Add a fallback check of Watch pid on Windows

False positives were detected when checking the previous watch process state

Signed-off-by: Guillaume Lours <705411+glours@users.noreply.github.com>

internal/locker/pidfile.go

@@ -18,10 +18,7 @@ package locker
 
 import (
 	"fmt"
-	"os"
 	"path/filepath"
-
-	"github.com/docker/docker/pkg/pidfile"
 )
 
 type Pidfile struct {
@@ -36,7 +33,3 @@ func NewPidfile(projectName string) (*Pidfile, error) {
 	path := filepath.Join(run, fmt.Sprintf("%s.pid", projectName))
 	return &Pidfile{path: path}, nil
 }
-
-func (f *Pidfile) Lock() error {
-	return pidfile.Write(f.path, os.Getpid())
-}

internal/locker/pidfile_unix.go

@@ -0,0 +1,29 @@
+//go:build !windows
+
+/*
+   Copyright 2023 Docker Compose CLI authors
+
+   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 locker
+
+import (
+	"os"
+
+	"github.com/docker/docker/pkg/pidfile"
+)
+
+func (f *Pidfile) Lock() error {
+	return pidfile.Write(f.path, os.Getpid())
+}

internal/locker/pidfile_windows.go

@@ -0,0 +1,47 @@
+//go:build windows
+
+/*
+   Copyright 2023 Docker Compose CLI authors
+
+   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 locker
+
+import (
+	"github.com/docker/docker/pkg/pidfile"
+	"github.com/mitchellh/go-ps"
+	"os"
+)
+
+func (f *Pidfile) Lock() error {
+	newPID := os.Getpid()
+	err := pidfile.Write(f.path, newPID)
+	if err != nil {
+		// Get PID registered in the file
+		pid, errPid := pidfile.Read(f.path)
+		if errPid != nil {
+			return err
+		}
+		// Some users faced issues on Windows where the process written in the pidfile was identified as still existing
+		// So we used a 2nd process library to verify if this not a false positive feedback
+		// Check if the process exists
+		process, errPid := ps.FindProcess(pid)
+		if process == nil && errPid == nil {
+			// If the process does not exist, remove the pidfile and try to lock again
+			_ = os.Remove(f.path)
+			return pidfile.Write(f.path, newPID)
+		}
+	}
+	return err
+}