summaryrefslogtreecommitdiffstats
path: root/test/chan
diff options
context:
space:
mode:
Diffstat (limited to 'test/chan')
-rw-r--r--test/chan/doubleselect.go87
-rw-r--r--test/chan/fifo.go56
-rw-r--r--test/chan/goroutines.go41
-rw-r--r--test/chan/nonblock.go282
-rw-r--r--test/chan/perm.go70
-rw-r--r--test/chan/powser1.go741
-rw-r--r--test/chan/powser2.go755
-rw-r--r--test/chan/select.go58
-rw-r--r--test/chan/select2.go54
-rw-r--r--test/chan/select3.go226
-rw-r--r--test/chan/select4.go31
-rw-r--r--test/chan/select5.go481
-rw-r--r--test/chan/select6.go34
-rw-r--r--test/chan/select7.go68
-rw-r--r--test/chan/select8.go55
-rw-r--r--test/chan/sendstmt.go37
-rw-r--r--test/chan/sieve1.go56
-rw-r--r--test/chan/sieve2.go188
-rw-r--r--test/chan/zerosize.go16
19 files changed, 3336 insertions, 0 deletions
diff --git a/test/chan/doubleselect.go b/test/chan/doubleselect.go
new file mode 100644
index 0000000..ff69dbe
--- /dev/null
+++ b/test/chan/doubleselect.go
@@ -0,0 +1,87 @@
+// run
+
+// Copyright 2009 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.
+
+// Test the situation in which two cases of a select can
+// both end up running. See http://codereview.appspot.com/180068.
+
+package main
+
+import (
+ "flag"
+ "runtime"
+)
+
+var iterations *int = flag.Int("n", 100000, "number of iterations")
+
+// sender sends a counter to one of four different channels. If two
+// cases both end up running in the same iteration, the same value will be sent
+// to two different channels.
+func sender(n int, c1, c2, c3, c4 chan<- int) {
+ defer close(c1)
+ defer close(c2)
+ defer close(c3)
+ defer close(c4)
+
+ for i := 0; i < n; i++ {
+ select {
+ case c1 <- i:
+ case c2 <- i:
+ case c3 <- i:
+ case c4 <- i:
+ }
+ }
+}
+
+// mux receives the values from sender and forwards them onto another channel.
+// It would be simpler to just have sender's four cases all be the same
+// channel, but this doesn't actually trigger the bug.
+func mux(out chan<- int, in <-chan int, done chan<- bool) {
+ for v := range in {
+ out <- v
+ }
+ done <- true
+}
+
+// recver gets a steam of values from the four mux's and checks for duplicates.
+func recver(in <-chan int) {
+ seen := make(map[int]bool)
+
+ for v := range in {
+ if _, ok := seen[v]; ok {
+ println("got duplicate value: ", v)
+ panic("fail")
+ }
+ seen[v] = true
+ }
+}
+
+func main() {
+ runtime.GOMAXPROCS(2)
+
+ flag.Parse()
+ c1 := make(chan int)
+ c2 := make(chan int)
+ c3 := make(chan int)
+ c4 := make(chan int)
+ done := make(chan bool)
+ cmux := make(chan int)
+ go sender(*iterations, c1, c2, c3, c4)
+ go mux(cmux, c1, done)
+ go mux(cmux, c2, done)
+ go mux(cmux, c3, done)
+ go mux(cmux, c4, done)
+ go func() {
+ <-done
+ <-done
+ <-done
+ <-done
+ close(cmux)
+ }()
+ // We keep the recver because it might catch more bugs in the future.
+ // However, the result of the bug linked to at the top is that we'll
+ // end up panicking with: "throw: bad g->status in ready".
+ recver(cmux)
+}
diff --git a/test/chan/fifo.go b/test/chan/fifo.go
new file mode 100644
index 0000000..0001bcf
--- /dev/null
+++ b/test/chan/fifo.go
@@ -0,0 +1,56 @@
+// run
+
+// Copyright 2009 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.
+
+// Test that unbuffered channels act as pure fifos.
+
+package main
+
+import "os"
+
+const N = 10
+
+func AsynchFifo() {
+ ch := make(chan int, N)
+ for i := 0; i < N; i++ {
+ ch <- i
+ }
+ for i := 0; i < N; i++ {
+ if <-ch != i {
+ print("bad receive\n")
+ os.Exit(1)
+ }
+ }
+}
+
+func Chain(ch <-chan int, val int, in <-chan int, out chan<- int) {
+ <-in
+ if <-ch != val {
+ panic(val)
+ }
+ out <- 1
+}
+
+// thread together a daisy chain to read the elements in sequence
+func SynchFifo() {
+ ch := make(chan int)
+ in := make(chan int)
+ start := in
+ for i := 0; i < N; i++ {
+ out := make(chan int)
+ go Chain(ch, i, in, out)
+ in = out
+ }
+ start <- 0
+ for i := 0; i < N; i++ {
+ ch <- i
+ }
+ <-in
+}
+
+func main() {
+ AsynchFifo()
+ SynchFifo()
+}
diff --git a/test/chan/goroutines.go b/test/chan/goroutines.go
new file mode 100644
index 0000000..6ffae7d
--- /dev/null
+++ b/test/chan/goroutines.go
@@ -0,0 +1,41 @@
+// run
+
+// Copyright 2009 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.
+
+// Torture test for goroutines.
+// Make a lot of goroutines, threaded together, and tear them down cleanly.
+
+package main
+
+import (
+ "os"
+ "strconv"
+)
+
+func f(left, right chan int) {
+ left <- <-right
+}
+
+func main() {
+ var n = 10000
+ if len(os.Args) > 1 {
+ var err error
+ n, err = strconv.Atoi(os.Args[1])
+ if err != nil {
+ print("bad arg\n")
+ os.Exit(1)
+ }
+ }
+ leftmost := make(chan int)
+ right := leftmost
+ left := leftmost
+ for i := 0; i < n; i++ {
+ right = make(chan int)
+ go f(left, right)
+ left = right
+ }
+ go func(c chan int) { c <- 1 }(right)
+ <-leftmost
+}
diff --git a/test/chan/nonblock.go b/test/chan/nonblock.go
new file mode 100644
index 0000000..7e3c0c7
--- /dev/null
+++ b/test/chan/nonblock.go
@@ -0,0 +1,282 @@
+// run
+
+// Copyright 2009 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.
+
+// Test channel operations that test for blocking.
+// Use several sizes and types of operands.
+
+package main
+
+import "runtime"
+import "time"
+
+func i32receiver(c chan int32, strobe chan bool) {
+ if <-c != 123 {
+ panic("i32 value")
+ }
+ strobe <- true
+}
+
+func i32sender(c chan int32, strobe chan bool) {
+ c <- 234
+ strobe <- true
+}
+
+func i64receiver(c chan int64, strobe chan bool) {
+ if <-c != 123456 {
+ panic("i64 value")
+ }
+ strobe <- true
+}
+
+func i64sender(c chan int64, strobe chan bool) {
+ c <- 234567
+ strobe <- true
+}
+
+func breceiver(c chan bool, strobe chan bool) {
+ if !<-c {
+ panic("b value")
+ }
+ strobe <- true
+}
+
+func bsender(c chan bool, strobe chan bool) {
+ c <- true
+ strobe <- true
+}
+
+func sreceiver(c chan string, strobe chan bool) {
+ if <-c != "hello" {
+ panic("s value")
+ }
+ strobe <- true
+}
+
+func ssender(c chan string, strobe chan bool) {
+ c <- "hello again"
+ strobe <- true
+}
+
+var ticker = time.Tick(10 * 1000) // 10 us
+func sleep() {
+ <-ticker
+ <-ticker
+ runtime.Gosched()
+ runtime.Gosched()
+ runtime.Gosched()
+}
+
+const maxTries = 10000 // Up to 100ms per test.
+
+func main() {
+ var i32 int32
+ var i64 int64
+ var b bool
+ var s string
+
+ var sync = make(chan bool)
+
+ for buffer := 0; buffer < 2; buffer++ {
+ c32 := make(chan int32, buffer)
+ c64 := make(chan int64, buffer)
+ cb := make(chan bool, buffer)
+ cs := make(chan string, buffer)
+
+ select {
+ case i32 = <-c32:
+ panic("blocked i32sender")
+ default:
+ }
+
+ select {
+ case i64 = <-c64:
+ panic("blocked i64sender")
+ default:
+ }
+
+ select {
+ case b = <-cb:
+ panic("blocked bsender")
+ default:
+ }
+
+ select {
+ case s = <-cs:
+ panic("blocked ssender")
+ default:
+ }
+
+ go i32receiver(c32, sync)
+ try := 0
+ Send32:
+ for {
+ select {
+ case c32 <- 123:
+ break Send32
+ default:
+ try++
+ if try > maxTries {
+ println("i32receiver buffer=", buffer)
+ panic("fail")
+ }
+ sleep()
+ }
+ }
+ <-sync
+
+ go i32sender(c32, sync)
+ if buffer > 0 {
+ <-sync
+ }
+ try = 0
+ Recv32:
+ for {
+ select {
+ case i32 = <-c32:
+ break Recv32
+ default:
+ try++
+ if try > maxTries {
+ println("i32sender buffer=", buffer)
+ panic("fail")
+ }
+ sleep()
+ }
+ }
+ if i32 != 234 {
+ panic("i32sender value")
+ }
+ if buffer == 0 {
+ <-sync
+ }
+
+ go i64receiver(c64, sync)
+ try = 0
+ Send64:
+ for {
+ select {
+ case c64 <- 123456:
+ break Send64
+ default:
+ try++
+ if try > maxTries {
+ panic("i64receiver")
+ }
+ sleep()
+ }
+ }
+ <-sync
+
+ go i64sender(c64, sync)
+ if buffer > 0 {
+ <-sync
+ }
+ try = 0
+ Recv64:
+ for {
+ select {
+ case i64 = <-c64:
+ break Recv64
+ default:
+ try++
+ if try > maxTries {
+ panic("i64sender")
+ }
+ sleep()
+ }
+ }
+ if i64 != 234567 {
+ panic("i64sender value")
+ }
+ if buffer == 0 {
+ <-sync
+ }
+
+ go breceiver(cb, sync)
+ try = 0
+ SendBool:
+ for {
+ select {
+ case cb <- true:
+ break SendBool
+ default:
+ try++
+ if try > maxTries {
+ panic("breceiver")
+ }
+ sleep()
+ }
+ }
+ <-sync
+
+ go bsender(cb, sync)
+ if buffer > 0 {
+ <-sync
+ }
+ try = 0
+ RecvBool:
+ for {
+ select {
+ case b = <-cb:
+ break RecvBool
+ default:
+ try++
+ if try > maxTries {
+ panic("bsender")
+ }
+ sleep()
+ }
+ }
+ if !b {
+ panic("bsender value")
+ }
+ if buffer == 0 {
+ <-sync
+ }
+
+ go sreceiver(cs, sync)
+ try = 0
+ SendString:
+ for {
+ select {
+ case cs <- "hello":
+ break SendString
+ default:
+ try++
+ if try > maxTries {
+ panic("sreceiver")
+ }
+ sleep()
+ }
+ }
+ <-sync
+
+ go ssender(cs, sync)
+ if buffer > 0 {
+ <-sync
+ }
+ try = 0
+ RecvString:
+ for {
+ select {
+ case s = <-cs:
+ break RecvString
+ default:
+ try++
+ if try > maxTries {
+ panic("ssender")
+ }
+ sleep()
+ }
+ }
+ if s != "hello again" {
+ panic("ssender value")
+ }
+ if buffer == 0 {
+ <-sync
+ }
+ }
+}
diff --git a/test/chan/perm.go b/test/chan/perm.go
new file mode 100644
index 0000000..4c94ab7
--- /dev/null
+++ b/test/chan/perm.go
@@ -0,0 +1,70 @@
+// errorcheck
+
+// Copyright 2009 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.
