assorted changes:

	- use a lock instead of a thread in once
		avoids deadlock in recursive once calls
	- implement os.Setenv
	- remove "export" from some scripts
	- remove _ from names in time package
	- fix time test for non-MTV machines

R=r
DELTA=265  (87 added, 58 deleted, 120 changed)
OCL=25057
CL=25057

src/lib/Makefile

@@ -94,11 +94,12 @@ test: test.files
 
 bignum.6: fmt.dirinstall
 bufio.6: io.dirinstall os.dirinstall
+exec.6: os.dirinstall
 flag.6: fmt.dirinstall
 log.6: fmt.dirinstall io.dirinstall os.dirinstall time.dirinstall
-testing.6: flag.install fmt.dirinstall
+once.6: sync.dirinstall
 strings.6: utf8.install
-exec.6: os.dirinstall
+testing.6: flag.install fmt.dirinstall
 
 fmt.dirinstall: io.dirinstall reflect.dirinstall strconv.dirinstall
 hash.dirinstall: os.dirinstall
@@ -108,7 +109,7 @@ json.dirinstall: container/array.dirinstall fmt.dirinstall io.dirinstall math.di
 	strconv.dirinstall strings.install utf8.install
 # TODO(rsc): net is not supposed to depend on fmt or strings or strconv
 net.dirinstall: fmt.dirinstall once.install os.dirinstall strconv.dirinstall strings.install
-os.dirinstall: syscall.dirinstall
+os.dirinstall: syscall.dirinstall once.install
 regexp.dirinstall: os.dirinstall
 reflect.dirinstall: strconv.dirinstall sync.dirinstall
 strconv.dirinstall: math.dirinstall os.dirinstall utf8.install

src/lib/once.go

@@ -4,74 +4,41 @@
 
 // For one-time initialization that is not done during init.
 // Wrap the initialization in a niladic function f() and call
-//	once.Do(&f)
-// If multiple processes call once.Do(&f) simultaneously
+//	once.Do(f)
+// If multiple processes call once.Do(f) simultaneously
 // with the same f argument, only one will call f, and the
 // others will block until f finishes running.
 
 package once
 
-type _Job struct {
-	done bool;
-	doit chan bool;	// buffer of 1
-}
+import "sync"
 
-type _Request struct {
-	f func();
-	reply chan *_Job
+type job struct {
+	done bool;
+	sync.Mutex;	// should probably be sync.Notification or some such
 }
 
-var service = make(chan _Request)
-var jobmap = make(map[func()]*_Job)
-
-// Moderate access to the jobmap.
-// Even if accesses were thread-safe (they should be but are not)
-// something needs to serialize creation of new jobs.
-// That's what the Server does.
-func server() {
-	for {
-		req := <-service;
-		job, present := jobmap[req.f];
-		if !present {
-			job = new(_Job);
-			job.doit = make(chan bool, 1);
-			job.doit <- true;
-			jobmap[req.f] = job
-		}
-		req.reply <- job
-	}
-}
+var jobs = make(map[func()]*job)
+var joblock sync.Mutex;
 
 func Do(f func()) {
-	// Look for job in map (avoids channel communication).
-	// If not there, ask map server to make one.
-	// TODO: Uncomment use of jobmap[f] once
-	// maps are thread-safe.
-	var job *_Job;
-	var present bool;
-	// job, present = jobmap[f]
+	joblock.Lock();
+	j, present := jobs[f];
 	if !present {
-		c := make(chan *_Job);
-		service <- _Request(f, c);
-		job = <-c
-	}
-
-	// Optimization
-	if job.done {
-		return
-	}
-
-	// If we're the first one, job.doit has a true waiting.
-	if <-job.doit {
+		// run it
+		j = new(job);
+		j.Lock();
+		jobs[f] = j;
+		joblock.Unlock();
 		f();
-		job.done = true
+		j.done = true;
+		j.Unlock();
+	} else {
+		// wait for it
+		joblock.Unlock();
+		if j.done != true {
+			j.Lock();
+			j.Unlock();
+		}
 	}
-
-	// Leave a false waiting for the next guy.
-	job.doit <- false
-}
-
-func init() {
-	go server()
 }
-

src/lib/os/env.go

@@ -3,25 +3,71 @@
 // license that can be found in the LICENSE file.
 
