grapher: integrate graph events from stdin with the stap process framework.

This was the original way to do graphing and had bitrotted some.

* grapher/StapParser.cxx (initIO): new catchHUP argument
  (ioCallback): Only disconnect signals, etc. on IN_HUP if catchHUP is
  true.
  (errIoCallback): Write error messages to stderr, not stdout.
* grapher/grapher.cxx (StapLauncher::launch): Don't catchHUP on our
  stap process children.
  (ProcWindow::refresh): Display something reasonable for the stap
  "process" that is feeding stdin.
  (main): Use StapParser::initIO to initialize parser reading from
  stdin.

3 files changed, 32 insertions, 21 deletions

diff --git a/grapher/StapParser.cxx b/grapher/StapParser.cxx
index a9a5109a..2513680b 100644
--- a/grapher/StapParser.cxx
+++ b/grapher/StapParser.cxx
@@ -86,9 +86,12 @@ vector<string> commaSplit(const boost::sub_range<Glib::ustring>& range)
     using namespace boost;
     if (ioCondition & Glib::IO_HUP)
       {
-        childDiedSignal().emit(getPid());
-        _ioConnection.disconnect();
-        _errIoConnection.disconnect();
+        if (_catchHUP)
+          {
+            childDiedSignal().emit(getPid());
+            _ioConnection.disconnect();
+            _errIoConnection.disconnect();
+          }
         return true;
       }
     if ((ioCondition & Glib::IO_IN) == 0)
@@ -261,22 +264,28 @@ vector<string> commaSplit(const boost::sub_range<Glib::ustring>& range)
         cerr << "StapParser: error reading from stderr!\n";
         return true;
       }
-    if (write(STDOUT_FILENO, buf, bytes_read) < 0)
+    if (write(STDERR_FILENO, buf, bytes_read) < 0)
       ;
     return true;
   }
 
-  void StapParser::initIo(int inFd, int errFd)
+  void StapParser::initIo(int inFd, int errFd, bool catchHUP)
   {
     _inFd = inFd;
     _errFd = errFd;
+    _catchHUP = catchHUP;
+    Glib::IOCondition inCond = Glib::IO_IN;
+    if (catchHUP)
+      inCond |= Glib::IO_HUP;
+    if (_errFd >= 0)
+      {    
+        _errIoConnection = Glib::signal_io()
+          .connect(sigc::mem_fun(*this, &StapParser::errIoCallback),
+                                  _errFd, Glib::IO_IN);
+      }
     _ioConnection = Glib::signal_io()
-      .connect(sigc::mem_fun(*this, &StapParser::errIoCallback),
-               _errFd,
-               Glib::IO_IN);
-    _errIoConnection = Glib::signal_io()
       .connect(sigc::mem_fun(*this, &StapParser::ioCallback),
-               _inFd,
-               Glib::IO_IN | Glib::IO_HUP);
+               _inFd, inCond);
+
   }
 }
diff --git a/grapher/StapParser.hxx b/grapher/StapParser.hxx
index 4dd711e6..24e84fc9 100644
--- a/grapher/StapParser.hxx
+++ b/grapher/StapParser.hxx
@@ -37,12 +37,13 @@ namespace systemtap
     int _errFd;
     int _inFd;
     unsigned char _lineEndChar;
+    bool _catchHUP;
     std::tr1::shared_ptr<StapProcess> _process;
     sigc::connection _ioConnection;
     sigc::connection _errIoConnection;
   public:
     StapParser()
-      :  _errFd(-1), _inFd(-1), _lineEndChar('\n')
+      :  _errFd(-1), _inFd(-1), _lineEndChar('\n'), _catchHUP(false)
     {
     }
     void parseData(std::tr1::shared_ptr<GraphDataBase> gdata,
@@ -65,7 +66,7 @@ namespace systemtap
     {
       _process = process;
     }
-    void initIo(int inFd, int errFd);
+    void initIo(int inFd, int errFd, bool catchHUP);
   };
 
   sigc::signal<void, pid_t>& childDiedSignal();
diff --git a/grapher/grapher.cxx b/grapher/grapher.cxx
index e3d5289a..6dead221 100644
--- a/grapher/grapher.cxx
+++ b/grapher/grapher.cxx
@@ -293,7 +293,7 @@ int StapLauncher::launch()
   sp->setProcess(proc);
   parsers.push_back(sp);
   parserListChangedSignal().emit();
-  sp->initIo(pipefd[0], pipefd[2]);
+  sp->initIo(pipefd[0], pipefd[2], false);
   return childPid;
 }
 
@@ -422,14 +422,19 @@ void ProcWindow::refresh()
        ++spitr)
     {
       shared_ptr<StapProcess> sp = (*spitr)->getProcess();
+      Gtk::TreeModel::iterator litr = _listStore->append();
+      Gtk::TreeModel::Row row = *litr;
       if (sp)
         {
-          Gtk::TreeModel::iterator litr = _listStore->append();
-          Gtk::TreeModel::Row row = *litr;
           row[_modelColumns._iconName] = sp->pid >= 0 ? "gtk-yes" : "gtk-no";
           row[_modelColumns._scriptName] = sp->script;
           row[_modelColumns._proc] = sp;
         }
+      else
+        {
+          row[_modelColumns._iconName] = "gtk-yes";
+          row[_modelColumns._scriptName] = "standard input";
+        }
     }
 }
 
@@ -615,11 +620,7 @@ int main(int argc, char** argv)
   if (argc == 2 && !std::strcmp(argv[1], "-"))
     {
       tr1::shared_ptr<StapParser> sp = launcher.makeStapParser();
-      sp->setInFd(STDIN_FILENO);
-      Glib::signal_io().connect(sigc::mem_fun(sp.get(),
-                                              &StapParser::ioCallback),
-                                STDIN_FILENO,
-                                Glib::IO_IN | Glib::IO_HUP);
+      sp->initIo(STDIN_FILENO, -1, true);
     }
   else if (argc > 1)
     {