Fix TestProcesslaunch regression caused by D7372

Summary:
After closing all the leaked file descriptors to the inferior tty, the following problem occured:
- when stdin, stdout and stderr are redirected, there are no slave descriptors open (which is good)
- lldb has a reader thread, which attempts to read from the master end of the tty
- this thread receives an EOF
- in response, it closes it's master end
- as this is the last open file descriptor for the master end, this deletes the tty and sends
  SIGHUP to the inferior (this is bad)

I fix this problem by making sure the master end remains open for the duration of the inferior
process by storing a copy of the file descriptor in ProcessMonitor. I create a copy to avoid
ownership issues with the reading thread.

Reviewers: ovyalov, emaste

Subscribers: lldb-commits

Differential Revision: http://reviews.llvm.org/D7440

llvm-svn: 228391

1 files changed, 2 insertions, 1 deletions

diff --git a/lldb/source/Plugins/Process/Linux/ProcessMonitor.h b/lldb/source/Plugins/Process/Linux/ProcessMonitor.h
index 27beaef9606..0543e930d40 100644
--- a/lldb/source/Plugins/Process/Linux/ProcessMonitor.h
+++ b/lldb/source/Plugins/Process/Linux/ProcessMonitor.h
@@ -84,7 +84,8 @@ public:
     /// Reads from this file descriptor yield both the standard output and
     /// standard error of this debugee.  Even if stderr and stdout were
     /// redirected on launch it may still happen that data is available on this
-    /// descriptor (if the inferior process opens /dev/tty, for example).
+    /// descriptor (if the inferior process opens /dev/tty, for example). This descriptor is
+    /// closed after a call to StopMonitor().
     ///
     /// If this monitor was attached to an existing process this method returns
     /// -1.