Added SchemaProxy mutex #163

Rendering causes bits to be set on structs in the model. Concurrency causes race issues with reading a writing of these bits, as there is no locking in the model.

Until now. locking prevents concurrent renders that use a shared model from conflicting with one another.

Addresses #163 and pb33f/libopenapi-validator#23

Signed-off-by: quobix <dave@quobix.com>

datamodel/high/base/schema.go

@@ -176,50 +176,50 @@ func NewSchema(schema *base.Schema) *Schema {
 		s.UniqueItems = &schema.UniqueItems.Value
 	}
 	if !schema.Contains.IsEmpty() {
-		s.Contains = &SchemaProxy{schema: &lowmodel.NodeReference[*base.SchemaProxy]{
+		s.Contains = NewSchemaProxy(&lowmodel.NodeReference[*base.SchemaProxy]{
 			ValueNode: schema.Contains.ValueNode,
 			Value:     schema.Contains.Value,
-		}}
+		})
 	}
 	if !schema.If.IsEmpty() {
-		s.If = &SchemaProxy{schema: &lowmodel.NodeReference[*base.SchemaProxy]{
+		s.If = NewSchemaProxy(&lowmodel.NodeReference[*base.SchemaProxy]{
 			ValueNode: schema.If.ValueNode,
 			Value:     schema.If.Value,
-		}}
+		})
 	}
 	if !schema.Else.IsEmpty() {
-		s.Else = &SchemaProxy{schema: &lowmodel.NodeReference[*base.SchemaProxy]{
+		s.Else = NewSchemaProxy(&lowmodel.NodeReference[*base.SchemaProxy]{
 			ValueNode: schema.Else.ValueNode,
 			Value:     schema.Else.Value,
-		}}
+		})
 	}
 	if !schema.Then.IsEmpty() {
-		s.Then = &SchemaProxy{schema: &lowmodel.NodeReference[*base.SchemaProxy]{
+		s.Then = NewSchemaProxy(&lowmodel.NodeReference[*base.SchemaProxy]{
 			ValueNode: schema.Then.ValueNode,
 			Value:     schema.Then.Value,
-		}}
+		})
 	}
 	if !schema.PropertyNames.IsEmpty() {
-		s.PropertyNames = &SchemaProxy{schema: &lowmodel.NodeReference[*base.SchemaProxy]{
+		s.PropertyNames = NewSchemaProxy(&lowmodel.NodeReference[*base.SchemaProxy]{
 			ValueNode: schema.PropertyNames.ValueNode,
 			Value:     schema.PropertyNames.Value,
-		}}
+		})
 	}
 	if !schema.UnevaluatedItems.IsEmpty() {
-		s.UnevaluatedItems = &SchemaProxy{schema: &lowmodel.NodeReference[*base.SchemaProxy]{
+		s.UnevaluatedItems = NewSchemaProxy(&lowmodel.NodeReference[*base.SchemaProxy]{
 			ValueNode: schema.UnevaluatedItems.ValueNode,
 			Value:     schema.UnevaluatedItems.Value,
-		}}
+		})
 	}
 	// check if unevaluated properties is a schema
 	if !schema.UnevaluatedProperties.IsEmpty() && schema.UnevaluatedProperties.Value.IsA() {
 		s.UnevaluatedProperties = &DynamicValue[*SchemaProxy, *bool]{
-			A: &SchemaProxy{
-				schema: &lowmodel.NodeReference[*base.SchemaProxy]{
+			A: NewSchemaProxy(
+				&lowmodel.NodeReference[*base.SchemaProxy]{
 					ValueNode: schema.UnevaluatedProperties.ValueNode,
 					Value:     schema.UnevaluatedProperties.Value.A,
 				},
-			},
+			),
 			N: 0,
 		}
 	}
@@ -325,11 +325,11 @@ func NewSchema(schema *base.Schema) *Schema {
 
 	// for every item, build schema async
 	buildSchema := func(sch lowmodel.ValueReference[*base.SchemaProxy], idx int, bChan chan buildResult) {
-		p := &SchemaProxy{schema: &lowmodel.NodeReference[*base.SchemaProxy]{
+		p := NewSchemaProxy(&lowmodel.NodeReference[*base.SchemaProxy]{
 			ValueNode: sch.ValueNode,
 			Value:     sch.Value,
 			Reference: sch.GetReference(),
-		}}
+		})
 
 		bChan <- buildResult{idx: idx, s: p}
 	}
@@ -358,13 +358,12 @@ func NewSchema(schema *base.Schema) *Schema {
 	buildProps := func(k lowmodel.KeyReference[string], v lowmodel.ValueReference[*base.SchemaProxy],
 		props map[string]*SchemaProxy, sw int,
 	) {
-		props[k.Value] = &SchemaProxy{
-			schema: &lowmodel.NodeReference[*base.SchemaProxy]{
-				Value:     v.Value,
-				KeyNode:   k.KeyNode,
-				ValueNode: v.ValueNode,
-			},
-		}
+		props[k.Value] = NewSchemaProxy(&lowmodel.NodeReference[*base.SchemaProxy]{
+			Value:     v.Value,
+			KeyNode:   k.KeyNode,
+			ValueNode: v.ValueNode,
+		},
+		)
 
