runtime: copy rdebug code from Go 1.7 runtime

    
    While we're at it, update the runtime/debug package, and start running
    its testsuite by default.  I'm not sure why runtime/debug was not
    previously updated to 1.7.  Doing that led me to fix some minor aspects
    of runtime.Stack and the C function runtime/debug.readGCStats.
    
    Reviewed-on: https://go-review.googlesource.com/31251

From-SVN: r241261

8 files changed, 111 insertions, 30 deletions

diff --git a/libgo/go/runtime/debug/garbage.go b/libgo/go/runtime/debug/garbage.go
index 8d52837..81444971 100644
--- a/libgo/go/runtime/debug/garbage.go
+++ b/libgo/go/runtime/debug/garbage.go
@@ -16,17 +16,10 @@ type GCStats struct {
 	NumGC          int64           // number of garbage collections
 	PauseTotal     time.Duration   // total pause for all collections
 	Pause          []time.Duration // pause history, most recent first
+	PauseEnd       []time.Time     // pause end times history, most recent first
 	PauseQuantiles []time.Duration
 }
 
-// Implemented in package runtime.
-func readGCStats(*[]time.Duration)
-func enableGC(bool) bool
-func setGCPercent(int) int
-func freeOSMemory()
-func setMaxStack(int) int
-func setMaxThreads(int) int
-
 // ReadGCStats reads statistics about garbage collection into stats.
 // The number of entries in the pause history is system-dependent;
 // stats.Pause slice will be reused if large enough, reallocated otherwise.
@@ -38,25 +31,36 @@ func setMaxThreads(int) int
 func ReadGCStats(stats *GCStats) {
 	// Create a buffer with space for at least two copies of the
 	// pause history tracked by the runtime. One will be returned
-	// to the caller and the other will be used as a temporary buffer
-	// for computing quantiles.
+	// to the caller and the other will be used as transfer buffer
+	// for end times history and as a temporary buffer for
+	// computing quantiles.
 	const maxPause = len(((*runtime.MemStats)(nil)).PauseNs)
-	if cap(stats.Pause) < 2*maxPause {
-		stats.Pause = make([]time.Duration, 2*maxPause)
+	if cap(stats.Pause) < 2*maxPause+3 {
+		stats.Pause = make([]time.Duration, 2*maxPause+3)
 	}
 
-	// readGCStats fills in the pause history (up to maxPause entries)
-	// and then three more: Unix ns time of last GC, number of GC,
-	// and total pause time in nanoseconds. Here we depend on the
-	// fact that time.Duration's native unit is nanoseconds, so the
-	// pauses and the total pause time do not need any conversion.
+	// readGCStats fills in the pause and end times histories (up to
+	// maxPause entries) and then three more: Unix ns time of last GC,
+	// number of GC, and total pause time in nanoseconds. Here we
+	// depend on the fact that time.Duration's native unit is
+	// nanoseconds, so the pauses and the total pause time do not need
+	// any conversion.
 	readGCStats(&stats.Pause)
 	n := len(stats.Pause) - 3
 	stats.LastGC = time.Unix(0, int64(stats.Pause[n]))
 	stats.NumGC = int64(stats.Pause[n+1])
 	stats.PauseTotal = stats.Pause[n+2]
+	n /= 2 // buffer holds pauses and end times
 	stats.Pause = stats.Pause[:n]
 
+	if cap(stats.PauseEnd) < maxPause {
+		stats.PauseEnd = make([]time.Time, 0, maxPause)
+	}
+	stats.PauseEnd = stats.PauseEnd[:0]
+	for _, ns := range stats.Pause[n : n+n] {
+		stats.PauseEnd = append(stats.PauseEnd, time.Unix(0, int64(ns)))
+	}
+
 	if len(stats.PauseQuantiles) > 0 {
 		if n == 0 {
 			for i := range stats.PauseQuantiles {
@@ -91,9 +95,9 @@ func (x byDuration) Less(i, j int) bool { return x[i] < x[j] }
 // at startup, or 100 if the variable is not set.
 // A negative percentage disables garbage collection.
 func SetGCPercent(percent int) int {
-	old := setGCPercent(percent)
+	old := setGCPercent(int32(percent))
 	runtime.GC()
-	return old
+	return int(old)
 }
 
 // FreeOSMemory forces a garbage collection followed by an
@@ -145,7 +149,9 @@ func SetMaxThreads(threads int) int {
 // that the runtime trigger only a panic, not a crash.
 // SetPanicOnFault applies only to the current goroutine.
 // It returns the previous setting.
-func SetPanicOnFault(enabled bool) bool
+func SetPanicOnFault(enabled bool) bool {
+	return setPanicOnFault(enabled)
+}
 
 // WriteHeapDump writes a description of the heap and the objects in
 // it to the given file descriptor.
diff --git a/libgo/go/runtime/debug/garbage_test.go b/libgo/go/runtime/debug/garbage_test.go
index 3d07cbb..6ec94aa 100644
--- a/libgo/go/runtime/debug/garbage_test.go
+++ b/libgo/go/runtime/debug/garbage_test.go
@@ -71,6 +71,19 @@ func TestReadGCStats(t *testing.T) {
 			t.Errorf("stats.PauseQuantiles[%d]=%d > stats.PauseQuantiles[%d]=%d", i, q[i], i+1, q[i+1])
 		}
 	}
+
+	// compare memory stats with gc stats:
+	if len(stats.PauseEnd) != n {
+		t.Fatalf("len(stats.PauseEnd) = %d, want %d", len(stats.PauseEnd), n)
+	}
+	off := (int(mstats.NumGC) + len(mstats.PauseEnd) - 1) % len(mstats.PauseEnd)
+	for i := 0; i < n; i++ {
+		dt := stats.PauseEnd[i]
+		if dt.UnixNano() != int64(mstats.PauseEnd[off]) {
+			t.Errorf("stats.PauseEnd[%d] = %d, want %d", i, dt, mstats.PauseEnd[off])
+		}
+		off = (off + len(mstats.PauseEnd) - 1) % len(mstats.PauseEnd)
+	}
 }
 
 var big = make([]byte, 1<<20)
diff --git a/libgo/go/runtime/debug/stack_test.go b/libgo/go/runtime/debug/stack_test.go
index 5f9f60c..67931d1 100644
--- a/libgo/go/runtime/debug/stack_test.go
+++ b/libgo/go/runtime/debug/stack_test.go
@@ -50,10 +50,12 @@ func TestStack(t *testing.T) {
 		check(t, lines[n], line)
 		n++
 	}
-	frame("stack_test.go", "\tmethod.N15_runtime_debug.T: return Stack()")
-	frame("stack_test.go", "\tmethod.N15_runtime_debug.T: return t.ptrmethod()")
-	frame("stack_test.go", "\tTestStack: b := T(0).method()")
-	frame("testing/testing.go", "")
+	n++
+	frame("stack.go", "runtime_debug.Stack")
+	frame("stack_test.go", "ptrmethod")
+	frame("stack_test.go", "method")
+	frame("stack_test.go", "runtime_debug_test.TestStack")
+	frame("testing.go", "")
 }
 
