thread safe imports and funcs

func.go

@@ -1,11 +1,6 @@
 package libsass
 
-import (
-	"runtime"
-	"unsafe"
-
-	"github.com/wellington/go-libsass/libs"
-)
+import "github.com/wellington/go-libsass/libs"
 
 // HandlerFunc describes the method signature for registering
 // a Go function to be called by libsass.
@@ -90,17 +85,5 @@ func (ctx *Context) SetFunc(goopts libs.SassOptions) {
 			Ctx:  ctx,
 		}
 	}
-	// TODO: this seems to run fine with garbage collection on
-	// surprisingly enough
-	// disable garbage collection of cookies. These need to
-	// be manually freed in the wrapper
-	// runtime.SetFinalizer(&cookies, nil)
-	gofns := make([]libs.SassFunc, len(cookies))
-	runtime.SetFinalizer(&gofns, nil)
-	for i, cookie := range cookies {
-		fn := libs.SassMakeFunction(cookie.Sign,
-			unsafe.Pointer(&cookies[i]))
-		gofns[i] = fn
-	}
-	libs.BindFuncs(goopts, gofns)
+	libs.BindFuncs(goopts, cookies)
 }

libs/export.go

@@ -4,6 +4,7 @@ package libs
 //
 import "C"
 import (
+	"fmt"
 	"sync"
 	"unsafe"
 )
@@ -29,10 +30,14 @@ var gobridgeMu sync.Mutex
 //
 //export GoBridge
 func GoBridge(cargs UnionSassValue, ptr unsafe.Pointer) UnionSassValue {
-	// gobridgeMu.Lock()
-	// defer gobridgeMu.Unlock()
 	// Recover the Cookie struct passed in
-	ck := *(*Cookie)(ptr)
+	idx := (*string)(ptr)
+	ck, ok := globalFuncs.get(idx).(Cookie)
+	if !ok {
+		fmt.Printf("failed to resolve Cookie %p\n", ptr)
+		return MakeNil()
+	}
+	// ck := *(*Cookie)(ptr)
 
 	var usv UnionSassValue
 	err := ck.Fn(ck.Ctx, cargs, &usv)

libs/func.go

@@ -28,9 +28,25 @@ func SassMakeFunction(signature string, ptr unsafe.Pointer) SassFunc {
 	return (SassFunc)(fn)
 }
 
+var globalFuncs SafeMap
+
+func init() {
+	globalFuncs.init()
+}
+
 // BindFuncs attaches a slice of Functions to a sass options. Signatures
 // are already defined in the SassFunc.
-func BindFuncs(opts SassOptions, funcs []SassFunc) {
+func BindFuncs(opts SassOptions, cookies []Cookie) {
+
+	funcs := make([]SassFunc, len(cookies))
+	for i, cookie := range cookies {
+		idx := globalFuncs.set(cookies[i])
+
+		fn := SassMakeFunction(cookie.Sign,
+			unsafe.Pointer(idx))
+		funcs[i] = fn
+	}
+
 	sz := C.size_t(len(funcs))
 	cfuncs := C.sass_make_function_list(sz)
 	for i, cfn := range funcs {

libs/importer.go

@@ -35,14 +35,14 @@ import (
 // delete it
 type SafeMap struct {
 	sync.RWMutex
-	m map[string]interface{}
+	m map[*string]interface{}
 }
 
 func (s *SafeMap) init() {
-	s.m = make(map[string]interface{})
+	s.m = make(map[*string]interface{})
 }
 
-func (s *SafeMap) get(idx string) interface{} {
+func (s *SafeMap) get(idx *string) interface{} {
 	s.RLock()
 	defer s.RUnlock()
 	return s.m[idx]
@@ -58,16 +58,16 @@ func randString(n int) string {
 	return string(b)
 }
 
-func (s *SafeMap) delete(idx string) {
+func (s *SafeMap) delete(idx *string) {
 	s.Lock()
 	delete(s.m, idx)
 	s.Unlock()
 }
 
 // set accepts an entry and returns an index for it
-func (s *SafeMap) set(ie interface{}) string {
-	idx := randString(8)
-
+func (s *SafeMap) set(ie interface{}) *string {
+	i := randString(8)
+	idx := &i
 	s.Lock()
 	s.m[idx] = ie
 	defer s.Unlock()
@@ -85,7 +85,7 @@ func init() {
 func BindImporter(opts SassOptions, entries []ImportEntry) {
 
 	idx := globalImports.set(entries)
-	ptr := unsafe.Pointer(&idx)
+	ptr := unsafe.Pointer(idx)
 
 	imper := C.sass_make_importer(
 		C.Sass_Importer_Fn(C.SassImporterHandler),

libs/wrap.go

@@ -77,9 +77,12 @@ func GetEntry(es []ImportEntry, parent string, path string) (string, error) {
 //export ImporterBridge
 func ImporterBridge(url *C.char, prev *C.char, ptr unsafe.Pointer) C.Sass_Import_List {
 	// Retrieve the index
-	fmt.Printf("iBridge: % #v\n", ptr)
-	idx := *(*string)(ptr)
-	entries := globalImports.get(idx).([]ImportEntry)
+	idx := (*string)(ptr)
+	entries, ok := globalImports.get(idx).([]ImportEntry)
+	if !ok {
+		fmt.Printf("failed to resolve import slice: %p\n", ptr)
+		entries = []ImportEntry{}
+	}
 
 	parent := C.GoString(prev)
 	rel := C.GoString(url)