the current thread's slot.
+func (h Handle[T]) Get() T {
+	if ptr := h.key.Get(); ptr != nil {
+		return (*slot[T])(ptr).value
+	}
+	var zero T
+	return zero
+}
+
+// Set stores v in the current thread's slot, creating it if necessary.
+func (h Handle[T]) Set(v T) {
+	s := h.ensureSlot()
+	s.value = v
+}
+
+// Clear zeroes the current thread's slot value without freeing the slot.
+func (h Handle[T]) Clear() {
+	if ptr := h.key.Get(); ptr != nil {
+		s := (*slot[T])(ptr)
+		var zero T
+		s.value = zero
+	}
+}
+
+func (h Handle[T]) ensureSlot() *slot[T] {
+	if ptr := h.key.Get(); ptr != nil {
+		return (*slot[T])(ptr)
+	}
+	size := unsafe.Sizeof(slot[T]{})
+	mem := c.Calloc(1, size)
+	if mem == nil {
+		panic("tls: failed to allocate thread slot")
+	}
+	s := (*slot[T])(mem)
+	s.destructor = h.destructor
+	if existing := h.key.Get(); existing != nil {
+		c.Free(mem)
+		return (*slot[T])(existing)
+	}
+	if ret := h.key.Set(mem); ret != 0 {
+		c.Free(mem)
+		c.Fprintf(c.Stderr, c.Str("tls: pthread_setspecific failed (errno=%d)\n"), ret)
+		panic("tls: failed to set thread local storage value")
+	}
+	registerSlot(s)
+	return s
+}
+
+func slotDestructor[T any](ptr c.Pointer) {
+	s := (*slot[T])(ptr)
+	if s == nil {
+		return
+	}
+	if s.destructor != nil {
+		s.destructor(&s.value)
+	}
+	deregisterSlot(s)
+	var zero T
+	s.value = zero
+	s.destructor = nil
+	c.Free(ptr)
+}

runtime/internal/clite/tls/tls_gc.go

@@ -0,0 +1,53 @@
+//go:build llgo && !nogc
+
+package tls
+
+import (
+	"unsafe"
+
+	c "github.com/goplus/llgo/runtime/internal/clite"
+	"github.com/goplus/llgo/runtime/internal/clite/bdwgc"
+)
+
+const slotRegistered = 1 << iota
+
+const maxSlotSize = 1 << 20 // 1 MiB sanity cap
+
+type slot[T any] struct {
+	value      T
+	state      uintptr
+	destructor func(*T)
+}
+
+func registerSlot[T any](s *slot[T]) {
+	if s.state&slotRegistered != 0 {
+		return
+	}
+	start, end := s.rootRange()
+	size := uintptr(end) - uintptr(start)
+	if size == 0 {
+		return
+	}
+	if size > maxSlotSize {
+		panic("tls: slot size exceeds maximum")
+	}
+	bdwgc.AddRoots(start, end)
+	s.state |= slotRegistered
+}
+
+func deregisterSlot[T any](s *slot[T]) {
+	if s == nil || s.state&slotRegistered == 0 {
+		return
+	}
+	s.state &^= slotRegistered
+	start, end := s.rootRange()
+	if uintptr(end) > uintptr(start) {
+		bdwgc.RemoveRoots(start, end)
+	}
+}
+
+func (s *slot[T]) rootRange() (start, end c.Pointer) {
+	begin := unsafe.Pointer(s)
+	endPtr := unsafe.Pointer(uintptr(begin) + unsafe.Sizeof(*s))
+	return c.Pointer(begin), c.Pointer(endPtr)
+}

runtime/internal/clite/tls/tls_nogc.go

@@ -0,0 +1,12 @@
+//go:build llgo && nogc
+
+package tls
+
+type slot[T any] struct {
+	value      T
+	destructor func(*T)
+}
+
+func registerSlot[T any](s *slot[T]) {}
+
+func deregisterSlot[T any](s *slot[T]) {}

