Fixing a problem with thread creation signal order dependency
llvm-svn: 190831
diff --git a/lldb/source/Plugins/Process/FreeBSD/ProcessMonitor.cpp b/lldb/source/Plugins/Process/FreeBSD/ProcessMonitor.cpp
index 7e0476c..1cf5045 100644
--- a/lldb/source/Plugins/Process/FreeBSD/ProcessMonitor.cpp
+++ b/lldb/source/Plugins/Process/FreeBSD/ProcessMonitor.cpp
@@ -1637,6 +1637,29 @@
// even though still has the file descriptor, we shouldn't close it here.
}
+// FIXME: On Linux, when a new thread is created, we receive to notifications,
+// (1) a SIGTRAP|PTRACE_EVENT_CLONE from the main process thread with the
+// child thread id as additional information, and (2) a SIGSTOP|SI_USER from
+// the new child thread indicating that it has is stopped because we attached.
+// We have no guarantee of the order in which these arrive, but we need both
+// before we are ready to proceed. We currently keep a list of threads which
+// have sent the initial SIGSTOP|SI_USER event. Then when we receive the
+// SIGTRAP|PTRACE_EVENT_CLONE notification, if the initial stop has not occurred
+// we call ProcessMonitor::WaitForInitialTIDStop() to wait for it.
+//
+// Right now, the above logic is in ProcessPOSIX, so we need a definition of
+// this function in the FreeBSD ProcessMonitor implementation even if it isn't
+// logically needed.
+//
+// We really should figure out what actually happens on FreeBSD and move the
+// Linux-specific logic out of ProcessPOSIX as needed.
+
+bool
+ProcessMonitor::WaitForInitialTIDStop(lldb::tid_t tid)
+{
+ return true;
+}
+
void
ProcessMonitor::StopOpThread()
{
diff --git a/lldb/source/Plugins/Process/FreeBSD/ProcessMonitor.h b/lldb/source/Plugins/Process/FreeBSD/ProcessMonitor.h
index ce66c03..5442867 100644
--- a/lldb/source/Plugins/Process/FreeBSD/ProcessMonitor.h
+++ b/lldb/source/Plugins/Process/FreeBSD/ProcessMonitor.h
@@ -193,6 +193,10 @@
void
StopMonitor();
+ // Waits for the initial stop message from a new thread.
+ bool
+ WaitForInitialTIDStop(lldb::tid_t tid);
+
private:
ProcessFreeBSD *m_process;