+
+// Test various correct and incorrect permutations of send-only,
+// receive-only, and bidirectional channels.
+// Does not compile.
+
+package main
+
+var (
+ cr <-chan int
+ cs chan<- int
+ c chan int
+)
+
+func main() {
+ cr = c // ok
+ cs = c // ok
+ c = cr // ERROR "illegal types|incompatible|cannot"
+ c = cs // ERROR "illegal types|incompatible|cannot"
+ cr = cs // ERROR "illegal types|incompatible|cannot"
+ cs = cr // ERROR "illegal types|incompatible|cannot"
+
+ var n int
+ <-n // ERROR "receive from non-chan|expected channel"
+ n <- 2 // ERROR "send to non-chan|must be channel"
+
+ c <- 0 // ok
+ <-c // ok
+ x, ok := <-c // ok
+ _, _ = x, ok
+
+ cr <- 0 // ERROR "send"
+ <-cr // ok
+ x, ok = <-cr // ok
+ _, _ = x, ok
+
+ cs <- 0 // ok
+ <-cs // ERROR "receive"
+ x, ok = <-cs // ERROR "receive"
+ _, _ = x, ok
+
+ select {
+ case c <- 0: // ok
+ case x := <-c: // ok
+ _ = x
+
+ case cr <- 0: // ERROR "send"
+ case x := <-cr: // ok
+ _ = x
+
+ case cs <- 0: // ok
+ case x := <-cs: // ERROR "receive"
+ _ = x
+ }
+
+ for _ = range cs { // ERROR "receive"
+ }
+
+ for range cs { // ERROR "receive"
+ }
+
+ close(c)
+ close(cs)
+ close(cr) // ERROR "receive"
+ close(n) // ERROR "invalid operation.*non-chan type|must be channel|not a channel"
+}
diff --git a/test/chan/powser1.go b/test/chan/powser1.go
new file mode 100644
index 0000000..e999dde
--- /dev/null
+++ b/test/chan/powser1.go
@@ -0,0 +1,741 @@
+// run
+
+// Copyright 2009 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.
+
+// Test concurrency primitives: power series.
+
+// Power series package
+// A power series is a channel, along which flow rational
+// coefficients. A denominator of zero signifies the end.
+// Original code in Newsqueak by Doug McIlroy.
+// See Squinting at Power Series by Doug McIlroy,
+// https://swtch.com/~rsc/thread/squint.pdf
+
+package main
+
+import "os"
+
+type rat struct {
+ num, den int64 // numerator, denominator
+}
+
+func (u rat) pr() {
+ if u.den == 1 {
+ print(u.num)
+ } else {
+ print(u.num, "/", u.den)
+ }
+ print(" ")
+}
+
+func (u rat) eq(c rat) bool {
+ return u.num == c.num && u.den == c.den
+}
+
+type dch struct {
+ req chan int
+ dat chan rat
+ nam int
+}
+
+type dch2 [2]*dch
+
+var chnames string
+var chnameserial int
+var seqno int
+
+func mkdch() *dch {
+ c := chnameserial % len(chnames)
+ chnameserial++
+ d := new(dch)
+ d.req = make(chan int)
+ d.dat = make(chan rat)
+ d.nam = c
+ return d
+}
+
+func mkdch2() *dch2 {
+ d2 := new(dch2)
+ d2[0] = mkdch()
+ d2[1] = mkdch()
+ return d2
+}
+
+// split reads a single demand channel and replicates its
+// output onto two, which may be read at different rates.
+// A process is created at first demand for a rat and dies
+// after the rat has been sent to both outputs.
+
+// When multiple generations of split exist, the newest
+// will service requests on one channel, which is
+// always renamed to be out[0]; the oldest will service
+// requests on the other channel, out[1]. All generations but the
+// newest hold queued data that has already been sent to
+// out[0]. When data has finally been sent to out[1],
+// a signal on the release-wait channel tells the next newer
+// generation to begin servicing out[1].
+
+func dosplit(in *dch, out *dch2, wait chan int) {
+ both := false // do not service both channels
+
+ select {
+ case <-out[0].req:
+
+ case <-wait:
+ both = true
+ select {
+ case <-out[0].req:
+
+ case <-out[1].req:
+ out[0], out[1] = out[1], out[0]
+ }
+ }
+
+ seqno++
+ in.req <- seqno
+ release := make(chan int)
+ go dosplit(in, out, release)
+ dat := <-in.dat
+ out[0].dat <- dat
+ if !both {
+ <-wait
+ }
+ <-out[1].req
+ out[1].dat <- dat
+ release <- 0
+}
+
+func split(in *dch, out *dch2) {
+ release := make(chan int)
+ go dosplit(in, out, release)
+ release <- 0
+}
+
+func put(dat rat, out *dch) {
+ <-out.req
+ out.dat <- dat
+}
+
+func get(in *dch) rat {
+ seqno++
+ in.req <- seqno
+ return <-in.dat
+}
+
+// Get one rat from each of n demand channels
+
+func getn(in []*dch) []rat {
+ n := len(in)
+ if n != 2 {
+ panic("bad n in getn")
+ }
+ req := new([2]chan int)
+ dat := new([2]chan rat)
+ out := make([]rat, 2)
+ var i int
+ var it rat
+ for i = 0; i < n; i++ {
+ req[i] = in[i].req
+ dat[i] = nil
+ }
+ for n = 2 * n; n > 0; n-- {
+ seqno++
+
+ select {
+ case req[0] <- seqno:
+ dat[0] = in[0].dat
+ req[0] = nil
+ case req[1] <- seqno:
+ dat[1] = in[1].dat
+ req[1] = nil
+ case it = <-dat[0]:
+ out[0] = it
+ dat[0] = nil
+ case it = <-dat[1]:
+ out[1] = it
+ dat[1] = nil
+ }
+ }
+ return out
+}
+
+// Get one rat from each of 2 demand channels
+
+func get2(in0 *dch, in1 *dch) []rat {
+ return getn([]*dch{in0, in1})
+}
+
+func copy(in *dch, out *dch) {
+ for {
+ <-out.req
+ out.dat <- get(in)
+ }
+}
+
+func repeat(dat rat, out *dch) {
+ for {
+ put(dat, out)
+ }
+}
+
+type PS *dch // power series
+type PS2 *[2]PS // pair of power series
+
+var Ones PS
+var Twos PS
+
+func mkPS() *dch {
+ return mkdch()
+}
+
+func mkPS2() *dch2 {
+ return mkdch2()
+}
+
+// Conventions
+// Upper-case for power series.
+// Lower-case for rationals.
+// Input variables: U,V,...
+// Output variables: ...,Y,Z
+
+// Integer gcd; needed for rational arithmetic
+
+func gcd(u, v int64) int64 {
+ if u < 0 {
+ return gcd(-u, v)
+ }
+ if u == 0 {
+ return v
+ }
+ return gcd(v%u, u)
+}
+
+// Make a rational from two ints and from one int
+
+func i2tor(u, v int64) rat {
+ g := gcd(u, v)
+ var r rat
+ if v > 0 {
+ r.num = u / g
+ r.den = v / g
+ } else {
+ r.num = -u / g
+ r.den = -v / g
+ }
+ return r
+}
+
+func itor(u int64) rat {
+ return i2tor(u, 1)
+}
+
+var zero rat
+var one rat
+
+// End mark and end test
+
+var finis rat
+
+func end(u rat) int64 {
+ if u.den == 0 {
+ return 1
+ }
+ return 0
+}
+
+// Operations on rationals
+
+func add(u, v rat) rat {
+ g := gcd(u.den, v.den)
+ return i2tor(u.num*(v.den/g)+v.num*(u.den/g), u.den*(v.den/g))
+}
+
+func mul(u, v rat) rat {
+ g1 := gcd(u.num, v.den)
+ g2 := gcd(u.den, v.num)
+ var r rat
+ r.num = (u.num / g1) * (v.num / g2)
+ r.den = (u.den / g2) * (v.den / g1)
+ return r
+}
+
+func neg(u rat) rat {
+ return i2tor(-u.num, u.den)
+}
+
+func sub(u, v rat) rat {
+ return add(u, neg(v))
+}
+
+func inv(u rat) rat { // invert a rat
+ if u.num == 0 {
+ panic("zero divide in inv")
+ }
+ return i2tor(u.den, u.num)
+}
+
+// print eval in floating point of PS at x=c to n terms
+func evaln(c rat, U PS, n int) {
+ xn := float64(1)
+ x := float64(c.num) / float64(c.den)
+ val := float64(0)
+ for i := 0; i < n; i++ {
+ u := get(U)
+ if end(u) != 0 {
+ break
+ }
+ val = val + x*float64(u.num)/float64(u.den)
+ xn = xn * x
+ }
+ print(val, "\n")
+}
+
+// Print n terms of a power series
+func printn(U PS, n int) {
+ done := false
+ for ; !done && n > 0; n-- {
+ u := get(U)
+ if end(u) != 0 {
+ done = true
+ } else {
+ u.pr()
+ }
+ }
+ print(("\n"))
+}
+
+// Evaluate n terms of power series U at x=c
+func eval(c rat, U PS, n int) rat {
+ if n == 0 {
+ return zero
+ }
+ y := get(U)
+ if end(y) != 0 {
+ return zero
+ }
+ return add(y, mul(c, eval(c, U, n-1)))
+}
+
+// Power-series constructors return channels on which power
+// series flow. They start an encapsulated generator that
+// puts the terms of the series on the channel.
