Fix signal handling for POSIX (only tested on Linux) processes in multi-threaded programs.

Also fix a related issue where if a thread exits after a thread continue, lldb would hang.

llvm-svn: 185944

1 files changed, 25 insertions, 3 deletions

diff --git a/lldb/source/Plugins/Process/Linux/ProcessMonitor.cpp b/lldb/source/Plugins/Process/Linux/ProcessMonitor.cpp
index 512639cecb3..fe617987baa 100644
--- a/lldb/source/Plugins/Process/Linux/ProcessMonitor.cpp
+++ b/lldb/source/Plugins/Process/Linux/ProcessMonitor.cpp
@@ -1236,6 +1236,8 @@ ProcessMonitor::Launch(LaunchArgs *args)
         log->Printf ("ProcessMonitor::%s() adding pid = %" PRIu64, __FUNCTION__, pid);
     process.GetThreadList().AddThread(inferior);
 
+    process.AddThreadForInitialStopIfNeeded(pid);
+
     // Let our process instance know the thread has stopped.
     process.SendMessage(ProcessMessage::Trace(pid));
 
@@ -1294,7 +1296,6 @@ ProcessMonitor::Attach(AttachArgs *args)
 
     // Use a map to keep track of the threads which we have attached/need to attach.
     Host::TidMap tids_to_attach;
-
     if (pid <= 1)
     {
         args->m_error.SetErrorToGenericError();
@@ -1360,6 +1361,7 @@ ProcessMonitor::Attach(AttachArgs *args)
                     log->Printf ("ProcessMonitor::%s() adding tid = %" PRIu64, __FUNCTION__, tid);
                 process.GetThreadList().AddThread(inferior);
                 it->second = true;
+                process.AddThreadForInitialStopIfNeeded(tid);
             }
         }
     }
@@ -1513,7 +1515,7 @@ ProcessMonitor::MonitorSIGTRAP(ProcessMonitor *monitor,
         if (!monitor->GetEventMessage(pid, &data))
             data = -1;
         if (log)
-            log->Printf ("ProcessMonitor::%s() received exit event, data = %lx, pid = %" PRIu64, __FUNCTION__, data, pid);
+            log->Printf ("ProcessMonitor::%s() received limbo event, data = %lx, pid = %" PRIu64, __FUNCTION__, data, pid);
         message = ProcessMessage::Limbo(pid, (data >> 8));
         break;
     }
@@ -1711,6 +1713,27 @@ ProcessMonitor::StopThread(lldb::tid_t tid)
                     return true;
                 break;
 
+            case ProcessMessage::eSignalMessage:
+                if (log)
+                    log->Printf ("ProcessMonitor::%s(bp) handling message", __FUNCTION__);
+                if (WSTOPSIG(status) == SIGSTOP)
+                {
+                    m_process->AddThreadForInitialStopIfNeeded(tid);
+                    thread->SetState(lldb::eStateStopped);
+                }
+                else
+                {
+                    m_process->SendMessage(message);
+                    // This isn't the stop we were expecting, but the thread is
+                    // stopped. SendMessage will handle processing of this event,
+                    // but we need to resume here to get the stop we are waiting
+                    // for (otherwise the thread will stop again immediately when
+                    // we try to resume).
+                    if (wait_pid == tid)
+                        Resume(wait_pid, eResumeSignalNone);
+                }
+                break;
+
             case ProcessMessage::eSignalDeliveredMessage:
                 // This is the stop we're expecting.
                 if (wait_pid == tid && WIFSTOPPED(status) && WSTOPSIG(status) == SIGSTOP && info.si_code == SI_TKILL)
@@ -1721,7 +1744,6 @@ ProcessMonitor::StopThread(lldb::tid_t tid)
                     return true;
                 }
                 // else fall-through
-            case ProcessMessage::eSignalMessage:
             case ProcessMessage::eBreakpointMessage:
             case ProcessMessage::eTraceMessage:
             case ProcessMessage::eWatchpointMessage: