fix Bug21211 : reworked test/api/multithreaded/test_listener_event_description.cpp to work properly on Linux/FreeBSD

[sbest]

Summary

Issue D5632 fixed an issue where linux would dump spurious output to tty on startup (due to a broadcast stop event). After the checkin, it was noticed on FreeBSD a unit test was now failing. On closer investigation I found the test was using the C++ API to launch an inferior while using an SBListener to monitor the public state changes. It was expecting to see:

eStateRunning
eStateStopped

On Linux/FreeBSD, there is an extra state change

eStateLaunching
eStateRunning
eStateStopped

I reworked the test to work for both cases.

[sbest]

friendly ping. I was waiting until the other change (D5838 ENABLE_STD_THREADS) landed and I could run the tests in api/multithreaded again. This is a rework of the test program logic to accommodate the fact that OSx and linux broadcast a different sequence of public events due to their different inferior launching.

I can confirm the test passes on Linux, and OSx. I assume it now will pass correctly on FreeBSD since it exhibited a similar failure to Linux when it got broken by D5632.

[emaste]

lgtm

[sbest]

Closed by commit rL222511 (authored by @sbest).

lldb/trunk/test/api/multithreaded/TestMultithreaded.py

class SBBreakpointCallbackCase(TestBase):
     @skipIfRemote
     @skipIfLinuxClang # buildbot clang version unable to use libstdc++ with c++11
     @skipIfNoSBHeaders
     def test_breakpoint_callback(self):
         """Test the that SBBreakpoint callback is invoked when a breakpoint is hit. """
         self.build_and_test('driver.cpp test_breakpoint_callback.cpp',
                             'test_breakpoint_callback')
 
-    @expectedFailureFreeBSD("llvm.org/21211")
     @skipIfi386
     @skipIfRemote
     @skipIfLinuxClang # buildbot clang version unable to use libstdc++ with c++11
     @skipIfNoSBHeaders
     def test_sb_api_listener_event_description(self):
         """ Test the description of an SBListener breakpoint event is valid."""
         self.build_and_test('driver.cpp listener_test.cpp test_listener_event_description.cpp',
                             'test_listener_event_description')

lldb/trunk/test/api/multithreaded/test_listener_event_description.cpp

 #include "lldb-headers.h"
 
 #include "common.h"
 
 using namespace lldb;
 using namespace std;
 
 // listener thread control
-extern atomic<bool> g_done; 
+extern atomic<bool> g_done;
+extern SBListener g_listener;
 
 multithreaded_queue<string> g_event_descriptions;
-
-extern SBListener g_listener;
+string g_error_desc;
 
 void listener_func() {
   while (!g_done) {
     SBEvent event;
     bool got_event = g_listener.WaitForEvent(1, event);
+
     if (got_event) {
       if (!event.IsValid())
         throw Exception("event is not valid in listener thread");
 
       SBStream description;
       event.GetDescription(description);
       string str(description.GetData());
       g_event_descriptions.push(str);
     }
   }
 }
 
-void check_listener(SBDebugger &dbg) {
-  array<string, 2> expected_states = {"running", "stopped"};
-  for(string & state : expected_states) {
-    bool got_description = false;
-    string desc = g_event_descriptions.pop(5, got_description);
+bool check_state(string &state, string &desc, bool got_description)
+{
+    g_error_desc.clear();
 
-    if (!got_description)
-      throw Exception("Did not get expected event description");
-
+    if(!got_description)
+    {
+        g_error_desc.append("Did not get expected event description");
+        return false;
+    }
 
     if (desc.find("state-changed") == desc.npos)
-      throw Exception("Event description incorrect: missing 'state-changed'");
+        g_error_desc.append("Event description incorrect: missing 'state-changed' ");
+
+    if (desc.find("pid = ") == desc.npos)
+        g_error_desc.append("Event description incorrect: missing process pid ");
 
     string state_search_str = "state = " + state;
     if (desc.find(state_search_str) == desc.npos)
-      throw Exception("Event description incorrect: expected state "
+    {
+        string errString = ("Event description incorrect: expected state "
                       + state
                       + " but desc was "
                       + desc);
+        g_error_desc.append(errString);
+    }
 
-    if (desc.find("pid = ") == desc.npos)
-      throw Exception("Event description incorrect: missing process pid");
+    if (g_error_desc.length() > 0)
+        return false;
+
+    cout << "check_state: " << state << "  OK\n";
+    return true;
+}
+
+void check_listener(SBDebugger &dbg)
+{
+    bool got_description;
+    string state;
+
+    // check for "launching" state, this may or may not be present
+    string desc = g_event_descriptions.pop(5, got_description);
+    state = "launching";
+    if (check_state(state, desc, got_description))
+    {
+        // found a 'launching' state, pop next one from queue
+        desc = g_event_descriptions.pop(5, got_description);
     }
+
+    state = "running";
+    if( !check_state(state, desc, got_description) )
+        throw Exception(g_error_desc);
+
+    desc = g_event_descriptions.pop(5, got_description);
+    state = "stopped";
+    if( !check_state(state, desc, got_description) )
+        throw Exception(g_error_desc);
 }