[lldb-vscode] stop read loop after termination

[wallace]

Summary

On Linux, when executing lldb-vscode on a remote machine, lldb-vscode doesn't die after the debug session ends. It keeps trying to read JSON input to no avail.
This diff indicates lldb-vscode to stop reading after a termination event has been processed.

[clayborg]

Does this have something to do with a multiplexor that funnels traffic through one tunnel? I am curious as to why the ReadJSON() doesn't exit after the other side closes down?

LGTM, but needs a test.

[wallace]

As we discussed privately, some remote connections use a mutiplexor socket that doesn't die when the debug session ends.

[wallace]

add a test

[wallace]

nit

[clayborg]

lldb/test/API/tools/lldb-vscode/launch/TestVSCode_launch.py

46–48

I don't think we need to run a program. Just send the initialize packet and then the terminate packet, then sleep?

[wallace]

address comments

[clayborg]

lgtm.

[clayborg]

Just watch the build bots carefully when you check this in!

[labath]

lldb/test/API/tools/lldb-vscode/launch/TestVSCode_launch.py

50–53

1 second is pretty short, and I wouldn't be surprised if it causes spurious failures.

Using popen.wait() would be _much_ better -- you can use a much larger timeout, while still having the test terminate quickly in the common case.

[wallace]

address comments

[wallace]

support python2.7

[labath]

lldb/test/API/tools/lldb-vscode/launch/TestVSCode_launch.py

55–56

I'll add this to my list of reasons for dropping python2 support. :)

lldb/test/API/tools/lldb-vscode/launch/TestVSCode_launch.py

 """
 Test lldb-vscode setBreakpoints request
 """
 
 
 import unittest2
 import vscode
 from lldbsuite.test.decorators import *
 from lldbsuite.test.lldbtest import *
 from lldbsuite.test import lldbutil
 import lldbvscode_testcase
+import time
 import os
 
 
 class TestVSCode_launch(lldbvscode_testcase.VSCodeTestCaseBase):
 
     mydir = TestBase.compute_mydir(__file__)
 
     @skipIfWindows
def test_default(self):
         self.assertTrue(output and len(output) > 0,
                         "expect program output")
         lines = output.splitlines()
         self.assertTrue(program in lines[0],
                         "make sure program path is in first argument")
 
     @skipIfWindows
     @skipIfRemote
+    def test_termination(self):
+        '''
+            Tests the correct termination of lldb-vscode upon a 'disconnect'
+            request.
+        '''
+        program = self.getBuildArtifact("a.out")
+        self.build_and_launch(program, stopOnEntry=True)
+        self.vscode.request_disconnect(terminateDebuggee=True) 
+        time.sleep(1)
+        # The underlying lldb-vscode process must have already finished even though
+        # we didn't close the communication socket explicitly
+        self.assertEqual(self.vscode.process.poll(), 0)
+
+    @skipIfWindows
+    @skipIfRemote
     def test_stopOnEntry(self):
         '''
             Tests the default launch of a simple program that stops at the
             entry point instead of continuing.
         '''
         program = self.getBuildArtifact("a.out")
         self.build_and_launch(program, stopOnEntry=True)
         self.set_function_breakpoints(['main'])
         stopped_events = self.continue_to_next_stop()
def test_commands(self):
         output = self.get_console(timeout=1.0)
         self.verify_commands('stopCommands', output, stopCommands)
 
         # Continue until the program exits
         self.continue_to_exit()
         # Get output from the console. This should contain both the
         # "exitCommands" that were run after the second breakpoint was hit
         output = self.get_console(timeout=1.0)
-        self.verify_commands('exitCommands', output, exitCommands)
+        self.verify_commands('exitCommands', output, exitCommands)q
 
     @skipIfWindows
     @skipIfRemote
     def test_extra_launch_commands(self):
         '''
             Tests the "luanchCommands" with extra launching settings
         '''
         self.build_and_create_debug_adaptor()

lldb/tools/lldb-vscode/lldb-vscode.cpp

if (portno != -1) {
     }
   } else {
     g_vsc.input.descriptor = StreamDescriptor::from_file(fileno(stdin), false);
     g_vsc.output.descriptor =
         StreamDescriptor::from_file(fileno(stdout), false);
   }
   auto request_handlers = GetRequestHandlers();
   uint32_t packet_idx = 0;
-  while (true) {
+  while (!g_vsc.sent_terminated_event) {
     std::string json = g_vsc.ReadJSON();
     if (json.empty())
       break;
 
     llvm::StringRef json_sref(json);
     llvm::Expected<llvm::json::Value> json_value = llvm::json::parse(json_sref);
     if (!json_value) {
       auto error = json_value.takeError();