Initial revision

git-svn-id: svn://localhost/trunk/ardour2@4 d708f5d6-7413-0410-9779-e7cbd77b26cf

libs/glibmm2/glibmm/exceptionhandler.cc

@@ -0,0 +1,159 @@
+// -*- c++ -*-
+/* $Id$ */
+
+/* exceptionhandler.cc
+ *
+ * Copyright 2002 The gtkmm Development Team
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Library General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Library General Public License for more details.
+ *
+ * You should have received a copy of the GNU Library General Public
+ * License along with this library; if not, write to the Free
+ * Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#include <glib.h>
+#include <exception>
+#include <list>
+
+#include <glibmmconfig.h>
+#include <glibmm/error.h>
+#include <glibmm/exceptionhandler.h>
+#include <glibmm/thread.h>
+
+GLIBMM_USING_STD(exception)
+GLIBMM_USING_STD(list)
+
+
+namespace
+{
+
+typedef sigc::signal<void> HandlerList;
+
+// Each thread has its own list of exception handlers
+// to avoid thread synchronization problems.
+static Glib::StaticPrivate<HandlerList> thread_specific_handler_list = GLIBMM_STATIC_PRIVATE_INIT;
+
+
+static void glibmm_exception_warning(const GError* error)
+{
+  g_assert(error != 0);
+
+  g_critical("\n"
+      "unhandled exception (type Glib::Error) in signal handler:\n"
+      "domain: %s\n"
+      "code  : %d\n"
+      "what  : %s\n",
+      g_quark_to_string(error->domain), error->code,
+      (error->message) ? error->message : "(null)");
+}
+
+static void glibmm_unexpected_exception()
+{
+  try
+  {
+    throw; // re-throw current exception
+  }
+  catch(const Glib::Error& error)
+  {
+    // Access the GError directly, to avoid possible exceptions from C++ code.
+    glibmm_exception_warning(error.gobj());
+
+    // For most failures that cause a Glib::Error exception, aborting the
+    // program seems too harsh.  Instead, give control back to the main loop.
+    return;
+  }
+  catch(const std::exception& except)
+  {
+    g_error("\n"
+        "unhandled exception (type std::exception) in signal handler:\n"
+        "what: %s\n", except.what());
+  }
+  catch(...)
+  {
+    g_error("\nunhandled exception (type unknown) in signal handler\n");
+  }
+}
+
+} // anonymous namespace
+
+
+namespace Glib
+{
+
+sigc::connection add_exception_handler(const sigc::slot<void>& slot)
+{
+  HandlerList* handler_list = thread_specific_handler_list.get();
+
+  if(!handler_list)
+  {
+    handler_list = new HandlerList();
+    thread_specific_handler_list.set(handler_list);
+  }
+
+  handler_list->slots().push_front(slot);
+  return handler_list->slots().begin();
+}
+
+// internal
+void exception_handlers_invoke() throw()
+{
+  // This function will be called from our GLib signal handler proxies
+  // if an exception has been caught.  It's not possible to throw C++
+  // exceptions through C signal handlers.  To handle this situation, the
+  // programmer can install slots to global Reusable Exception Handlers.
+  //
+  // A handler has to re-throw the current exception in a try block, and then
+  // catch the exceptions it knows about.  Any unknown exceptions should just
+  // fall through, i.e. the handler must not do catch(...).
+  //
+  // We now invoke each of the installed slots until the exception has been
+  // handled.  If there are no more handlers in the list and the exception
+  // is still unhandled, call glibmm_unexpected_exception().
+
+  if(HandlerList *const handler_list = thread_specific_handler_list.get())
+  {
+    HandlerList::iterator pslot = handler_list->slots().begin();
+
+    while(pslot != handler_list->slots().end())
+    {
+      // Calling an empty slot would mean ignoring the exception,
+      // thus we have to check for dead slots explicitly.
+      if(pslot->empty())
+      {
+        pslot = handler_list->slots().erase(pslot);
+        continue;
+      }
+
+      // Call the Reusable Exception Handler, which should re-throw
+      // the exception that's currently on the stack.
+      try
+      {
+        (*pslot)();
+      }
+      catch(...) // unhandled, try next slot
+      {
+        ++pslot;
+        continue;
+      }
+
+      // The exception has either been handled or ignored.
+      // Give control back to the GLib main loop.
+      return;
+    }
+  }
+
+  // Critical: The exception is still unhandled.
+  glibmm_unexpected_exception();
+}
+
+} // namespace Glib
+