runtime/internal/clite/tls/tls_test.go

@@ -0,0 +1,125 @@
+//go:build llgo
+
+package tls_test
+
+import (
+	"fmt"
+	"sync"
+	"testing"
+
+	"github.com/goplus/llgo/runtime/internal/clite/tls"
+)
+
+func TestAllocReadWrite(t *testing.T) {
+	h := tls.Alloc[int](nil)
+	if got := h.Get(); got != 0 {
+		t.Fatalf("zero slot = %d, want 0", got)
+	}
+	h.Set(42)
+	if got := h.Get(); got != 42 {
+		t.Fatalf("Set/Get mismatch: got %d", got)
+	}
+	h.Clear()
+	if got := h.Get(); got != 0 {
+		t.Fatalf("Clear() did not reset slot, got %d", got)
+	}
+}
+
+func TestAllocThreadLocalIsolation(t *testing.T) {
+	h := tls.Alloc[int](nil)
+	h.Set(7)
+
+	const want = 99
+	var wg sync.WaitGroup
+	wg.Add(1)
+	go func() {
+		defer wg.Done()
+		if got := h.Get(); got != 0 {
+			t.Errorf("new goroutine initial value = %d, want 0", got)
+		}
+		h.Set(want)
+		if got := h.Get(); got != want {
+			t.Errorf("goroutine value = %d, want %d", got, want)
+		}
+	}()
+	wg.Wait()
+
+	if got := h.Get(); got != 7 {
+		t.Fatalf("main goroutine value changed to %d", got)
+	}
+}
+
+func TestDestructorRuns(t *testing.T) {
+	var mu sync.Mutex
+	var calls int
+	values := make([]int, 0, 1)
+
+	h := tls.Alloc[*int](func(p **int) {
+		mu.Lock()
+		defer mu.Unlock()
+		if p != nil && *p != nil {
+			calls++
+			values = append(values, **p)
+		}
+	})
+
+	var wg sync.WaitGroup
+	wg.Add(1)
+	go func() {
+		defer wg.Done()
+		val := new(int)
+		*val = 123
+		h.Set(val)
+	}()
+	wg.Wait()
+
+	mu.Lock()
+	defer mu.Unlock()
+	if calls == 0 {
+		t.Fatalf("expected destructor to be invoked")
+	}
+	if len(values) != 1 || values[0] != 123 {
+		t.Fatalf("destructor saw unexpected values: %v", values)
+	}
+}
+
+func TestAllocStress(t *testing.T) {
+	const sequentialIterations = 200_000
+
+	h := tls.Alloc[int](nil)
+	for i := 0; i < sequentialIterations; i++ {
+		h.Set(i)
+		if got := h.Get(); got != i {
+			t.Fatalf("stress iteration %d: got %d want %d", i, got, i)
+		}
+	}
+
+	var wg sync.WaitGroup
+	const (
+		goroutines             = 32
+		iterationsPerGoroutine = 1_000
+	)
+	errs := make(chan error, goroutines)
+	wg.Add(goroutines)
+	for g := 0; g < goroutines; g++ {
+		go func(offset int) {
+			defer wg.Done()
+			local := tls.Alloc[int](nil)
+			for i := 0; i < iterationsPerGoroutine; i++ {
+				v := offset*iterationsPerGoroutine + i
+				local.Set(v)
+				if got := local.Get(); got != v {
+					errs <- fmt.Errorf("goroutine %d iteration %d: got %d want %d", offset, i, got, v)
+					return
+				}
+			}
+		}(g)
+	}
+	wg.Wait()
+	close(errs)
+	for err := range errs {
+		if err != nil {
+			t.Fatal(err)
+		}
+	}
+}

ssa/di.go

@@ -53,6 +53,96 @@ func newDIBuilder(prog Program, pkg Package, positioner Positioner) diBuilder {
 	return b
 }
 
