[test] Persist packets between expect_gdbremote_sequence invocations

Summary:
Some tests (Hc_then_Csignal_signals_correct_thread, at least) were sending a "continue" packet in
one expect_gdbremote_sequence invocation, and "expecting" the stop-reply in another call. This
posed a problem, because the were packets were not persisted between the two invocations, and if
the stub was exceptionally fast to respond, the packet would be received in the first invocation
(where it would be ignored) and then the second invocation would fail because it could not find
the packet.

Since doing matching in two invocations seems like a reasonable use of the packet pump, instead
of fixing the test, I make sure the packet_pump supports this usage by making the list of
captured packets persistent.

Reviewers: tfiala

Subscribers: lldb-commits

Differential Revision: http://reviews.llvm.org/D18140

llvm-svn: 263629

3 files changed, 41 insertions, 30 deletions

diff --git a/lldb/packages/Python/lldbsuite/test/tools/lldb-server/gdbremote_testcase.py b/lldb/packages/Python/lldbsuite/test/tools/lldb-server/gdbremote_testcase.py
index 5c54eb53090..49323cd4078 100644
--- a/lldb/packages/Python/lldbsuite/test/tools/lldb-server/gdbremote_testcase.py
+++ b/lldb/packages/Python/lldbsuite/test/tools/lldb-server/gdbremote_testcase.py
@@ -78,6 +78,7 @@ class GdbRemoteTestCaseBase(TestBase):
         self.setUpBaseLogging()
         self._remote_server_log_file = None
         self.debug_monitor_extra_args = []
+        self._pump_queues = socket_packet_pump.PumpQueues()
 
         if self.isVerboseLoggingRequested():
             # If requested, full logs go to a log file
@@ -109,6 +110,8 @@ class GdbRemoteTestCaseBase(TestBase):
             self.stub_hostname = "localhost"
 
     def tearDown(self):
+        self._pump_queues.verify_queues_empty()
+
         if self._remote_server_log_file is not None:
             lldb.remote_platform.Get(lldb.SBFileSpec(self._remote_server_log_file),
                     lldb.SBFileSpec(self.getLocalServerLogFile()))
@@ -629,7 +632,8 @@ class GdbRemoteTestCaseBase(TestBase):
     def expect_gdbremote_sequence(self, timeout_seconds=None):
         if not timeout_seconds:
             timeout_seconds = self._TIMEOUT_SECONDS
-        return expect_lldb_gdbserver_replay(self, self.sock, self.test_sequence, timeout_seconds, self.logger)
+        return expect_lldb_gdbserver_replay(self, self.sock, self.test_sequence,
+                self._pump_queues, timeout_seconds, self.logger)
 
     _KNOWN_REGINFO_KEYS = [
         "name",
diff --git a/lldb/packages/Python/lldbsuite/test/tools/lldb-server/lldbgdbserverutils.py b/lldb/packages/Python/lldbsuite/test/tools/lldb-server/lldbgdbserverutils.py
index c0ea841e2a0..18b570d4d82 100644
--- a/lldb/packages/Python/lldbsuite/test/tools/lldb-server/lldbgdbserverutils.py
+++ b/lldb/packages/Python/lldbsuite/test/tools/lldb-server/lldbgdbserverutils.py
@@ -154,6 +154,7 @@ def expect_lldb_gdbserver_replay(
     asserter,
     sock,
     test_sequence,
+    pump_queues,
     timeout_seconds,
     logger=None):
     """Replay socket communication with lldb-gdbserver and verify responses.
@@ -193,7 +194,7 @@ def expect_lldb_gdbserver_replay(
         return {}
 
     context = {"O_count":0, "O_content":""}
-    with socket_packet_pump.SocketPacketPump(sock, logger) as pump:
+    with socket_packet_pump.SocketPacketPump(sock, pump_queues, logger) as pump:
         # Grab the first sequence entry.
         sequence_entry = test_sequence.entries.pop(0)
         
