Prevent TestLldbGdbServer shutdown cleanup failures from failing the test.

Adds try/except blocks around clean-up code. Prevents a race between gdb
remote kill command reception by llgs (which leads llgs to shut down)
and the pexpect server kill (which can fail if the kill command handling
completes first). Warnings are emitted on the logger for any clean-up
code that fails.

llvm-svn: 207273

lldb/test/tools/lldb-gdbserver/TestLldbGdbServer.py

@@ -36,12 +36,20 @@ class LldbGdbServerTestCase(TestBase):
 
     def create_socket(self):
         sock = socket.socket()
+        logger = self.logger
 
         def shutdown_socket():
             if sock:
-                # send the kill packet so lldb-gdbserver shuts down gracefully
-                sock.sendall(LldbGdbServerTestCase._GDBREMOTE_KILL_PACKET)
-                sock.close()
+                try:
+                    # send the kill packet so lldb-gdbserver shuts down gracefully
+                    sock.sendall(LldbGdbServerTestCase._GDBREMOTE_KILL_PACKET)
+                except:
+                    logger.warning("failed to send kill packet to debug monitor: {}; ignoring".format(sys.exc_info()[0]))
+
+                try:
+                    sock.close()
+                except:
+                    logger.warning("failed to close socket to debug monitor: {}; ignoring".format(sys.exc_info()[0]))
 
         self.addTearDownHook(shutdown_socket)
 
@@ -57,8 +65,13 @@ class LldbGdbServerTestCase(TestBase):
             server.logfile_read = sys.stdout
 
         # Schedule lldb-gdbserver to be shutting down during teardown.
+        logger = self.logger
         def shutdown_lldb_gdbserver():
-            server.close()
+            try:
+                server.close()
+            except:
+                logger.warning("failed to close pexpect server for debug monitor: {}; ignoring".format(sys.exc_info()[0]))
+
         self.addTearDownHook(shutdown_lldb_gdbserver)
 
         # Wait until we receive the server ready message before continuing.