See https://golang.org/design/12914-monotonic for details.
Fixes #12914.
Change-Id: I80edc2e6c012b4ace7161c84cf067d444381a009
Reviewed-on: https://go-review.googlesource.com/36255
Run-TryBot: Russ Cox <rsc@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Caleb Spare <cespare@gmail.com>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
var b bytes.Buffer
tw := NewWriter(&b)
hdr := &Header{
- Name: "file.txt",
- Uid: 1 << 21, // too big for 8 octal digits
- Size: int64(len(data)),
- ModTime: time.Now(),
+ Name: "file.txt",
+ Uid: 1 << 21, // too big for 8 octal digits
+ Size: int64(len(data)),
+ // AddDate to strip monotonic clock reading,
+ // and Round to discard sub-second precision,
+ // both of which are not included in the tar header
+ // and would otherwise break the round-trip check
+ // below.
+ ModTime: time.Now().AddDate(0, 0, 0).Round(1 * time.Second),
}
- // tar only supports second precision.
- hdr.ModTime = hdr.ModTime.Add(-time.Duration(hdr.ModTime.Nanosecond()) * time.Nanosecond)
if err := tw.WriteHeader(hdr); err != nil {
t.Fatalf("tw.WriteHeader: %v", err)
}
}
func TestGobEncodeIsZero(t *testing.T) {
- x := isZeroBug{time.Now(), "hello", -55, isZeroBugArray{1, 2}, isZeroBugInterface{}}
+ x := isZeroBug{time.Unix(1e9, 0), "hello", -55, isZeroBugArray{1, 2}, isZeroBugInterface{}}
b := new(bytes.Buffer)
enc := NewEncoder(b)
err := enc.Encode(x)
_ = time.Time{}
_ = time.Time{sec /* ERROR "unknown field" */ : 0}
_ = time.Time{
- 0 /* ERROR implicit assignment to unexported field sec in time.Time literal */,
+ 0 /* ERROR implicit assignment to unexported field wall in time.Time literal */,
0 /* ERROR implicit assignment */ ,
nil /* ERROR implicit assignment */ ,
}
// in asm_*.s
func return0()
-//go:linkname time_now time.now
-func time_now() (sec int64, nsec int32)
+func walltime() (sec int64, nsec int32)
// in asm_*.s
// not called directly; definitions here supply type information for traceback.
func prefetchnta(addr uintptr)
func unixnanotime() int64 {
- sec, nsec := time_now()
+ sec, nsec := walltime()
return sec*1e9 + int64(nsec)
}
ADCL $0, DX
RET
-// func now() (sec int64, nsec int32)
-TEXT time·now(SB),NOSPLIT,$0
+// func walltime() (sec int64, nsec int32)
+TEXT runtime·walltime(SB),NOSPLIT,$0
CALL runtime·now(SB)
MOVL $1000000000, CX
DIVL CX
MOVQ AX, ret+0(FP)
RET
-// func now() (sec int64, nsec int32)
-TEXT time·now(SB),NOSPLIT,$0-12
+// func walltime() (sec int64, nsec int32)
+TEXT runtime·walltime(SB),NOSPLIT,$0-12
CALL nanotime<>(SB)
// generated code for
MOVW R0, ret+12(FP)
RET
-TEXT time·now(SB), 7, $32
+TEXT runtime·walltime(SB), 7, $32
MOVW $8(R13), R0 // timeval
MOVW $0, R1 // zone
MOVW $0, R2 // see issue 16570
SVC $0x80
RET
-TEXT time·now(SB),NOSPLIT,$40-12
+TEXT runtime·walltime(SB),NOSPLIT,$40-12
MOVD RSP, R0 // timeval
MOVD R0, R9 // this is how dyld calls gettimeofday
MOVW $0, R1 // zone
SYSCALL
RET
-// func now() (sec int64, nsec int32)
-TEXT time·now(SB), NOSPLIT, $32
+// func walltime() (sec int64, nsec int32)
+TEXT runtime·walltime(SB), NOSPLIT, $32
MOVL $232, AX // clock_gettime
MOVQ $0, DI // CLOCK_REALTIME
LEAQ 8(SP), SI
INT $0x80
RET
-// func now() (sec int64, nsec int32)
-TEXT time·now(SB), NOSPLIT, $32
+// func walltime() (sec int64, nsec int32)
+TEXT runtime·walltime(SB), NOSPLIT, $32
MOVL $232, AX // clock_gettime
LEAL 12(SP), BX
MOVL $0, 4(SP) // CLOCK_REALTIME
SYSCALL
RET
-// func now() (sec int64, nsec int32)
-TEXT time·now(SB), NOSPLIT, $32
+// func walltime() (sec int64, nsec int32)
+TEXT runtime·walltime(SB), NOSPLIT, $32
MOVL $232, AX // clock_gettime
MOVQ $0, DI // CLOCK_REALTIME
LEAQ 8(SP), SI
SWI $0
RET
-// func now() (sec int64, nsec int32)
-TEXT time·now(SB), NOSPLIT, $32
+// func walltime() (sec int64, nsec int32)
+TEXT runtime·walltime(SB), NOSPLIT, $32
MOVW $0, R0 // CLOCK_REALTIME
MOVW $8(R13), R1
MOVW $SYS_clock_gettime, R7
MOVL AX, ret+12(FP)
RET
-// func now() (sec int64, nsec int32)
-TEXT time·now(SB), NOSPLIT, $32
+// func walltime() (sec int64, nsec int32)
+TEXT runtime·walltime(SB), NOSPLIT, $32
MOVL $265, AX // syscall - clock_gettime
MOVL $0, BX // CLOCK_REALTIME
LEAL 8(SP), CX
MOVL AX, ret+24(FP)
RET
-// func now() (sec int64, nsec int32)
-TEXT time·now(SB),NOSPLIT,$16
+// func walltime() (sec int64, nsec int32)
+TEXT runtime·walltime(SB),NOSPLIT,$16
// Be careful. We're calling a function with gcc calling convention here.
// We're guaranteed 128 bytes on entry, and we've taken 16, and the
// call uses another 8.