+
+// Make a pair of power series identical to a given power series
+
+func Split(U PS) *dch2 {
+ UU := mkdch2()
+ go split(U, UU)
+ return UU
+}
+
+// Add two power series
+func Add(U, V PS) PS {
+ Z := mkPS()
+ go func() {
+ var uv []rat
+ for {
+ <-Z.req
+ uv = get2(U, V)
+ switch end(uv[0]) + 2*end(uv[1]) {
+ case 0:
+ Z.dat <- add(uv[0], uv[1])
+ case 1:
+ Z.dat <- uv[1]
+ copy(V, Z)
+ case 2:
+ Z.dat <- uv[0]
+ copy(U, Z)
+ case 3:
+ Z.dat <- finis
+ }
+ }
+ }()
+ return Z
+}
+
+// Multiply a power series by a constant
+func Cmul(c rat, U PS) PS {
+ Z := mkPS()
+ go func() {
+ done := false
+ for !done {
+ <-Z.req
+ u := get(U)
+ if end(u) != 0 {
+ done = true
+ } else {
+ Z.dat <- mul(c, u)
+ }
+ }
+ Z.dat <- finis
+ }()
+ return Z
+}
+
+// Subtract
+
+func Sub(U, V PS) PS {
+ return Add(U, Cmul(neg(one), V))
+}
+
+// Multiply a power series by the monomial x^n
+
+func Monmul(U PS, n int) PS {
+ Z := mkPS()
+ go func() {
+ for ; n > 0; n-- {
+ put(zero, Z)
+ }
+ copy(U, Z)
+ }()
+ return Z
+}
+
+// Multiply by x
+
+func Xmul(U PS) PS {
+ return Monmul(U, 1)
+}
+
+func Rep(c rat) PS {
+ Z := mkPS()
+ go repeat(c, Z)
+ return Z
+}
+
+// Monomial c*x^n
+
+func Mon(c rat, n int) PS {
+ Z := mkPS()
+ go func() {
+ if c.num != 0 {
+ for ; n > 0; n = n - 1 {
+ put(zero, Z)
+ }
+ put(c, Z)
+ }
+ put(finis, Z)
+ }()
+ return Z
+}
+
+func Shift(c rat, U PS) PS {
+ Z := mkPS()
+ go func() {
+ put(c, Z)
+ copy(U, Z)
+ }()
+ return Z
+}
+
+// simple pole at 1: 1/(1-x) = 1 1 1 1 1 ...
+
+// Convert array of coefficients, constant term first
+// to a (finite) power series
+
+/*
+func Poly(a []rat) PS {
+ Z:=mkPS()
+ begin func(a []rat, Z PS) {
+ j:=0
+ done:=0
+ for j=len(a); !done&&j>0; j=j-1)
+ if(a[j-1].num!=0) done=1
+ i:=0
+ for(; i<j; i=i+1) put(a[i],Z)
+ put(finis,Z)
+ }()
+ return Z
+}
+*/
+
+// Multiply. The algorithm is
+// let U = u + x*UU
+// let V = v + x*VV
+// then UV = u*v + x*(u*VV+v*UU) + x*x*UU*VV
+
+func Mul(U, V PS) PS {
+ Z := mkPS()
+ go func() {
+ <-Z.req
+ uv := get2(U, V)
+ if end(uv[0]) != 0 || end(uv[1]) != 0 {
+ Z.dat <- finis
+ } else {
+ Z.dat <- mul(uv[0], uv[1])
+ UU := Split(U)
+ VV := Split(V)
+ W := Add(Cmul(uv[0], VV[0]), Cmul(uv[1], UU[0]))
+ <-Z.req
+ Z.dat <- get(W)
+ copy(Add(W, Mul(UU[1], VV[1])), Z)
+ }
+ }()
+ return Z
+}
+
+// Differentiate
+
+func Diff(U PS) PS {
+ Z := mkPS()
+ go func() {
+ <-Z.req
+ u := get(U)
+ if end(u) == 0 {
+ done := false
+ for i := 1; !done; i++ {
+ u = get(U)
+ if end(u) != 0 {
+ done = true
+ } else {
+ Z.dat <- mul(itor(int64(i)), u)
+ <-Z.req
+ }
+ }
+ }
+ Z.dat <- finis
+ }()
+ return Z
+}
+
+// Integrate, with const of integration
+func Integ(c rat, U PS) PS {
+ Z := mkPS()
+ go func() {
+ put(c, Z)
+ done := false
+ for i := 1; !done; i++ {
+ <-Z.req
+ u := get(U)
+ if end(u) != 0 {
+ done = true
+ }
+ Z.dat <- mul(i2tor(1, int64(i)), u)
+ }
+ Z.dat <- finis
+ }()
+ return Z
+}
+
+// Binomial theorem (1+x)^c
+
+func Binom(c rat) PS {
+ Z := mkPS()
+ go func() {
+ n := 1
+ t := itor(1)
+ for c.num != 0 {
+ put(t, Z)
+ t = mul(mul(t, c), i2tor(1, int64(n)))
+ c = sub(c, one)
+ n++
+ }
+ put(finis, Z)
+ }()
+ return Z
+}
+
+// Reciprocal of a power series
+// let U = u + x*UU
+// let Z = z + x*ZZ
+// (u+x*UU)*(z+x*ZZ) = 1
+// z = 1/u
+// u*ZZ + z*UU +x*UU*ZZ = 0
+// ZZ = -UU*(z+x*ZZ)/u
+
+func Recip(U PS) PS {
+ Z := mkPS()
+ go func() {
+ ZZ := mkPS2()
+ <-Z.req
+ z := inv(get(U))
+ Z.dat <- z
+ split(Mul(Cmul(neg(z), U), Shift(z, ZZ[0])), ZZ)
+ copy(ZZ[1], Z)
+ }()
+ return Z
+}
+
+// Exponential of a power series with constant term 0
+// (nonzero constant term would make nonrational coefficients)
+// bug: the constant term is simply ignored
+// Z = exp(U)
+// DZ = Z*DU
+// integrate to get Z
+
+func Exp(U PS) PS {
+ ZZ := mkPS2()
+ split(Integ(one, Mul(ZZ[0], Diff(U))), ZZ)
+ return ZZ[1]
+}
+
+// Substitute V for x in U, where the leading term of V is zero
+// let U = u + x*UU
+// let V = v + x*VV
+// then S(U,V) = u + VV*S(V,UU)
+// bug: a nonzero constant term is ignored
+
+func Subst(U, V PS) PS {
+ Z := mkPS()
+ go func() {
+ VV := Split(V)
+ <-Z.req
+ u := get(U)
+ Z.dat <- u
+ if end(u) == 0 {
+ if end(get(VV[0])) != 0 {
+ put(finis, Z)
+ } else {
+ copy(Mul(VV[0], Subst(U, VV[1])), Z)
+ }
+ }
+ }()
+ return Z
+}
+
+// Monomial Substitution: U(c x^n)
+// Each Ui is multiplied by c^i and followed by n-1 zeros
+
+func MonSubst(U PS, c0 rat, n int) PS {
+ Z := mkPS()
+ go func() {
+ c := one
+ for {
+ <-Z.req
+ u := get(U)
+ Z.dat <- mul(u, c)
+ c = mul(c, c0)
+ if end(u) != 0 {
+ Z.dat <- finis
+ break
+ }
+ for i := 1; i < n; i++ {
+ <-Z.req
+ Z.dat <- zero
+ }
+ }
+ }()
+ return Z
+}
+
+func Init() {
+ chnameserial = -1
+ seqno = 0
+ chnames = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz"
+ zero = itor(0)
+ one = itor(1)
+ finis = i2tor(1, 0)
+ Ones = Rep(one)
+ Twos = Rep(itor(2))
+}
+
+func check(U PS, c rat, count int, str string) {
+ for i := 0; i < count; i++ {
+ r := get(U)
+ if !r.eq(c) {
+ print("got: ")
+ r.pr()
+ print("should get ")
+ c.pr()
+ print("\n")
+ panic(str)
+ }
+ }
+}
+
+const N = 10
+
+func checka(U PS, a []rat, str string) {
+ for i := 0; i < N; i++ {
+ check(U, a[i], 1, str)
+ }
+}
+
+func main() {
+ Init()
+ if len(os.Args) > 1 { // print
+ print("Ones: ")
+ printn(Ones, 10)
+ print("Twos: ")
+ printn(Twos, 10)
+ print("Add: ")
+ printn(Add(Ones, Twos), 10)
+ print("Diff: ")
+ printn(Diff(Ones), 10)
+ print("Integ: ")
+ printn(Integ(zero, Ones), 10)
+ print("CMul: ")
+ printn(Cmul(neg(one), Ones), 10)
+ print("Sub: ")
+ printn(Sub(Ones, Twos), 10)
+ print("Mul: ")
+ printn(Mul(Ones, Ones), 10)
+ print("Exp: ")
+ printn(Exp(Ones), 15)
+ print("MonSubst: ")
+ printn(MonSubst(Ones, neg(one), 2), 10)
+ print("ATan: ")
+ printn(Integ(zero, MonSubst(Ones, neg(one), 2)), 10)
+ } else { // test
+ check(Ones, one, 5, "Ones")
+ check(Add(Ones, Ones), itor(2), 0, "Add Ones Ones") // 1 1 1 1 1
+ check(Add(Ones, Twos), itor(3), 0, "Add Ones Twos") // 3 3 3 3 3
+ a := make([]rat, N)
+ d := Diff(Ones)
+ for i := 0; i < N; i++ {
+ a[i] = itor(int64(i + 1))
+ }
+ checka(d, a, "Diff") // 1 2 3 4 5
+ in := Integ(zero, Ones)
+ a[0] = zero // integration constant
+ for i := 1; i < N; i++ {
+ a[i] = i2tor(1, int64(i))
+ }
+ checka(in, a, "Integ") // 0 1 1/2 1/3 1/4 1/5
+ check(Cmul(neg(one), Twos), itor(-2), 10, "CMul") // -1 -1 -1 -1 -1
+ check(Sub(Ones, Twos), itor(-1), 0, "Sub Ones Twos") // -1 -1 -1 -1 -1
+ m := Mul(Ones, Ones)
+ for i := 0; i < N; i++ {
+ a[i] = itor(int64(i + 1))
+ }
+ checka(m, a, "Mul") // 1 2 3 4 5
+ e := Exp(Ones)
+ a[0] = itor(1)
+ a[1] = itor(1)
+ a[2] = i2tor(3, 2)
+ a[3] = i2tor(13, 6)
+ a[4] = i2tor(73, 24)
+ a[5] = i2tor(167, 40)
+ a[6] = i2tor(4051, 720)
+ a[7] = i2tor(37633, 5040)
+ a[8] = i2tor(43817, 4480)
+ a[9] = i2tor(4596553, 362880)
+ checka(e, a, "Exp") // 1 1 3/2 13/6 73/24
+ at := Integ(zero, MonSubst(Ones, neg(one), 2))
+ for c, i := 1, 0; i < N; i++ {
+ if i%2 == 0 {
+ a[i] = zero
+ } else {
+ a[i] = i2tor(int64(c), int64(i))
+ c *= -1
+ }
+ }
+ checka(at, a, "ATan") // 0 -1 0 -1/3 0 -1/5
+ /*
+ t := Revert(Integ(zero, MonSubst(Ones, neg(one), 2)))
+ a[0] = zero
+ a[1] = itor(1)
+ a[2] = zero
+ a[3] = i2tor(1,3)
+ a[4] = zero
+ a[5] = i2tor(2,15)
+ a[6] = zero
+ a[7] = i2tor(17,315)
+ a[8] = zero
+ a[9] = i2tor(62,2835)
+ checka(t, a, "Tan") // 0 1 0 1/3 0 2/15
+ */
+ }
+}
diff --git a/test/chan/powser2.go b/test/chan/powser2.go
new file mode 100644
index 0000000..72cbba8
--- /dev/null
+++ b/test/chan/powser2.go
@@ -0,0 +1,755 @@
+// run
+
+// Copyright 2009 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.
