vm: allow Diagnose to directly return diagnosis

Rather than writing the diagnosis to the kernel console, Diagnose can
now directly return the extra debugging info, which will be appended ot
the kernel console log.

1 files changed, 35 insertions, 12 deletions

diff --git a/vm/vm_test.go b/vm/vm_test.go
index 626ad62cb..ac86ad9c5 100644
--- a/vm/vm_test.go
+++ b/vm/vm_test.go
@@ -31,9 +31,10 @@ func (pool *testPool) Create(workdir string, index int) (vmimpl.Instance, error)
 }
 
 type testInstance struct {
-	outc        chan []byte
-	errc        chan error
-	diagnoseBug bool
+	outc           chan []byte
+	errc           chan error
+	diagnoseBug    bool
+	diagnoseNoWait bool
 }
 
 func (inst *testInstance) Copy(hostSrc string) (string, error) {
@@ -49,13 +50,20 @@ func (inst *testInstance) Run(timeout time.Duration, stop <-chan bool, command s
 	return inst.outc, inst.errc, nil
 }
 
-func (inst *testInstance) Diagnose() bool {
+func (inst *testInstance) Diagnose() ([]byte, bool) {
+	var diag []byte
 	if inst.diagnoseBug {
-		inst.outc <- []byte("BUG: DIAGNOSE\n")
+		diag = []byte("BUG: DIAGNOSE\n")
 	} else {
-		inst.outc <- []byte("DIAGNOSE\n")
+		diag = []byte("DIAGNOSE\n")
 	}
-	return true
+
+	if inst.diagnoseNoWait {
+		return diag, false
+	}
+
+	inst.outc <- diag
+	return nil, true
 }
 
 func (inst *testInstance) Close() {
@@ -74,11 +82,12 @@ func init() {
 }
 
 type Test struct {
-	Name        string
-	CanExit     bool // if the program is allowed to exit normally
-	DiagnoseBug bool // Diagnose produces output that is detected as kernel crash
-	Body        func(outc chan []byte, errc chan error)
-	Report      *report.Report
+	Name           string
+	CanExit        bool // if the program is allowed to exit normally
+	DiagnoseBug    bool // Diagnose produces output that is detected as kernel crash
+	DiagnoseNoWait bool // Diagnose returns output directly rather than to console
+	Body           func(outc chan []byte, errc chan error)
+	Report         *report.Report
 }
 
 var tests = []*Test{
@@ -121,6 +130,19 @@ var tests = []*Test{
 		},
 	},
 	{
+		Name: "diagnose-no-wait",
+		Body: func(outc chan []byte, errc chan error) {
+			errc <- nil
+		},
+		DiagnoseNoWait: true,
+		Report: &report.Report{
+			Title: lostConnectionCrash,
+			Output: []byte(
+				"DIAGNOSIS:\nDIAGNOSE\n",
+			),
+		},
+	},
+	{
 		Name: "kernel-crashes",
 		Body: func(outc chan []byte, errc chan error) {
 			outc <- []byte("BUG: bad\n")
@@ -280,6 +302,7 @@ func testMonitorExecution(t *testing.T, test *Test) {
 	}
 	testInst := inst.impl.(*testInstance)
 	testInst.diagnoseBug = test.DiagnoseBug
+	testInst.diagnoseNoWait = test.DiagnoseNoWait
 	done := make(chan bool)
 	go func() {
 		test.Body(testInst.outc, testInst.errc)