MOVW R0, ret+12(FP)
RET
-TEXT time·now(SB), NOSPLIT, $32
+TEXT runtime·walltime(SB), NOSPLIT, $32
MOVW $0, R0 // CLOCK_REALTIME
MOVW $8(R13), R1 // timespec
MOVW $SYS_clock_gettime, R7
MOVW R0, ret+24(FP)
RET
-// func now() (sec int64, nsec int32)
-TEXT time·now(SB),NOSPLIT,$24-12
+// func walltime() (sec int64, nsec int32)
+TEXT runtime·walltime(SB),NOSPLIT,$24-12
MOVW $0, R0 // CLOCK_REALTIME
MOVD RSP, R1
MOVD $SYS_clock_gettime, R8
MOVW R2, ret+24(FP)
RET
-// func now() (sec int64, nsec int32)
-TEXT time·now(SB),NOSPLIT,$16
+// func walltime() (sec int64, nsec int32)
+TEXT runtime·walltime(SB),NOSPLIT,$16
MOVW $0, R4 // CLOCK_REALTIME
MOVV $0(R29), R5
MOVV $SYS_clock_gettime, R2
MOVW R2, ret+12(FP)
RET
-// func now() (sec int64, nsec int32)
-TEXT time·now(SB),NOSPLIT,$8-12
+// func walltime() (sec int64, nsec int32)
+TEXT runtime·walltime(SB),NOSPLIT,$8-12
MOVW $0, R4 // CLOCK_REALTIME
MOVW $4(R29), R5
MOVW $SYS_clock_gettime, R2
MOVW R3, ret+24(FP)
RET
-// func now() (sec int64, nsec int32)
-TEXT time·now(SB),NOSPLIT,$16
+// func walltime() (sec int64, nsec int32)
+TEXT runtime·walltime(SB),NOSPLIT,$16
MOVD $0, R3 // CLOCK_REALTIME
MOVD $0(R1), R4
SYSCALL $SYS_clock_gettime
MOVW R2, ret+24(FP)
RET
-// func now() (sec int64, nsec int32)
-TEXT time·now(SB),NOSPLIT,$16
+// func walltime() (sec int64, nsec int32)
+TEXT runtime·walltime(SB),NOSPLIT,$16
MOVW $0, R2 // CLOCK_REALTIME
MOVD $tp-16(SP), R3
MOVW $SYS_clock_gettime, R1
MOVL AX, ret+24(FP)
RET
-TEXT time·now(SB),NOSPLIT,$20
+TEXT runtime·walltime(SB),NOSPLIT,$20
MOVL $0, 0(SP) // real time clock
LEAL 8(SP), AX
MOVL AX, 4(SP) // timespec
RET
TEXT syscall·now(SB),NOSPLIT,$0
- JMP time·now(SB)
+ JMP runtime·walltime(SB)
TEXT runtime·nacl_clock_gettime(SB),NOSPLIT,$8
MOVL arg1+0(FP), AX
MOVL AX, ret+24(FP)
RET
-TEXT time·now(SB),NOSPLIT,$16
+TEXT runtime·walltime(SB),NOSPLIT,$16
MOVQ runtime·faketime(SB), AX
CMPQ AX, $0
JEQ realtime
RET
TEXT syscall·now(SB),NOSPLIT,$0
- JMP time·now(SB)
+ JMP runtime·walltime(SB)
TEXT runtime·nacl_clock_gettime(SB),NOSPLIT,$0
MOVL arg1+0(FP), DI
MOVW R0, ret+24(FP)
RET
-TEXT time·now(SB),NOSPLIT,$16
+TEXT runtime·walltime(SB),NOSPLIT,$16
MOVW $0, R0 // real time clock
MOVW $4(R13), R1
NACL_SYSCALL(SYS_clock_gettime)
RET
TEXT syscall·now(SB),NOSPLIT,$0
- B time·now(SB)
+ B runtime·walltime(SB)
TEXT runtime·nacl_clock_gettime(SB),NOSPLIT,$0
MOVW arg1+0(FP), R0
INT $0x80
RET
-// func now() (sec int64, nsec int32)
-TEXT time·now(SB), NOSPLIT, $32
+// func walltime() (sec int64, nsec int32)
+TEXT runtime·walltime(SB), NOSPLIT, $32
LEAL 12(SP), BX
MOVL $0, 4(SP) // arg 1 - clock_id
MOVL BX, 8(SP) // arg 2 - tp
SYSCALL
RET
-// func now() (sec int64, nsec int32)
-TEXT time·now(SB), NOSPLIT, $32
+// func walltime() (sec int64, nsec int32)
+TEXT runtime·walltime(SB), NOSPLIT, $32
MOVQ $0, DI // arg 1 - clock_id
LEAQ 8(SP), SI // arg 2 - tp
MOVL $427, AX // sys_clock_gettime
SWI $0xa001a9 // sys_setitimer
RET
-// func now() (sec int64, nsec int32)
-TEXT time·now(SB), NOSPLIT, $32
+// func walltime() (sec int64, nsec int32)
+TEXT runtime·walltime(SB), NOSPLIT, $32
MOVW $0, R0 // CLOCK_REALTIME
MOVW $8(R13), R1
SWI $0xa001ab // clock_gettime
INT $0x80
RET
-// func now() (sec int64, nsec int32)
-TEXT time·now(SB), NOSPLIT, $32
+// func walltime() (sec int64, nsec int32)
+TEXT runtime·walltime(SB), NOSPLIT, $32
LEAL 12(SP), BX
MOVL $0, 4(SP) // arg 1 - clock_id
MOVL BX, 8(SP) // arg 2 - tp
SYSCALL
RET
-// func now() (sec int64, nsec int32)
-TEXT time·now(SB), NOSPLIT, $32
+// func walltime() (sec int64, nsec int32)
+TEXT runtime·walltime(SB), NOSPLIT, $32
MOVQ $0, DI // arg 1 - clock_id
LEAQ 8(SP), SI // arg 2 - tp
MOVL $87, AX // sys_clock_gettime
SWI $0
RET
