libgo: Update to weekly.2011-12-22.

From-SVN: r183150

4 files changed, 242 insertions, 65 deletions

diff --git a/libgo/go/testing/benchmark.go b/libgo/go/testing/benchmark.go
index e81e5c5..4ce6370 100644
--- a/libgo/go/testing/benchmark.go
+++ b/libgo/go/testing/benchmark.go
@@ -25,12 +25,12 @@ type InternalBenchmark struct {
 // B is a type passed to Benchmark functions to manage benchmark
 // timing and to specify the number of iterations to run.
 type B struct {
+	common
 	N         int
 	benchmark InternalBenchmark
-	ns        time.Duration
 	bytes     int64
-	start     time.Time
 	timerOn   bool
+	result    BenchmarkResult
 }
 
 // StartTimer starts timing a test.  This function is called automatically
@@ -48,7 +48,7 @@ func (b *B) StartTimer() {
 // want to measure.
 func (b *B) StopTimer() {
 	if b.timerOn {
-		b.ns += time.Now().Sub(b.start)
+		b.duration += time.Now().Sub(b.start)
 		b.timerOn = false
 	}
 }
@@ -59,7 +59,7 @@ func (b *B) ResetTimer() {
 	if b.timerOn {
 		b.start = time.Now()
 	}
-	b.ns = 0
+	b.duration = 0
 }
 
 // SetBytes records the number of bytes processed in a single operation.
@@ -70,7 +70,7 @@ func (b *B) nsPerOp() int64 {
 	if b.N <= 0 {
 		return 0
 	}
-	return b.ns.Nanoseconds() / int64(b.N)
+	return b.duration.Nanoseconds() / int64(b.N)
 }
 
 // runN runs a single benchmark for the specified number of iterations.
@@ -127,17 +127,25 @@ func roundUp(n int) int {
 	return 10 * base
 }
 
-// run times the benchmark function.  It gradually increases the number
+// run times the benchmark function in a separate goroutine.
+func (b *B) run() BenchmarkResult {
+	go b.launch()
+	<-b.signal
+	return b.result
+}
+
+// launch launches the benchmark function.  It gradually increases the number
 // of benchmark iterations until the benchmark runs for a second in order
 // to get a reasonable measurement.  It prints timing information in this form
 //		testing.BenchmarkHello	100000		19 ns/op
-func (b *B) run() BenchmarkResult {
+// launch is run by the fun function as a separate goroutine.
+func (b *B) launch() {
 	// Run the benchmark for a single iteration in case it's expensive.
 	n := 1
 	b.runN(n)
 	// Run the benchmark for at least the specified amount of time.
 	d := time.Duration(*benchTime * float64(time.Second))
-	for b.ns < d && n < 1e9 {
+	for !b.failed && b.duration < d && n < 1e9 {
 		last := n
 		// Predict iterations/sec.
 		if b.nsPerOp() == 0 {
@@ -153,7 +161,8 @@ func (b *B) run() BenchmarkResult {
 		n = roundUp(n)
 		b.runN(n)
 	}
-	return BenchmarkResult{b.N, b.ns, b.bytes}
+	b.result = BenchmarkResult{b.N, b.duration, b.bytes}
+	b.signal <- b
 }
 
