grapher: implement restarting a stap process

* grapher/StapParser.cxx (StapParser::disconnect): new function
* grapher/StapParser.hxx (StapProcess::StapProcess): initialize argv to 0
* grapher/grapher.cxx (StapLauncher::setArgs): Set argv to 0
  (StapLauncher launch, launchUsingParser): Refactor launch(),
  extracting function a that (re)launches a stap process using an
  existing parser.
  (StapLauncher::onChildDied): call disconnect() on dead parser.
  (GrapherWindow::_graphicalLauncher, setGraphicalLauncher): delete
  member, replacing with...
  (graphicalLauncher): new variable
  (ProcModelColumns): Store parser object in the list model instead of
  just a StapProcess object.
  (ProcWindow::onRestart): new function
  (ProcWindow::refresh): Preserve the list selection when the process
  list is refreshed.
  (ProcWindow::onSelectionChanged): Manage the restart button's state.

1 files changed, 18 insertions, 0 deletions

diff --git a/grapher/StapParser.cxx b/grapher/StapParser.cxx
index 2513680b..2595e8cc 100644
--- a/grapher/StapParser.cxx
+++ b/grapher/StapParser.cxx
@@ -288,4 +288,22 @@ vector<string> commaSplit(const boost::sub_range<Glib::ustring>& range)
                _inFd, inCond);
 
   }
+
+  void StapParser::disconnect()
+  {
+    if (_ioConnection.connected())
+      _ioConnection.disconnect();
+    if (_errIoConnection.connected())
+      _errIoConnection.disconnect();
+    if (_inFd >= 0)
+      {
+        close(_inFd);
+        _inFd = -1;
+      }
+    if (_errFd >= 0)
+      {
+        close(_errFd);
+        _errFd = -1;
+      }
+  }
 }