Rewrite the flaky test_restart_bug test in a more deterministic way

Summary:
The test was trying to reproduce a bug in handling of two concurrent
events, which was impossible to do reliably in a black-box style test.
In practice, this meant the test was only ever failing on remote
targets, as these were slow enough to trigger this.

Fortunately, we now have the ability to mock the server side of the
connection, which means we can simulate the failure deterministically,
so I rewrite the test to use the new gdb-client framework.

I've needed to add a couple of new packets to the mock server to be able
to do this. Instead of trying to guess how a "typical" gdb-client test
will want to handle this, I throw an exception in the implementation to
force the user to override them (the packets are only sent if the test
explicitly performs some action which will trigger them, so a basic test
which e.g. does not need the "continue" functionality will not need to
implement them).

Reviewers: owenpshaw

Subscribers: srhines, lldb-commits

Differential Revision: https://reviews.llvm.org/D42959

llvm-svn: 324590

1 files changed, 0 insertions, 86 deletions

diff --git a/lldb/packages/Python/lldbsuite/test/functionalities/signal/raise/TestRaise.py b/lldb/packages/Python/lldbsuite/test/functionalities/signal/raise/TestRaise.py
index e8a2c598e27..dfc54a639ea 100644
--- a/lldb/packages/Python/lldbsuite/test/functionalities/signal/raise/TestRaise.py
+++ b/lldb/packages/Python/lldbsuite/test/functionalities/signal/raise/TestRaise.py
@@ -188,89 +188,3 @@ class RaiseTestCase(TestBase):
 
         # reset signal handling to default
         self.set_handle(signal, default_pass, default_stop, default_notify)
-
-    @skipIfTargetAndroid()
-    def test_restart_bug(self):
-        """Test that we catch a signal in the edge case where the process receives it while we are
-        about to interrupt it"""
-        self.build()
-        exe = self.getBuildArtifact("a.out")
-
-        # Create a target by the debugger.
-        target = self.dbg.CreateTarget(exe)
-        self.assertTrue(target, VALID_TARGET)
-        bkpt = target.BreakpointCreateByName("main")
-        self.assertTrue(bkpt.IsValid(), VALID_BREAKPOINT)
-
-        # launch the inferior and don't wait for it to stop
-        self.dbg.SetAsync(True)
-        error = lldb.SBError()
-        listener = lldb.SBListener("my listener")
-        process = target.Launch(listener,
-                                ["SIGSTOP"],  # argv
-                                None,        # envp
-                                None,        # stdin_path
-                                None,        # stdout_path
-                                None,        # stderr_path
-                                None,        # working directory
-                                0,           # launch flags
-                                False,       # Stop at entry
-                                error)       # error
-
-        self.assertTrue(process and process.IsValid(), PROCESS_IS_VALID)
-
-        event = lldb.SBEvent()
-
-        # Give the child enough time to reach the breakpoint,
-        # while clearing out all the pending events.
-        # The last WaitForEvent call will time out after 2 seconds.
-        while listener.WaitForEvent(2, event):
-            if self.TraceOn():
-                print(
-                    "Process changing state to:",
-                    self.dbg.StateAsCString(
-                        process.GetStateFromEvent(event)))
-
-        # now the process should be stopped
-        self.assertEqual(
-            process.GetState(),
-            lldb.eStateStopped,
-            PROCESS_STOPPED)
-        self.assertEqual(len(lldbutil.get_threads_stopped_at_breakpoint(
-            process, bkpt)), 1, "A thread should be stopped at breakpoint")
-
-        # Remove all breakpoints. This makes sure we don't have to single-step over them when we
-        # resume the process below
-        target.DeleteAllBreakpoints()
-
-        # resume the process and immediately try to set another breakpoint. When using the remote
-        # stub, this will trigger a request to stop the process just as it is about to stop
-        # naturally due to a SIGSTOP signal it raises. Make sure we do not lose
-        # this signal.
-        process.Continue()
-        self.assertTrue(target.BreakpointCreateByName(
-            "handler").IsValid(), VALID_BREAKPOINT)
-
-        # Clear the events again
-        while listener.WaitForEvent(2, event):
-            if self.TraceOn():
-                print(
-                    "Process changing state to:",
-                    self.dbg.StateAsCString(
-                        process.GetStateFromEvent(event)))
-
-        # The process should be stopped due to a signal
-        self.assertEqual(process.GetState(), lldb.eStateStopped)
-        thread = lldbutil.get_stopped_thread(process, lldb.eStopReasonSignal)
-        self.assertTrue(
-            thread.IsValid(),
-            "Thread should be stopped due to a signal")
-        self.assertTrue(
-            thread.GetStopReasonDataCount() >= 1,
-            "There was data in the event.")
-        signo = process.GetUnixSignals().GetSignalNumberFromName("SIGSTOP")
-        self.assertEqual(thread.GetStopReasonDataAtIndex(0), signo,
-                         "The stop signal was %s" % signal)
-
-        # We are done
-        process.Kill()