 // The results of a benchmark run.
@@ -215,14 +224,32 @@ func RunBenchmarks(matchString func(pat, str string) (bool, error), benchmarks [
 		}
 		for _, procs := range cpuList {
 			runtime.GOMAXPROCS(procs)
-			b := &B{benchmark: Benchmark}
+			b := &B{
+				common: common{
+					signal: make(chan interface{}),
+				},
+				benchmark: Benchmark,
+			}
 			benchName := Benchmark.Name
 			if procs != 1 {
 				benchName = fmt.Sprintf("%s-%d", Benchmark.Name, procs)
 			}
 			fmt.Printf("%s\t", benchName)
 			r := b.run()
+			if b.failed {
+				// The output could be very long here, but probably isn't.
+				// We print it all, regardless, because we don't want to trim the reason
+				// the benchmark failed.
+				fmt.Printf("--- FAIL: %s\n%s", benchName, b.output)
+				continue
+			}
 			fmt.Printf("%v\n", r)
+			// Unlike with tests, we ignore the -chatty flag and always print output for
+			// benchmarks since the output generation time will skew the results.
+			if len(b.output) > 0 {
+				b.trimOutput()
+				fmt.Printf("--- BENCH: %s\n%s", benchName, b.output)
+			}
 			if p := runtime.GOMAXPROCS(-1); p != procs {
 				fmt.Fprintf(os.Stderr, "testing: %s left GOMAXPROCS set to %d\n", benchName, p)
 			}
@@ -230,9 +257,31 @@ func RunBenchmarks(matchString func(pat, str string) (bool, error), benchmarks [
 	}
 }
 
+// trimOutput shortens the output from a benchmark, which can be very long.
+func (b *B) trimOutput() {
+	// The output is likely to appear multiple times because the benchmark
+	// is run multiple times, but at least it will be seen. This is not a big deal
+	// because benchmarks rarely print, but just in case, we trim it if it's too long.
+	const maxNewlines = 10
+	for nlCount, j := 0, 0; j < len(b.output); j++ {
+		if b.output[j] == '\n' {
+			nlCount++
+			if nlCount >= maxNewlines {
+				b.output = append(b.output[:j], "\n\t... [output truncated]\n"...)
+				break
+			}
+		}
+	}
+}
+
 // Benchmark benchmarks a single function. Useful for creating
 // custom benchmarks that do not use gotest.
 func Benchmark(f func(b *B)) BenchmarkResult {
-	b := &B{benchmark: InternalBenchmark{"", f}}
+	b := &B{
+		common: common{
+			signal: make(chan interface{}),
+		},
+		benchmark: InternalBenchmark{"", f},
+	}
 	return b.run()
 }
diff --git a/libgo/go/testing/example.go b/libgo/go/testing/example.go
index e23f13b..fdeda13 100644
--- a/libgo/go/testing/example.go
+++ b/libgo/go/testing/example.go
@@ -9,6 +9,7 @@ import (
 	"fmt"
 	"io"
 	"os"
+	"strings"
 	"time"
 )
 
@@ -67,11 +68,9 @@ func RunExamples(examples []InternalExample) (ok bool) {
 
 		// report any errors
 		tstr := fmt.Sprintf("(%.2f seconds)", dt.Seconds())
-		if out != eg.Output {
-			fmt.Printf(
-				"--- FAIL: %s %s\ngot:\n%s\nwant:\n%s\n",
-				eg.Name, tstr, out, eg.Output,
-			)
+		if g, e := strings.TrimSpace(out), strings.TrimSpace(eg.Output); g != e {
+			fmt.Printf("--- FAIL: %s %s\ngot:\n%s\nwant:\n%s\n",
+				eg.Name, tstr, g, e)
 			ok = false
 		} else if *chatty {
 			fmt.Printf("--- PASS: %s %s\n", eg.Name, tstr)
diff --git a/libgo/go/testing/testing.go b/libgo/go/testing/testing.go
index ca2fced..16890e0 100644
--- a/libgo/go/testing/testing.go
+++ b/libgo/go/testing/testing.go
@@ -23,8 +23,8 @@
 //     }
 // The benchmark package will vary b.N until the benchmark function lasts
 // long enough to be timed reliably.  The output
-//     testing.BenchmarkHello	500000	      4076 ns/op
-// means that the loop ran 500000 times at a speed of 4076 ns per loop.
+//     testing.BenchmarkHello    10000000    282 ns/op
+// means that the loop ran 10000000 times at a speed of 282 ns per loop.
 //
 // If a benchmark needs some expensive setup before running, the timer
 // may be stopped:
@@ -70,6 +70,17 @@ var (
 	cpuList []int
 )
 