 		switch sw {
 		case 0:
@@ -418,11 +417,13 @@ func NewSchema(schema *base.Schema) *Schema {
 	}
 	if !schema.Items.IsEmpty() {
 		if schema.Items.Value.IsA() {
-			items = &DynamicValue[*SchemaProxy, bool]{A: &SchemaProxy{schema: &lowmodel.NodeReference[*base.SchemaProxy]{
-				ValueNode: schema.Items.ValueNode,
-				Value:     schema.Items.Value.A,
-				KeyNode:   schema.Items.KeyNode,
-			}}}
+			items = &DynamicValue[*SchemaProxy, bool]{
+				A: NewSchemaProxy(&lowmodel.NodeReference[*base.SchemaProxy]{
+					ValueNode: schema.Items.ValueNode,
+					Value:     schema.Items.Value.A,
+					KeyNode:   schema.Items.KeyNode,
+				},
+				)}
 		} else {
 			items = &DynamicValue[*SchemaProxy, bool]{N: 1, B: schema.Items.Value.B}
 		}

datamodel/high/base/schema_proxy.go

@@ -9,6 +9,7 @@ import (
 	"github.com/pb33f/libopenapi/datamodel/low/base"
 	"github.com/pb33f/libopenapi/utils"
 	"gopkg.in/yaml.v3"
+	"sync"
 )
 
 // SchemaProxy exists as a stub that will create a Schema once (and only once) the Schema() method is called. An
@@ -49,40 +50,47 @@ type SchemaProxy struct {
 	buildError error
 	rendered   *Schema
 	refStr     string
+	lock       *sync.Mutex
 }
 
 // NewSchemaProxy creates a new high-level SchemaProxy from a low-level one.
 func NewSchemaProxy(schema *low.NodeReference[*base.SchemaProxy]) *SchemaProxy {
-	return &SchemaProxy{schema: schema}
+	return &SchemaProxy{schema: schema, lock: &sync.Mutex{}}
 }
 
 // CreateSchemaProxy will create a new high-level SchemaProxy from a high-level Schema, this acts the same
 // as if the SchemaProxy is pre-rendered.
 func CreateSchemaProxy(schema *Schema) *SchemaProxy {
-	return &SchemaProxy{rendered: schema}
+	return &SchemaProxy{rendered: schema, lock: &sync.Mutex{}}
 }
 
 // CreateSchemaProxyRef will create a new high-level SchemaProxy from a reference string, this is used only when
 // building out new models from scratch that require a reference rather than a schema implementation.
 func CreateSchemaProxyRef(ref string) *SchemaProxy {
-	return &SchemaProxy{refStr: ref}
+	return &SchemaProxy{refStr: ref, lock: &sync.Mutex{}}
 }
 
 // Schema will create a new Schema instance using NewSchema from the low-level SchemaProxy backing this high-level one.
 // If there is a problem building the Schema, then this method will return nil. Use GetBuildError to gain access
 // to that building error.
 func (sp *SchemaProxy) Schema() *Schema {
+	sp.lock.Lock()
 	if sp.rendered == nil {
+
 		s := sp.schema.Value.Schema()
 		if s == nil {
 			sp.buildError = sp.schema.Value.GetBuildError()
+			sp.lock.Unlock()
 			return nil
 		}
 		sch := NewSchema(s)
 		sch.ParentProxy = sp
+
 		sp.rendered = sch
+		sp.lock.Unlock()
 		return sch
 	} else {
+		sp.lock.Unlock()
 		return sp.rendered
 	}
 }

datamodel/high/base/schema_test.go

@@ -57,7 +57,7 @@ func TestNewSchemaProxy(t *testing.T) {
 		ValueNode: idxNode.Content[0],
 	}
 
-	sch1 := SchemaProxy{schema: &lowproxy}
+	sch1 := NewSchemaProxy(&lowproxy)
 	assert.Nil(t, sch1.Schema())
 	assert.Error(t, sch1.GetBuildError())
 
@@ -98,7 +98,7 @@ func TestNewSchemaProxyRender(t *testing.T) {
 		ValueNode: idxNode.Content[0],
 	}
 
-	sch1 := SchemaProxy{schema: &lowproxy}
+	sch1 := NewSchemaProxy(&lowproxy)
 	assert.NotNil(t, sch1.Schema())
 	assert.NoError(t, sch1.GetBuildError())
 
@@ -1125,7 +1125,7 @@ components:
 		ValueNode: idxNode.Content[0],
 	}
 
-	sch1 := SchemaProxy{schema: &lowproxy}
+	sch1 := NewSchemaProxy(&lowproxy)
 	compiled := sch1.Schema()
 
 	// now render it out, it should be identical.
@@ -1177,7 +1177,7 @@ components:
 		ValueNode: idxNode.Content[0],
 	}
 
-	sch1 := SchemaProxy{schema: &lowproxy}
+	sch1 := NewSchemaProxy(&lowproxy)
 	compiled := sch1.Schema()
 
 	// now render it out, it should be identical.