diff --git a/model_struct.go b/model_struct.go index 5234b287..d9e2e90f 100644 --- a/model_struct.go +++ b/model_struct.go @@ -17,6 +17,10 @@ var DefaultTableNameHandler = func(db *DB, defaultTableName string) string { return defaultTableName } +// lock for mutating global cached model metadata +var structsLock sync.Mutex + +// global cache of model metadata var modelStructsMap sync.Map // ModelStruct model definition @@ -419,8 +423,12 @@ func (scope *Scope) GetModelStruct() *ModelStruct { for idx, foreignKey := range foreignKeys { if foreignField := getForeignField(foreignKey, toFields); foreignField != nil { if associationField := getForeignField(associationForeignKeys[idx], modelStruct.StructFields); associationField != nil { - // source foreign keys + // mark field as foreignkey, use global lock to avoid race + structsLock.Lock() foreignField.IsForeignKey = true + structsLock.Unlock() + + // association foreign keys relationship.AssociationForeignFieldNames = append(relationship.AssociationForeignFieldNames, associationField.Name) relationship.AssociationForeignDBNames = append(relationship.AssociationForeignDBNames, associationField.DBName) @@ -523,8 +531,12 @@ func (scope *Scope) GetModelStruct() *ModelStruct { for idx, foreignKey := range foreignKeys { if foreignField := getForeignField(foreignKey, toFields); foreignField != nil { if scopeField := getForeignField(associationForeignKeys[idx], modelStruct.StructFields); scopeField != nil { + // mark field as foreignkey, use global lock to avoid race + structsLock.Lock() foreignField.IsForeignKey = true - // source foreign keys + structsLock.Unlock() + + // association foreign keys relationship.AssociationForeignFieldNames = append(relationship.AssociationForeignFieldNames, scopeField.Name) relationship.AssociationForeignDBNames = append(relationship.AssociationForeignDBNames, scopeField.DBName) @@ -582,7 +594,10 @@ func (scope *Scope) GetModelStruct() *ModelStruct { for idx, foreignKey := range foreignKeys { if foreignField := getForeignField(foreignKey, modelStruct.StructFields); foreignField != nil { if associationField := getForeignField(associationForeignKeys[idx], toFields); associationField != nil { + // mark field as foreignkey, use global lock to avoid race + structsLock.Lock() foreignField.IsForeignKey = true + structsLock.Unlock() // association foreign keys relationship.AssociationForeignFieldNames = append(relationship.AssociationForeignFieldNames, associationField.Name) diff --git a/model_struct_test.go b/model_struct_test.go new file mode 100644 index 00000000..2ae419a0 --- /dev/null +++ b/model_struct_test.go @@ -0,0 +1,93 @@ +package gorm_test + +import ( + "sync" + "testing" + + "github.com/jinzhu/gorm" +) + +type ModelA struct { + gorm.Model + Name string + + ModelCs []ModelC `gorm:"foreignkey:OtherAID"` +} + +type ModelB struct { + gorm.Model + Name string + + ModelCs []ModelC `gorm:"foreignkey:OtherBID"` +} + +type ModelC struct { + gorm.Model + Name string + + OtherAID uint64 + OtherA *ModelA `gorm:"foreignkey:OtherAID"` + OtherBID uint64 + OtherB *ModelB `gorm:"foreignkey:OtherBID"` +} + +// This test will try to cause a race condition on the model's foreignkey metadata +func TestModelStructRaceSameModel(t *testing.T) { + // use a WaitGroup to execute as much in-sync as possible + // it's more likely to hit a race condition than without + n := 32 + start := sync.WaitGroup{} + start.Add(n) + + // use another WaitGroup to know when the test is done + done := sync.WaitGroup{} + done.Add(n) + + for i := 0; i < n; i++ { + go func() { + start.Wait() + + // call GetStructFields, this had a race condition before we fixed it + DB.NewScope(&ModelA{}).GetStructFields() + + done.Done() + }() + + start.Done() + } + + done.Wait() +} + +// This test will try to cause a race condition on the model's foreignkey metadata +func TestModelStructRaceDifferentModel(t *testing.T) { + // use a WaitGroup to execute as much in-sync as possible + // it's more likely to hit a race condition than without + n := 32 + start := sync.WaitGroup{} + start.Add(n) + + // use another WaitGroup to know when the test is done + done := sync.WaitGroup{} + done.Add(n) + + for i := 0; i < n; i++ { + i := i + go func() { + start.Wait() + + // call GetStructFields, this had a race condition before we fixed it + if i%2 == 0 { + DB.NewScope(&ModelA{}).GetStructFields() + } else { + DB.NewScope(&ModelB{}).GetStructFields() + } + + done.Done() + }() + + start.Done() + } + + done.Wait() +}