Merge pull request #111 from klueska/simplify-lib

Remove need for newDynamicLibraryFunc

pkg/nvml/lib.go

@@ -34,27 +34,19 @@ const (
 var errLibraryNotLoaded = errors.New("library not loaded")
 var errLibraryAlreadyLoaded = errors.New("library already loaded")
 
-// newDynamicLibraryFunc defines a function to create a new dynamicLibrary
-type newDynamicLibraryFunc func(path string, flags int) dynamicLibrary
-
 // library represents an nvml library.
 // This includes a reference to the underlying DynamicLibrary
 type library struct {
 	sync.Mutex
-	path              string
-	flags             int
-	refcount          refcount
-	dl                dynamicLibrary
-	newDynamicLibrary newDynamicLibraryFunc
+	path     string
+	refcount refcount
+	dl       dynamicLibrary
 }
 
 // libnvml is a global instance of the nvml library.
 var libnvml = library{
-	path:  defaultNvmlLibraryName,
-	flags: defaultNvmlLibraryLoadFlags,
-	newDynamicLibrary: func(path string, flags int) dynamicLibrary {
-		return dl.New(path, flags)
-	},
+	path: defaultNvmlLibraryName,
+	dl:   dl.New(defaultNvmlLibraryName, defaultNvmlLibraryLoadFlags),
 }
 
 var _ Interface = (*library)(nil)
@@ -72,7 +64,7 @@ func GetLibrary() Library {
 // Lookup checks whether the specified library symbol exists in the library.
 // Note that this requires that the library be loaded.
 func (l *library) Lookup(name string) error {
-	if l == nil || l.dl == nil {
+	if l == nil || l.refcount == 0 {
 		return fmt.Errorf("error looking up %s: %w", name, errLibraryNotLoaded)
 	}
 	return l.dl.Lookup(name)
@@ -89,12 +81,10 @@ func (l *library) load() (rerr error) {
 		return nil
 	}
 
-	dl := l.newDynamicLibrary(l.path, l.flags)
-	if err := dl.Open(); err != nil {
+	if err := l.dl.Open(); err != nil {
 		return fmt.Errorf("error opening %s: %w", l.path, err)
 	}
 
-	l.dl = dl
 	l.updateVersionedSymbols()
 
 	return nil
@@ -116,8 +106,6 @@ func (l *library) close() (rerr error) {
 		return fmt.Errorf("error closing %s: %w", l.path, err)
 	}
 
-	l.dl = nil
-
 	return nil
 }
 
@@ -267,13 +255,19 @@ func (l *library) updateVersionedSymbols() {
 	}
 }
 
+// libraryOptions hold the paramaters than can be set by a LibraryOption
+type libraryOptions struct {
+	path  string
+	flags int
+}
+
 // LibraryOption represents a functional option to configure the underlying NVML library
-type LibraryOption func(*library)
+type LibraryOption func(*libraryOptions)
 
 // WithLibraryPath provides an option to set the library name to be used by the NVML library.
 func WithLibraryPath(path string) LibraryOption {
-	return func(l *library) {
-		l.path = path
+	return func(o *libraryOptions) {
+		o.path = path
 	}
 }
 
@@ -282,20 +276,24 @@ func WithLibraryPath(path string) LibraryOption {
 func SetLibraryOptions(opts ...LibraryOption) error {
 	libnvml.Lock()
 	defer libnvml.Unlock()
-	if libnvml.dl != nil {
+	if libnvml.refcount != 0 {
 		return errLibraryAlreadyLoaded
 	}
 
+	o := libraryOptions{}
 	for _, opt := range opts {
-		opt(&libnvml)
+		opt(&o)
 	}
 
-	if libnvml.path == "" {
-		libnvml.path = defaultNvmlLibraryName
+	if o.path == "" {
+		o.path = defaultNvmlLibraryName
 	}
-	if libnvml.flags == 0 {
-		libnvml.flags = defaultNvmlLibraryLoadFlags
+	if o.flags == 0 {
+		o.flags = defaultNvmlLibraryLoadFlags
 	}
 
+	libnvml.path = o.path
+	libnvml.dl = dl.New(o.path, o.flags)
+
 	return nil
 }

pkg/nvml/lib_test.go

@@ -25,11 +25,7 @@ import (
 )
 
 func newTestLibrary(dl dynamicLibrary) *library {
-	return &library{
-		newDynamicLibrary: func(string, int) dynamicLibrary {
-			return dl
-		},
-	}
+	return &library{dl: dl}
 }
 
 func TestLookupFromDefault(t *testing.T) {
@@ -132,9 +128,9 @@ func TestLookupFromDefault(t *testing.T) {
 			require.ErrorIs(t, l.Lookup("symbol"), tc.expectedLookupErrror)
 			require.ErrorIs(t, l.close(), tc.expectedCloseError)
 			if tc.expectedCloseError == nil {
-				require.Nil(t, l.dl)
+				require.Equal(t, 0, int(l.refcount))
 			} else {
-				require.Equal(t, tc.dl, l.dl)
+				require.Equal(t, 1, int(l.refcount))
 			}
 		})
 	}