 // Environment variables.
-// Setenv doesn't exist yet: don't have the run-time hooks yet
 
 package os
 
-import os "os"
+import (
+	"once";
+	"os";
+)
 
 var (
 	ENOENV = NewError("no such environment variable");
+
+	env map[string] string;
 )
 
-func Getenv(s string) (v string, err *Error) {
-	n := len(s);
-	if n == 0 {
-		return "", EINVAL
+func copyenv() {
+	env = make(map[string] string);
+	for i, s := range sys.Envs {
+		for j := 0; j < len(s); j++ {
+			if s[j] == '=' {
+				env[s[0:j]] = s[j+1:len(s)];
+				break;
+			}
+		}
+	}
+}
+
+func Getenv(key string) (value string, err *Error) {
+	once.Do(copyenv);
+
+	if len(key) == 0 {
+		return "", EINVAL;
+	}
+	v, ok := env[key];
+	if !ok {
+		return "", ENOENV;
 	}
-	for i, e := range sys.Envs {
-		if len(e) > n && e[n] == '=' && e[0:n] == s {
-			return e[n+1:len(e)], nil
+	return v, nil;
+}
+
+func Setenv(key, value string) *Error {
+	once.Do(copyenv);
+
+	if len(key) == 0 {
+		return EINVAL;
+	}
+	env[key] = value;
+	return nil;
+}
+
+func Clearenv() {
+	once.Do(copyenv);	// prevent copyenv in Getenv/Setenv
+	env = make(map[string] string);
+}
+
+func Environ() []string {
+	once.Do(copyenv);
+	a := make([]string, len(env));
+	i := 0;
+	for k, v := range(env) {
+		// check i < len(a) for safety,
+		// in case env is changing underfoot.
+		if i < len(a) {
+			a[i] = k + "=" + v;
+			i++;
 		}
 	}
-	return "", ENOENV
+	return a[0:i];
 }

src/lib/os/exec.go

@@ -27,6 +27,9 @@ func ForkExec(argv0 string, argv []string, envv []string, fd []*FD)
 }
 
 func Exec(argv0 string, argv []string, envv []string) *Error {
+	if envv == nil {
+		envv = Environ();
+	}
 	e := syscall.Exec(argv0, argv, envv);
 	return ErrnoToError(e);
 }

src/lib/syscall/mkdarwin

@@ -10,7 +10,7 @@ print <<EOF;
 
 package syscall
 
-export const (
+const (
 EOF
 
 while(<>){

src/lib/syscall/mklinux

@@ -11,7 +11,7 @@ print <<EOF;
 
 package syscall
 
-export const(
+const(
 EOF
 
 while(<>){
@@ -25,4 +25,7 @@ while(<>){
 
 print <<EOF;
 )
+
+func _darwin_system_call_conflict() {
+}
 EOF

src/lib/syscall/mksignal

@@ -10,7 +10,7 @@ print <<EOF;
 
 package syscall
 
-export const(
+const(
 EOF
 
 while(<>){

src/lib/time/time.go

@@ -138,7 +138,7 @@ func SecondsToUTC(sec int64) *Time {
 	}
 	t.Month = m+1;
 	t.Day = yday+1;
-	t.Zone = "GMT";
+	t.Zone = "UTC";
 
 	return t;
 }
@@ -149,12 +149,12 @@ func UTC() *Time {
 
 // TODO: Should this return an error?
 func SecondsToLocalTime(sec int64) *Time {
-	zone, offset, err := time.LookupTimezone(sec);
+	z, offset, err := time.LookupTimezone(sec);
 	if err != nil {
 		return SecondsToUTC(sec)
 	}
 	t := SecondsToUTC(sec+int64(offset));
-	t.Zone = zone;
+	t.Zone = z;
 	t.ZoneOffset = offset;
 	return t
 }

src/lib/time/time_test.go

@@ -5,31 +5,39 @@
 package time
 
 import (
+	"os";
 	"testing";
 	"time";
 )
 
-type _TimeTest struct {
+func init() {
+	// Force US Pacific time for daylight-savings
+	// tests below (localtests).  Needs to be set
+	// before the first call into the time library.
+	os.Setenv("TZ", "US/Pacific");
+}
+
+type TimeTest struct {
 	seconds int64;
 	golden Time;
 }
 