+
+// Test concurrency primitives: power series.
+
+// Like powser1.go but uses channels of interfaces.
+// Has not been cleaned up as much as powser1.go, to keep
+// it distinct and therefore a different test.
+
+// Power series package
+// A power series is a channel, along which flow rational
+// coefficients. A denominator of zero signifies the end.
+// Original code in Newsqueak by Doug McIlroy.
+// See Squinting at Power Series by Doug McIlroy,
+// https://swtch.com/~rsc/thread/squint.pdf
+
+package main
+
+import "os"
+
+type rat struct {
+ num, den int64 // numerator, denominator
+}
+
+type item interface {
+ pr()
+ eq(c item) bool
+}
+
+func (u *rat) pr() {
+ if u.den == 1 {
+ print(u.num)
+ } else {
+ print(u.num, "/", u.den)
+ }
+ print(" ")
+}
+
+func (u *rat) eq(c item) bool {
+ c1 := c.(*rat)
+ return u.num == c1.num && u.den == c1.den
+}
+
+type dch struct {
+ req chan int
+ dat chan item
+ nam int
+}
+
+type dch2 [2]*dch
+
+var chnames string
+var chnameserial int
+var seqno int
+
+func mkdch() *dch {
+ c := chnameserial % len(chnames)
+ chnameserial++
+ d := new(dch)
+ d.req = make(chan int)
+ d.dat = make(chan item)
+ d.nam = c
+ return d
+}
+
+func mkdch2() *dch2 {
+ d2 := new(dch2)
+ d2[0] = mkdch()
+ d2[1] = mkdch()
+ return d2
+}
+
+// split reads a single demand channel and replicates its
+// output onto two, which may be read at different rates.
+// A process is created at first demand for an item and dies
+// after the item has been sent to both outputs.
+
+// When multiple generations of split exist, the newest
+// will service requests on one channel, which is
+// always renamed to be out[0]; the oldest will service
+// requests on the other channel, out[1]. All generations but the
+// newest hold queued data that has already been sent to
+// out[0]. When data has finally been sent to out[1],
+// a signal on the release-wait channel tells the next newer
+// generation to begin servicing out[1].
+
+func dosplit(in *dch, out *dch2, wait chan int) {
+ both := false // do not service both channels
+
+ select {
+ case <-out[0].req:
+
+ case <-wait:
+ both = true
+ select {
+ case <-out[0].req:
+
+ case <-out[1].req:
+ out[0], out[1] = out[1], out[0]
+ }
+ }
+
+ seqno++
+ in.req <- seqno
+ release := make(chan int)
+ go dosplit(in, out, release)
+ dat := <-in.dat
+ out[0].dat <- dat
+ if !both {
+ <-wait
+ }
+ <-out[1].req
+ out[1].dat <- dat
+ release <- 0
+}
+
+func split(in *dch, out *dch2) {
+ release := make(chan int)
+ go dosplit(in, out, release)
+ release <- 0
+}
+
+func put(dat item, out *dch) {
+ <-out.req
+ out.dat <- dat
+}
+
+func get(in *dch) *rat {
+ seqno++
+ in.req <- seqno
+ return (<-in.dat).(*rat)
+}
+
+// Get one item from each of n demand channels
+
+func getn(in []*dch) []item {
+ n := len(in)
+ if n != 2 {
+ panic("bad n in getn")
+ }
+ req := make([]chan int, 2)
+ dat := make([]chan item, 2)
+ out := make([]item, 2)
+ var i int
+ var it item
+ for i = 0; i < n; i++ {
+ req[i] = in[i].req
+ dat[i] = nil
+ }
+ for n = 2 * n; n > 0; n-- {
+ seqno++
+
+ select {
+ case req[0] <- seqno:
+ dat[0] = in[0].dat
+ req[0] = nil
+ case req[1] <- seqno:
+ dat[1] = in[1].dat
+ req[1] = nil
+ case it = <-dat[0]:
+ out[0] = it
+ dat[0] = nil
+ case it = <-dat[1]:
+ out[1] = it
+ dat[1] = nil
+ }
+ }
+ return out
+}
+
+// Get one item from each of 2 demand channels
+
+func get2(in0 *dch, in1 *dch) []item {
+ return getn([]*dch{in0, in1})
+}
+
+func copy(in *dch, out *dch) {
+ for {
+ <-out.req
+ out.dat <- get(in)
+ }
+}
+
+func repeat(dat item, out *dch) {
+ for {
+ put(dat, out)
+ }
+}
+
+type PS *dch // power series
+type PS2 *[2]PS // pair of power series
+
+var Ones PS
+var Twos PS
+
+func mkPS() *dch {
+ return mkdch()
+}
+
+func mkPS2() *dch2 {
+ return mkdch2()
+}
+
+// Conventions
+// Upper-case for power series.
+// Lower-case for rationals.
+// Input variables: U,V,...
+// Output variables: ...,Y,Z
+
+// Integer gcd; needed for rational arithmetic
+
+func gcd(u, v int64) int64 {
+ if u < 0 {
+ return gcd(-u, v)
+ }
+ if u == 0 {
+ return v
+ }
+ return gcd(v%u, u)
+}
+
+// Make a rational from two ints and from one int
+
+func i2tor(u, v int64) *rat {
+ g := gcd(u, v)
+ r := new(rat)
+ if v > 0 {
+ r.num = u / g
+ r.den = v / g
+ } else {
+ r.num = -u / g
+ r.den = -v / g
+ }
+ return r
+}
+
+func itor(u int64) *rat {
+ return i2tor(u, 1)
+}
+
+var zero *rat
+var one *rat
+
+// End mark and end test
+
+var finis *rat
+
+func end(u *rat) int64 {
+ if u.den == 0 {
+ return 1
+ }
+ return 0
+}
+
+// Operations on rationals
+
+func add(u, v *rat) *rat {
+ g := gcd(u.den, v.den)
+ return i2tor(u.num*(v.den/g)+v.num*(u.den/g), u.den*(v.den/g))
+}
+
+func mul(u, v *rat) *rat {
+ g1 := gcd(u.num, v.den)
+ g2 := gcd(u.den, v.num)
+ r := new(rat)
+ r.num = (u.num / g1) * (v.num / g2)
+ r.den = (u.den / g2) * (v.den / g1)
+ return r
+}
+
+func neg(u *rat) *rat {
+ return i2tor(-u.num, u.den)
+}
+
+func sub(u, v *rat) *rat {
+ return add(u, neg(v))
+}
+
+func inv(u *rat) *rat { // invert a rat
+ if u.num == 0 {
+ panic("zero divide in inv")
+ }
+ return i2tor(u.den, u.num)
+}
+
+// print eval in floating point of PS at x=c to n terms
+func Evaln(c *rat, U PS, n int) {
+ xn := float64(1)
+ x := float64(c.num) / float64(c.den)
+ val := float64(0)
+ for i := 0; i < n; i++ {
+ u := get(U)
+ if end(u) != 0 {
+ break
+ }
+ val = val + x*float64(u.num)/float64(u.den)
+ xn = xn * x
+ }
+ print(val, "\n")
+}
+
+// Print n terms of a power series
+func Printn(U PS, n int) {
+ done := false
+ for ; !done && n > 0; n-- {
+ u := get(U)
+ if end(u) != 0 {
+ done = true
+ } else {
+ u.pr()
+ }
+ }
+ print(("\n"))
+}
+
+func Print(U PS) {
+ Printn(U, 1000000000)
+}
+
+// Evaluate n terms of power series U at x=c
+func eval(c *rat, U PS, n int) *rat {
+ if n == 0 {
+ return zero
+ }
+ y := get(U)
+ if end(y) != 0 {
+ return zero
+ }
+ return add(y, mul(c, eval(c, U, n-1)))
+}
+
+// Power-series constructors return channels on which power
+// series flow. They start an encapsulated generator that
+// puts the terms of the series on the channel.
+
+// Make a pair of power series identical to a given power series
+
+func Split(U PS) *dch2 {
+ UU := mkdch2()
+ go split(U, UU)
+ return UU
+}
+
+// Add two power series
+func Add(U, V PS) PS {
+ Z := mkPS()
+ go func(U, V, Z PS) {
+ var uv []item
+ for {
+ <-Z.req
+ uv = get2(U, V)
+ switch end(uv[0].(*rat)) + 2*end(uv[1].(*rat)) {
+ case 0:
+ Z.dat <- add(uv[0].(*rat), uv[1].(*rat))
+ case 1:
+ Z.dat <- uv[1]
+ copy(V, Z)
+ case 2:
+ Z.dat <- uv[0]
+ copy(U, Z)
+ case 3:
+ Z.dat <- finis
+ }
+ }
+ }(U, V, Z)
+ return Z
+}
+
+// Multiply a power series by a constant
+func Cmul(c *rat, U PS) PS {
+ Z := mkPS()
+ go func(c *rat, U, Z PS) {
+ done := false
+ for !done {
+ <-Z.req
+ u := get(U)
+ if end(u) != 0 {
+ done = true
+ } else {
+ Z.dat <- mul(c, u)
+ }
+ }
+ Z.dat <- finis
+ }(c, U, Z)
+ return Z
+}
+
+// Subtract
+
+func Sub(U, V PS) PS {
+ return Add(U, Cmul(neg(one), V))
+}
+
+// Multiply a power series by the monomial x^n
+
+func Monmul(U PS, n int) PS {
+ Z := mkPS()
+ go func(n int, U PS, Z PS) {
+ for ; n > 0; n-- {
+ put(zero, Z)
+ }
+ copy(U, Z)
+ }(n, U, Z)
+ return Z
+}
+
+// Multiply by x
+
+func Xmul(U PS) PS {
+ return Monmul(U, 1)
+}
+
+func Rep(c *rat) PS {
+ Z := mkPS()
+ go repeat(c, Z)
+ return Z
+}
+
+// Monomial c*x^n
+
+func Mon(c *rat, n int) PS {
+ Z := mkPS()
+ go func(c *rat, n int, Z PS) {
+ if c.num != 0 {
+ for ; n > 0; n = n - 1 {
+ put(zero, Z)
+ }
+ put(c, Z)
+ }
+ put(finis, Z)
+ }(c, n, Z)
+ return Z
+}
+
+func Shift(c *rat, U PS) PS {
+ Z := mkPS()
+ go func(c *rat, U, Z PS) {
+ put(c, Z)
+ copy(U, Z)
+ }(c, U, Z)
+ return Z
+}
+
+// simple pole at 1: 1/(1-x) = 1 1 1 1 1 ...
