summaryrefslogtreecommitdiff
path: root/glib/glibmm/exceptionhandler.cc
diff options
context:
space:
mode:
Diffstat (limited to 'glib/glibmm/exceptionhandler.cc')
-rw-r--r--glib/glibmm/exceptionhandler.cc193
1 files changed, 193 insertions, 0 deletions
diff --git a/glib/glibmm/exceptionhandler.cc b/glib/glibmm/exceptionhandler.cc
new file mode 100644
index 00000000..52408b91
--- /dev/null
+++ b/glib/glibmm/exceptionhandler.cc
@@ -0,0 +1,193 @@
+// -*- 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>
+
+GTKMM_USING_STD(exception)
+GTKMM_USING_STD(list)
+
+
+namespace
+{
+
+typedef std::list< SigC::Slot0<void> > HandlerList;
+
+// Each thread has its own list of exception handlers
+// to avoid thread synchronization problems.
+Glib::StaticPrivate<HandlerList> thread_specific_handler_list = GLIBMM_STATIC_PRIVATE_INIT;
+
+
+class HandlerConnectionNode : public SigC::ConnectionNode
+{
+public:
+ explicit HandlerConnectionNode(const SigC::Slot0<void>& slot)
+ : SigC::ConnectionNode(static_cast<SigC::SlotNode*>(slot.impl())) {}
+
+ virtual void notify(bool from_child);
+};
+
+void HandlerConnectionNode::notify(bool from_child)
+{
+ if(HandlerList *const handler_list = thread_specific_handler_list.get())
+ {
+ // We can't use remove_if() because it's possible to insert the same
+ // slot multiple times, although unlikely. std::list<>::remove_if()
+ // would remove only the first matching element.
+
+ HandlerList::iterator pslot = handler_list->begin();
+
+ while(pslot != handler_list->end())
+ {
+ if(pslot->impl() == slot().impl())
+ pslot = handler_list->erase(pslot);
+ else
+ ++pslot;
+ }
+ }
+
+ SigC::ConnectionNode::notify(from_child);
+}
+
+
+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)");
+}
+
+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::Slot0<void>& slot)
+{
+ HandlerList* handler_list = thread_specific_handler_list.get();
+
+ if(!handler_list)
+ {
+ handler_list = new HandlerList();
+ thread_specific_handler_list.set(handler_list);
+ }
+
+ const SigC::Connection connection (new HandlerConnectionNode(slot));
+ handler_list->push_front(slot);
+
+ return connection;
+}
+
+// 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->begin();
+
+ while(pslot != handler_list->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->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
+