Change threads

services/process/server/process.go

@@ -230,7 +230,7 @@ func (s *server) GetStacks(ctx context.Context, req *pb.GetStacksRequest) (*pb.G
 		// New thread so append last entry and start over.
 		if fields[0] == "Thread" {
 			// Depending on wrapper/gdb this may have additional fields but we don't need them.
-			if len(fields) < 6 {
+			if len(fields) < 4 {
 				recorder.CounterOrLog(ctx, processGetStacksFailureCounter, 1, attribute.String("reason", "parse_err"))
 				return nil, status.Errorf(codes.Internal, "unparsable pstack output for new thread: %s", text)
 			}
@@ -244,13 +244,21 @@ func (s *server) GetStacks(ctx context.Context, req *pb.GetStacksRequest) (*pb.G
 				recorder.CounterOrLog(ctx, processGetStacksFailureCounter, 1, attribute.String("reason", "parse_err"))
 				return nil, status.Errorf(codes.Internal, "can't parse thread number: %s : %v", text, err)
 			}
-			if n, err := fmt.Sscanf(fields[3], "0x%x", &stack.ThreadId); n != 1 || err != nil {
-				recorder.CounterOrLog(ctx, processGetStacksFailureCounter, 1, attribute.String("reason", "parse_err"))
-				return nil, status.Errorf(codes.Internal, "can't parse thread id: %s : %v", text, err)
+			if fields[2] == "(Thread" && len(fields) >= 6 {
+				if n, err := fmt.Sscanf(fields[3], "0x%x", &stack.ThreadId); n != 1 || err != nil {
+					recorder.CounterOrLog(ctx, processGetStacksFailureCounter, 1, attribute.String("reason", "parse_err"))
+					return nil, status.Errorf(codes.Internal, "can't parse thread id: %s : %v", text, err)
+				}
+				if n, err := fmt.Sscanf(fields[5], "%d", &stack.Lwp); n != 1 || err != nil {
+					recorder.CounterOrLog(ctx, processGetStacksFailureCounter, 1, attribute.String("reason", "parse_err"))
+					return nil, status.Errorf(codes.Internal, "can't parse lwp: %s : %v", text, err)
+				}
 			}
-			if n, err := fmt.Sscanf(fields[5], "%d", &stack.Lwp); n != 1 || err != nil {
-				recorder.CounterOrLog(ctx, processGetStacksFailureCounter, 1, attribute.String("reason", "parse_err"))
-				return nil, status.Errorf(codes.Internal, "can't parse lwp: %s : %v", text, err)
+			if fields[2] == "(LWP" {
+				if n, err := fmt.Sscanf(fields[3], "%d", &stack.Lwp); n != 1 || err != nil {
+					recorder.CounterOrLog(ctx, processGetStacksFailureCounter, 1, attribute.String("reason", "parse_err"))
+					return nil, status.Errorf(codes.Internal, "can't parse lwp: %s : %v", text, err)
+				}
 			}
 			numEntries++
 			continue