+func hasTypeParam(typ types.Type) bool {
+	visited := make(map[types.Type]bool)
+	var visit func(types.Type) bool
+	visit = func(tt types.Type) bool {
+		if tt == nil {
+			return false
+		}
+		if visited[tt] {
+			return false
+		}
+		visited[tt] = true
+		switch t := tt.(type) {
+		case *types.TypeParam:
+			return true
+		case *types.Named:
+			if tp := t.TypeParams(); tp != nil && tp.Len() > 0 {
+				if ta := t.TypeArgs(); ta == nil || ta.Len() == 0 {
+					return true
+				}
+			}
+			if ta := t.TypeArgs(); ta != nil {
+				for i := 0; i < ta.Len(); i++ {
+					if visit(ta.At(i)) {
+						return true
+					}
+				}
+			}
+			return visit(t.Underlying())
+		case *types.Pointer:
+			return visit(t.Elem())
+		case *types.Slice:
+			return visit(t.Elem())
+		case *types.Array:
+			return visit(t.Elem())
+		case *types.Map:
+			return visit(t.Key()) || visit(t.Elem())
+		case *types.Chan:
+			return visit(t.Elem())
+		case *types.Signature:
+			if tp := t.TypeParams(); tp != nil && tp.Len() > 0 {
+				return true
+			}
+			if params := t.Params(); params != nil {
+				for i := 0; i < params.Len(); i++ {
+					if visit(params.At(i).Type()) {
+						return true
+					}
+				}
+			}
+			if results := t.Results(); results != nil {
+				for i := 0; i < results.Len(); i++ {
+					if visit(results.At(i).Type()) {
+						return true
+					}
+				}
+			}
+			return false
+		case *types.Tuple:
+			for i := 0; i < t.Len(); i++ {
+				if visit(t.At(i).Type()) {
+					return true
+				}
+			}
+			return false
+		case *types.Struct:
+			for i := 0; i < t.NumFields(); i++ {
+				if visit(t.Field(i).Type()) {
+					return true
+				}
+			}
+			return false
+		case *types.Interface:
+			for i := 0; i < t.NumMethods(); i++ {
+				if visit(t.Method(i).Type()) {
+					return true
+				}
+			}
+			for i := 0; i < t.NumEmbeddeds(); i++ {
+				if visit(t.EmbeddedType(i)) {
+					return true
+				}
+			}
+			return false
+		default:
+			return false
+		}
+	}
+	return visit(typ)
+}
+
 // New method to add named metadata operand
 func (b diBuilder) addNamedMetadataOperand(name string, intValue int, stringValue string, intValue2 int) {
 	ctx := b.m.Context()
@@ -522,6 +612,9 @@ func (b diBuilder) dbgValue(v Expr, dv DIVar, scope DIScope, pos token.Position,
 }
 
 func (b diBuilder) diType(t Type, pos token.Position) DIType {
+	if hasTypeParam(t.RawType()) {
+		return &aDIType{}
+	}
 	name := t.RawType().String()
 	return b.diTypeEx(name, t, pos)
 }

