// so there is no risk of polluting the entire cache with data accessed once.
// Another goal of DirectIO is to minimize the mutation of data by the kernel
// before issuing IO to underlying devices. ZFS users often enable features like
// compression and checksumming which currently necessitates mutating data in
// the kernel.
//
// DirectIO semantics for a filesystem like ZFS would be quite different than

// Tests for port availability logic written for server startup sequence.
func TestCheckPortAvailability(t *testing.T) {
	if runtime.GOOS != "linux" {
		t.Skip()
	}

	l, err := net.Listen("tcp", "localhost:0") // ask kernel for a free port.
	if err != nil {
		t.Fatal(err)
	}
	defer l.Close()

	port := l.Addr().(*net.TCPAddr).Port

	testCases := []struct {
		host        string
		port        int
		expectedErr error
	}{

		_ = setMaxResources(ctx)
	})

	// Verify kernel release and version.
	if oldLinux() {
		warnings = append(warnings, color.YellowBold("- Detected Linux kernel version older than 4.0.0 release, there are some known potential performance problems with this kernel version. MinIO recommends a minimum of 4.x.x linux kernel version for best performance"))
	}

	maxProcs := runtime.GOMAXPROCS(0)

func fixLongPath(path string) string {
	// Do nothing (and don't allocate) if the path is "short".
	// Empirically (at least on the Windows Server 2013 builder),
	// the kernel is arbitrarily okay with < 248 bytes. That
	// matches what the docs above say:
	// "When using an API to create a directory, the specified
	// path cannot be so long that you cannot append an 8.3 file

	if err != nil {
		buf, err = os.ReadFile(cgroupV1MemLimitFile)
	}
	if err != nil {
		return 0
	}
	limit, err = strconv.ParseUint(strings.TrimSpace(string(buf)), 10, 64)
	if err != nil {
		// The kernel can return valid but non integer values
		// but still, no need to interpret more
		return 0
	}
	if limit == cgroupMemNoLimit {
		// No limit set, It's the highest positive signed 64-bit

			//    os.IsNotExist(err),
			//    "... : no such process",
			//    "... : bad file descriptor.
			continue
		}
		lines := strings.Split(string(d), "\n")
		for _, line := range lines {
			// Different kernel vintages pad differently.
			line = strings.TrimSpace(line)
			if strings.HasPrefix(line, "Pid:\t") {
				// On loaded systems, it is possible
				// for a TID to be reused really
				// quickly. As such, we need to

}

// Alpine and some distros struggles with this - ipset CLI utilities support this, but
// the kernel can be out of sync with the CLI utility, leading to errors like:
//
// ipset v7.10: Argument `comment' is supported in the kernel module of the set type hash:ip
// starting from the revision 3 and you have installed revision 1 only.
// Your kernel is behind your ipset utility.
//

import (
	"os"

	"github.com/ncw/directio"
	"golang.org/x/sys/unix"
)

// ODirectPlatform indicates if the platform supports O_DIRECT
const ODirectPlatform = true

// OpenFileDirectIO - bypass kernel cache.
func OpenFileDirectIO(filePath string, flag int, perm os.FileMode) (*os.File, error) {
	return directio.OpenFile(filePath, flag, perm)
}

// DisableDirectIO - disables directio mode.

	mt.Assert(ztunnelConnected.Name(), nil, monitortest.Exactly(1))

	// we should get the fd to dev null. note that we can't assert the fd number
	// as the kernel may have given us a different number that refers to the same file.
	assert.Equal(t, len(fds), 1)
	// in theory we should close the fd, but it's just a test..

	assert.Equal(t, m.Payload.(*zdsapi.WorkloadRequest_Add).Add.Uid, uid)

import (
	"os"
	"syscall"

	"github.com/ncw/directio"
	"golang.org/x/sys/unix"
)

// ODirectPlatform indicates if the platform supports O_DIRECT
const ODirectPlatform = true

// OpenFileDirectIO - bypass kernel cache.
func OpenFileDirectIO(filePath string, flag int, perm os.FileMode) (*os.File, error) {
	return directio.OpenFile(filePath, flag, perm)
}

// DisableDirectIO - disables directio mode.