feat: support fastrand in Go 1.22 (bytedance#206)

Co-authored-by: ZhangYunHao <[email protected]>

internal/runtimex/runtime_go_1.22.go

@@ -0,0 +1,25 @@
+// Copyright 2024 ByteDance Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+//go:build go1.22
+// +build go1.22
+
+package runtimex
+
+import (
+	_ "unsafe" // for linkname
+)
+
+//go:linkname Fastrand runtime.cheaprand
+func Fastrand() uint32

internal/runtimex/runtime.go → internal/runtimex/runtime_pre_go_1.22.go

@@ -12,6 +12,9 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
+//go:build !go1.22
+// +build !go1.22
+
 package runtimex
 
 import (

internal/runtimex/runtime_test.go

@@ -0,0 +1,38 @@
+// Copyright 2024 ByteDance Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package runtimex
+
+import "testing"
+
+func TestFastrand(t *testing.T) {
+	var isRandom bool
+	for i := 0; i < 3; i++ {
+		x := Fastrand()
+		y := Fastrand()
+		if x != y {
+			isRandom = true
+			break
+		}
+	}
+	if !isRandom {
+		t.Fatal("Invalid fastrand results")
+	}
+}
+
+func BenchmarkFastrand(b *testing.B) {
+	for i := 0; i < b.N; i++ {
+		Fastrand()
+	}
+}