-// func now() (sec int64, nsec int32)
-TEXT time·now(SB), NOSPLIT, $32
+// func walltime() (sec int64, nsec int32)
+TEXT runtime·walltime(SB), NOSPLIT, $32
MOVW CLOCK_REALTIME, R0 // arg 1 - clock_id
MOVW $8(R13), R1 // arg 2 - tp
MOVW $87, R12 // sys_clock_gettime
MOVL $-1, ret_hi+8(FP)
RET
-// func now() (sec int64, nsec int32)
-TEXT time·now(SB),NOSPLIT,$8-12
+// func walltime() (sec int64, nsec int32)
+TEXT runtime·walltime(SB),NOSPLIT,$8-12
CALL runtime·nanotime(SB)
MOVL 0(SP), AX
MOVL 4(SP), DX
MOVQ AX, ret+8(FP)
RET
-// func now() (sec int64, nsec int32)
-TEXT time·now(SB),NOSPLIT,$8-12
+// func walltime() (sec int64, nsec int32)
+TEXT runtime·walltime(SB),NOSPLIT,$8-12
CALL runtime·nanotime(SB)
MOVQ 0(SP), AX
RET
// time.now() (sec int64, nsec int32)
-TEXT time·now(SB),NOSPLIT,$12-12
+TEXT runtime·walltime(SB),NOSPLIT,$12-12
// use nsec system call to get current time in nanoseconds
MOVW $sysnsec_lo-8(SP), R0 // destination addr
MOVW R0,res-12(SP)
CALL AX
RET
-// func now() (sec int64, nsec int32)
-TEXT time·now(SB),NOSPLIT,$8-12
+// func walltime() (sec int64, nsec int32)
+TEXT runtime·walltime(SB),NOSPLIT,$8-12
CALL runtime·nanotime(SB)
MOVQ 0(SP), AX
MOVL BP, SP
RET
-// func now() (sec int64, nsec int32)
-TEXT time·now(SB),NOSPLIT,$8-12
+// func walltime() (sec int64, nsec int32)
+TEXT runtime·walltime(SB),NOSPLIT,$8-12
CALL runtime·unixnano(SB)
MOVL 0(SP), AX
MOVL 4(SP), DX
MOVQ 32(SP), SP
RET
-// func now() (sec int64, nsec int32)
-TEXT time·now(SB),NOSPLIT,$8-12
+// func walltime() (sec int64, nsec int32)
+TEXT runtime·walltime(SB),NOSPLIT,$8-12
CALL runtime·unixnano(SB)
MOVQ 0(SP), AX
func time_runtimeNano() int64 {
return nanotime()
}
+
+var startNano = nanotime()
+
+//go:linkname time_now time.now
+func time_now() (sec int64, nsec int32, mono uint64) {
+ sec, nsec = walltime()
+ return sec, nsec, uint64(nanotime() - startNano + 1)
+}
var (
ForceZipFileForTesting = forceZipFileForTesting
ParseTimeZone = parseTimeZone
+ SetMono = (*Time).setMono
+ GetMono = (*Time).mono
)
// String returns the time formatted using the format string
// "2006-01-02 15:04:05.999999999 -0700 MST"
+//
+// If the time has a monotonic clock reading, the returned string
+// includes a final field "m±<value>", where value is the monotonic
+// clock reading formatted as a decimal number of seconds.
func (t Time) String() string {
- return t.Format("2006-01-02 15:04:05.999999999 -0700 MST")
+ s := t.Format("2006-01-02 15:04:05.999999999 -0700 MST")
+
+ // Format monotonic clock reading as m=±ddd.nnnnnnnnn.
+ if t.wall&hasMonotonic != 0 {
+ m2 := t.ext
+ m1, m2 := m2/1e9, m2%1e9
+ if m2 < 0 {
+ m2 += 1e9
+ m1--
+ }
+ sign := byte('+')
+ if m1 < 0 {
+ sign = '-'
+ m1 = -m1
+ }
+ m0, m1 := m1/1e9, m1%1e9
+ var buf []byte
+ buf = append(buf, " m="...)
+ buf = append(buf, sign)
+ wid := 0
+ if m0 != 0 {
+ buf = appendInt(buf, int(m0), 0)
+ wid = 9
+ }
+ buf = appendInt(buf, int(m1), wid)
+ buf = append(buf, '.')
+ buf = appendInt(buf, int(m2), 9)
+ s += string(buf)
+ }
+ return s
}
// Format returns a textual representation of the time value formatted
if zoneOffset != -1 {
t := Date(year, Month(month), day, hour, min, sec, nsec, UTC)
- t.sec -= int64(zoneOffset)
+ t.addSec(-int64(zoneOffset))
// Look for local zone with the given offset.
// If that zone was in effect at the given time, use it.
- name, offset, _, _, _ := local.lookup(t.sec + internalToUnix)
+ name, offset, _, _, _ := local.lookup(t.unixSec())
if offset == zoneOffset && (zoneName == "" || name == zoneName) {
t.setLoc(local)
return t, nil
t := Date(year, Month(month), day, hour, min, sec, nsec, UTC)
// Look for local zone with the given offset.
// If that zone was in effect at the given time, use it.
