internal/fakecgo: disable race in fakecgo (#319)

Closes #318

Author: TotallyGamerJet

.github/workflows/test.yml

@@ -129,10 +129,16 @@ jobs:
            sudo apt-get install g++-multilib
            env CGO_ENABLED=1 GOARCH=386 go test -shuffle=on -v -count=10 ./...
 
-      - name: go test race
+      - name: go test race (no Cgo)
+        if: ${{ runner.os == 'macOS' &&  !startsWith(matrix.go, '1.18.') && !startsWith(matrix.go, '1.19.') }}
+        run: |
+          # -race usually requires Cgo, but macOS is an exception. See https://go.dev/doc/articles/race_detector#Requirements
+          env CGO_ENABLED=0 go test -race -shuffle=on -v -count=10 ./...
+
+      - name: go test race (Cgo)
         if: ${{ !startsWith(matrix.go, '1.18.') && !startsWith(matrix.go, '1.19.') }}
         run: |
-          go test -race -shuffle=on -v -count=10 ./...
+          env CGO_ENABLED=1 go test -race -shuffle=on -v -count=10 ./...
 
   freebsd:
     strategy:

internal/fakecgo/gen.go

@@ -37,6 +37,7 @@ func call5(fn, a1, a2, a3, a4, a5 uintptr) uintptr
 
 {{ range . -}}
 //go:nosplit
+//go:norace
 func {{.Name}}(
 {{- range .Args -}}
 	{{- if .Name -}}

internal/fakecgo/go_libinit.go

@@ -19,6 +19,7 @@ var (
 )
 
 //go:nosplit
+//go:norace
 func x_cgo_notify_runtime_init_done() {
 	pthread_mutex_lock(&runtime_init_mu)
 	runtime_init_done = 1
@@ -28,6 +29,8 @@ func x_cgo_notify_runtime_init_done() {
 
 // Store the g into a thread-specific value associated with the pthread key pthread_g.
 // And pthread_key_destructor will dropm when the thread is exiting.
+//
+//go:norace
 func x_cgo_bindm(g unsafe.Pointer) {
 	// We assume this will always succeed, otherwise, there might be extra M leaking,
 	// when a C thread exits after a cgo call.