* All other timestamps are calculated as the wall clock time at last sync + elapsed time since.
 * <p>
 * This clock deals relatively well when the system wall clock shift is adjusted by small amounts.
 * It also deals relatively well when the system wall clock jumps forward by large amounts (this clock will jump with it).
 * It does not deal as well with large jumps back in time.
 * <p>

	if err := checkCompilerFlags("TEST", "test", []string{"-Wall"}); err != nil {
		t.Fatalf("unexpected error for -Wall: %v", err)
	}
	os.Setenv("CGO_TEST_DISALLOW", "-Wall")
	if err := checkCompilerFlags("TEST", "test", []string{"-Wall"}); err == nil {
		t.Fatalf("missing error for -Wall with CGO_TEST_DISALLOW=-Wall")
	}
	os.Setenv("CGO_TEST_ALLOW", "-Wall") // disallow wins

// clock reading.
type Time struct {
	// wall and ext encode the wall time seconds, wall time nanoseconds,
	// and optional monotonic clock reading in nanoseconds.
	//
	// From high to low bit position, wall encodes a 1-bit flag (hasMonotonic),
	// a 33-bit seconds field, and a 30-bit wall time nanoseconds field.
	// The nanoseconds field is in the range [0, 999999999].

	defer t.Stop()

	// If this test fails, we will either throw (when siftdownTimer detects
	// bad when on update), or other timers will hang (if the timer in a
	// heap is in a bad state). There is no reliable way to test this, but
	// we wait on a short timer here as a smoke test (alternatively, timers
	// in later tests may hang).
	<-After(25 * Millisecond)
}

var (
	MinMonoTime = Time{wall: 1 << 63, ext: -1 << 63, loc: UTC}

 *
 * The provider is _required_ to provide monotonic timestamps.
 *
 * @since 4.2
 */
@ServiceScope(Scope.BuildTree.class)
public interface BuildScanClock {

    /**
     * The current wall clock time.
     */
    long getCurrentTime();

// Distribution of checkpoint write durations.
auto* checkpoint_write_durations = monitoring::Sampler<1>::New(
    {
        "/tensorflow/core/checkpoint/write/write_durations",  // Metric name.
        "Distribution of the wall time duration in microseconds of the "
        "checkpoint write operation.",  // Metric description.
        "api_label"                     // Cell label.
    },

    }

    /**
     * Measures elapsed time.
     *
     * Timers use System.nanoTime() to measure elapsed time,
     * and are therefore not synchronized with {@link #clock()} or the system wall clock.
     *
     * System.nanoTime() does not consider time elapsed while the system is in hibernation.
     * Therefore, timers effectively measure the elapsed time, of which the system was awake.
     */

        when:
        setNanos(delta)

        then:
        clock.currentTime == START_MILLIS + Math.max(0, delta)

        where:
        delta << [0, 100, -100]
    }

    def "resyncs with system wall clock"() {
        when:
        setNanos(10)

        then:
        clock.currentTime == time(10)

        when:
        setNanos(15)

        then:
        clock.currentTime == time(15)

// go run linux/mksysnum.go -Wall -Werror -static -I/tmp/loong64/include /tmp/loong64/include/asm/unistd.h
// Code generated by the command above; see README.md. DO NOT EDIT.

//go:build loong64 && linux

package unix

const (
	SYS_IO_SETUP                = 0
	SYS_IO_DESTROY              = 1
	SYS_IO_SUBMIT               = 2
	SYS_IO_CANCEL               = 3
	SYS_IO_GETEVENTS            = 4
	SYS_SETXATTR                = 5

// go run linux/mksysnum.go -Wall -Werror -static -I/tmp/arm64/include -fsigned-char /tmp/arm64/include/asm/unistd.h
// Code generated by the command above; see README.md. DO NOT EDIT.

//go:build arm64 && linux

package unix

const (
	SYS_IO_SETUP                = 0
	SYS_IO_DESTROY              = 1
	SYS_IO_SUBMIT               = 2
	SYS_IO_CANCEL               = 3
	SYS_IO_GETEVENTS            = 4
	SYS_SETXATTR                = 5