- offset, _, ok := local.lookupName(zoneName, t.sec+internalToUnix)
+ offset, _, ok := local.lookupName(zoneName, t.unixSec())
if ok {
- t.sec -= int64(offset)
+ t.addSec(-int64(offset))
t.setLoc(local)
return t, nil
}
--- /dev/null
+// Copyright 2017 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package time_test
+
+import (
+ "regexp"
+ "testing"
+ . "time"
+)
+
+func TestHasMonotonicClock(t *testing.T) {
+ yes := func(expr string, tt Time) {
+ if GetMono(&tt) == 0 {
+ t.Errorf("%s: missing monotonic clock reading", expr)
+ }
+ }
+ no := func(expr string, tt Time) {
+ if GetMono(&tt) != 0 {
+ t.Errorf("%s: unexpected monotonic clock reading", expr)
+ }
+ }
+
+ yes("<-After(1)", <-After(1))
+ ticker := NewTicker(1)
+ yes("<-Tick(1)", <-ticker.C)
+ ticker.Stop()
+ no("Date(2009, 11, 23, 0, 0, 0, 0, UTC)", Date(2009, 11, 23, 0, 0, 0, 0, UTC))
+ tp, _ := Parse(UnixDate, "Sat Mar 7 11:06:39 PST 2015")
+ no(`Parse(UnixDate, "Sat Mar 7 11:06:39 PST 2015")`, tp)
+ no("Unix(1486057371, 0)", Unix(1486057371, 0))
+
+ yes("Now()", Now())
+
+ tu := Unix(1486057371, 0)
+ tm := tu
+ SetMono(&tm, 123456)
+ no("tu", tu)
+ yes("tm", tm)
+
+ no("tu.Add(1)", tu.Add(1))
+ no("tu.In(UTC)", tu.In(UTC))
+ no("tu.AddDate(1, 1, 1)", tu.AddDate(1, 1, 1))
+ no("tu.AddDate(0, 0, 0)", tu.AddDate(0, 0, 0))
+ no("tu.Local()", tu.Local())
+ no("tu.UTC()", tu.UTC())
+ no("tu.Round(2)", tu.Round(2))
+ no("tu.Truncate(2)", tu.Truncate(2))
+
+ yes("tm.Add(1)", tm.Add(1))
+ no("tm.AddDate(1, 1, 1)", tm.AddDate(1, 1, 1))
+ no("tm.AddDate(0, 0, 0)", tm.AddDate(0, 0, 0))
+ yes("tm.In(UTC)", tm.In(UTC))
+ yes("tm.Local()", tm.Local())
+ yes("tm.UTC()", tm.UTC())
+ yes("tm.Round(2)", tm.Round(2))
+ yes("tm.Truncate(2)", tm.Truncate(2))
+}
+
+func TestMonotonicAdd(t *testing.T) {
+ tm := Unix(1486057371, 123456)
+ SetMono(&tm, 123456789012345)
+
+ t2 := tm.Add(1e8)
+ if t2.Nanosecond() != 100123456 {
+ t.Errorf("t2.Nanosecond() = %d, want 100123456", t2.Nanosecond())
+ }
+ if GetMono(&t2) != 123456889012345 {
+ t.Errorf("t2.mono = %d, want 123456889012345", GetMono(&t2))
+ }
+
+ t3 := tm.Add(-9e18) // wall now out of range
+ if t3.Nanosecond() != 123456 {
+ t.Errorf("t3.Nanosecond() = %d, want 123456", t3.Nanosecond())
+ }
+ if GetMono(&t3) != 0 {
+ t.Errorf("t3.mono = %d, want 0 (wall time out of range for monotonic reading)", GetMono(&t3))
+ }
+
+ t4 := tm.Add(+9e18) // wall now out of range
+ if t4.Nanosecond() != 123456 {
+ t.Errorf("t4.Nanosecond() = %d, want 123456", t4.Nanosecond())
+ }
+ if GetMono(&t4) != 0 {
+ t.Errorf("t4.mono = %d, want 0 (wall time out of range for monotonic reading)", GetMono(&t4))
+ }
+
+ tn := Now()
+ tn1 := tn.Add(1 * Hour)
+ Sleep(100 * Millisecond)
+ d := Until(tn1)
+ if d < 59*Minute {
+ t.Errorf("Until(Now().Add(1*Hour)) = %v, wanted at least 59m", d)
+ }
+ now := Now()
+ if now.After(tn1) {
+ t.Errorf("Now().After(Now().Add(1*Hour)) = true, want false")
+ }
+ if !tn1.After(now) {
+ t.Errorf("Now().Add(1*Hour).After(now) = false, want true")
+ }
+ if tn1.Before(now) {
+ t.Errorf("Now().Add(1*Hour).Before(Now()) = true, want false")
+ }
+ if !now.Before(tn1) {
+ t.Errorf("Now().Before(Now().Add(1*Hour)) = false, want true")
+ }
+}
+
+func TestMonotonicSub(t *testing.T) {
+ t1 := Unix(1483228799, 995e6)
+ SetMono(&t1, 123456789012345)
+
+ t2 := Unix(1483228799, 5e6)
+ SetMono(&t2, 123456789012345+10e6)
+
+ t3 := Unix(1483228799, 995e6)
+ SetMono(&t3, 123456789012345+1e9)
+
+ t1w := t1.AddDate(0, 0, 0)
+ if GetMono(&t1w) != 0 {
+ t.Fatalf("AddDate didn't strip monotonic clock reading")
+ }
+ t2w := t2.AddDate(0, 0, 0)
+ if GetMono(&t2w) != 0 {
+ t.Fatalf("AddDate didn't strip monotonic clock reading")
+ }
+ t3w := t3.AddDate(0, 0, 0)
+ if GetMono(&t3w) != 0 {
+ t.Fatalf("AddDate didn't strip monotonic clock reading")
+ }
+
+ sub := func(txs, tys string, tx, txw, ty, tyw Time, d, dw Duration) {
+ check := func(expr string, d, want Duration) {
+ if d != want {
+ t.Errorf("%s = %v, want %v", expr, d, want)
+ }
+ }
+ check(txs+".Sub("+tys+")", tx.Sub(ty), d)
