From cbd6c34131a138c25e33ef038fb7485190637793 Mon Sep 17 00:00:00 2001
From: Rob Pike <r@golang.org>
Date: Fri, 10 Feb 2012 14:31:08 +1100
Subject: [PATCH] testing/script: delete Dead code.

Fixes #2961.

R=golang-dev, bradfitz
CC=golang-dev
https://golang.org/cl/5650053
---
 doc/go1.html                          |  11 +
 doc/go1.tmpl                          |  11 +
 src/pkg/testing/script/script.go      | 358 --------------------------
 src/pkg/testing/script/script_test.go |  75 ------
 4 files changed, 22 insertions(+), 433 deletions(-)
 delete mode 100644 src/pkg/testing/script/script.go
 delete mode 100644 src/pkg/testing/script/script_test.go

diff --git a/doc/go1.html b/doc/go1.html
index 0fc7db47c5a..c2613aaeab2 100644
--- a/doc/go1.html
+++ b/doc/go1.html
@@ -1612,6 +1612,17 @@ Existing code is unaffected, although benchmarks that use <code>println</code>
 or <code>panic</code> should be updated to use the new methods.
 </p>
 
+<h3 id="testing_script">The testing/script package</h3>
+
+<p>
+The testing/script package has been deleted. It was a dreg.
+</p>
+
+<p>
+<em>Updating</em>:
+No code is likely to be affected.
+</p>
+
 <h3 id="url">The url package</h3>
 
 <p>
diff --git a/doc/go1.tmpl b/doc/go1.tmpl
index 4a0a2833558..0700b3c6d81 100644
--- a/doc/go1.tmpl
+++ b/doc/go1.tmpl
@@ -1502,6 +1502,17 @@ Existing code is unaffected, although benchmarks that use <code>println</code>
 or <code>panic</code> should be updated to use the new methods.
 </p>
 
+<h3 id="testing_script">The testing/script package</h3>
+
+<p>
+The testing/script package has been deleted. It was a dreg.
+</p>
+
+<p>
+<em>Updating</em>:
+No code is likely to be affected.
+</p>
+
 <h3 id="url">The url package</h3>
 
 <p>
diff --git a/src/pkg/testing/script/script.go b/src/pkg/testing/script/script.go
deleted file mode 100644
index d8f8093af90..00000000000
--- a/src/pkg/testing/script/script.go
+++ /dev/null
@@ -1,358 +0,0 @@
-// 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.
-
-// Package script aids in the testing of code that uses channels.
-package script
-
-import (
-	"fmt"
-	"math/rand"
-	"reflect"
-	"strings"
-)
-
-// An Event is an element in a partially ordered set that either sends a value
-// to a channel or expects a value from a channel.
-type Event struct {
-	name         string
-	occurred     bool
-	predecessors []*Event
-	action       action
-}
-
-type action interface {
-	// getSend returns nil if the action is not a send action.
-	getSend() sendAction
-	// getRecv returns nil if the action is not a receive action.
-	getRecv() recvAction
-	// getChannel returns the channel that the action operates on.
-	getChannel() interface{}
-}
-
-type recvAction interface {
-	recvMatch(interface{}) bool
-}
-
-type sendAction interface {
-	send()
-}
-
-// isReady returns true if all the predecessors of an Event have occurred.
-func (e Event) isReady() bool {
-	for _, predecessor := range e.predecessors {
-		if !predecessor.occurred {
-			return false
-		}
-	}
-
-	return true
-}
-
-// A Recv action reads a value from a channel and uses reflect.DeepMatch to
-// compare it with an expected value.
-type Recv struct {
-	Channel  interface{}
-	Expected interface{}
-}
-
-func (r Recv) getRecv() recvAction { return r }
-
-func (Recv) getSend() sendAction { return nil }
-
-func (r Recv) getChannel() interface{} { return r.Channel }
-
-func (r Recv) recvMatch(chanEvent interface{}) bool {
-	c, ok := chanEvent.(channelRecv)
-	if !ok || c.channel != r.Channel {
-		return false
-	}
-
-	return reflect.DeepEqual(c.value, r.Expected)
-}
-
-// A RecvMatch action reads a value from a channel and calls a function to
-// determine if the value matches.
-type RecvMatch struct {
-	Channel interface{}
-	Match   func(interface{}) bool
-}
-
-func (r RecvMatch) getRecv() recvAction { return r }
-
-func (RecvMatch) getSend() sendAction { return nil }
-
-func (r RecvMatch) getChannel() interface{} { return r.Channel }
-
-func (r RecvMatch) recvMatch(chanEvent interface{}) bool {
-	c, ok := chanEvent.(channelRecv)
-	if !ok || c.channel != r.Channel {
-		return false
-	}
-
-	return r.Match(c.value)
-}
-
-// A Closed action matches if the given channel is closed. The closing is
-// treated as an event, not a state, thus Closed will only match once for a
-// given channel.
-type Closed struct {
-	Channel interface{}
-}
-
-func (r Closed) getRecv() recvAction { return r }
-
-func (Closed) getSend() sendAction { return nil }
-
-func (r Closed) getChannel() interface{} { return r.Channel }
-
-func (r Closed) recvMatch(chanEvent interface{}) bool {
-	c, ok := chanEvent.(channelClosed)
-	if !ok || c.channel != r.Channel {
-		return false
-	}
-
-	return true
-}
-
-// A Send action sends a value to a channel. The value must match the
-// type of the channel exactly unless the channel if of type chan interface{}.
-type Send struct {
-	Channel interface{}
-	Value   interface{}
-}
-
-func (Send) getRecv() recvAction { return nil }
-
-func (s Send) getSend() sendAction { return s }
-
-func (s Send) getChannel() interface{} { return s.Channel }
-
-type empty struct {
-	x interface{}
-}
-
-func newEmptyInterface(e empty) reflect.Value {
-	return reflect.ValueOf(e).Field(0)
-}
-
-func (s Send) send() {
-	// With reflect.ChanValue.Send, we must match the types exactly. So, if
-	// s.Channel is a chan interface{} we convert s.Value to an interface{}
-	// first.
-	c := reflect.ValueOf(s.Channel)
-	var v reflect.Value
-	if iface := c.Type().Elem(); iface.Kind() == reflect.Interface && iface.NumMethod() == 0 {
-		v = newEmptyInterface(empty{s.Value})
-	} else {
-		v = reflect.ValueOf(s.Value)
-	}
-	c.Send(v)
-}
-
-// A Close action closes the given channel.
-type Close struct {
-	Channel interface{}
-}
-
-func (Close) getRecv() recvAction { return nil }
-
-func (s Close) getSend() sendAction { return s }
-
-func (s Close) getChannel() interface{} { return s.Channel }
-
-func (s Close) send() { reflect.ValueOf(s.Channel).Close() }
-
-// A ReceivedUnexpected error results if no active Events match a value
-// received from a channel.
-type ReceivedUnexpected struct {
-	Value interface{}
-	ready []*Event
-}
-
-func (r ReceivedUnexpected) Error() string {
-	names := make([]string, len(r.ready))
-	for i, v := range r.ready {
-		names[i] = v.name
-	}
-	return fmt.Sprintf("received unexpected value on one of the channels: %#v. Runnable events: %s", r.Value, strings.Join(names, ", "))
-}
-
-// A SetupError results if there is a error with the configuration of a set of
-// Events.
-type SetupError string
-
-func (s SetupError) Error() string { return string(s) }
-
-func NewEvent(name string, predecessors []*Event, action action) *Event {
-	e := &Event{name, false, predecessors, action}
-	return e
-}
-
-// Given a set of Events, Perform repeatedly iterates over the set and finds the
-// subset of ready Events (that is, all of their predecessors have
-// occurred). From that subset, it pseudo-randomly selects an Event to perform.
-// If the Event is a send event, the send occurs and Perform recalculates the ready
-// set. If the event is a receive event, Perform waits for a value from any of the
-// channels that are contained in any of the events. That value is then matched
-// against the ready events. The first event that matches is considered to
-// have occurred and Perform recalculates the ready set.
-//
-// Perform continues this until all Events have occurred.
-//
-// Note that uncollected goroutines may still be reading from any of the
-// channels read from after Perform returns.
-//
-// For example, consider the problem of testing a function that reads values on
-// one channel and echos them to two output channels. To test this we would
-// create three events: a send event and two receive events. Each of the
-// receive events must list the send event as a predecessor but there is no
-// ordering between the receive events.
-//
-//  send := NewEvent("send", nil, Send{c, 1})
-//  recv1 := NewEvent("recv 1", []*Event{send}, Recv{c, 1})
-//  recv2 := NewEvent("recv 2", []*Event{send}, Recv{c, 1})
-//  Perform(0, []*Event{send, recv1, recv2})
-//
-// At first, only the send event would be in the ready set and thus Perform will
-// send a value to the input channel. Now the two receive events are ready and
-// Perform will match each of them against the values read from the output channels.
-//
-// It would be invalid to list one of the receive events as a predecessor of
-// the other. At each receive step, all the receive channels are considered,
-// thus Perform may see a value from a channel that is not in the current ready
-// set and fail.
-func Perform(seed int64, events []*Event) (err error) {
-	r := rand.New(rand.NewSource(seed))
-
-	channels, err := getChannels(events)
-	if err != nil {
-		return
-	}
-	multiplex := make(chan interface{})
-	for _, channel := range channels {
-		go recvValues(multiplex, channel)
-	}
-
-Outer:
-	for {
-		ready, err := readyEvents(events)
-		if err != nil {
-			return err
-		}
-
-		if len(ready) == 0 {
-			// All events occurred.
-			break
-		}
-
-		event := ready[r.Intn(len(ready))]
-		if send := event.action.getSend(); send != nil {
-			send.send()
-			event.occurred = true
-			continue
-		}
-
-		v := <-multiplex
-		for _, event := range ready {
-			if recv := event.action.getRecv(); recv != nil && recv.recvMatch(v) {
-				event.occurred = true
-				continue Outer
-			}
-		}
-
-		return ReceivedUnexpected{v, ready}
-	}
-
-	return nil
-}
-
-// getChannels returns all the channels listed in any receive events.
-func getChannels(events []*Event) ([]interface{}, error) {
-	channels := make([]interface{}, len(events))
-
-	j := 0
-	for _, event := range events {
-		if recv := event.action.getRecv(); recv == nil {
-			continue
-		}
-		c := event.action.getChannel()
-		if reflect.ValueOf(c).Kind() != reflect.Chan {
-			return nil, SetupError("one of the channel values is not a channel")
-		}
-
-		duplicate := false
-		for _, other := range channels[0:j] {
-			if c == other {
-				duplicate = true
-				break
-			}
-		}
-
-		if !duplicate {
-			channels[j] = c
-			j++
-		}
-	}
-
-	return channels[0:j], nil
-}
-
-// recvValues is a multiplexing helper function. It reads values from the given
-// channel repeatedly, wrapping them up as either a channelRecv or
-// channelClosed structure, and forwards them to the multiplex channel.
-func recvValues(multiplex chan<- interface{}, channel interface{}) {
-	c := reflect.ValueOf(channel)
-
-	for {
-		v, ok := c.Recv()
-		if !ok {
-			multiplex <- channelClosed{channel}
-			return
-		}
-
-		multiplex <- channelRecv{channel, v.Interface()}
-	}
-}
-
-type channelClosed struct {
-	channel interface{}
-}
-
-type channelRecv struct {
-	channel interface{}
-	value   interface{}
-}
-
-// readyEvents returns the subset of events that are ready.
-func readyEvents(events []*Event) ([]*Event, error) {
-	ready := make([]*Event, len(events))
-
-	j := 0
-	eventsWaiting := false
-	for _, event := range events {
-		if event.occurred {
-			continue
-		}
-
-		eventsWaiting = true
-		if event.isReady() {
-			ready[j] = event
-			j++
-		}
-	}
-
-	if j == 0 && eventsWaiting {
-		names := make([]string, len(events))
-		for _, event := range events {
-			if event.occurred {
-				continue
-			}
-			names[j] = event.name
-		}
-
-		return nil, SetupError("dependency cycle in events. These events are waiting to run but cannot: " + strings.Join(names, ", "))
-	}
-
-	return ready[0:j], nil
-}
diff --git a/src/pkg/testing/script/script_test.go b/src/pkg/testing/script/script_test.go
deleted file mode 100644
index e9ab142c2b1..00000000000
--- a/src/pkg/testing/script/script_test.go
+++ /dev/null
@@ -1,75 +0,0 @@
-// 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.
-
-package script
-
-import (
-	"testing"
-)
-
-func TestNoop(t *testing.T) {
-	err := Perform(0, nil)
-	if err != nil {
-		t.Errorf("Got error: %s", err)
-	}
-}
-
-func TestSimple(t *testing.T) {
-	c := make(chan int)
-	defer close(c)
-
-	a := NewEvent("send", nil, Send{c, 1})
-	b := NewEvent("recv", []*Event{a}, Recv{c, 1})
-
-	err := Perform(0, []*Event{a, b})
-	if err != nil {
-		t.Errorf("Got error: %s", err)
-	}
-}
-
-func TestFail(t *testing.T) {
-	c := make(chan int)
-	defer close(c)
-
-	a := NewEvent("send", nil, Send{c, 2})
-	b := NewEvent("recv", []*Event{a}, Recv{c, 1})
-
-	err := Perform(0, []*Event{a, b})
-	if err == nil {
-		t.Errorf("Failed to get expected error")
-	} else if _, ok := err.(ReceivedUnexpected); !ok {
-		t.Errorf("Error returned was of the wrong type: %s", err)
-	}
-}
-
-func TestClose(t *testing.T) {
-	c := make(chan int)
-
-	a := NewEvent("close", nil, Close{c})
-	b := NewEvent("closed", []*Event{a}, Closed{c})
-
-	err := Perform(0, []*Event{a, b})
-	if err != nil {
-		t.Errorf("Got error: %s", err)
-	}
-}
-
-func matchOne(v interface{}) bool {
-	if i, ok := v.(int); ok && i == 1 {
-		return true
-	}
-	return false
-}
-
-func TestRecvMatch(t *testing.T) {
-	c := make(chan int)
-
-	a := NewEvent("send", nil, Send{c, 1})
-	b := NewEvent("recv", []*Event{a}, RecvMatch{c, matchOne})
-
-	err := Perform(0, []*Event{a, b})
-	if err != nil {
-		t.Errorf("Got error: %s", err)
-	}
-}