Fix rare failure in TestProcessIO

Summary:
There was a race condition in Process class, where we would not wait for process stdout to
propagate fully before we would shut down the connection (repro case: slow down the stdio thread
by placing a sleep right at the end of the while loop in Communication::ReadThread). The Process
class already tried to solve this problem by synchronizing with the read thread in
Process::ShouldBroadcastEvent, but unfortunately the connection got closed before that in
Process::SetExitStatus. I solve this issue by delaying the connection shutdown until we get a
chance to process the event and synchronize. Alternatively, I could have moved the
synchronization point to an earlier point in SetExitStatus, but it seems safer to delay the
shutdown until other things get a chance to notice the process has exited.

Reviewers: clayborg, ovyalov

Subscribers: lldb-commits

Differential Revision: http://reviews.llvm.org/D12558

llvm-svn: 246753
This commit is contained in:
Pavel Labath 2015-09-03 09:30:17 +00:00
parent 61efbc32a6
commit a9a43373e1
1 changed files with 5 additions and 6 deletions

View File

@ -1479,12 +1479,7 @@ Process::SetExitStatus (int status, const char *cstr)
else
m_exit_string.clear();
// When we exit, we no longer need to the communication channel
m_stdio_communication.Disconnect();
m_stdio_communication.StopReadThread();
m_stdin_forward = false;
// And we don't need the input reader anymore as well
// When we exit, we don't need the input reader anymore
if (m_process_input_reader)
{
m_process_input_reader->SetIsDone(true);
@ -4159,6 +4154,10 @@ Process::ShouldBroadcastEvent (Event *event_ptr)
case eStateExited:
case eStateUnloaded:
m_stdio_communication.SynchronizeWithReadThread();
m_stdio_communication.Disconnect();
m_stdio_communication.StopReadThread();
m_stdin_forward = false;
// fall-through
case eStateConnected:
case eStateAttaching: