fmt: make formatter know about new keywords `shared`, `rlock` (#5779)

vlib/v/ast/str.v

@@ -32,7 +32,7 @@ pub fn (node &FnDecl) stringify(t &table.Table) string {
 	mut receiver := ''
 	if node.is_method {
 		mut styp := t.type_to_str(node.receiver.typ)
-		mut m := if node.rec_mut { 'mut ' } else { '' }
+		mut m := if node.rec_mut { node.receiver.typ.share().str() + ' ' } else { '' }
 		if node.rec_mut {
 			styp = styp[1..] // remove &
 		}
@@ -72,7 +72,7 @@ pub fn (node &FnDecl) stringify(t &table.Table) string {
 		should_add_type := is_last_arg || node.args[i + 1].typ != arg.typ || (node.is_variadic &&
 			i == node.args.len - 2)
 		if arg.is_mut {
-			f.write('mut ')
+			f.write(arg.typ.share().str() + ' ')
 		}
 		f.write(arg.name)
 		mut s := t.type_to_str(arg.typ)

vlib/v/fmt/fmt.v

@@ -250,7 +250,7 @@ pub fn (mut f Fmt) stmt(node ast.Stmt) {
 				if left is ast.Ident {
 					var_info := left.var_info()
 					if var_info.is_mut {
-						f.write('mut ')
+						f.write(var_info.share.str() + ' ')
 					}
 					f.expr(left)
 					if i < node.left.len - 1 {
@@ -517,7 +517,7 @@ pub fn (mut f Fmt) type_decl(node ast.TypeDecl) {
 				f.write(arg.name)
 				mut s := f.table.type_to_str(arg.typ).replace(f.cur_mod + '.', '')
 				if arg.is_mut {
-					f.write('mut ')
+					f.write(arg.typ.share().str() + ' ')
 					if s.starts_with('&') {
 						s = s[1..]
 					}
@@ -1054,7 +1054,7 @@ pub fn (mut f Fmt) wrap_long_line(penalty int, add_indent bool) bool {
 pub fn (mut f Fmt) call_args(args []ast.CallArg) {
 	for i, arg in args {
 		if arg.is_mut {
-			f.write('mut ')
+			f.write(arg.share.str() + ' ')
 		}
 		if i > 0 {
 			f.wrap_long_line(2, true)
@@ -1173,7 +1173,11 @@ pub fn (mut f Fmt) short_module(name string) string {
 }
 
 pub fn (mut f Fmt) lock_expr(lex ast.LockExpr) {
-	f.write('lock ')
+	f.write(if lex.is_rlock {
+		'rlock '
+	} else {
+		'lock '
+	})
 	for i, v in lex.lockeds {
 		if i > 0 {
 			f.write(', ')

vlib/v/fmt/tests/shared_expected.vv

@@ -0,0 +1,58 @@
+import sync
+import time
+
+struct St {
+mut:
+	a int
+}
+
+fn (shared x St) f(shared z St) {
+	for _ in 0 .. reads_per_thread {
+		rlock x { // other instances may read at the same time
+			time.sleep_ms(1)
+			assert x.a == 7 || x.a == 5
+		}
+	}
+	lock z {
+		z.a--
+	}
+}
+
+const (
+	reads_per_thread = 30
+	read_threads     = 10
+	writes           = 5
+)
+
+fn test_shared_lock() {
+	// object with separate read/write lock
+	shared x := &St{
+		a: 5
+	}
+	shared z := &St{
+		a: read_threads
+	}
+	for _ in 0 .. read_threads {
+		go x.f(shared z)
+	}
+	for i in 0 .. writes {
+		lock x { // wait for ongoing reads to finish, don't start new ones
+			x.a = 17 // this value should never be read
+			time.sleep_ms(50)
+			x.a = if (i & 1) == 0 { 7 } else { 5 }
+		} // now new reads are possible again
+		time.sleep_ms(20)
+	}
+	// wait until all read threads are finished
+	for finished := false; true; {
+		mut rr := 0
+		rlock z {
+			rr = z.a
+			finished = z.a == 0
+		}
+		if finished {
+			break
+		}
+		time.sleep_ms(100)
+	}
+}

vlib/v/fmt/tests/shared_input.vv

@@ -0,0 +1,60 @@
+import sync
+import time
+
+struct St {
+mut:
+	a int
+}
+
+fn (shared x St) f(shared z St) {
+	for _ in 0 .. reads_per_thread {
+		rlock x { // other instances may read at the same time
+			time.sleep_ms(1)
+			assert x.a == 7 || x.a == 5
+		}
+	}
+	lock z {
+		z.a--
+	}
+}
+
+const (
+	reads_per_thread = 30
+	read_threads     = 10
+	writes           = 5
+)
+
+fn test_shared_lock() {
+	// object with separate read/write lock
+shared x := &St {
+a: 5
+}
+	shared z :=
+&St{
+		a: read_threads
+      	}
+	for  _  in 0.. read_threads {
+		go x.f(shared z)
+	}
+  	for  i in 0..writes {
+ lock x { // wait for ongoing reads to finish, don't start new ones
+			 x.a = 17 // this value should never be read
+	time.sleep_ms(50)
+	x.a = if (i & 1) == 0 {
+7} else {5}
+	} // now new reads are possible again
+time.sleep_ms(20)
+	}
+	// wait until all read threads are finished
+for finished:=false;; {
+	mut rr := 0
+		  rlock z {
+  rr = z.a
+	  finished = z.a == 0
+}
+if finished {
+		break
+		     }
+			time.sleep_ms(100)
+			}
+}