log: for atomic, underlying types must be same

but what the client code sends to SetConsole is out of pkg log's control
and hence it must accomodate for changing underlying types of whatever
implements the Console interface

Author: ignoramous

intra/log/logger.go

@@ -96,17 +96,22 @@ func (a *atom[T]) get() (zz T) {
 	return zz
 }
 
-func (a *atom[T]) set(t T) {
+func (a *atom[T]) set(t T) (ok bool) {
 	if a == nil {
 		return
 	}
-	if IsNil(t) {
+	if isNil(t) {
 		zz := &atom[T]{}
 		*a = *zz
 		return
 	}
+	old := a.get()
+	if !typeEq(old, t) {
+		r := &atom[T]{}
+		*a = *r
+	}
 	aa := (*atomic.Value)(a)
-	aa.Store(t)
+	return aa.CompareAndSwap(old, t)
 }
 
 const pcbuckets = 512
@@ -304,7 +309,7 @@ func (l *simpleLogger) consoleDispatcher() {
 			continue
 		}
 		load := (len(l.cmsgC) / cap(l.cmsgC) * 100) // load percentage
-		if c := l.c.get(); c != nil && !IsNil(c) {  // look for l.c on every msg
+		if c := l.c.get(); c != nil && !isNil(c) {  // look for l.c on every msg
 			switch m.t {
 			case NONE:
 				// drop
@@ -405,7 +410,7 @@ func (l *simpleLogger) emitStack(at int, msgs ...string) {
 		}
 		if !sendtoconsole {
 			l.err(at+nextframe, msg)
-		} else if c != nil && !IsNil(c) {
+		} else if c != nil && !isNil(c) {
 			// c.Stack() on the same go routine, since
 			// the caller (ex: core.Recover) may exit
 			// immediately once simpleLogger.Stack() returns
@@ -687,8 +692,8 @@ top:
 }
 
 // Cannot import pkg core here.
-// from: intra/core/typ.go:IsNil
-func IsNil(x any) bool {
+// from: intra/core/typ.go:isNil
+func isNil(x any) bool {
 	// from: stackoverflow.com/a/76595928
 	if x == nil {
 		return true
@@ -701,3 +706,13 @@ func IsNil(x any) bool {
 	}
 	return false
 }
+
+// from: intra/core/typ.go:typeEq
+func typeEq(a, b any) bool {
+	if isNil(a) {
+		return false
+	} else if isNil(b) {
+		return false
+	}
+	return reflect.TypeOf(a) == reflect.TypeOf(b)
+}