[Lldb-commits] [PATCH] D128893: [lldb] [llgs] Fix disabling non-stop mode

[Michał Górny via Phabricator via lldb-commits]

mgorny created this revision.
mgorny added reviewers: labath, krytarowski, emaste, jingham.
Herald added a subscriber: arichardson.
Herald added a project: All.
mgorny requested review of this revision.

Stop all processes and clear notification queues when disabling non-stop
mode.  Ensure that no stop notifications are sent for processes stopped
due to the mode switch.

Sponsored by: The FreeBSD Foundation


https://reviews.llvm.org/D128893

Files:
  lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationServerLLGS.cpp
  lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationServerLLGS.h
  lldb/test/API/tools/lldb-server/TestNonStop.py


Index: lldb/test/API/tools/lldb-server/TestNonStop.py
===================================================================
--- lldb/test/API/tools/lldb-server/TestNonStop.py
+++ lldb/test/API/tools/lldb-server/TestNonStop.py
@@ -368,3 +368,33 @@
              "send packet: $OK#00",
              ], True)
         self.expect_gdbremote_sequence()
+
+    @add_test_categories(["llgs"])
+    def test_leave_nonstop(self):
+        self.build()
+        self.set_inferior_startup_launch()
+        procs = self.prep_debug_monitor_and_inferior(
+                inferior_args=["thread:new", "thread:new", "stop", "sleep:15"])
+        self.test_sequence.add_log_lines(
+            ["read packet: $QNonStop:1#00",
+             "send packet: $OK#00",
+             # stop is used to synchronize starting threads
+             "read packet: $c#63",
+             "send packet: $OK#00",
+             {"direction": "send", "regex": "%Stop:T.*"},
+             "read packet: $c#63",
+             "send packet: $OK#00",
+             # verify that the threads are running now
+             "read packet: $?#00",
+             "send packet: $OK#00",
+             "read packet: $QNonStop:0#00",
+             "send packet: $OK#00",
+             # we should issue some random request now to verify that the stub
+             # did not send stop reasons -- we may verify whether notification
+             # queue was cleared while at it
+             "read packet: $vStopped#00",
+             "send packet: $Eff#00",
+             "read packet: $?#00",
+             {"direction": "send", "regex": "[$]T.*"},
+             ], True)
+        self.expect_gdbremote_sequence()
Index: lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationServerLLGS.h
===================================================================
--- lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationServerLLGS.h
+++ lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationServerLLGS.h
@@ -97,6 +97,7 @@
   std::unordered_map<lldb::pid_t, std::unique_ptr<NativeProcessProtocol>>
       m_debugged_processes;
   std::unordered_set<lldb::pid_t> m_vkilled_processes;
+  std::unordered_set<lldb::pid_t> m_inhibit_stop_reason_processes;
 
   Communication m_stdio_communication;
   MainLoop::ReadHandleUP m_stdio_handle_up;
Index: lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationServerLLGS.cpp
===================================================================
--- lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationServerLLGS.cpp
+++ lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationServerLLGS.cpp
@@ -1910,6 +1910,12 @@
     bool force_synchronous) {
   Log *log = GetLog(LLDBLog::Process);
 
+  auto process_it = m_inhibit_stop_reason_processes.find(process.GetID());
+  if (process_it != m_inhibit_stop_reason_processes.end()) {
+    m_inhibit_stop_reason_processes.erase(process_it);
+    return PacketResult::Success;
+  }
+
   switch (process_state) {
   case eStateAttaching:
   case eStateLaunching:
@@ -3906,12 +3912,28 @@
 GDBRemoteCommunication::PacketResult
 GDBRemoteCommunicationServerLLGS::Handle_QNonStop(
     StringExtractorGDBRemote &packet) {
+  Log *log = GetLog(LLDBLog::Process);
+
   StringRef packet_str{packet.GetStringRef()};
   assert(packet_str.startswith("QNonStop:"));
   packet_str.consume_front("QNonStop:");
   if (packet_str == "0") {
+    for (const auto &process_it : m_debugged_processes) {
+      if (process_it.second->IsRunning()) {
+        Status error = process_it.second->Interrupt();
+        if (error.Fail()) {
+          LLDB_LOG(log,
+                   "while disabling nonstop, failed to halt process {0}: {1}",
+                   process_it.first, error);
+          return SendErrorResponse(0x41);
+        }
+        // we must not send stop reasons after QNonStop
+        m_inhibit_stop_reason_processes.insert(process_it.first);
+      }
+    }
+    m_stdio_notification_queue.clear();
+    m_stop_notification_queue.clear();
     m_non_stop = false;
-    // TODO: stop all threads
   } else if (packet_str == "1") {
     m_non_stop = true;
   } else


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