Improve darwin tun performance

internal/fdbased_darwin/processor_mutex.go

@@ -0,0 +1,64 @@
+package fdbased
+
+import (
+	"reflect"
+
+	"github.com/sagernet/gvisor/pkg/sync"
+	"github.com/sagernet/gvisor/pkg/sync/locking"
+)
+
+// Mutex is sync.Mutex with the correctness validator.
+type processorMutex struct {
+	mu sync.Mutex
+}
+
+var processorprefixIndex *locking.MutexClass
+
+// lockNames is a list of user-friendly lock names.
+// Populated in init.
+var processorlockNames []string
+
+// lockNameIndex is used as an index passed to NestedLock and NestedUnlock,
+// referring to an index within lockNames.
+// Values are specified using the "consts" field of go_template_instance.
+type processorlockNameIndex int
+
+// DO NOT REMOVE: The following function automatically replaced with lock index constants.
+// LOCK_NAME_INDEX_CONSTANTS
+const ()
+
+// Lock locks m.
+// +checklocksignore
+func (m *processorMutex) Lock() {
+	locking.AddGLock(processorprefixIndex, -1)
+	m.mu.Lock()
+}
+
+// NestedLock locks m knowing that another lock of the same type is held.
+// +checklocksignore
+func (m *processorMutex) NestedLock(i processorlockNameIndex) {
+	locking.AddGLock(processorprefixIndex, int(i))
+	m.mu.Lock()
+}
+
+// Unlock unlocks m.
+// +checklocksignore
+func (m *processorMutex) Unlock() {
+	locking.DelGLock(processorprefixIndex, -1)
+	m.mu.Unlock()
+}
+
+// NestedUnlock unlocks m knowing that another lock of the same type is held.
+// +checklocksignore
+func (m *processorMutex) NestedUnlock(i processorlockNameIndex) {
+	locking.DelGLock(processorprefixIndex, int(i))
+	m.mu.Unlock()
+}
+
+// DO NOT REMOVE: The following function is automatically replaced.
+func processorinitLockNames() {}
+
+func init() {
+	processorinitLockNames()
+	processorprefixIndex = locking.NewMutexClass(reflect.TypeOf(processorMutex{}), processorlockNames)
+}