+// common holds the elements common between T and B and
+// captures common methods such as Errorf.
+type common struct {
+	output   []byte    // Output generated by test or benchmark.
+	failed   bool      // Test or benchmark has failed.
+	start    time.Time // Time test or benchmark started
+	duration time.Duration
+	self     interface{}      // To be sent on signal channel when done.
+	signal   chan interface{} // Output for serial tests.
+}
+
 // Short reports whether the -test.short flag is set.
 func Short() bool {
 	return *short
@@ -79,7 +90,7 @@ func Short() bool {
 // If addFileLine is true, it also prefixes the string with the file and line of the call site.
 func decorate(s string, addFileLine bool) string {
 	if addFileLine {
-		_, file, line, ok := runtime.Caller(3) // decorate + log + public function.
+		_, file, line, ok := runtime.Caller(4) // decorate + log + public function.
 		if ok {
 			// Truncate file name at last file name separator.
 			if index := strings.LastIndex(file, "/"); index >= 0 {
@@ -111,70 +122,68 @@ func decorate(s string, addFileLine bool) string {
 // T is a type passed to Test functions to manage test state and support formatted test logs.
 // Logs are accumulated during execution and dumped to standard error when done.
 type T struct {
-	name          string        // Name of test.
-	errors        string        // Error string from test.
-	failed        bool          // Test has failed.
-	ch            chan *T       // Output for serial tests.
-	startParallel chan bool     // Parallel tests will wait on this.
-	start         time.Time     // Time test started
-	dt            time.Duration // Length of test
+	common
+	name          string    // Name of test.
+	startParallel chan bool // Parallel tests will wait on this.
 }
 
-// Fail marks the Test function as having failed but continues execution.
-func (t *T) Fail() { t.failed = true }
+// Fail marks the function as having failed but continues execution.
+func (c *common) Fail() { c.failed = true }
 
-// Failed returns whether the Test function has failed.
-func (t *T) Failed() bool { return t.failed }
+// Failed returns whether the function has failed.
+func (c *common) Failed() bool { return c.failed }
 
-// FailNow marks the Test function as having failed and stops its execution.
+// FailNow marks the function as having failed and stops its execution.
 // Execution will continue at the next Test.
-func (t *T) FailNow() {
-	t.dt = time.Now().Sub(t.start)
-	t.Fail()
-	t.ch <- t
+func (c *common) FailNow() {
+	c.duration = time.Now().Sub(c.start)
+	c.Fail()
+	c.signal <- c.self
 	runtime.Goexit()
 }
 
 // log generates the output. It's always at the same stack depth.
-func (t *T) log(s string) { t.errors += decorate(s, true) }
+func (c *common) log(s string) {
+	c.output = append(c.output, decorate(s, true)...)
+}
 
-// Log formats its arguments using default formatting, analogous to Print(),
+// Log formats its arguments using default formatting, analogous to Println(),
 // and records the text in the error log.
-func (t *T) Log(args ...interface{}) { t.log(fmt.Sprintln(args...)) }
+func (c *common) Log(args ...interface{}) { c.log(fmt.Sprintln(args...)) }
 
 // Logf formats its arguments according to the format, analogous to Printf(),
 // and records the text in the error log.
-func (t *T) Logf(format string, args ...interface{}) { t.log(fmt.Sprintf(format, args...)) }
+func (c *common) Logf(format string, args ...interface{}) { c.log(fmt.Sprintf(format, args...)) }
 
 // Error is equivalent to Log() followed by Fail().
-func (t *T) Error(args ...interface{}) {
-	t.log(fmt.Sprintln(args...))
-	t.Fail()
+func (c *common) Error(args ...interface{}) {
+	c.log(fmt.Sprintln(args...))
+	c.Fail()
 }
 
 // Errorf is equivalent to Logf() followed by Fail().
-func (t *T) Errorf(format string, args ...interface{}) {
-	t.log(fmt.Sprintf(format, args...))
-	t.Fail()
+func (c *common) Errorf(format string, args ...interface{}) {
+	c.log(fmt.Sprintf(format, args...))
+	c.Fail()
 }
 
