Improve Windows time support by using QueryPerformanceCounter and

GetSystemTimePreciseAsFileTime.

Author: heistp

README.md

@@ -326,11 +326,18 @@ See [CHANGES.md](CHANGES.md).
 
 _Planned for v1.0.0..._
 
-- Improve Windows time accuracy:
-  - Use QueryPerformanceCounter for monotonic clock
-  - Use GetSystemTimePreciseAsFileTime for wall clock
-  - Replace all references to time.Time with irtt.Time
-  - Remove server processing time calculation hack
+- Solidify TimeSource, Time and new Windows timer support:
+  - Add --timesrc to client and server
+  - Fall back to Go functions as necessary for older Windows versions
+  - Make sure all calls to TimeSource.Now pass in only needed clocks
+  - Find a better way to log warnings than fmt.Fprintf(os.Stderr) in timesrc_win.go
+  - Rename Time.Mono to Monotonic, or others from Monotonic to Mono for
+    consistency
+- Improve diagnostic commands:
+  - Change bench command to output in columns
+  - Rename sleep command to timer and add --timesrc, --sleep, --timer and --tcomp
+  - Rename timer command to resolution and add --timesrc
+  - Rename clock command to drift and add --timesrc
 - Improve output flexibility:
   - Allow specifying a format string for text output with optional units for times
   - Add format abbreviations for CSV, space delimited, etc.

cconfig.go

@@ -19,6 +19,7 @@ type ClientConfig struct {
 	DF         DF
 	TTL        int
 	Timer      Timer
+	TimeSource TimeSource
 	Waiter     Waiter
 	Filler     Filler
 	FillOne    bool
@@ -47,6 +48,7 @@ func NewClientConfig() *ClientConfig {
 		DF:         DefaultDF,
 		TTL:        DefaultTTL,
 		Timer:      DefaultTimer,
+		TimeSource: DefaultTimeSource,
 		Waiter:     DefaultWait,
 		ThreadLock: DefaultThreadLock,
 	}
@@ -85,6 +87,7 @@ func (c *ClientConfig) MarshalJSON() ([]byte, error) {
 		DF            DF            `json:"df"`
 		TTL           int           `json:"ttl"`
 		Timer         string        `json:"timer"`
+		TimeSource    string        `json:"time_source"`
 		Waiter        string        `json:"waiter"`
 		Filler        string        `json:"filler"`
 		FillOne       bool          `json:"fill_one"`
@@ -101,6 +104,7 @@ func (c *ClientConfig) MarshalJSON() ([]byte, error) {
 		DF:            c.DF,
 		TTL:           c.TTL,
 		Timer:         c.Timer.String(),
+		TimeSource:    c.TimeSource.String(),
 		Waiter:        c.Waiter.String(),
 		Filler:        fstr,
 		FillOne:       c.FillOne,

client.go

@@ -99,7 +99,8 @@ func (c *Client) Run(ctx context.Context) (r *Result, err error) {
 	}
 
 	// create recorder
-	if c.rec, err = newRecorder(pcount(c.Duration, c.Interval), c.Handler); err != nil {
+	if c.rec, err = newRecorder(pcount(c.Duration, c.Interval), c.TimeSource,
+		c.Handler); err != nil {
 		return
 	}
 
@@ -308,7 +309,7 @@ func (c *Client) send(ctx context.Context) error {
 	p.updateHMAC()
 
 	// record the start time of the test and calculate the end
-	t := time.Now()
+	t := c.TimeSource.Now(BothClocks)
 	c.rec.Start = t
 	end := c.rec.Start.Add(c.Duration)
 
@@ -346,8 +347,8 @@ func (c *Client) send(ctx context.Context) error {
 		p.updateHMAC()
 
 		// set the current base interval we're at
-		tnext := c.rec.Start.Add(
-			c.Interval * (time.Now().Sub(c.rec.Start) / c.Interval))
+		tnext := c.rec.Start.Add(c.Interval *
+			(c.TimeSource.Now(Monotonic).Sub(c.rec.Start) / c.Interval))
 
 		// if we're under half-way to the next interval, sleep until the next
 		// interval, but if we're over half-way, sleep until the interval after
@@ -358,17 +359,17 @@ func (c *Client) send(ctx context.Context) error {
 			tnext = tnext.Add(2 * c.Interval)
 		}
 
-		// break if tnext if after the end of the test
+		// break if tnext is after the end of the test
 		if !tnext.Before(end) {
 			break
 		}
 
 		// calculate sleep duration
-		tsleep := time.Now()
+		tsleep := c.TimeSource.Now(Monotonic)
 		dsleep := tnext.Sub(tsleep)
 
 		// sleep
-		t, err = c.Timer.Sleep(ctx, tsleep, dsleep)
+		t, err = c.Timer.Sleep(ctx, c.TimeSource, tsleep, dsleep)
 		if err != nil {
 			return err
 		}

code_string.go

@@ -24,12 +24,14 @@ type nconn struct {
 	dscpSupport bool
 	ttl         int
 	df          DF
+	timeSource  TimeSource
 }
 
-func (n *nconn) init(conn *net.UDPConn, ipVer IPVersion) {
+func (n *nconn) init(conn *net.UDPConn, ipVer IPVersion, ts TimeSource) {
 	n.conn = conn
 	n.ipVer = ipVer
 	n.df = DFDefault
+	n.timeSource = ts
 
 	// create x/net conns for socket options
 	if n.ipVer&IPv4 != 0 {
@@ -149,7 +151,7 @@ func dial(ctx context.Context, cfg *ClientConfig) (cc *cconn, err error) {
 
 	// create cconn
 	cc = &cconn{nconn: &nconn{}, cfg: cfg}
-	cc.init(conn, cfg.IPVersion)
+	cc.init(conn, cfg.IPVersion, cfg.TimeSource)
 
 	// open connection to server
 	err = cc.open(ctx)
@@ -254,8 +256,8 @@ func (c *cconn) send(p *packet) (err error) {
 	}
 	var n int
 	n, err = c.conn.Write(p.bytes())
-	p.tsent = time.Now()
-	p.trcvd = time.Time{}
+	p.tsent = c.timeSource.Now(BothClocks)
+	p.trcvd = Time{}
 	if err != nil {
 		return
 	}
@@ -268,8 +270,8 @@ func (c *cconn) send(p *packet) (err error) {
 func (c *cconn) receive(p *packet) (err error) {
 	var n int
 	n, err = c.conn.Read(p.readTo())
-	p.trcvd = time.Now()
-	p.tsent = time.Time{}
+	p.trcvd = c.timeSource.Now(BothClocks)
+	p.tsent = Time{}
 	p.dscp = 0
 	if err != nil {
 		return
@@ -334,30 +336,31 @@ type lconn struct {
 }
 
 // listen creates an lconn by listening on a UDP address.
-func listen(laddr *net.UDPAddr, setSrcIP bool) (l *lconn, err error) {
+func listen(laddr *net.UDPAddr, setSrcIP bool, ts TimeSource) (l *lconn, err error) {
 	ipVer := IPVersionFromUDPAddr(laddr)
 	var conn *net.UDPConn
 	conn, err = net.ListenUDP(ipVer.udpNetwork(), laddr)
 	if err != nil {
 		return
 	}
 	l = &lconn{nconn: &nconn{}, setSrcIP: setSrcIP && laddr.IP.IsUnspecified()}
-	l.init(conn, ipVer)
+	l.init(conn, ipVer, ts)
 	return
 }
 
 // listenAll creates lconns on multiple addresses, with separate lconns for IPv4
 // and IPv6, so that socket options can be set correctly, which is not possible
 // with a dual stack conn.
-func listenAll(ipVer IPVersion, addrs []string, setSrcIP bool) (lconns []*lconn, err error) {
+func listenAll(ipVer IPVersion, addrs []string, setSrcIP bool,
+	ts TimeSource) (lconns []*lconn, err error) {
 	laddrs, err := resolveListenAddrs(addrs, ipVer)
 	if err != nil {
 		return
 	}
 	lconns = make([]*lconn, 0, 16)
 	for _, laddr := range laddrs {
 		var l *lconn
-		l, err = listen(laddr, setSrcIP)
+		l, err = listen(laddr, setSrcIP, ts)
 		if err != nil {
 			return
 		}
@@ -385,8 +388,8 @@ func (l *lconn) send(p *packet) (err error) {
 		l.cm6.Src = p.srcIP
 		n, err = l.ip6conn.WriteTo(p.bytes(), &l.cm6, p.raddr)
 	}
-	p.tsent = time.Now()
-	p.trcvd = time.Time{}
+	p.tsent = l.timeSource.Now(BothClocks)
+	p.trcvd = Time{}
 	if err != nil {
 		return
 	}
@@ -428,8 +431,8 @@ func (l *lconn) receive(p *packet) (err error) {
 	}
 	p.srcIP = nil
 	p.dscp = 0
-	p.trcvd = time.Now()
-	p.tsent = time.Time{}
+	p.trcvd = l.timeSource.Now(BothClocks)
+	p.tsent = Time{}
 	if err != nil {
 		return
 	}

