blob: 4ab12c775600fc0ebd568c6765cf4b50ff9b708a [file] [log] [blame]
// $G $D/$F.go && $L $F.$A && ./$A.out
// 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 close(c), closed(c).
//
// TODO(rsc): Doesn't check behavior of close(c) when there
// are blocked senders/receivers.
package main
type Chan interface {
Send(int);
Nbsend(int) bool;
Recv() int;
Nbrecv() (int, bool);
Close();
Closed() bool;
Impl() string;
}
// direct channel operations
type XChan chan int
func (c XChan) Send(x int) {
c <- x
}
func (c XChan) Nbsend(x int) bool {
return c <- x;
}
func (c XChan) Recv() int {
return <-c
}
func (c XChan) Nbrecv() (int, bool) {
x, ok := <-c;
return x, ok;
}
func (c XChan) Close() {
close(c)
}
func (c XChan) Closed() bool {
return closed(c)
}
func (c XChan) Impl() string {
return "(<- operator)"
}
// indirect operations via select
type SChan chan int
func (c SChan) Send(x int) {
select {
case c <- x:
}
}
func (c SChan) Nbsend(x int) bool {
select {
case c <- x:
return true;
default:
return false;
}
panic("nbsend");
}
func (c SChan) Recv() int {
select {
case x := <-c:
return x;
}
panic("recv");
}
func (c SChan) Nbrecv() (int, bool) {
select {
case x := <-c:
return x, true;
default:
return 0, false;
}
panic("nbrecv");
}
func (c SChan) Close() {
close(c)
}
func (c SChan) Closed() bool {
return closed(c)
}
func (c SChan) Impl() string {
return "(select)";
}
func test1(c Chan) {
// not closed until the close signal (a zero value) has been received.
if c.Closed() {
println("test1: Closed before Recv zero:", c.Impl());
}
for i := 0; i < 3; i++ {
// recv a close signal (a zero value)
if x := c.Recv(); x != 0 {
println("test1: recv on closed got non-zero:", x, c.Impl());
}
// should now be closed.
if !c.Closed() {
println("test1: not closed after recv zero", c.Impl());
}
// should work with ,ok: received a value without blocking, so ok == true.
x, ok := c.Nbrecv();
if !ok {
println("test1: recv on closed got not ok", c.Impl());
}
if x != 0 {
println("test1: recv ,ok on closed got non-zero:", x, c.Impl());
}
}
// send should work with ,ok too: sent a value without blocking, so ok == true.
ok := c.Nbsend(1);
if !ok {
println("test1: send on closed got not ok", c.Impl());
}
// but the value should have been discarded.
if x := c.Recv(); x != 0 {
println("test1: recv on closed got non-zero after send on closed:", x, c.Impl());
}
// similarly Send.
c.Send(2);
if x := c.Recv(); x != 0 {
println("test1: recv on closed got non-zero after send on closed:", x, c.Impl());
}
}
func testasync1(c Chan) {
// not closed until the close signal (a zero value) has been received.
if c.Closed() {
println("testasync1: Closed before Recv zero:", c.Impl());
}
// should be able to get the last value via Recv
if x := c.Recv(); x != 1 {
println("testasync1: Recv did not get 1:", x, c.Impl());
}
test1(c);
}
func testasync2(c Chan) {
// not closed until the close signal (a zero value) has been received.
if c.Closed() {
println("testasync2: Closed before Recv zero:", c.Impl());
}
// should be able to get the last value via Nbrecv
if x, ok := c.Nbrecv(); !ok || x != 1 {
println("testasync2: Nbrecv did not get 1, true:", x, ok, c.Impl());
}
test1(c);
}
func closedsync() chan int {
c := make(chan int);
close(c);
return c;
}
func closedasync() chan int {
c := make(chan int, 2);
c <- 1;
close(c);
return c;
}
func main() {
test1(XChan(closedsync()));
test1(SChan(closedsync()));
testasync1(XChan(closedasync()));
testasync1(SChan(closedasync()));
testasync2(XChan(closedasync()));
testasync2(SChan(closedasync()));
}