+ check(txs+"w.Sub("+tys+")", txw.Sub(ty), dw)
+ check(txs+".Sub("+tys+"w)", tx.Sub(tyw), dw)
+ check(txs+"w.Sub("+tys+"w)", txw.Sub(tyw), dw)
+ }
+ sub("t1", "t1", t1, t1w, t1, t1w, 0, 0)
+ sub("t1", "t2", t1, t1w, t2, t2w, -10*Millisecond, 990*Millisecond)
+ sub("t1", "t3", t1, t1w, t3, t3w, -1000*Millisecond, 0)
+
+ sub("t2", "t1", t2, t2w, t1, t1w, 10*Millisecond, -990*Millisecond)
+ sub("t2", "t2", t2, t2w, t2, t2w, 0, 0)
+ sub("t2", "t3", t2, t2w, t3, t3w, -990*Millisecond, -990*Millisecond)
+
+ sub("t3", "t1", t3, t3w, t1, t1w, 1000*Millisecond, 0)
+ sub("t3", "t2", t3, t3w, t2, t2w, 990*Millisecond, 990*Millisecond)
+ sub("t3", "t3", t3, t3w, t3, t3w, 0, 0)
+
+ cmp := func(txs, tys string, tx, txw, ty, tyw Time, c, cw int) {
+ check := func(expr string, b, want bool) {
+ if b != want {
+ t.Errorf("%s = %v, want %v", expr, b, want)
+ }
+ }
+ check(txs+".After("+tys+")", tx.After(ty), c > 0)
+ check(txs+"w.After("+tys+")", txw.After(ty), cw > 0)
+ check(txs+".After("+tys+"w)", tx.After(tyw), cw > 0)
+ check(txs+"w.After("+tys+"w)", txw.After(tyw), cw > 0)
+
+ check(txs+".Before("+tys+")", tx.Before(ty), c < 0)
+ check(txs+"w.Before("+tys+")", txw.Before(ty), cw < 0)
+ check(txs+".Before("+tys+"w)", tx.Before(tyw), cw < 0)
+ check(txs+"w.Before("+tys+"w)", txw.Before(tyw), cw < 0)
+
+ check(txs+".Equal("+tys+")", tx.Equal(ty), c == 0)
+ check(txs+"w.Equal("+tys+")", txw.Equal(ty), cw == 0)
+ check(txs+".Equal("+tys+"w)", tx.Equal(tyw), cw == 0)
+ check(txs+"w.Equal("+tys+"w)", txw.Equal(tyw), cw == 0)
+ }
+
+ cmp("t1", "t1", t1, t1w, t1, t1w, 0, 0)
+ cmp("t1", "t2", t1, t1w, t2, t2w, -1, +1)
+ cmp("t1", "t3", t1, t1w, t3, t3w, -1, 0)
+
+ cmp("t2", "t1", t2, t2w, t1, t1w, +1, -1)
+ cmp("t2", "t2", t2, t2w, t2, t2w, 0, 0)
+ cmp("t2", "t3", t2, t2w, t3, t3w, -1, -1)
+
+ cmp("t3", "t1", t3, t3w, t1, t1w, +1, 0)
+ cmp("t3", "t2", t3, t3w, t2, t2w, +1, +1)
+ cmp("t3", "t3", t3, t3w, t3, t3w, 0, 0)
+}
+
+func TestMonotonicOverflow(t *testing.T) {
+ t1 := Now().Add(-30 * Second)
+ d := Until(t1)
+ if d < -35*Second || -30*Second < d {
+ t.Errorf("Until(Now().Add(-30s)) = %v, want roughly -30s (-35s to -30s)", d)
+ }
+
+ t1 = Now().Add(30 * Second)
+ d = Until(t1)
+ if d < 25*Second || 30*Second < d {
+ t.Errorf("Until(Now().Add(-30s)) = %v, want roughly 30s (25s to 30s)", d)
+ }
+
+ t0 := Now()
+ t1 = t0.Add(Duration(1<<63 - 1))
+ if GetMono(&t1) != 0 {
+ t.Errorf("Now().Add(maxDuration) has monotonic clock reading (%v => %v %d %d)", t0.String(), t1.String(), t0.Unix(), t1.Unix())
+ }
+ t2 := t1.Add(-Duration(1<<63 - 1))
+ d = Since(t2)
+ if d < -10*Second || 10*Second < d {
+ t.Errorf("Since(Now().Add(max).Add(-max)) = %v, want [-10s, 10s]", d)
+ }
+
+ t0 = Now()
+ t1 = t0.Add(1 * Hour)
+ Sleep(100 * Millisecond)
+ t2 = Now().Add(-5 * Second)
+ if !t1.After(t2) {
+ t.Errorf("Now().Add(1*Hour).After(Now().Add(-5*Second)) = false, want true\nt1=%v\nt2=%v", t1, t2)
+ }
+ if t2.After(t1) {
+ t.Errorf("Now().Add(-5*Second).After(Now().Add(1*Hour)) = true, want false\nt1=%v\nt2=%v", t1, t2)
+ }
+ if t1.Before(t2) {
+ t.Errorf("Now().Add(1*Hour).Before(Now().Add(-5*Second)) = true, want false\nt1=%v\nt2=%v", t1, t2)
+ }
+ if !t2.Before(t1) {
+ t.Errorf("Now().Add(-5*Second).Before(Now().Add(1*Hour)) = false, want true\nt1=%v\nt2=%v", t1, t2)
+ }
+}
+
+func TestMonotonicString(t *testing.T) {
+ t1 := Now()
+ re := regexp.MustCompile(` m=\+[0-9]+\.[0-9]{9}$`)
+ if !re.MatchString(t1.String()) {
+ t.Errorf("Now().String() = %q, want match for /%s/", t1.String(), re)
+ }
+
+ t2 := Now().Add(-5 * Hour)
+ re = regexp.MustCompile(` m=-[0-9]+\.[0-9]{9}$`)
+ if !re.MatchString(t2.String()) {
+ t.Errorf("Now().Add(-5*Hour).String() = %q, want match for /%s/", t2.String(), re)
+ }
+
+ t3 := Now().Add(1.2e18)
+ re = regexp.MustCompile(` m=\+120[0-9]{7}\.[0-9]{9}$`)
+ if !re.MatchString(t3.String()) {
+ t.Errorf("Now().Add(12e17).String() = %q, want match for /%s/", t3.String(), re)
+ }
+}
//
// The calendrical calculations always assume a Gregorian calendar, with
// no leap seconds.