conn.go

@@ -53,6 +53,10 @@ var DefaultWait = &WaitMaxRTT{time.Duration(4) * time.Second, 3}
 // DefaultTimer is the default timer implementation, CompTimer.
 var DefaultTimer = NewCompTimer(DefaultCompTimerAverage)
 
+// DefaultTimeSource is the default TimeSource implementation (WindowsTimeSource
+// for Windows and GoTimeSource for everything else).
+var DefaultTimeSource = NewDefaultTimeSource()
+
 // DefaultFillPattern is the default fill pattern.
 var DefaultFillPattern = []byte("irtt")
 

defaults.go

@@ -770,6 +770,8 @@ time\-to\-live (https://en.wikipedia.org/wiki/Time_to_live) value
 \f[I]timer\f[] the timer used: simple, comp, hybrid or busy (irtt client
 \-\-timer flag)
 .IP \[bu] 2
+\f[I]time_source\f[] the time source used: go or windows
+.IP \[bu] 2
 \f[I]waiter\f[] the waiter used: fixed duration, multiple of RTT or
 multiple of max RTT (irtt client \f[I]\-\-wait\f[] flag)
 .IP \[bu] 2
@@ -804,7 +806,10 @@ statistics for the results
 .nf
 \f[C]
 "stats":\ {
-\ \ \ \ "start_time":\ "2017\-10\-16T21:05:23.502719056+02:00",
+\ \ \ \ "start_time":\ {
+\ \ \ \ \ \ \ \ "wall":\ 1528621979787034330,
+\ \ \ \ \ \ \ \ "monotonic":\ 5136247
+\ \ \ \ },
 \ \ \ \ "send_call":\ {
 \ \ \ \ \ \ \ \ "total":\ 79547,
 \ \ \ \ \ \ \ \ "n":\ 3,
@@ -943,7 +948,8 @@ following attributes:
 .PP
 The regular attributes in \f[I]stats\f[] are as follows:
 .IP \[bu] 2
-\f[I]start_time\f[] the start time of the test, in TZ format
+\f[I]start_time\f[] the start time of the test (see \f[I]round_trips\f[]
+Notes for descriptions of \f[I]wall\f[] and \f[I]monotonic\f[] values)
 .IP \[bu] 2
 \f[I]send_call\f[] a duration stats object for the call time when
 sending packets
@@ -1144,8 +1150,8 @@ each round\-trip is a single request to / reply from the server
 January 1, 1970 UTC
 .PP
 \f[B]Note:\f[] \f[I]monotonic\f[] values are the number of nanoseconds
-since the start of the test for the client, and since start of the
-process for the server
+since some arbitrary point in time, so can only be relied on to measure
+duration
 .IP \[bu] 2
 \f[I]seqno\f[] the sequence number
 .IP \[bu] 2