 func check(t *testing.T, line, has string) {
diff --git a/libgo/go/runtime/debug/stubs.go b/libgo/go/runtime/debug/stubs.go
new file mode 100644
index 0000000..2cba136
--- /dev/null
+++ b/libgo/go/runtime/debug/stubs.go
@@ -0,0 +1,17 @@
+// Copyright 2014 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 debug
+
+import (
+	"time"
+)
+
+// Implemented in package runtime.
+func readGCStats(*[]time.Duration)
+func freeOSMemory()
+func setMaxStack(int) int
+func setGCPercent(int32) int32
+func setPanicOnFault(bool) bool
+func setMaxThreads(int) int
diff --git a/libgo/go/runtime/mprof.go b/libgo/go/runtime/mprof.go
index 8d11031..a2701e3 100644
--- a/libgo/go/runtime/mprof.go
+++ b/libgo/go/runtime/mprof.go
@@ -623,7 +623,7 @@ func Stack(buf []byte, all bool) int {
 		gp.m.traceback = 1
 		gp.writebuf = buf[0:0:len(buf)]
 		goroutineheader(gp)
-		traceback()
+		traceback(1)
 		if all {
 			tracebackothers(gp)
 		}
@@ -653,7 +653,7 @@ func tracealloc(p unsafe.Pointer, size uintptr, typ *_type) {
 	}
 	if gp.m.curg == nil || gp == gp.m.curg {
 		goroutineheader(gp)
-		traceback()
+		traceback(1)
 	} else {
 		goroutineheader(gp.m.curg)
 		// FIXME: Can't do traceback of other g.
@@ -669,7 +669,7 @@ func tracefree(p unsafe.Pointer, size uintptr) {
 	gp.m.traceback = 2
 	print("tracefree(", p, ", ", hex(size), ")\n")
 	goroutineheader(gp)
-	traceback()
+	traceback(1)
 	print("\n")
 	gp.m.traceback = 0
 	unlock(&tracelock)
diff --git a/libgo/go/runtime/rdebug.go b/libgo/go/runtime/rdebug.go
new file mode 100644
index 0000000..76535a9
--- /dev/null
+++ b/libgo/go/runtime/rdebug.go
@@ -0,0 +1,27 @@
+// Copyright 2014 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 runtime
+
+import _ "unsafe" // for go:linkname
+
+// Define maxstacksize here for gccgo. For gc it is defined in
+// stack.go, but gccgo doesn't use that file. Or, for that matter,
+// maxstacksize.
+var maxstacksize uintptr = 1 << 20 // enough until runtime.main sets it for real
+
+//go:linkname setMaxStack runtime_debug.setMaxStack
+func setMaxStack(in int) (out int) {
+	out = int(maxstacksize)
+	maxstacksize = uintptr(in)
+	return out
+}
+
+//go:linkname setPanicOnFault runtime_debug.setPanicOnFault
+func setPanicOnFault(new bool) (old bool) {
+	_g_ := getg()
+	old = _g_.paniconfault
+	_g_.paniconfault = new
+	return old
+}
diff --git a/libgo/go/runtime/stubs.go b/libgo/go/runtime/stubs.go
index 477c6be..3db8fea 100644
--- a/libgo/go/runtime/stubs.go
+++ b/libgo/go/runtime/stubs.go
@@ -444,3 +444,19 @@ func setprofilebucket(p unsafe.Pointer, b *bucket)
 
 // Currently in proc.c.
 func tracebackothers(*g)
+
+// Temporary for gccgo until we port mgc.go.
+func setgcpercent(int32) int32
+
+//go:linkname setGCPercent runtime_debug.setGCPercent
+func setGCPercent(in int32) (out int32) {
+	return setgcpercent(in)
+}
+
+// Temporary for gccgo until we port proc.go.
+func setmaxthreads(int) int
+
+//go:linkname setMaxThreads runtime_debug.setMaxThreads
+func setMaxThreads(in int) (out int) {
+	return setmaxthreads(in)
+}
diff --git a/libgo/go/runtime/traceback_gccgo.go b/libgo/go/runtime/traceback_gccgo.go
index 4f3d7c0..b102826 100644
--- a/libgo/go/runtime/traceback_gccgo.go
+++ b/libgo/go/runtime/traceback_gccgo.go
@@ -67,9 +67,9 @@ func callers(skip int, locbuf []location) int {
 // traceback prints a traceback of the current goroutine.
 // This differs from the gc version, which is given pc, sp, lr and g and
 // can print a traceback of any goroutine.
-func traceback() {
+func traceback(skip int32) {
 	var locbuf [100]location
-	c := c_callers(1, &locbuf[0], int32(len(locbuf)), false)
+	c := c_callers(skip+1, &locbuf[0], int32(len(locbuf)), false)
 	printtrace(locbuf[:c], getg())
 }
 
@@ -77,7 +77,7 @@ func traceback() {
 func printtrace(locbuf []location, gp *g) {
 	for i := range locbuf {
 		if showframe(locbuf[i].function, gp) {
-			print(locbuf[i].function, "\n\t", locbuf[i].filename, ":", locbuf[i].lineno)
+			print(locbuf[i].function, "\n\t", locbuf[i].filename, ":", locbuf[i].lineno, "\n")
 		}
 	}
 }