+//
+// Monotonic Clocks
+//
+// Operating systems provide both a “wall clock,” which is subject to
+// changes for clock synchronization, and a “monotonic clock,” which is
+// not. The general rule is that the wall clock is for telling time and
+// the monotonic clock is for measuring time. Rather than split the API,
+// in this package the Time returned by time.Now contains both a wall
+// clock reading and a monotonic clock reading; later time-telling
+// operations use the wall clock reading, but later time-measuring
+// operations, specifically comparisons and subtractions, use the
+// monotonic clock reading.
+//
+// For example, this code always computes a positive elapsed time of
+// approximately 20 milliseconds, even if the wall clock is changed during
+// the operation being timed:
+//
+// t := time.Now()
+// ... operation that takes 20 milliseconds ...
+// u := time.Now()
+// elapsed := t.Sub(u)
+//
+// Other idioms, such as time.Since(start), time.Until(deadline), and
+// time.Now().Before(deadline), are similarly robust against wall clock
+// resets.
+//
+// The rest of this section gives the precise details of how operations
+// use monotonic clocks, but understanding those details is not required
+// to use this package.
+//
+// The Time returned by time.Now contains a monotonic clock reading.
+// If Time t has a monotonic clock reading, t.Add, t.Round, and
+// t.Truncate add the same duration to both the wall clock and
+// monotonic clock readings to compute the result. Similarly, t.In,
+// t.Local, and t.UTC, which are defined to change only the Time's
+// Location, pass any monotonic clock reading through unmodified.
+// Because t.AddDate(y, m, d) is a wall time computation, it always
+// strips any monotonic clock reading from its result.
+//
+// If Times t and u both contain monotonic clock readings, the operations
+// t.After(u), t.Before(u), t.Equal(u), and t.Sub(u) are carried out
+// using the monotonic clock readings alone, ignoring the wall clock
+// readings. If either t or u contains no monotonic clock reading, these
+// operations fall back to using the wall clock readings.
+//
+// Because the monotonic clock reading has no meaning outside
+// the current process, the serialized forms generated by t.GobEncode,
+// t.MarshalBinary, t.MarshalJSON, and t.MarshalText omit the monotonic
+// clock reading, and t.Format provides no format for it. Similarly, the
+// constructors time.Date, time.Parse, time.ParseInLocation, and time.Unix,
+// as well as the unmarshalers t.GobDecode, t.UnmarshalBinary.
+// t.UnmarshalJSON, and t.UnmarshalText always create times with
+// no monotonic clock reading.
+//
+// Note that the Go == operator includes the monotonic clock reading in
+// its comparison. If time values returned from time.Now and time values
+// constructed by other means (for example, by time.Parse or time.Unix)
+// are meant to compare equal when used as map keys, the times returned
+// by time.Now must have the monotonic clock reading stripped, by setting
+// t = t.AddDate(0, 0, 0). In general, prefer t.Equal(u) to t == u, since
+// t.Equal uses the most accurate comparison available and correctly
+// handles the case when only one of its arguments has a monotonic clock
+// reading.
+//
+// For debugging, the result of t.String does include the monotonic
+// clock reading if present. If t != u because of different monotonic clock readings,
+// that difference will be visible when printing t.String() and u.String().
+//
package time
import "errors"
// without first guaranteeing that the identical Location has been set for all
// values, which can be achieved through use of the UTC or Local method.
//
+// In addition to the required “wall clock” reading, a Time may contain an optional
+// reading of the current process's monotonic clock, to provide additional precision
+// for comparison or subtraction.
+// See the “Monotonic Clocks” section in the package documentation for details.
+//
type Time struct {
- // sec gives the number of seconds elapsed since
- // January 1, year 1 00:00:00 UTC.
- sec int64
-
- // nsec specifies a non-negative nanosecond
- // offset within the second named by Seconds.
- // It must be in the range [0, 999999999].
- nsec int32
+ // 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].
+ // If the hasMonotonic bit is 0, then the 33-bit field must be zero
+ // and the full signed 64-bit wall seconds since Jan 1 year 1 is stored in ext.
+ // If the hasMonotonic bit is 1, then the 33-bit field holds a 33-bit
+ // unsigned wall seconds since Jan 1 year 1885, and ext holds a
+ // signed 64-bit monotonic clock reading, nanoseconds since process start.
+ wall uint64
+ ext int64
// loc specifies the Location that should be used to
// determine the minute, hour, month, day, and year
loc *Location
}
+const (
+ hasMonotonic = 1 << 63
+ maxWall = wallToInternal + (1<<33 - 1) // year 2157
+ minWall = wallToInternal // year 1885
+ nsecMask = 1<<30 - 1
+ nsecShift = 30
+)
+
+// These helpers for manipulating the wall and monotonic clock readings
+// take pointer receivers, even when they don't modify the time,
+// to make them cheaper to call.
+
+// nsec returns the time's nanoseconds.
+func (t *Time) nsec() int32 {
+ return int32(t.wall & nsecMask)
+}
+
+// sec returns the time's seconds since Jan 1 year 1.
+func (t *Time) sec() int64 {
+ if t.wall&hasMonotonic != 0 {
+ return wallToInternal + int64(t.wall<<1>>(nsecShift+1))
+ }
+ return int64(t.ext)
+}
+
+// unixSec returns the time's seconds since Jan 1 1970 (Unix time).
+func (t *Time) unixSec() int64 { return t.sec() + internalToUnix }
+
+// addSec adds d seconds to the time.
+func (t *Time) addSec(d int64) {
+ if t.wall&hasMonotonic != 0 {
+ sec := int64(t.wall << 1 >> (nsecShift + 1))
+ dsec := sec + d
+ if 0 <= dsec && dsec <= 1<<33-1 {
+ t.wall = t.wall&nsecMask | uint64(dsec)<<nsecShift | hasMonotonic
+ return
+ }
+ // Wall second now out of range for packed field.
+ // Move to ext.
+ t.ext = t.sec()
+ t.wall &= nsecMask
+ }
+
+ // TODO: Check for overflow.
+ t.ext += d
+}
+
+// setLoc sets the location associated with the time.
func (t *Time) setLoc(loc *Location) {
if loc == &utcLoc {
loc = nil
t.loc = loc
}
+// setMono sets the monotonic clock reading in t.