doc/irtt-client.1

@@ -611,6 +611,7 @@ <h2 id="config">config</h2>
 <li><em>df</em> the do-not-fragment setting (0 == OS default, 1 == false, 2 == true)</li>
 <li><em>ttl</em> the IP <a href="https://en.wikipedia.org/wiki/Time_to_live">time-to-live</a> value</li>
 <li><em>timer</em> the timer used: simple, comp, hybrid or busy (irtt client --timer flag)</li>
+<li><em>time_source</em> the time source used: go or windows</li>
 <li><em>waiter</em> the waiter used: fixed duration, multiple of RTT or multiple of max RTT (irtt client <em>--wait</em> flag)</li>
 <li><em>filler</em> the packet filler used: none, rand or pattern (irtt client <em>--fill</em> flag)</li>
 <li><em>fill_one</em> whether to fill only once and repeat for all packets (irtt client <em>--fill-one</em> flag)</li>
@@ -625,7 +626,10 @@ <h2 id="config">config</h2>
 <h2 id="stats">stats</h2>
 <p>statistics for the results</p>
 <pre><code>&quot;stats&quot;: {
-    &quot;start_time&quot;: &quot;2017-10-16T21:05:23.502719056+02:00&quot;,
+    &quot;start_time&quot;: {
+        &quot;wall&quot;: 1528621979787034330,
+        &quot;monotonic&quot;: 5136247
+    },
     &quot;send_call&quot;: {
         &quot;total&quot;: 79547,
         &quot;n&quot;: 3,
@@ -751,7 +755,7 @@ <h2 id="stats">stats</h2>
 </ul>
 <p>The regular attributes in <em>stats</em> are as follows:</p>
 <ul>
-<li><em>start_time</em> the start time of the test, in TZ format</li>
+<li><em>start_time</em> the start time of the test (see <em>round_trips</em> Notes for descriptions of <em>wall</em> and <em>monotonic</em> values)</li>
 <li><em>send_call</em> a duration stats object for the call time when sending packets</li>
 <li><em>timer_error</em> a duration stats object for the observed sleep time error</li>
 <li><em>rtt</em> a duration stats object for the round-trip time</li>
@@ -873,7 +877,7 @@ <h2 id="round_trips">round_trips</h2>
     }
 ]</code></pre>
 <p><strong>Note:</strong> <em>wall</em> values are from Go’s <em>time.Time.UnixNano()</em>, the number of nanoseconds elapsed since January 1, 1970 UTC</p>
-<p><strong>Note:</strong> <em>monotonic</em> values are the number of nanoseconds since the start of the test for the client, and since start of the process for the server</p>
+<p><strong>Note:</strong> <em>monotonic</em> values are the number of nanoseconds since some arbitrary point in time, so can only be relied on to measure duration</p>
 <ul>
 <li><em>seqno</em> the sequence number</li>
 <li><em>lost</em> the lost status of the packet, which can be one of <em>false</em>, <em>true</em>, <em>true_down</em> or <em>true_up</em>. The <em>true_down</em> and <em>true_up</em> values are only possible if the <em>ReceivedStats</em> parameter includes <em>ReceivedStatsWindow</em> (irtt client <em>--stats</em> flag). Even then, if it could not be determined whether the packet was lost upstream or downstream, the value <em>true</em> is used.</li>

doc/irtt-client.html

@@ -355,6 +355,7 @@ the configuration used for the test
 - *df* the do-not-fragment setting (0 == OS default, 1 == false, 2 == true)
 - *ttl* the IP [time-to-live](https://en.wikipedia.org/wiki/Time_to_live) value
 - *timer* the timer used: simple, comp, hybrid or busy (irtt client \--timer flag)
+- *time_source* the time source used: go or windows
 - *waiter* the waiter used: fixed duration, multiple of RTT or multiple of max RTT
   (irtt client *\--wait* flag)
 - *filler* the packet filler used: none, rand or pattern (irtt client *\--fill*
@@ -377,7 +378,10 @@ statistics for the results
 
 ```
 "stats": {
-    "start_time": "2017-10-16T21:05:23.502719056+02:00",
+    "start_time": {
+        "wall": 1528621979787034330,
+        "monotonic": 5136247
+    },
     "send_call": {
         "total": 79547,
         "n": 3,
@@ -507,7 +511,8 @@ nanosecond duration values and has the following attributes:
 
 The regular attributes in *stats* are as follows:
 
-- *start_time* the start time of the test, in TZ format
+- *start_time* the start time of the test (see *round_trips* Notes for
+  descriptions of *wall* and *monotonic* values)
 - *send_call* a duration stats object for the call time when sending packets
 - *timer_error* a duration stats object for the observed sleep time error
 - *rtt* a duration stats object for the round-trip time
@@ -663,8 +668,8 @@ each round-trip is a single request to / reply from the server
 **Note:** *wall* values are from Go's *time.Time.UnixNano()*, the number of nanoseconds
 elapsed since January 1, 1970 UTC
 
-**Note:** *monotonic* values are the number of nanoseconds since the start of the test for
-the client, and since start of the process for the server
+**Note:** *monotonic* values are the number of nanoseconds since some arbitrary
+point in time, so can only be relied on to measure duration
 
 - *seqno* the sequence number
 - *lost* the lost status of the packet, which can be one of *false*, *true*,

doc/irtt-client.md

@@ -89,7 +89,6 @@ send delay and IPDV.
 
 # BUGS
 
-- Windows has severe timer issues that may make measurements unreliable
 - Windows is unable to set DSCP values for IPv6.
 - Windows is unable to set the source IP address, so `--set-src-ip` may not be used
   on the server.