+
+// Convert array of coefficients, constant term first
+// to a (finite) power series
+
+/*
+func Poly(a [] *rat) PS{
+ Z:=mkPS()
+ begin func(a [] *rat, Z PS){
+ j:=0
+ done:=0
+ for j=len(a); !done&&j>0; j=j-1)
+ if(a[j-1].num!=0) done=1
+ i:=0
+ for(; i<j; i=i+1) put(a[i],Z)
+ put(finis,Z)
+ }()
+ return Z
+}
+*/
+
+// Multiply. The algorithm is
+// let U = u + x*UU
+// let V = v + x*VV
+// then UV = u*v + x*(u*VV+v*UU) + x*x*UU*VV
+
+func Mul(U, V PS) PS {
+ Z := mkPS()
+ go func(U, V, Z PS) {
+ <-Z.req
+ uv := get2(U, V)
+ if end(uv[0].(*rat)) != 0 || end(uv[1].(*rat)) != 0 {
+ Z.dat <- finis
+ } else {
+ Z.dat <- mul(uv[0].(*rat), uv[1].(*rat))
+ UU := Split(U)
+ VV := Split(V)
+ W := Add(Cmul(uv[0].(*rat), VV[0]), Cmul(uv[1].(*rat), UU[0]))
+ <-Z.req
+ Z.dat <- get(W)
+ copy(Add(W, Mul(UU[1], VV[1])), Z)
+ }
+ }(U, V, Z)
+ return Z
+}
+
+// Differentiate
+
+func Diff(U PS) PS {
+ Z := mkPS()
+ go func(U, Z PS) {
+ <-Z.req
+ u := get(U)
+ if end(u) == 0 {
+ done := false
+ for i := 1; !done; i++ {
+ u = get(U)
+ if end(u) != 0 {
+ done = true
+ } else {
+ Z.dat <- mul(itor(int64(i)), u)
+ <-Z.req
+ }
+ }
+ }
+ Z.dat <- finis
+ }(U, Z)
+ return Z
+}
+
+// Integrate, with const of integration
+func Integ(c *rat, U PS) PS {
+ Z := mkPS()
+ go func(c *rat, U, Z PS) {
+ put(c, Z)
+ done := false
+ for i := 1; !done; i++ {
+ <-Z.req
+ u := get(U)
+ if end(u) != 0 {
+ done = true
+ }
+ Z.dat <- mul(i2tor(1, int64(i)), u)
+ }
+ Z.dat <- finis
+ }(c, U, Z)
+ return Z
+}
+
+// Binomial theorem (1+x)^c
+
+func Binom(c *rat) PS {
+ Z := mkPS()
+ go func(c *rat, Z PS) {
+ n := 1
+ t := itor(1)
+ for c.num != 0 {
+ put(t, Z)
+ t = mul(mul(t, c), i2tor(1, int64(n)))
+ c = sub(c, one)
+ n++
+ }
+ put(finis, Z)
+ }(c, Z)
+ return Z
+}
+
+// Reciprocal of a power series
+// let U = u + x*UU
+// let Z = z + x*ZZ
+// (u+x*UU)*(z+x*ZZ) = 1
+// z = 1/u
+// u*ZZ + z*UU +x*UU*ZZ = 0
+// ZZ = -UU*(z+x*ZZ)/u
+
+func Recip(U PS) PS {
+ Z := mkPS()
+ go func(U, Z PS) {
+ ZZ := mkPS2()
+ <-Z.req
+ z := inv(get(U))
+ Z.dat <- z
+ split(Mul(Cmul(neg(z), U), Shift(z, ZZ[0])), ZZ)
+ copy(ZZ[1], Z)
+ }(U, Z)
+ return Z
+}
+
+// Exponential of a power series with constant term 0
+// (nonzero constant term would make nonrational coefficients)
+// bug: the constant term is simply ignored
+// Z = exp(U)
+// DZ = Z*DU
+// integrate to get Z
+
+func Exp(U PS) PS {
+ ZZ := mkPS2()
+ split(Integ(one, Mul(ZZ[0], Diff(U))), ZZ)
+ return ZZ[1]
+}
+
+// Substitute V for x in U, where the leading term of V is zero
+// let U = u + x*UU
+// let V = v + x*VV
+// then S(U,V) = u + VV*S(V,UU)
+// bug: a nonzero constant term is ignored
+
+func Subst(U, V PS) PS {
+ Z := mkPS()
+ go func(U, V, Z PS) {
+ VV := Split(V)
+ <-Z.req
+ u := get(U)
+ Z.dat <- u
+ if end(u) == 0 {
+ if end(get(VV[0])) != 0 {
+ put(finis, Z)
+ } else {
+ copy(Mul(VV[0], Subst(U, VV[1])), Z)
+ }
+ }
+ }(U, V, Z)
+ return Z
+}
+
+// Monomial Substitution: U(c x^n)
+// Each Ui is multiplied by c^i and followed by n-1 zeros
+
+func MonSubst(U PS, c0 *rat, n int) PS {
+ Z := mkPS()
+ go func(U, Z PS, c0 *rat, n int) {
+ c := one
+ for {
+ <-Z.req
+ u := get(U)
+ Z.dat <- mul(u, c)
+ c = mul(c, c0)
+ if end(u) != 0 {
+ Z.dat <- finis
+ break
+ }
+ for i := 1; i < n; i++ {
+ <-Z.req
+ Z.dat <- zero
+ }
+ }
+ }(U, Z, c0, n)
+ return Z
+}
+
+func Init() {
+ chnameserial = -1
+ seqno = 0
+ chnames = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz"
+ zero = itor(0)
+ one = itor(1)
+ finis = i2tor(1, 0)
+ Ones = Rep(one)
+ Twos = Rep(itor(2))
+}
+
+func check(U PS, c *rat, count int, str string) {
+ for i := 0; i < count; i++ {
+ r := get(U)
+ if !r.eq(c) {
+ print("got: ")
+ r.pr()
+ print("should get ")
+ c.pr()
+ print("\n")
+ panic(str)
+ }
+ }
+}
+
+const N = 10
+
+func checka(U PS, a []*rat, str string) {
+ for i := 0; i < N; i++ {
+ check(U, a[i], 1, str)
+ }
+}
+
+func main() {
+ Init()
+ if len(os.Args) > 1 { // print
+ print("Ones: ")
+ Printn(Ones, 10)
+ print("Twos: ")
+ Printn(Twos, 10)
+ print("Add: ")
+ Printn(Add(Ones, Twos), 10)
+ print("Diff: ")
+ Printn(Diff(Ones), 10)
+ print("Integ: ")
+ Printn(Integ(zero, Ones), 10)
+ print("CMul: ")
+ Printn(Cmul(neg(one), Ones), 10)
+ print("Sub: ")
+ Printn(Sub(Ones, Twos), 10)
+ print("Mul: ")
+ Printn(Mul(Ones, Ones), 10)
+ print("Exp: ")
+ Printn(Exp(Ones), 15)
+ print("MonSubst: ")
+ Printn(MonSubst(Ones, neg(one), 2), 10)
+ print("ATan: ")
+ Printn(Integ(zero, MonSubst(Ones, neg(one), 2)), 10)
+ } else { // test
+ check(Ones, one, 5, "Ones")
+ check(Add(Ones, Ones), itor(2), 0, "Add Ones Ones") // 1 1 1 1 1
+ check(Add(Ones, Twos), itor(3), 0, "Add Ones Twos") // 3 3 3 3 3
+ a := make([]*rat, N)
+ d := Diff(Ones)
+ for i := 0; i < N; i++ {
+ a[i] = itor(int64(i + 1))
+ }
+ checka(d, a, "Diff") // 1 2 3 4 5
+ in := Integ(zero, Ones)
+ a[0] = zero // integration constant
+ for i := 1; i < N; i++ {
+ a[i] = i2tor(1, int64(i))
+ }
+ checka(in, a, "Integ") // 0 1 1/2 1/3 1/4 1/5
+ check(Cmul(neg(one), Twos), itor(-2), 10, "CMul") // -1 -1 -1 -1 -1
+ check(Sub(Ones, Twos), itor(-1), 0, "Sub Ones Twos") // -1 -1 -1 -1 -1
+ m := Mul(Ones, Ones)
+ for i := 0; i < N; i++ {
+ a[i] = itor(int64(i + 1))
+ }
+ checka(m, a, "Mul") // 1 2 3 4 5
+ e := Exp(Ones)
+ a[0] = itor(1)
+ a[1] = itor(1)
+ a[2] = i2tor(3, 2)
+ a[3] = i2tor(13, 6)
+ a[4] = i2tor(73, 24)
+ a[5] = i2tor(167, 40)
+ a[6] = i2tor(4051, 720)
+ a[7] = i2tor(37633, 5040)
+ a[8] = i2tor(43817, 4480)
+ a[9] = i2tor(4596553, 362880)
+ checka(e, a, "Exp") // 1 1 3/2 13/6 73/24
+ at := Integ(zero, MonSubst(Ones, neg(one), 2))
+ for c, i := 1, 0; i < N; i++ {
+ if i%2 == 0 {
+ a[i] = zero
+ } else {
+ a[i] = i2tor(int64(c), int64(i))
+ c *= -1
+ }
+ }
+ checka(at, a, "ATan") // 0 -1 0 -1/3 0 -1/5
+ /*
+ t := Revert(Integ(zero, MonSubst(Ones, neg(one), 2)))
+ a[0] = zero
+ a[1] = itor(1)
+ a[2] = zero
+ a[3] = i2tor(1,3)
+ a[4] = zero
+ a[5] = i2tor(2,15)
+ a[6] = zero
+ a[7] = i2tor(17,315)
+ a[8] = zero
+ a[9] = i2tor(62,2835)
+ checka(t, a, "Tan") // 0 1 0 1/3 0 2/15
+ */
+ }
+}
diff --git a/test/chan/select.go b/test/chan/select.go
new file mode 100644
index 0000000..38fa7e1
--- /dev/null
+++ b/test/chan/select.go
@@ -0,0 +1,58 @@
+// run
+
+// Copyright 2009 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.
+
+// Test simple select.
+
+package main
+
+var counter uint
+var shift uint
+
+func GetValue() uint {
+ counter++
+ return 1 << shift
+}
+
+func Send(a, b chan uint) int {
+ var i int
+
+LOOP:
+ for {
+ select {
+ case a <- GetValue():
+ i++
+ a = nil
+ case b <- GetValue():
+ i++
+ b = nil
+ default:
+ break LOOP
+ }
+ shift++
+ }
+ return i
+}
+
+func main() {
+ a := make(chan uint, 1)
+ b := make(chan uint, 1)
+ if v := Send(a, b); v != 2 {
+ println("Send returned", v, "!= 2")
+ panic("fail")
+ }
+ if av, bv := <-a, <-b; av|bv != 3 {
+ println("bad values", av, bv)
+ panic("fail")
+ }
+ if v := Send(a, nil); v != 1 {
+ println("Send returned", v, "!= 1")
+ panic("fail")
+ }
+ if counter != 10 {
+ println("counter is", counter, "!= 10")
+ panic("fail")
+ }
+}
diff --git a/test/chan/select2.go b/test/chan/select2.go
new file mode 100644
index 0000000..31e27d7
--- /dev/null
+++ b/test/chan/select2.go
@@ -0,0 +1,54 @@
+// run
+
+// Copyright 2010 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.