ssa/di_test.go

@@ -0,0 +1,124 @@
+//go:build !llgo
+
+package ssa
+
+import (
+	"go/token"
+	"go/types"
+	"testing"
+)
+
+func TestHasTypeParam(t *testing.T) {
+	generic := newGenericNamedType("Box")
+	instantiated, err := types.Instantiate(types.NewContext(), generic, []types.Type{types.Typ[types.String]}, true)
+	if err != nil {
+		t.Fatalf("Instantiate: %v", err)
+	}
+
+	arrayType := func() types.Type {
+		tp := newTypeParam("ArrayElem")
+		return types.NewArray(tp, 3)
+	}()
+
+	chanType := types.NewChan(types.SendRecv, newTypeParam("ChanElem"))
+
+	tupleType := func() types.Type {
+		tp := newTypeParam("TupleElem")
+		elem := types.NewVar(token.NoPos, nil, "v", tp)
+		return types.NewTuple(elem)
+	}()
+
+	structWithParam := func() types.Type {
+		tp := newTypeParam("StructElem")
+		field := types.NewVar(token.NoPos, nil, "value", tp)
+		return types.NewStruct([]*types.Var{field}, nil)
+	}()
+
+	signatureWithParam := func() types.Type {
+		tp := newTypeParam("SigParam")
+		params := types.NewTuple(types.NewVar(token.NoPos, nil, "x", tp))
+		return types.NewSignatureType(nil, nil, []*types.TypeParam{tp}, params, types.NewTuple(), false)
+	}()
+
+	signatureWithResult := func() types.Type {
+		tp := newTypeParam("SigResult")
+		results := types.NewTuple(types.NewVar(token.NoPos, nil, "res", tp))
+		return types.NewSignatureType(nil, nil, []*types.TypeParam{tp}, types.NewTuple(), results, false)
+	}()
+
+	interfaceWithParam := func() types.Type {
+		tp := newTypeParam("IfaceParam")
+		params := types.NewTuple(types.NewVar(token.NoPos, nil, "v", tp))
+		method := types.NewFunc(token.NoPos, nil, "Do", types.NewSignatureType(nil, nil, []*types.TypeParam{tp}, params, types.NewTuple(), false))
+		iface := types.NewInterfaceType([]*types.Func{method}, nil)
+		iface.Complete()
+		return iface
+	}()
+
+	interfaceWithEmbed := func() types.Type {
+		base := interfaceWithParam
+		tp := newTypeParam("EmbedParam")
+		embedMethod := types.NewFunc(token.NoPos, nil, "Run", types.NewSignatureType(nil, nil, []*types.TypeParam{tp}, types.NewTuple(), types.NewTuple(), false))
+		iface := types.NewInterfaceType([]*types.Func{embedMethod}, []types.Type{base})
+		iface.Complete()
+		return iface
+	}()
+
+	selfRecursive := func() types.Type {
+		typeName := types.NewTypeName(token.NoPos, nil, "Node", nil)
+		placeholder := types.NewStruct(nil, nil)
+		named := types.NewNamed(typeName, placeholder, nil)
+		field := types.NewVar(token.NoPos, nil, "next", types.NewPointer(named))
+		structType := types.NewStruct([]*types.Var{field}, nil)
+		named.SetUnderlying(structType)
+		return named
+	}()
+
+	tests := []struct {
+		name string
+		typ  types.Type
+		want bool
+	}{
+		{"basic", types.Typ[types.Int], false},
+		{"typeParam", newTypeParam("T"), true},
+		{"pointerToTypeParam", types.NewPointer(newTypeParam("PtrT")), true},
+		{"sliceOfTypeParam", types.NewSlice(newTypeParam("SliceT")), true},
+		{"arrayOfTypeParam", arrayType, true},
+		{"mapWithTypeParam", types.NewMap(newTypeParam("MapKey"), types.Typ[types.String]), true},
+		{"chanOfTypeParam", chanType, true},
+		{"tupleWithTypeParam", tupleType, true},
+		{"structWithTypeParam", structWithParam, true},
+		{"signatureWithTypeParam", signatureWithParam, true},
+		{"signatureWithResultTypeParam", signatureWithResult, true},
+		{"interfaceWithTypeParam", interfaceWithParam, true},
+		{"interfaceWithEmbeddedTypeParam", interfaceWithEmbed, true},
+		{"namedGeneric", generic, true},
+		{"pointerToNamedGeneric", types.NewPointer(generic), true},
+		{"namedInstanceNoParam", instantiated, false},
+		{"selfRecursiveStruct", selfRecursive, false},
+	}
+
+	for _, tc := range tests {
+		tc := tc
+		t.Run(tc.name, func(t *testing.T) {
+			if got := hasTypeParam(tc.typ); got != tc.want {
+				t.Fatalf("hasTypeParam(%s) = %v, want %v", tc.name, got, tc.want)
+			}
+		})
+	}
+}
+
+func newTypeParam(name string) *types.TypeParam {
+	iface := types.NewInterfaceType(nil, nil)
+	iface.Complete()
+	return types.NewTypeParam(types.NewTypeName(token.NoPos, nil, name, nil), iface)
+}
+
+func newGenericNamedType(name string) *types.Named {
+	tp := newTypeParam("T")
+	field := types.NewVar(token.NoPos, nil, "value", tp)
+	structType := types.NewStruct([]*types.Var{field}, nil)
+	named := types.NewNamed(types.NewTypeName(token.NoPos, nil, name, nil), structType, nil)
+	named.SetTypeParams([]*types.TypeParam{tp})
+	return named
+}