services/process/server/process_linux_test.go

@@ -30,12 +30,16 @@ var (
 		"./testdata/linux_bad3.ps", // bad nice value
 	}
 
-	testdataPstackNoThreads              = "./testdata/linux_pstack_no_threads.txt"
-	testdataPstackNoThreadsTextProto     = "./testdata/linux_pstack_no_threads.textproto"
-	testdataPstackThreads                = "./testdata/linux_pstack_threads.txt"
-	testdataPstackThreadsTextProto       = "./testdata/linux_pstack_threads.textproto"
-	testdataPstackThreadsBadThread       = "./testdata/linux_pstack_threads_bad_thread.txt"
-	testdataPstackThreadsBadThreadNumber = "./testdata/linux_pstack_threads_bad_thread_number.txt"
-	testdataPstackThreadsBadThreadID     = "./testdata/linux_pstack_threads_bad_thread_id.txt"
-	testdataPstackThreadsBadLwp          = "./testdata/linux_pstack_threads_bad_lwp.txt"
+	testdataPstackNoThreads                    = "./testdata/linux_pstack_no_threads.txt"
+	testdataPstackNoThreadsTextProto           = "./testdata/linux_pstack_no_threads.textproto"
+	testdataPstackThreads                      = "./testdata/linux_pstack_threads.txt"
+	testdataPstackThreadsTextProto             = "./testdata/linux_pstack_threads.textproto"
+	testdataPstackSingleThread                 = "./testdata/linux_pstack_single_thread.txt"
+	testdataPstackSingleThreadTextProto        = "./testdata/linux_pstack_single_thread.textproto"
+	testdataPstackSingleThreadWithLWP          = "./testdata/linux_pstack_single_thread_with_lwp.txt"
+	testdataPstackSingleThreadWithLWPTextProto = "./testdata/linux_pstack_single_thread_with_lwp.textproto"
+	testdataPstackThreadsBadThread             = "./testdata/linux_pstack_threads_bad_thread.txt"
+	testdataPstackThreadsBadThreadNumber       = "./testdata/linux_pstack_threads_bad_thread_number.txt"
+	testdataPstackThreadsBadThreadID           = "./testdata/linux_pstack_threads_bad_thread_id.txt"
+	testdataPstackThreadsBadLwp                = "./testdata/linux_pstack_threads_bad_lwp.txt"
 )

services/process/server/process_test.go

@@ -294,8 +294,8 @@ func TestPstackNative(t *testing.T) {
 	})
 	testutil.FatalOnErr("can't get native pstack", err, t)
 
-	// We're a go program. We have multiple threads.
-	if len(resp.Stacks) <= 1 {
+	// We're a go program. We have one or more threads.
+	if len(resp.Stacks) < 1 {
 		t.Fatalf("Not enough threads in native response. Response: %+v", prototext.Format(resp))
 	}
 
@@ -372,6 +372,20 @@ func TestPstack(t *testing.T) {
 			validate: testdataPstackThreadsTextProto,
 			pid:      1,
 		},
+		{
+			name:     "A program with a single thread",
+			command:  testutil.ResolvePath(t, "cat"),
+			input:    testdataPstackSingleThread,
+			validate: testdataPstackSingleThreadTextProto,
+			pid:      1,
+		},
+		{
+			name:     "A program with a single thread with an lwp",
+			command:  testutil.ResolvePath(t, "cat"),
+			input:    testdataPstackSingleThreadWithLWP,
+			validate: testdataPstackSingleThreadWithLWPTextProto,
+			pid:      1,
+		},
 		{
 			name:    "bad pid - zero",
 			command: testutil.ResolvePath(t, "cat"),

services/process/server/testdata/linux_pstack_single_thread.textproto

@@ -0,0 +1,5 @@
+stacks : <
+  thread_number : 1
+  stacks : "#0  0x00000000000807ec in runtime.futex.abi0 ()"
+  stacks : "#1  0x000000000004556c in runtime.futexsleep ()"
+>

services/process/server/testdata/linux_pstack_single_thread.txt

@@ -0,0 +1,3 @@
+Thread 1 (process 2947021):
+#0  0x00000000000807ec in runtime.futex.abi0 ()
+#1  0x000000000004556c in runtime.futexsleep ()

services/process/server/testdata/linux_pstack_single_thread_with_lwp.textproto

@@ -0,0 +1,6 @@
+stacks : <
+  thread_number : 9
+  lwp : 19049
+  stacks : "#0  0x00000000000807ec in runtime.futex.abi0 ()"
+  stacks : "#1  0x000000000004556c in runtime.futexsleep ()"
+>

services/process/server/testdata/linux_pstack_single_thread_with_lwp.txt

@@ -0,0 +1,3 @@
+Thread 9 (LWP 19049 "go"):
+#0  0x00000000000807ec in runtime.futex.abi0 ()
+#1  0x000000000004556c in runtime.futexsleep ()