+
+// Test that selects do not consume undue memory.
+
+package main
+
+import "runtime"
+
+func sender(c chan int, n int) {
+ for i := 0; i < n; i++ {
+ c <- 1
+ }
+}
+
+func receiver(c, dummy chan int, n int) {
+ for i := 0; i < n; i++ {
+ select {
+ case <-c:
+ // nothing
+ case <-dummy:
+ panic("dummy")
+ }
+ }
+}
+
+func main() {
+ runtime.MemProfileRate = 0
+
+ c := make(chan int)
+ dummy := make(chan int)
+
+ // warm up
+ go sender(c, 100000)
+ receiver(c, dummy, 100000)
+ runtime.GC()
+ memstats := new(runtime.MemStats)
+ runtime.ReadMemStats(memstats)
+ alloc := memstats.Alloc
+
+ // second time shouldn't increase footprint by much
+ go sender(c, 100000)
+ receiver(c, dummy, 100000)
+ runtime.GC()
+ runtime.ReadMemStats(memstats)
+
+ // Be careful to avoid wraparound.
+ if memstats.Alloc > alloc && memstats.Alloc-alloc > 1.1e5 {
+ println("BUG: too much memory for 100,000 selects:", memstats.Alloc-alloc)
+ }
+}
diff --git a/test/chan/select3.go b/test/chan/select3.go
new file mode 100644
index 0000000..dd14c73
--- /dev/null
+++ b/test/chan/select3.go
@@ -0,0 +1,226 @@
+// run
+
+// Copyright 2010 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.
+
+// Test the semantics of the select statement
+// for basic empty/non-empty cases.
+
+package main
+
+import "time"
+
+const always = "function did not"
+const never = "function did"
+
+func unreachable() {
+ panic("control flow shouldn't reach here")
+}
+
+// Calls f and verifies that f always/never panics depending on signal.
+func testPanic(signal string, f func()) {
+ defer func() {
+ s := never
+ if recover() != nil {
+ s = always // f panicked
+ }
+ if s != signal {
+ panic(signal + " panic")
+ }
+ }()
+ f()
+}
+
+// Calls f and empirically verifies that f always/never blocks depending on signal.
+func testBlock(signal string, f func()) {
+ c := make(chan string)
+ go func() {
+ f()
+ c <- never // f didn't block
+ }()
+ go func() {
+ if signal == never {
+ // Wait a long time to make sure that we don't miss our window by accident on a slow machine.
+ time.Sleep(10 * time.Second)
+ } else {
+ // Wait as short a time as we can without false negatives.
+ // 10ms should be long enough to catch most failures.
+ time.Sleep(10 * time.Millisecond)
+ }
+ c <- always // f blocked always
+ }()
+ if <-c != signal {
+ panic(signal + " block")
+ }
+}
+
+func main() {
+ const async = 1 // asynchronous channels
+ var nilch chan int
+ closedch := make(chan int)
+ close(closedch)
+
+ // sending/receiving from a nil channel blocks
+ testBlock(always, func() {
+ nilch <- 7
+ })
+ testBlock(always, func() {
+ <-nilch
+ })
+
+ // sending/receiving from a nil channel inside a select is never selected
+ testPanic(never, func() {
+ select {
+ case nilch <- 7:
+ unreachable()
+ default:
+ }
+ })
+ testPanic(never, func() {
+ select {
+ case <-nilch:
+ unreachable()
+ default:
+ }
+ })
+
+ // sending to an async channel with free buffer space never blocks
+ testBlock(never, func() {
+ ch := make(chan int, async)
+ ch <- 7
+ })
+
+ // receiving from a closed channel never blocks
+ testBlock(never, func() {
+ for i := 0; i < 10; i++ {
+ if <-closedch != 0 {
+ panic("expected zero value when reading from closed channel")
+ }
+ if x, ok := <-closedch; x != 0 || ok {
+ println("closedch:", x, ok)
+ panic("expected 0, false from closed channel")
+ }
+ }
+ })
+
+ // sending to a closed channel panics.
+ testPanic(always, func() {
+ closedch <- 7
+ })
+
+ // receiving from a non-ready channel always blocks
+ testBlock(always, func() {
+ ch := make(chan int)
+ <-ch
+ })
+
+ // empty selects always block
+ testBlock(always, func() {
+ select {}
+ })
+
+ // selects with only nil channels always block
+ testBlock(always, func() {
+ select {
+ case <-nilch:
+ unreachable()
+ }
+ })
+ testBlock(always, func() {
+ select {
+ case nilch <- 7:
+ unreachable()
+ }
+ })
+ testBlock(always, func() {
+ select {
+ case <-nilch:
+ unreachable()
+ case nilch <- 7:
+ unreachable()
+ }
+ })
+
+ // selects with non-ready non-nil channels always block
+ testBlock(always, func() {
+ ch := make(chan int)
+ select {
+ case <-ch:
+ unreachable()
+ }
+ })
+
+ // selects with default cases don't block
+ testBlock(never, func() {
+ select {
+ default:
+ }
+ })
+ testBlock(never, func() {
+ select {
+ case <-nilch:
+ unreachable()
+ default:
+ }
+ })
+ testBlock(never, func() {
+ select {
+ case nilch <- 7:
+ unreachable()
+ default:
+ }
+ })
+
+ // selects with ready channels don't block
+ testBlock(never, func() {
+ ch := make(chan int, async)
+ select {
+ case ch <- 7:
+ default:
+ unreachable()
+ }
+ })
+ testBlock(never, func() {
+ ch := make(chan int, async)
+ ch <- 7
+ select {
+ case <-ch:
+ default:
+ unreachable()
+ }
+ })
+
+ // selects with closed channels behave like ordinary operations
+ testBlock(never, func() {
+ select {
+ case <-closedch:
+ }
+ })
+ testBlock(never, func() {
+ select {
+ case x := (<-closedch):
+ _ = x
+ }
+ })
+ testBlock(never, func() {
+ select {
+ case x, ok := (<-closedch):
+ _, _ = x, ok
+ }
+ })
+ testPanic(always, func() {
+ select {
+ case closedch <- 7:
+ }
+ })
+
+ // select should not get confused if it sees itself
+ testBlock(always, func() {
+ c := make(chan int)
+ select {
+ case c <- 1:
+ case <-c:
+ }
+ })
+}
diff --git a/test/chan/select4.go b/test/chan/select4.go
new file mode 100644
index 0000000..5003640
--- /dev/null
+++ b/test/chan/select4.go
@@ -0,0 +1,31 @@
+// run
+
+// Copyright 2010 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
+
+// Test that a select statement proceeds when a value is ready.
+
+package main
+
+func f() *int {
+ println("BUG: called f")
+ return new(int)
+}
+
+func main() {
+ var x struct {
+ a int
+ }
+ c := make(chan int, 1)
+ c1 := make(chan int)
+ c <- 42
+ select {
+ case *f() = <-c1:
+ // nothing
+ case x.a = <-c:
+ if x.a != 42 {
+ println("BUG:", x.a)
+ }
+ }
+}
diff --git a/test/chan/select5.go b/test/chan/select5.go
new file mode 100644
index 0000000..8b98c3a
--- /dev/null
+++ b/test/chan/select5.go
@@ -0,0 +1,481 @@
+// runoutput
+
+// Copyright 2011 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.
+
+// Generate test of channel operations and simple selects.
+// The output of this program is compiled and run to do the
+// actual test.
+
+// Each test does only one real send or receive at a time, but phrased
+// in various ways that the compiler may or may not rewrite
+// into simpler expressions.
+
+package main
+
+import (
+ "bufio"
+ "fmt"
+ "io"
+ "os"
+ "text/template"
+)
+
+func main() {
+ out := bufio.NewWriter(os.Stdout)
+ fmt.Fprintln(out, header)
+ a := new(arg)
+
+ // Generate each test as a separate function to avoid
+ // hitting the gc optimizer with one enormous function.
+ // If we name all the functions init we don't have to
+ // maintain a list of which ones to run.
+ do := func(t *template.Template) {
+ for ; next(); a.reset() {
+ fmt.Fprintln(out, `func init() {`)
+ run(t, a, out)
+ fmt.Fprintln(out, `}`)
+ }
+ }
+
+ do(recv)
+ do(send)
+ do(recvOrder)
+ do(sendOrder)
+ do(nonblock)
+
+ fmt.Fprintln(out, "//", a.nreset, "cases")
+ out.Flush()
+}
+
+func run(t *template.Template, a interface{}, out io.Writer) {
+ if err := t.Execute(out, a); err != nil {
+ panic(err)
+ }
+}
+
+type arg struct {
+ def bool
+ nreset int
+}
+
+func (a *arg) Maybe() bool {
+ return maybe()
+}
+
+func (a *arg) MaybeDefault() bool {
+ if a.def {
+ return false
+ }
+ a.def = maybe()
+ return a.def
+}
+
+func (a *arg) MustDefault() bool {
+ return !a.def
+}
+
+func (a *arg) reset() {
+ a.def = false
+ a.nreset++
+}
+
+const header = `// GENERATED BY select5.go; DO NOT EDIT
+
+package main
+
+// channel is buffered so test is single-goroutine.
+// we are not interested in the concurrency aspects
+// of select, just testing that the right calls happen.
+var c = make(chan int, 1)
+var nilch chan int
+var n = 1
+var x int
+var i interface{}
+var dummy = make(chan int)
+var m = make(map[int]int)
+var order = 0
+
+func f(p *int) *int {
+ return p
+}
+
+// check order of operations by ensuring that
+// successive calls to checkorder have increasing o values.