+// If t cannot hold a monotonic clock reading,
+// because its wall time is too large,
+// setMono is a no-op.
+func (t *Time) setMono(m int64) {
+ if t.wall&hasMonotonic == 0 {
+ sec := int64(t.ext)
+ if sec < minWall || maxWall < sec {
+ return
+ }
+ t.wall |= hasMonotonic | uint64(sec-minWall)<<nsecShift
+ }
+ t.ext = m
+}
+
+// mono returns t's monotonic clock reading.
+// It returns 0 for a missing reading.
+// This function is used only for testing,
+// so it's OK that technically 0 is a valid
+// monotonic clock reading as well.
+func (t *Time) mono() int64 {
+ if t.wall&hasMonotonic == 0 {
+ return 0
+ }
+ return t.ext
+}
+
// After reports whether the time instant t is after u.
func (t Time) After(u Time) bool {
- return t.sec > u.sec || t.sec == u.sec && t.nsec > u.nsec
+ if t.wall&u.wall&hasMonotonic != 0 {
+ return t.ext > u.ext
+ }
+ ts := t.sec()
+ us := u.sec()
+ return ts > us || ts == us && t.nsec() > u.nsec()
}
// Before reports whether the time instant t is before u.
func (t Time) Before(u Time) bool {
- return t.sec < u.sec || t.sec == u.sec && t.nsec < u.nsec
+ if t.wall&u.wall&hasMonotonic != 0 {
+ return t.ext < u.ext
+ }
+ return t.sec() < u.sec() || t.sec() == u.sec() && t.nsec() < u.nsec()
}
// Equal reports whether t and u represent the same time instant.
// For example, 6:00 +0200 CEST and 4:00 UTC are Equal.
// Do not use == with Time values.
func (t Time) Equal(u Time) bool {
- return t.sec == u.sec && t.nsec == u.nsec
+ if t.wall&u.wall&hasMonotonic != 0 {
+ return t.ext == u.ext
+ }
+ return t.sec() == u.sec() && t.nsec() == u.nsec()
}
// A Month specifies a month of the year (January = 1, ...).
unixToInternal int64 = (1969*365 + 1969/4 - 1969/100 + 1969/400) * secondsPerDay
internalToUnix int64 = -unixToInternal
+
+ wallToInternal int64 = (1884*365 + 1884/4 - 1884/100 + 1884/400) * secondsPerDay
+ internalToWall int64 = -wallToInternal
)
// IsZero reports whether t represents the zero time instant,
// January 1, year 1, 00:00:00 UTC.
func (t Time) IsZero() bool {
- return t.sec == 0 && t.nsec == 0
+ return t.sec() == 0 && t.nsec() == 0
}
// abs returns the time t as an absolute time, adjusted by the zone offset.
if l == nil || l == &localLoc {
l = l.get()
}
- sec := t.sec + internalToUnix
+ sec := t.unixSec()
if l != &utcLoc {
if l.cacheZone != nil && l.cacheStart <= sec && sec < l.cacheEnd {
sec += int64(l.cacheZone.offset)
l = l.get()
}
// Avoid function call if we hit the local time cache.
- sec := t.sec + internalToUnix
+ sec := t.unixSec()
if l != &utcLoc {
if l.cacheZone != nil && l.cacheStart <= sec && sec < l.cacheEnd {
name = l.cacheZone.name
// Nanosecond returns the nanosecond offset within the second specified by t,
// in the range [0, 999999999].
func (t Time) Nanosecond() int {
- return int(t.nsec)
+ return int(t.nsec())
}
// YearDay returns the day of the year specified by t, in the range [1,365] for non-leap years,
// Add returns the time t+d.
func (t Time) Add(d Duration) Time {
- t.sec += int64(d / 1e9)
- nsec := t.nsec + int32(d%1e9)
+ dsec := int64(d / 1e9)
+ nsec := t.nsec() + int32(d%1e9)
if nsec >= 1e9 {
- t.sec++
+ dsec++
nsec -= 1e9
} else if nsec < 0 {
- t.sec--
+ dsec--
nsec += 1e9
}
- t.nsec = nsec
+ t.wall = t.wall&^nsecMask | uint64(nsec) // update nsec
+ t.addSec(dsec)
+ if t.wall&hasMonotonic != 0 {
+ te := t.ext + int64(d)
+ if d < 0 && te > int64(t.ext) || d > 0 && te < int64(t.ext) {
+ // Monotonic clock reading now out of range; degrade to wall-only.
+ t.ext = t.sec()
+ t.wall &= nsecMask
+ } else {
+ t.ext = te
+ }
+ }
return t
}
// will be returned.
// To compute t-d for a duration d, use t.Add(-d).
func (t Time) Sub(u Time) Duration {
- d := Duration(t.sec-u.sec)*Second + Duration(t.nsec-u.nsec)
+ if t.wall&u.wall&hasMonotonic != 0 {
+ te := int64(t.ext)
+ ue := int64(u.ext)
+ d := Duration(te - ue)
+ if d < 0 && te > ue {
+ return maxDuration // t - u is positive out of range
+ }
+ if d > 0 && te < ue {
+ return minDuration // t - u is negative out of range
+ }
+ return d
+ }
+ d := Duration(t.sec()-u.sec())*Second + Duration(t.nsec()-u.nsec())
// Check for overflow or underflow.
switch {
case u.Add(d).Equal(t):
func (t Time) AddDate(years int, months int, days int) Time {
year, month, day := t.Date()
hour, min, sec := t.Clock()
- return Date(year+years, month+Month(months), day+days, hour, min, sec, int(t.nsec), t.Location())
+ return Date(year+years, month+Month(months), day+days, hour, min, sec, int(t.nsec()), t.Location())
}
const (
}
// Provided by package runtime.
-func now() (sec int64, nsec int32)
+func now() (sec int64, nsec int32, mono uint64)
// Now returns the current local time.
func Now() Time {
- sec, nsec := now()
- return Time{sec + unixToInternal, nsec, Local}
+ sec, nsec, mono := now()
+ t := unixTime(sec, nsec)
+ t.setMono(int64(mono))
+ return t
+}
+
+func unixTime(sec int64, nsec int32) Time {
+ return Time{uint64(nsec), sec + unixToInternal, Local}
}
// UTC returns t with the location set to UTC.