-var utctests = []_TimeTest (
-	_TimeTest(0, Time(1970, 1, 1, 0, 0, 0, Thursday, 0, "GMT")),
-	_TimeTest(1221681866, Time(2008, 9, 17, 20, 4, 26, Wednesday, 0, "GMT")),
-	_TimeTest(-1221681866, Time(1931, 4, 16, 3, 55, 34, Thursday, 0, "GMT")),
-	_TimeTest(1e18, Time(31688740476, 10, 23, 1, 46, 40, Friday, 0, "GMT")),
-	_TimeTest(-1e18, Time(-31688736537, 3, 10, 22, 13, 20, Tuesday, 0, "GMT")),
-	_TimeTest(0x7fffffffffffffff, Time(292277026596, 12, 4, 15, 30, 7, Sunday, 0, "GMT")),
-	_TimeTest(-0x8000000000000000, Time(-292277022657, 1, 27, 8, 29, 52, Sunday, 0, "GMT"))
+var utctests = []TimeTest (
+	TimeTest(0, Time(1970, 1, 1, 0, 0, 0, Thursday, 0, "UTC")),
+	TimeTest(1221681866, Time(2008, 9, 17, 20, 4, 26, Wednesday, 0, "UTC")),
+	TimeTest(-1221681866, Time(1931, 4, 16, 3, 55, 34, Thursday, 0, "UTC")),
+	TimeTest(1e18, Time(31688740476, 10, 23, 1, 46, 40, Friday, 0, "UTC")),
+	TimeTest(-1e18, Time(-31688736537, 3, 10, 22, 13, 20, Tuesday, 0, "UTC")),
+	TimeTest(0x7fffffffffffffff, Time(292277026596, 12, 4, 15, 30, 7, Sunday, 0, "UTC")),
+	TimeTest(-0x8000000000000000, Time(-292277022657, 1, 27, 8, 29, 52, Sunday, 0, "UTC"))
 )
 
-var localtests = []_TimeTest (
-	_TimeTest(0, Time(1969, 12, 31, 16, 0, 0, Wednesday, -8*60*60, "PST")),
-	_TimeTest(1221681866, Time(2008, 9, 17, 13, 4, 26, Wednesday, -7*60*60, "PDT"))
+var localtests = []TimeTest (
+	TimeTest(0, Time(1969, 12, 31, 16, 0, 0, Wednesday, -8*60*60, "PST")),
+	TimeTest(1221681866, Time(2008, 9, 17, 13, 4, 26, Wednesday, -7*60*60, "PDT"))
 )
 
-func _Same(t, u *Time) bool {
+func same(t, u *Time) bool {
 	return t.Year == u.Year
 		&& t.Month == u.Month
 		&& t.Day == u.Day
@@ -50,7 +58,7 @@ func TestSecondsToUTC(t *testing.T) {
 		if newsec != sec {
 			t.Errorf("SecondsToUTC(%d).Seconds() = %d", sec, newsec);
 		}
-		if !_Same(tm, golden) {
+		if !same(tm, golden) {
 			t.Errorf("SecondsToUTC(%d):", sec);
 			t.Errorf("  want=%v", *golden);
 			t.Errorf("  have=%v", *tm);
@@ -67,7 +75,7 @@ func TestSecondsToLocalTime(t *testing.T) {
 		if newsec != sec {
 			t.Errorf("SecondsToLocalTime(%d).Seconds() = %d", sec, newsec);
 		}
-		if !_Same(tm, golden) {
+		if !same(tm, golden) {
 			t.Errorf("SecondsToLocalTime(%d):", sec);
 			t.Errorf("  want=%v", *golden);
 			t.Errorf("  have=%v", *tm);

src/lib/time/zoneinfo.go

@@ -16,8 +16,10 @@ import (
 )
 
 const (
-	_MaxFileSize = 8192;	// actual files are closer to 1K
-	_HeaderSize = 4+16+4*7
+	maxFileSize = 8192;	// actual files are closer to 1K
+	headerSize = 4+16+4*7;
+
+	zoneDir = "/usr/share/zoneinfo/";
 )
 
 var (
@@ -26,13 +28,13 @@ var (
 )
 
 // Simple I/O interface to binary blob of data.
-type _Data struct {
+type data struct {
 	p []byte;
 	error bool;
 }
 
 
-func (d *_Data) Read(n int) []byte {
+func (d *data) read(n int) []byte {
 	if len(d.p) < n {
 		d.p = nil;
 		d.error = true;
@@ -43,8 +45,8 @@ func (d *_Data) Read(n int) []byte {
 	return p
 }
 
-func (d *_Data) Big4() (n uint32, ok bool) {
-	p := d.Read(4);
+func (d *data) big4() (n uint32, ok bool) {
+	p := d.read(4);
 	if len(p) < 4 {
 		d.error = true;
 		return 0, false
@@ -52,8 +54,8 @@ func (d *_Data) Big4() (n uint32, ok bool) {
 	return uint32(p[0]) << 24 | uint32(p[1]) << 16 | uint32(p[2]) << 8 | uint32(p[3]), true
 }
 