+func checkorder(o int) {
+ if o <= order {
+ println("invalid order", o, "after", order)
+ panic("order")
+ }
+ order = o
+}
+
+func fc(c chan int, o int) chan int {
+ checkorder(o)
+ return c
+}
+
+func fp(p *int, o int) *int {
+ checkorder(o)
+ return p
+}
+
+func fn(n, o int) int {
+ checkorder(o)
+ return n
+}
+
+func die(x int) {
+ println("have", x, "want", n)
+ panic("chan")
+}
+
+func main() {
+ // everything happens in init funcs
+}
+`
+
+func parse(name, s string) *template.Template {
+ t, err := template.New(name).Parse(s)
+ if err != nil {
+ panic(fmt.Sprintf("%q: %s", name, err))
+ }
+ return t
+}
+
+var recv = parse("recv", `
+ {{/* Send n, receive it one way or another into x, check that they match. */}}
+ c <- n
+ {{if .Maybe}}
+ x = <-c
+ {{else}}
+ select {
+ {{/* Blocking or non-blocking, before the receive. */}}
+ {{/* The compiler implements two-case select where one is default with custom code, */}}
+ {{/* so test the default branch both before and after the send. */}}
+ {{if .MaybeDefault}}
+ default:
+ panic("nonblock")
+ {{end}}
+ {{/* Receive from c. Different cases are direct, indirect, :=, interface, and map assignment. */}}
+ {{if .Maybe}}
+ case x = <-c:
+ {{else}}{{if .Maybe}}
+ case *f(&x) = <-c:
+ {{else}}{{if .Maybe}}
+ case y := <-c:
+ x = y
+ {{else}}{{if .Maybe}}
+ case i = <-c:
+ x = i.(int)
+ {{else}}
+ case m[13] = <-c:
+ x = m[13]
+ {{end}}{{end}}{{end}}{{end}}
+ {{/* Blocking or non-blocking again, after the receive. */}}
+ {{if .MaybeDefault}}
+ default:
+ panic("nonblock")
+ {{end}}
+ {{/* Dummy send, receive to keep compiler from optimizing select. */}}
+ {{if .Maybe}}
+ case dummy <- 1:
+ panic("dummy send")
+ {{end}}
+ {{if .Maybe}}
+ case <-dummy:
+ panic("dummy receive")
+ {{end}}
+ {{/* Nil channel send, receive to keep compiler from optimizing select. */}}
+ {{if .Maybe}}
+ case nilch <- 1:
+ panic("nilch send")
+ {{end}}
+ {{if .Maybe}}
+ case <-nilch:
+ panic("nilch recv")
+ {{end}}
+ }
+ {{end}}
+ if x != n {
+ die(x)
+ }
+ n++
+`)
+
+var recvOrder = parse("recvOrder", `
+ {{/* Send n, receive it one way or another into x, check that they match. */}}
+ {{/* Check order of operations along the way by calling functions that check */}}
+ {{/* that the argument sequence is strictly increasing. */}}
+ order = 0
+ c <- n
+ {{if .Maybe}}
+ {{/* Outside of select, left-to-right rule applies. */}}
+ {{/* (Inside select, assignment waits until case is chosen, */}}
+ {{/* so right hand side happens before anything on left hand side. */}}
+ *fp(&x, 1) = <-fc(c, 2)
+ {{else}}{{if .Maybe}}
+ m[fn(13, 1)] = <-fc(c, 2)
+ x = m[13]
+ {{else}}
+ select {
+ {{/* Blocking or non-blocking, before the receive. */}}
+ {{/* The compiler implements two-case select where one is default with custom code, */}}
+ {{/* so test the default branch both before and after the send. */}}
+ {{if .MaybeDefault}}
+ default:
+ panic("nonblock")
+ {{end}}
+ {{/* Receive from c. Different cases are direct, indirect, :=, interface, and map assignment. */}}
+ {{if .Maybe}}
+ case *fp(&x, 100) = <-fc(c, 1):
+ {{else}}{{if .Maybe}}
+ case y := <-fc(c, 1):
+ x = y
+ {{else}}{{if .Maybe}}
+ case i = <-fc(c, 1):
+ x = i.(int)
+ {{else}}
+ case m[fn(13, 100)] = <-fc(c, 1):
+ x = m[13]
+ {{end}}{{end}}{{end}}
+ {{/* Blocking or non-blocking again, after the receive. */}}
+ {{if .MaybeDefault}}
+ default:
+ panic("nonblock")
+ {{end}}
+ {{/* Dummy send, receive to keep compiler from optimizing select. */}}
+ {{if .Maybe}}
+ case fc(dummy, 2) <- fn(1, 3):
+ panic("dummy send")
+ {{end}}
+ {{if .Maybe}}
+ case <-fc(dummy, 4):
+ panic("dummy receive")
+ {{end}}
+ {{/* Nil channel send, receive to keep compiler from optimizing select. */}}
+ {{if .Maybe}}
+ case fc(nilch, 5) <- fn(1, 6):
+ panic("nilch send")
+ {{end}}
+ {{if .Maybe}}
+ case <-fc(nilch, 7):
+ panic("nilch recv")
+ {{end}}
+ }
+ {{end}}{{end}}
+ if x != n {
+ die(x)
+ }
+ n++
+`)
+
+var send = parse("send", `
+ {{/* Send n one way or another, receive it into x, check that they match. */}}
+ {{if .Maybe}}
+ c <- n
+ {{else}}
+ select {
+ {{/* Blocking or non-blocking, before the receive (same reason as in recv). */}}
+ {{if .MaybeDefault}}
+ default:
+ panic("nonblock")
+ {{end}}
+ {{/* Send c <- n. No real special cases here, because no values come back */}}
+ {{/* from the send operation. */}}
+ case c <- n:
+ {{/* Blocking or non-blocking. */}}
+ {{if .MaybeDefault}}
+ default:
+ panic("nonblock")
+ {{end}}
+ {{/* Dummy send, receive to keep compiler from optimizing select. */}}
+ {{if .Maybe}}
+ case dummy <- 1:
+ panic("dummy send")
+ {{end}}
+ {{if .Maybe}}
+ case <-dummy:
+ panic("dummy receive")
+ {{end}}
+ {{/* Nil channel send, receive to keep compiler from optimizing select. */}}
+ {{if .Maybe}}
+ case nilch <- 1:
+ panic("nilch send")
+ {{end}}
+ {{if .Maybe}}
+ case <-nilch:
+ panic("nilch recv")
+ {{end}}
+ }
+ {{end}}
+ x = <-c
+ if x != n {
+ die(x)
+ }
+ n++
+`)
+
+var sendOrder = parse("sendOrder", `
+ {{/* Send n one way or another, receive it into x, check that they match. */}}
+ {{/* Check order of operations along the way by calling functions that check */}}
+ {{/* that the argument sequence is strictly increasing. */}}
+ order = 0
+ {{if .Maybe}}
+ fc(c, 1) <- fn(n, 2)
+ {{else}}
+ select {
+ {{/* Blocking or non-blocking, before the receive (same reason as in recv). */}}
+ {{if .MaybeDefault}}
+ default:
+ panic("nonblock")
+ {{end}}
+ {{/* Send c <- n. No real special cases here, because no values come back */}}
+ {{/* from the send operation. */}}
+ case fc(c, 1) <- fn(n, 2):
+ {{/* Blocking or non-blocking. */}}
+ {{if .MaybeDefault}}
+ default:
+ panic("nonblock")
+ {{end}}
+ {{/* Dummy send, receive to keep compiler from optimizing select. */}}
+ {{if .Maybe}}
+ case fc(dummy, 3) <- fn(1, 4):
+ panic("dummy send")
+ {{end}}
+ {{if .Maybe}}
+ case <-fc(dummy, 5):
+ panic("dummy receive")
+ {{end}}
+ {{/* Nil channel send, receive to keep compiler from optimizing select. */}}
+ {{if .Maybe}}
+ case fc(nilch, 6) <- fn(1, 7):
+ panic("nilch send")
+ {{end}}
+ {{if .Maybe}}
+ case <-fc(nilch, 8):
+ panic("nilch recv")
+ {{end}}
+ }
+ {{end}}
+ x = <-c
+ if x != n {
+ die(x)
+ }
+ n++
+`)
+
+var nonblock = parse("nonblock", `
+ x = n
+ {{/* Test various combinations of non-blocking operations. */}}
+ {{/* Receive assignments must not edit or even attempt to compute the address of the lhs. */}}
+ select {
+ {{if .MaybeDefault}}
+ default:
+ {{end}}
+ {{if .Maybe}}
+ case dummy <- 1:
+ panic("dummy <- 1")
+ {{end}}
+ {{if .Maybe}}
+ case nilch <- 1:
+ panic("nilch <- 1")
+ {{end}}
+ {{if .Maybe}}
+ case <-dummy:
+ panic("<-dummy")
+ {{end}}
+ {{if .Maybe}}
+ case x = <-dummy:
+ panic("<-dummy x")
+ {{end}}
+ {{if .Maybe}}
+ case **(**int)(nil) = <-dummy:
+ panic("<-dummy (and didn't crash saving result!)")
+ {{end}}
+ {{if .Maybe}}
+ case <-nilch:
+ panic("<-nilch")
+ {{end}}
+ {{if .Maybe}}
+ case x = <-nilch:
+ panic("<-nilch x")
+ {{end}}
+ {{if .Maybe}}
+ case **(**int)(nil) = <-nilch:
+ panic("<-nilch (and didn't crash saving result!)")
+ {{end}}
+ {{if .MustDefault}}
+ default:
+ {{end}}
+ }
+ if x != n {
+ die(x)
+ }
+ n++
+`)
+
+// Code for enumerating all possible paths through
+// some logic. The logic should call choose(n) when
+// it wants to choose between n possibilities.
+// On successive runs through the logic, choose(n)
+// will return 0, 1, ..., n-1. The helper maybe() is
+// similar but returns true and then false.
+//
+// Given a function gen that generates an output
+// using choose and maybe, code can generate all
+// possible outputs using
+//
+// for next() {
+// gen()
+// }
+
+type choice struct {
+ i, n int
+}
+
+var choices []choice
+var cp int = -1
+
+func maybe() bool {
+ return choose(2) == 0
+}
+
+func choose(n int) int {
+ if cp >= len(choices) {
+ // never asked this before: start with 0.
+ choices = append(choices, choice{0, n})
+ cp = len(choices)
+ return 0
+ }
+ // otherwise give recorded answer
+ if n != choices[cp].n {
+ panic("inconsistent choices")
+ }
+ i := choices[cp].i
+ cp++
+ return i
+}
+
+func next() bool {
+ if cp < 0 {
+ // start a new round
+ cp = 0
+ return true
+ }
+
+ // increment last choice sequence
+ cp = len(choices) - 1
+ for cp >= 0 && choices[cp].i == choices[cp].n-1 {
+ cp--
+ }
+ if cp < 0 {
+ choices = choices[:0]
+ return false
+ }
+ choices[cp].i++
+ choices = choices[:cp+1]
+ cp = 0
+ return true
+}
diff --git a/test/chan/select6.go b/test/chan/select6.go
new file mode 100644
index 0000000..6e8129f
--- /dev/null
+++ b/test/chan/select6.go
@@ -0,0 +1,34 @@
+// run
+
+// Copyright 2011 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.
+
+// Test for select: Issue 2075
+// A bug in select corrupts channel queues of failed cases
+// if there are multiple waiters on those channels and the
+// select is the last in the queue. If further waits are made
+// on the channel without draining it first then those waiters
+// will never wake up. In the code below c1 is such a channel.
+
+package main
+
+func main() {
+ c1 := make(chan bool)
+ c2 := make(chan bool)
+ c3 := make(chan bool)
+ go func() { <-c1 }()
+ go func() {
+ select {
+ case <-c1:
+ panic("dummy")
+ case <-c2:
+ c3 <- true
+ }
+ <-c1
+ }()
+ go func() { c2 <- true }()
+ <-c3
+ c1 <- true
+ c1 <- true
+}
diff --git a/test/chan/select7.go b/test/chan/select7.go
new file mode 100644
index 0000000..f7222ca
--- /dev/null
+++ b/test/chan/select7.go
@@ -0,0 +1,68 @@
+// run
+
+// Copyright 2011 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.
