Windows specific : ensure all child processes are killed when parent exits (also works when killing parent). From Desktop code

cli/dockerclassic/job_windows.go

@@ -0,0 +1,93 @@
+package dockerclassic
+
+import (
+	"fmt"
+	"os"
+	"syscall"
+	"unsafe"
+)
+
+func init() {
+	if err := killSubProcessesOnClose(); err != nil {
+		fmt.Println("failed to create job:", err)
+	}
+}
+
+var (
+	kernel32 = syscall.NewLazyDLL("kernel32.dll")
+)
+
+type jobObjectExtendedLimitInformation struct {
+	BasicLimitInformation struct {
+		PerProcessUserTimeLimit uint64
+		PerJobUserTimeLimit     uint64
+		LimitFlags              uint32
+		MinimumWorkingSetSize   uintptr
+		MaximumWorkingSetSize   uintptr
+		ActiveProcessLimit      uint32
+		Affinity                uintptr
+		PriorityClass           uint32
+		SchedulingClass         uint32
+	}
+	IoInfo struct {
+		ReadOperationCount  uint64
+		WriteOperationCount uint64
+		OtherOperationCount uint64
+		ReadTransferCount   uint64
+		WriteTransferCount  uint64
+		OtherTransferCount  uint64
+	}
+	ProcessMemoryLimit    uintptr
+	JobMemoryLimit        uintptr
+	PeakProcessMemoryUsed uintptr
+	PeakJobMemoryUsed     uintptr
+}
+
+// killSubProcessesOnClose will ensure on windows that all child processes of the current process are killed if parent is killed.
+func killSubProcessesOnClose() error {
+	job, err := createJobObject()
+	if err != nil {
+		return err
+	}
+	info := jobObjectExtendedLimitInformation{}
+	info.BasicLimitInformation.LimitFlags = 0x2000
+	if err := setInformationJobObject(job, info); err != nil {
+		_ = syscall.CloseHandle(job)
+		return err
+	}
+	proc, err := syscall.GetCurrentProcess()
+	if err != nil {
+		_ = syscall.CloseHandle(job)
+		return err
+	}
+	if err := assignProcessToJobObject(job, proc); err != nil {
+		_ = syscall.CloseHandle(job)
+		return err
+	}
+	return nil
+}
+
+func createJobObject() (syscall.Handle, error) {
+	res, _, err := kernel32.NewProc("CreateJobObjectW").Call(uintptr(unsafe.Pointer(nil)), uintptr(unsafe.Pointer(nil)))
+	if res == 0 {
+		return syscall.InvalidHandle, os.NewSyscallError("CreateJobObject", err)
+	}
+	return syscall.Handle(res), nil
+}
+
+func setInformationJobObject(job syscall.Handle, info jobObjectExtendedLimitInformation) error {
+	infoClass := uint32(9)
+	res, _, err := kernel32.NewProc("SetInformationJobObject").Call(uintptr(job), uintptr(infoClass), uintptr(unsafe.Pointer(&info)), uintptr(uint32(unsafe.Sizeof(info))))
+	if res == 0 {
+		return os.NewSyscallError("SetInformationJobObject", err)
+	}
+	return nil
+}
+
+func assignProcessToJobObject(job syscall.Handle, process syscall.Handle) error {
+	res, _, err := kernel32.NewProc("AssignProcessToJobObject").Call(uintptr(job), uintptr(process))
+	if res == 0 {
+		return os.NewSyscallError("AssignProcessToJobObject", err)
+	}
+	return nil
+}