 // Fatal is equivalent to Log() followed by FailNow().
-func (t *T) Fatal(args ...interface{}) {
-	t.log(fmt.Sprintln(args...))
-	t.FailNow()
+func (c *common) Fatal(args ...interface{}) {
+	c.log(fmt.Sprintln(args...))
+	c.FailNow()
 }
 
 // Fatalf is equivalent to Logf() followed by FailNow().
-func (t *T) Fatalf(format string, args ...interface{}) {
-	t.log(fmt.Sprintf(format, args...))
-	t.FailNow()
+func (c *common) Fatalf(format string, args ...interface{}) {
+	c.log(fmt.Sprintf(format, args...))
+	c.FailNow()
 }
 
 // Parallel signals that this test is to be run in parallel with (and only with) 
 // other parallel tests in this CPU group.
 func (t *T) Parallel() {
-	t.ch <- nil       // Release main testing loop
-	<-t.startParallel // Wait for serial tests to finish
+	t.signal <- (*T)(nil) // Release main testing loop
+	<-t.startParallel     // Wait for serial tests to finish
 }
 
 // An internal type but exported because it is cross-package; part of the implementation
@@ -187,8 +196,8 @@ type InternalTest struct {
 func tRunner(t *T, test *InternalTest) {
 	t.start = time.Now()
 	test.F(t)
-	t.dt = time.Now().Sub(t.start)
-	t.ch <- t
+	t.duration = time.Now().Sub(t.start)
+	t.signal <- t
 }
 
 // An internal function but exported because it is cross-package; part of the implementation
@@ -211,13 +220,13 @@ func Main(matchString func(pat, str string) (bool, error), tests []InternalTest,
 	after()
 }
 
-func report(t *T) {
-	tstr := fmt.Sprintf("(%.2f seconds)", t.dt.Seconds())
+func (t *T) report() {
+	tstr := fmt.Sprintf("(%.2f seconds)", t.duration.Seconds())
 	format := "--- %s: %s %s\n%s"
 	if t.failed {
-		fmt.Printf(format, "FAIL", t.name, tstr, t.errors)
+		fmt.Printf(format, "FAIL", t.name, tstr, t.output)
 	} else if *chatty {
-		fmt.Printf(format, "PASS", t.name, tstr, t.errors)
+		fmt.Printf(format, "PASS", t.name, tstr, t.output)
 	}
 }
 
@@ -227,9 +236,14 @@ func RunTests(matchString func(pat, str string) (bool, error), tests []InternalT
 		fmt.Fprintln(os.Stderr, "testing: warning: no tests to run")
 		return
 	}
-	ch := make(chan *T)
 	for _, procs := range cpuList {
 		runtime.GOMAXPROCS(procs)
+		// We build a new channel tree for each run of the loop.
+		// collector merges in one channel all the upstream signals from parallel tests.
+		// If all tests pump to the same channel, a bug can occur where a test
+		// kicks off a goroutine that Fails, yet the test still delivers a completion signal,
+		// which skews the counting.
+		var collector = make(chan interface{})
 
 		numParallel := 0
 		startParallel := make(chan bool)
@@ -247,17 +261,27 @@ func RunTests(matchString func(pat, str string) (bool, error), tests []InternalT
 			if procs != 1 {
 				testName = fmt.Sprintf("%s-%d", tests[i].Name, procs)
 			}
-			t := &T{ch: ch, name: testName, startParallel: startParallel}
+			t := &T{
+				common: common{
+					signal: make(chan interface{}),
+				},
+				name:          testName,
+				startParallel: startParallel,
+			}
+			t.self = t
 			if *chatty {
 				fmt.Printf("=== RUN %s\n", t.name)
 			}
 			go tRunner(t, &tests[i])
-			out := <-t.ch
+			out := (<-t.signal).(*T)
 			if out == nil { // Parallel run.
+				go func() {
+					collector <- <-t.signal
+				}()
 				numParallel++
 				continue
 			}
-			report(t)
+			t.report()
 			ok = ok && !out.failed
 		}
 