+
+// Test select when discarding a value.
+
+package main
+
+import "runtime"
+
+func recv1(c <-chan int) {
+ <-c
+}
+
+func recv2(c <-chan int) {
+ select {
+ case <-c:
+ }
+}
+
+func recv3(c <-chan int) {
+ c2 := make(chan int)
+ select {
+ case <-c:
+ case <-c2:
+ }
+}
+
+func send1(recv func(<-chan int)) {
+ c := make(chan int)
+ go recv(c)
+ runtime.Gosched()
+ c <- 1
+}
+
+func send2(recv func(<-chan int)) {
+ c := make(chan int)
+ go recv(c)
+ runtime.Gosched()
+ select {
+ case c <- 1:
+ }
+}
+
+func send3(recv func(<-chan int)) {
+ c := make(chan int)
+ go recv(c)
+ runtime.Gosched()
+ c2 := make(chan int)
+ select {
+ case c <- 1:
+ case c2 <- 1:
+ }
+}
+
+func main() {
+ send1(recv1)
+ send2(recv1)
+ send3(recv1)
+ send1(recv2)
+ send2(recv2)
+ send3(recv2)
+ send1(recv3)
+ send2(recv3)
+ send3(recv3)
+}
diff --git a/test/chan/select8.go b/test/chan/select8.go
new file mode 100644
index 0000000..20bca3a
--- /dev/null
+++ b/test/chan/select8.go
@@ -0,0 +1,55 @@
+// run
+
+// Copyright 2019 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.
+
+// Test break statements in a select.
+// Gccgo had a bug in handling this.
+// Test 1,2,3-case selects, so it covers both the general
+// code path and the specialized optimizations for one-
+// and two-case selects.
+
+package main
+
+var ch = make(chan int)
+
+func main() {
+ go func() {
+ for {
+ ch <- 5
+ }
+ }()
+
+ select {
+ case <-ch:
+ break
+ panic("unreachable")
+ }
+
+ select {
+ default:
+ break
+ panic("unreachable")
+ }
+
+ select {
+ case <-ch:
+ break
+ panic("unreachable")
+ default:
+ break
+ panic("unreachable")
+ }
+
+ select {
+ case <-ch:
+ break
+ panic("unreachable")
+ case ch <- 10:
+ panic("unreachable")
+ default:
+ break
+ panic("unreachable")
+ }
+}
diff --git a/test/chan/sendstmt.go b/test/chan/sendstmt.go
new file mode 100644
index 0000000..d296a55
--- /dev/null
+++ b/test/chan/sendstmt.go
@@ -0,0 +1,37 @@
+// run
+
+// Copyright 2011 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.
+
+// Test various parsing cases that are a little
+// different now that send is a statement, not an expression.
+
+package main
+
+func main() {
+ chanchan()
+ sendprec()
+}
+
+func chanchan() {
+ cc := make(chan chan int, 1)
+ c := make(chan int, 1)
+ cc <- c
+ select {
+ case <-cc <- 2:
+ default:
+ panic("nonblock")
+ }
+ if <-c != 2 {
+ panic("bad receive")
+ }
+}
+
+func sendprec() {
+ c := make(chan bool, 1)
+ c <- false || true // not a syntax error: same as c <- (false || true)
+ if !<-c {
+ panic("sent false")
+ }
+}
diff --git a/test/chan/sieve1.go b/test/chan/sieve1.go
new file mode 100644
index 0000000..acc310f
--- /dev/null
+++ b/test/chan/sieve1.go
@@ -0,0 +1,56 @@
+// run
+
+// Copyright 2009 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.
+
+// Test concurrency primitives: classical inefficient concurrent prime sieve.
+
+// Generate primes up to 100 using channels, checking the results.
+// This sieve consists of a linear chain of divisibility filters,
+// equivalent to trial-dividing each n by all primes p ≤ n.
+
+package main
+
+// Send the sequence 2, 3, 4, ... to channel 'ch'.
+func Generate(ch chan<- int) {
+ for i := 2; ; i++ {
+ ch <- i // Send 'i' to channel 'ch'.
+ }
+}
+
+// Copy the values from channel 'in' to channel 'out',
+// removing those divisible by 'prime'.
+func Filter(in <-chan int, out chan<- int, prime int) {
+ for i := range in { // Loop over values received from 'in'.
+ if i%prime != 0 {
+ out <- i // Send 'i' to channel 'out'.
+ }
+ }
+}
+
+// The prime sieve: Daisy-chain Filter processes together.
+func Sieve(primes chan<- int) {
+ ch := make(chan int) // Create a new channel.
+ go Generate(ch) // Start Generate() as a subprocess.
+ for {
+ // Note that ch is different on each iteration.
+ prime := <-ch
+ primes <- prime
+ ch1 := make(chan int)
+ go Filter(ch, ch1, prime)
+ ch = ch1
+ }
+}
+
+func main() {
+ primes := make(chan int)
+ go Sieve(primes)
+ a := []int{2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37, 41, 43, 47, 53, 59, 61, 67, 71, 73, 79, 83, 89, 97}
+ for i := 0; i < len(a); i++ {
+ if x := <-primes; x != a[i] {
+ println(x, " != ", a[i])
+ panic("fail")
+ }
+ }
+}
diff --git a/test/chan/sieve2.go b/test/chan/sieve2.go
new file mode 100644
index 0000000..09e5c52
--- /dev/null
+++ b/test/chan/sieve2.go
@@ -0,0 +1,188 @@
+// run
+
+// Copyright 2009 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.
+
+// Test concurrency primitives: prime sieve of Eratosthenes.
+
+// Generate primes up to 100 using channels, checking the results.
+// This sieve is Eratosthenesque and only considers odd candidates.
+// See discussion at <http://blog.onideas.ws/eratosthenes.go>.
+
+package main
+
+import (
+ "container/heap"
+ "container/ring"
+)
+
+// Return a chan of odd numbers, starting from 5.
+func odds() chan int {
+ out := make(chan int, 50)
+ go func() {
+ n := 5
+ for {
+ out <- n
+ n += 2
+ }
+ }()
+ return out
+}
+
+// Return a chan of odd multiples of the prime number p, starting from p*p.
+func multiples(p int) chan int {
+ out := make(chan int, 10)
+ go func() {
+ n := p * p
+ for {
+ out <- n
+ n += 2 * p
+ }
+ }()
+ return out
+}
+
+type PeekCh struct {
+ head int
+ ch chan int
+}
+
+// Heap of PeekCh, sorting by head values, satisfies Heap interface.
+type PeekChHeap []*PeekCh
+
+func (h *PeekChHeap) Less(i, j int) bool {
+ return (*h)[i].head < (*h)[j].head
+}
+
+func (h *PeekChHeap) Swap(i, j int) {
+ (*h)[i], (*h)[j] = (*h)[j], (*h)[i]
+}
+
+func (h *PeekChHeap) Len() int {
+ return len(*h)
+}
+
+func (h *PeekChHeap) Pop() (v interface{}) {
+ *h, v = (*h)[:h.Len()-1], (*h)[h.Len()-1]
+ return
+}
+
+func (h *PeekChHeap) Push(v interface{}) {
+ *h = append(*h, v.(*PeekCh))
+}
+
+// Return a channel to serve as a sending proxy to 'out'.
+// Use a goroutine to receive values from 'out' and store them
+// in an expanding buffer, so that sending to 'out' never blocks.
+func sendproxy(out chan<- int) chan<- int {
+ proxy := make(chan int, 10)
+ go func() {
+ n := 16 // the allocated size of the circular queue
+ first := ring.New(n)
+ last := first
+ var c chan<- int
+ var e int
+ for {
+ c = out
+ if first == last {
+ // buffer empty: disable output
+ c = nil
+ } else {
+ e = first.Value.(int)
+ }
+ select {
+ case e = <-proxy:
+ last.Value = e
+ if last.Next() == first {
+ // buffer full: expand it
+ last.Link(ring.New(n))
+ n *= 2
+ }
+ last = last.Next()
+ case c <- e:
+ first = first.Next()
+ }
+ }
+ }()
+ return proxy
+}
+
+// Return a chan int of primes.
+func Sieve() chan int {
+ // The output values.
+ out := make(chan int, 10)
+ out <- 2
+ out <- 3
+
+ // The channel of all composites to be eliminated in increasing order.
+ composites := make(chan int, 50)
+
+ // The feedback loop.
+ primes := make(chan int, 10)
+ primes <- 3
+
+ // Merge channels of multiples of 'primes' into 'composites'.
+ go func() {
+ var h PeekChHeap
+ min := 15
+ for {
+ m := multiples(<-primes)
+ head := <-m
+ for min < head {
+ composites <- min
+ minchan := heap.Pop(&h).(*PeekCh)
+ min = minchan.head
+ minchan.head = <-minchan.ch
+ heap.Push(&h, minchan)
+ }
+ for min == head {
+ minchan := heap.Pop(&h).(*PeekCh)
+ min = minchan.head
+ minchan.head = <-minchan.ch
+ heap.Push(&h, minchan)
+ }
+ composites <- head
+ heap.Push(&h, &PeekCh{<-m, m})
+ }
+ }()
+
+ // Sieve out 'composites' from 'candidates'.
+ go func() {
+ // In order to generate the nth prime we only need multiples of
+ // primes ≤ sqrt(nth prime). Thus, the merging goroutine will
+ // receive from 'primes' much slower than this goroutine
+ // will send to it, making the buffer accumulate and block this
+ // goroutine from sending, causing a deadlock. The solution is to
+ // use a proxy goroutine to do automatic buffering.
+ primes := sendproxy(primes)
+
+ candidates := odds()
+ p := <-candidates
+
+ for {
+ c := <-composites
+ for p < c {
+ primes <- p
+ out <- p
+ p = <-candidates
+ }
+ if p == c {
+ p = <-candidates
+ }
+ }
+ }()
+
+ return out
+}
+
+func main() {
+ primes := Sieve()
+ a := []int{2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37, 41, 43, 47, 53, 59, 61, 67, 71, 73, 79, 83, 89, 97}
+ for i := 0; i < len(a); i++ {
+ if x := <-primes; x != a[i] {
+ println(x, " != ", a[i])
+ panic("fail")
+ }
+ }
+}
diff --git a/test/chan/zerosize.go b/test/chan/zerosize.go
new file mode 100644
index 0000000..50aca85
--- /dev/null
+++ b/test/chan/zerosize.go
@@ -0,0 +1,16 @@
+// run
+
+// Copyright 2011 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.
+
+// Test making channels of a zero-sized type.
+
+package main
+
+func main() {
+ _ = make(chan [0]byte)
+ _ = make(chan [0]byte, 1)
+ _ = make(chan struct{})
+ _ = make(chan struct{}, 1)
+}
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-11 19:17:13 +0000