@@ -220,14 +221,14 @@ def expect_lldb_gdbserver_replay(
                 if sequence_entry.is_output_matcher():
                     try:
                         # Grab next entry from the output queue.
-                        content = pump.output_queue().get(True, timeout_seconds)
+                        content = pump_queues.output_queue().get(True, timeout_seconds)
                     except queue.Empty:
                         if logger:
                             logger.warning("timeout waiting for stub output (accumulated output:{})".format(pump.get_accumulated_output()))
                         raise Exception("timed out while waiting for output match (accumulated output: {})".format(pump.get_accumulated_output()))
                 else:
                     try:
-                        content = pump.packet_queue().get(True, timeout_seconds)
+                        content = pump_queues.packet_queue().get(True, timeout_seconds)
                     except queue.Empty:
                         if logger:
                             logger.warning("timeout waiting for packet match (receive buffer: {})".format(pump.get_receive_buffer()))
diff --git a/lldb/packages/Python/lldbsuite/test/tools/lldb-server/socket_packet_pump.py b/lldb/packages/Python/lldbsuite/test/tools/lldb-server/socket_packet_pump.py
index f6430b56ee4..9f594b7df73 100644
--- a/lldb/packages/Python/lldbsuite/test/tools/lldb-server/socket_packet_pump.py
+++ b/lldb/packages/Python/lldbsuite/test/tools/lldb-server/socket_packet_pump.py
@@ -26,6 +26,33 @@ def _dump_queue(the_queue):
         print(codecs.encode(the_queue.get(True), "string_escape"))
         print("\n")
 
+class PumpQueues(object):
+    def __init__(self):
+        self._output_queue = queue.Queue()
+        self._packet_queue = queue.Queue()
+
+    def output_queue(self):
+        return self._output_queue
+
+    def packet_queue(self):
+        return self._packet_queue
+
+    def verify_queues_empty(self):
+        # Warn if there is any content left in any of the queues.
+        # That would represent unmatched packets.
+        if not self.output_queue().empty():
+            print("warning: output queue entries still exist:")
+            _dump_queue(self.output_queue())
+            print("from here:")
+            traceback.print_stack()
+
+        if not self.packet_queue().empty():
+            print("warning: packet queue entries still exist:")
+            _dump_queue(self.packet_queue())
+            print("from here:")
+            traceback.print_stack()
+
+
 class SocketPacketPump(object):
     """A threaded packet reader that partitions packets into two streams.
 
@@ -40,18 +67,17 @@ class SocketPacketPump(object):
 
     _GDB_REMOTE_PACKET_REGEX = re.compile(r'^\$([^\#]*)#[0-9a-fA-F]{2}')
 
-    def __init__(self, pump_socket, logger=None):
+    def __init__(self, pump_socket, pump_queues, logger=None):
         if not pump_socket:
             raise Exception("pump_socket cannot be None")
 
-        self._output_queue = queue.Queue()
-        self._packet_queue = queue.Queue()
         self._thread = None
         self._stop_thread = False
         self._socket = pump_socket
         self._logger = logger
         self._receive_buffer = ""
         self._accumulated_output = ""
+        self._pump_queues = pump_queues
 
     def __enter__(self):
         """Support the python 'with' statement.
@@ -66,20 +92,6 @@ class SocketPacketPump(object):
         Shut down the pump thread."""
         self.stop_pump_thread()
 
-        # Warn if there is any content left in any of the queues.
-        # That would represent unmatched packets.
-        if not self.output_queue().empty():
-            print("warning: output queue entries still exist:")
-            _dump_queue(self.output_queue())
-            print("from here:")
-            traceback.print_stack()
-
-        if not self.packet_queue().empty():
-            print("warning: packet queue entries still exist:")
-            _dump_queue(self.packet_queue())
-            print("from here:")
-            traceback.print_stack()
-
     def start_pump_thread(self):
         if self._thread:
             raise Exception("pump thread is already running")
@@ -92,12 +104,6 @@ class SocketPacketPump(object):
         if self._thread:
             self._thread.join()
 
-    def output_queue(self):
-        return self._output_queue
-
-    def packet_queue(self):
-        return self._packet_queue
-
     def _process_new_bytes(self, new_bytes):
         if not new_bytes:
             return
@@ -114,7 +120,7 @@ class SocketPacketPump(object):
                 has_more = False
             # handle '+' ack
             elif self._receive_buffer[0] == "+":
-                self._packet_queue.put("+")
+                self._pump_queues.packet_queue().put("+")
                 self._receive_buffer = self._receive_buffer[1:]
                 if self._logger:
                     self._logger.debug(
@@ -132,10 +138,10 @@ class SocketPacketPump(object):
                     if new_output_content:
                         # This was an $O packet with new content.
                         self._accumulated_output += new_output_content
-                        self._output_queue.put(self._accumulated_output)
+                        self._pump_queues.output_queue().put(self._accumulated_output)
                     else:
                         # Any packet other than $O.
-                        self._packet_queue.put(packet_match.group(0))
+                        self._pump_queues.packet_queue().put(packet_match.group(0))
 
                     # Remove the parsed packet from the receive
                     # buffer.