@@ -269,8 +293,8 @@ func RunTests(matchString func(pat, str string) (bool, error), tests []InternalT
 				numParallel--
 				continue
 			}
-			t := <-ch
-			report(t)
+			t := (<-collector).(*T)
+			t.report()
 			ok = ok && !t.failed
 			running--
 		}
diff --git a/libgo/go/testing/wrapper.go b/libgo/go/testing/wrapper.go
new file mode 100644
index 0000000..2bef9df
--- /dev/null
+++ b/libgo/go/testing/wrapper.go
@@ -0,0 +1,105 @@
+// 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.
+
+// This file contains wrappers so t.Errorf etc. have documentation.
+// TODO: delete when godoc shows exported methods for unexported embedded fields.
+// TODO: need to change the argument to runtime.Caller in testing.go from 4 to 3 at that point.
+
+package testing
+
+// Fail marks the function as having failed but continues execution.
+func (b *B) Fail() {
+	b.common.Fail()
+}
+
+// Failed returns whether the function has failed.
+func (b *B) Failed() bool {
+	return b.common.Failed()
+}
+
+// FailNow marks the function as having failed and stops its execution.
+// Execution will continue at the next Test.
+func (b *B) FailNow() {
+	b.common.FailNow()
+}
+
+// Log formats its arguments using default formatting, analogous to Println(),
+// and records the text in the error log.
+func (b *B) Log(args ...interface{}) {
+	b.common.Log(args...)
+}
+
+// Logf formats its arguments according to the format, analogous to Printf(),
+// and records the text in the error log.
+func (b *B) Logf(format string, args ...interface{}) {
+	b.common.Logf(format, args...)
+}
+
+// Error is equivalent to Log() followed by Fail().
+func (b *B) Error(args ...interface{}) {
+	b.common.Error(args...)
+}
+
+// Errorf is equivalent to Logf() followed by Fail().
+func (b *B) Errorf(format string, args ...interface{}) {
+	b.common.Errorf(format, args...)
+}
+
+// Fatal is equivalent to Log() followed by FailNow().
+func (b *B) Fatal(args ...interface{}) {
+	b.common.Fatal(args...)
+}
+
+// Fatalf is equivalent to Logf() followed by FailNow().
+func (b *B) Fatalf(format string, args ...interface{}) {
+	b.common.Fatalf(format, args...)
+}
+
+// Fail marks the function as having failed but continues execution.
+func (t *T) Fail() {
+	t.common.Fail()
+}
+
+// Failed returns whether the function has failed.
+func (t *T) Failed() bool {
+	return t.common.Failed()
+}
+
+// FailNow marks the function as having failed and stops its execution.
+// Execution will continue at the next Test.
+func (t *T) FailNow() {
+	t.common.FailNow()
+}
+
+// Log formats its arguments using default formatting, analogous to Println(),
+// and records the text in the error log.
+func (t *T) Log(args ...interface{}) {
+	t.common.Log(args...)
+}
+
+// Logf formats its arguments according to the format, analogous to Printf(),
+// and records the text in the error log.
+func (t *T) Logf(format string, args ...interface{}) {
+	t.common.Logf(format, args...)
+}
+
+// Error is equivalent to Log() followed by Fail().
+func (t *T) Error(args ...interface{}) {
+	t.common.Error(args...)
+}
+
+// Errorf is equivalent to Logf() followed by Fail().
+func (t *T) Errorf(format string, args ...interface{}) {
+	t.common.Errorf(format, args...)
+}
+
+// Fatal is equivalent to Log() followed by FailNow().
+func (t *T) Fatal(args ...interface{}) {
+	t.common.Fatal(args...)
+}
+
+// Fatalf is equivalent to Logf() followed by FailNow().
+func (t *T) Fatalf(format string, args ...interface{}) {
+	t.common.Fatalf(format, args...)
+}