-func (d *_Data) Byte() (n byte, ok bool) {
-	p := d.Read(1);
+func (d *data) byte() (n byte, ok bool) {
+	p := d.read(1);
 	if len(p) < 1 {
 		d.error = true;
 		return 0, false
@@ -63,7 +65,7 @@ func (d *_Data) Byte() (n byte, ok bool) {
 
 
 // Make a string by stopping at the first NUL
-func _ByteString(p []byte) string {
+func byteString(p []byte) string {
 	for i := 0; i < len(p); i++ {
 		if p[i] == 0 {
 			return string(p[0:i])
@@ -73,31 +75,29 @@ func _ByteString(p []byte) string {
 }
 
 // Parsed representation
-type _Zone struct {
+type zone struct {
 	utcoff int;
 	isdst bool;
 	name string;
 }
 
-type _Zonetime struct {
+type zonetime struct {
 	time int32;		// transition time, in seconds since 1970 GMT
-	zone *_Zone;		// the zone that goes into effect at that time
+	zone *zone;		// the zone that goes into effect at that time
 	isstd, isutc bool;	// ignored - no idea what these mean
 }
 
-func parseinfo(bytes []byte) (zt []_Zonetime, err *os.Error) {
-
-	data1 := _Data(bytes, false);
-	data := &data1;
+func parseinfo(bytes []byte) (zt []zonetime, err *os.Error) {
+	d := data(bytes, false);
 
 	// 4-byte magic "TZif"
-	if magic := data.Read(4); string(magic) != "TZif" {
+	if magic := d.read(4); string(magic) != "TZif" {
 		return nil, BadZoneinfo
 	}
 
 	// 1-byte version, then 15 bytes of padding
 	var p []byte;
-	if p = data.Read(16); len(p) != 16 || p[0] != 0 && p[0] != '2' {
+	if p = d.read(16); len(p) != 16 || p[0] != 0 && p[0] != '2' {
 		return nil, BadZoneinfo
 	}
 	vers := p[0];
@@ -119,7 +119,7 @@ func parseinfo(bytes []byte) (zt []_Zonetime, err *os.Error) {
 	)
 	var n [6]int;
 	for i := 0; i < 6; i++ {
-		nn, ok := data.Big4();
+		nn, ok := d.big4();
 		if !ok {
 			return nil, BadZoneinfo
 		}
@@ -127,32 +127,29 @@ func parseinfo(bytes []byte) (zt []_Zonetime, err *os.Error) {
 	}
 
 	// Transition times.
-	txtimes1 := _Data(data.Read(n[NTime]*4), false);
-	txtimes := &txtimes1;
+	txtimes := data(d.read(n[NTime]*4), false);
 
 	// Time zone indices for transition times.
-	txzones := data.Read(n[NTime]);
+	txzones := d.read(n[NTime]);
 
 	// Zone info structures
-	zonedata1 := _Data(data.Read(n[NZone]*6), false);
-	zonedata := &zonedata1;
+	zonedata := data(d.read(n[NZone]*6), false);
 
 	// Time zone abbreviations.
-	abbrev := data.Read(n[NChar]);
+	abbrev := d.read(n[NChar]);
 
 	// Leap-second time pairs
-	leapdata1 := _Data(data.Read(n[NLeap]*8), false);
-	leapdata := &leapdata1;
+	leapdata := data(d.read(n[NLeap]*8), false);
 
 	// Whether tx times associated with local time types
 	// are specified as standard time or wall time.
-	isstd := data.Read(n[NStdWall]);
+	isstd := d.read(n[NStdWall]);
 
 	// Whether tx times associated with local time types
 	// are specified as UTC or local time.
-	isutc := data.Read(n[NUTCLocal]);
+	isutc := d.read(n[NUTCLocal]);
 
-	if data.error {	// ran out of data
+	if d.error {	// ran out of data
 		return nil, BadZoneinfo
 	}
 
@@ -163,38 +160,38 @@ func parseinfo(bytes []byte) (zt []_Zonetime, err *os.Error) {
 	// Now we can build up a useful data structure.
 	// First the zone information.
 	//	utcoff[4] isdst[1] nameindex[1]
-	zone := make([]_Zone, n[NZone]);
-	for i := 0; i < len(zone); i++ {
+	z := make([]zone, n[NZone]);
+	for i := 0; i < len(z); i++ {
 		var ok bool;
 		var n uint32;
-		if n, ok = zonedata.Big4(); !ok {
+		if n, ok = zonedata.big4(); !ok {
 			return nil, BadZoneinfo
 		}
-		zone[i].utcoff = int(n);
+		z[i].utcoff = int(n);
 		var b byte;
-		if b, ok = zonedata.Byte(); !ok {
+		if b, ok = zonedata.byte(); !ok {
 			return nil, BadZoneinfo
 		}
-		zone[i].isdst = b != 0;
-		if b, ok = zonedata.Byte(); !ok || int(b) >= len(abbrev) {
+		z[i].isdst = b != 0;
+		if b, ok = zonedata.byte(); !ok || int(b) >= len(abbrev) {
 			return nil, BadZoneinfo
 		}
-		zone[i].name = _ByteString(abbrev[b:len(abbrev)])
+		z[i].name = byteString(abbrev[b:len(abbrev)])
 	}
 
 	// Now the transition time info.
-	zt = make([]_Zonetime, n[NTime]);
+	zt = make([]zonetime, n[NTime]);
 	for i := 0; i < len(zt); i++ {
 		var ok bool;
 		var n uint32;
-		if n, ok = txtimes.Big4(); !ok {
+		if n, ok = txtimes.big4(); !ok {
 			return nil, BadZoneinfo
 		}
 		zt[i].time = int32(n);
-		if int(txzones[i]) >= len(zone) {
+		if int(txzones[i]) >= len(z) {
 			return nil, BadZoneinfo
 		}
-		zt[i].zone = &zone[txzones[i]];
+		zt[i].zone = &z[txzones[i]];
 		if i < len(isstd) {
 			zt[i].isstd = isstd[i] != 0
 		}
@@ -208,52 +205,56 @@ func parseinfo(bytes []byte) (zt []_Zonetime, err *os.Error) {
 func readfile(name string, max int) (p []byte, err *os.Error) {
 	fd, e := os.Open(name, os.O_RDONLY, 0);
 	if e != nil {
-		return nil, e
+		return nil, e;
 	}
-	p = make([]byte, max+1)[0:0];
-	n := 0;
-	for len(p) < max {
-		nn, e := fd.Read(p[n:cap(p)]);
-		if e != nil {
+	p = make([]byte, max);
+	n, err1 := io.Readn(fd, p);
 	fd.Close();
-			return nil, e
+	if err1 == nil {	// too long
+		return nil, BadZoneinfo;
 	}
-		if nn == 0 {
-			fd.Close();
-			return p, nil
+	if err1 != io.ErrEOF {
+		return nil, err1;
 	}
-		p = p[0:n+nn]
-	}
-	fd.Close();
-	return nil, BadZoneinfo	// too long
+	return p[0:n], nil;
 }
 
-
-func readinfofile(name string) (tx []_Zonetime, err *os.Error) {
-	data, e := readfile(name, _MaxFileSize);
+func readinfofile(name string) (tx []zonetime, err *os.Error) {
+	buf, e := readfile(name, maxFileSize);
 	if e != nil {
 		return nil, e
 	}
-	tx, err = parseinfo(data);
+	tx, err = parseinfo(buf);
 	return tx, err
 }
 
-var zones []_Zonetime
+var zones []zonetime
 var zoneerr *os.Error
 
-func _SetupZone() {
-	// TODO: /etc/localtime is the default time zone info
-	// for the system, but libc allows setting an environment
-	// variable in order to direct reading a different file
-	// (in /usr/share/zoneinfo).  We should check that
-	// environment variable.
+func setupZone() {
+	// consult $TZ to find the time zone to use.
+	// no $TZ means use the system default /etc/localtime.
+	// $TZ="" means use UTC.
+	// $TZ="foo" means use /usr/share/zoneinfo/foo.
+
+	tz, err := os.Getenv("TZ");
+	var file string;
+	switch {
+	case err == os.ENOENV:
 		zones, zoneerr = readinfofile("/etc/localtime");
+	case err != nil:
+		zoneerr = err;
+	case len(tz) > 0:
+		zones, zoneerr = readinfofile(zoneDir + tz);
+	case len(tz) == 0:
+		// do nothing: use UTC
+	}
 }
 
 func LookupTimezone(sec int64) (zone string, offset int, err *os.Error) {
-	once.Do(_SetupZone);
+	once.Do(setupZone);
 	if zoneerr != nil || len(zones) == 0 {
-		return "GMT", 0, zoneerr
+		return "UTC", 0, zoneerr
 	}
 
 	// Binary search for entry with largest time <= sec