// Zone computes the time zone in effect at time t, returning the abbreviated
// name of the zone (such as "CET") and its offset in seconds east of UTC.
func (t Time) Zone() (name string, offset int) {
- name, offset, _, _, _ = t.loc.lookup(t.sec + internalToUnix)
+ name, offset, _, _, _ = t.loc.lookup(t.unixSec())
return
}
// Unix returns t as a Unix time, the number of seconds elapsed
// since January 1, 1970 UTC.
func (t Time) Unix() int64 {
- return t.sec + internalToUnix
+ return t.unixSec()
}
// UnixNano returns t as a Unix time, the number of nanoseconds elapsed
// 1678 or after 2262). Note that this means the result of calling UnixNano
// on the zero Time is undefined.
func (t Time) UnixNano() int64 {
- return (t.sec+internalToUnix)*1e9 + int64(t.nsec)
+ return (t.unixSec())*1e9 + int64(t.nsec())
}
const timeBinaryVersion byte = 1
offsetMin = int16(offset)
}
+ sec := t.sec()
+ nsec := t.nsec()
enc := []byte{
timeBinaryVersion, // byte 0 : version
- byte(t.sec >> 56), // bytes 1-8: seconds
- byte(t.sec >> 48),
- byte(t.sec >> 40),
- byte(t.sec >> 32),
- byte(t.sec >> 24),
- byte(t.sec >> 16),
- byte(t.sec >> 8),
- byte(t.sec),
- byte(t.nsec >> 24), // bytes 9-12: nanoseconds
- byte(t.nsec >> 16),
- byte(t.nsec >> 8),
- byte(t.nsec),
+ byte(sec >> 56), // bytes 1-8: seconds
+ byte(sec >> 48),
+ byte(sec >> 40),
+ byte(sec >> 32),
+ byte(sec >> 24),
+ byte(sec >> 16),
+ byte(sec >> 8),
+ byte(sec),
+ byte(nsec >> 24), // bytes 9-12: nanoseconds
+ byte(nsec >> 16),
+ byte(nsec >> 8),
+ byte(nsec),
byte(offsetMin >> 8), // bytes 13-14: zone offset in minutes
byte(offsetMin),
}
}
buf = buf[1:]
- t.sec = int64(buf[7]) | int64(buf[6])<<8 | int64(buf[5])<<16 | int64(buf[4])<<24 |
+ sec := int64(buf[7]) | int64(buf[6])<<8 | int64(buf[5])<<16 | int64(buf[4])<<24 |
int64(buf[3])<<32 | int64(buf[2])<<40 | int64(buf[1])<<48 | int64(buf[0])<<56
buf = buf[8:]
- t.nsec = int32(buf[3]) | int32(buf[2])<<8 | int32(buf[1])<<16 | int32(buf[0])<<24
+ nsec := int32(buf[3]) | int32(buf[2])<<8 | int32(buf[1])<<16 | int32(buf[0])<<24
buf = buf[4:]
offset := int(int16(buf[1])|int16(buf[0])<<8) * 60
+ *t = Time{}
+ t.wall = uint64(nsec)
+ t.ext = sec
+
if offset == -1*60 {
t.setLoc(&utcLoc)
- } else if _, localoff, _, _, _ := Local.lookup(t.sec + internalToUnix); offset == localoff {
+ } else if _, localoff, _, _, _ := Local.lookup(t.unixSec()); offset == localoff {
t.setLoc(Local)
} else {
t.setLoc(FixedZone("", offset))
sec--
}
}
- return Time{sec + unixToInternal, int32(nsec), Local}
+ return unixTime(sec, int32(nsec))
}
func isLeap(year int) bool {
unix -= int64(offset)
}
- t := Time{unix + unixToInternal, int32(nsec), nil}
+ t := unixTime(unix, int32(nsec))
t.setLoc(loc)
return t
}
// but it's still here in case we change our minds.
func div(t Time, d Duration) (qmod2 int, r Duration) {
neg := false
- nsec := t.nsec
- if t.sec < 0 {
+ nsec := t.nsec()
+ sec := t.sec()
+ if sec < 0 {
// Operate on absolute value.
neg = true
- t.sec = -t.sec
+ sec = -sec
nsec = -nsec
if nsec < 0 {
nsec += 1e9
- t.sec-- // t.sec >= 1 before the -- so safe
+ sec-- // sec >= 1 before the -- so safe
}
}
// Special case: d is a multiple of 1 second.
case d%Second == 0:
d1 := int64(d / Second)
- qmod2 = int(t.sec/d1) & 1
- r = Duration(t.sec%d1)*Second + Duration(nsec)
+ qmod2 = int(sec/d1) & 1
+ r = Duration(sec%d1)*Second + Duration(nsec)
// General case.
// This could be faster if more cleverness were applied,
// No one will care about these cases.
default:
// Compute nanoseconds as 128-bit number.
- sec := uint64(t.sec)
+ sec := uint64(sec)
tmp := (sec >> 32) * 1e9
u1 := tmp >> 32
u0 := tmp << 32
// Fill in the cache with information about right now,
// since that will be the most common lookup.
- sec, _ := now()
+ sec, _, _ := now()
for i := range tx {
if tx[i].when <= sec && (i+1 == len(tx) || sec < tx[i+1].when) {
l.cacheStart = tx[i].when
// Fill in the cache with information about right now,
// since that will be the most common lookup.
- sec, _ := now()
+ sec, _, _ := now()
for i := range tx {
if tx[i].when <= sec && (i+1 == len(tx) || sec < tx[i+1].when) {
l.cacheStart = tx[i].when
day -= 7
}
}
- return t.sec + int64(day-1)*secondsPerDay + internalToUnix
+ return t.sec() + int64(day-1)*secondsPerDay + internalToUnix
}
func initLocalFromTZI(i *syscall.Timezoneinformation) {