From a9a43373e17ca0eb1cb667c9be97da577cc70b99 Mon Sep 17 00:00:00 2001
From: Pavel Labath <labath@google.com>
Date: Thu, 3 Sep 2015 09:30:17 +0000
Subject: [PATCH] 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
---
lldb/source/Target/Process.cpp | 11 +++++------
1 file changed, 5 insertions(+), 6 deletions(-)
diff --git a/lldb/source/Target/Process.cpp b/lldb/source/Target/Process.cpp
index 531a14c00fab..c771be0bf9a5 100644
--- a/lldb/source/Target/Process.cpp
+++ b/lldb/source/Target/Process.cpp
@@ -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: