rollback to 3428, before the mysterious removal of libs/* at 3431/3432

git-svn-id: svn://localhost/ardour2/branches/3.0@3435 d708f5d6-7413-0410-9779-e7cbd77b26cf

1 files changed, 57 insertions, 0 deletions

diff --git a/libs/pbd/pbd/crossthread.h b/libs/pbd/pbd/crossthread.h
new file mode 100644
index 0000000000..b815cfd319
--- /dev/null
+++ b/libs/pbd/pbd/crossthread.h
@@ -0,0 +1,57 @@
+/*
+    Copyright (C) 2000-2007 Paul Davis 
+
+    This program is free software; you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation; either version 2 of the License, or
+    (at your option) any later version.
+
+    This program 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 General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program; if not, write to the Free Software
+    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+
+*/
+
+#ifndef __pbd__crossthread_h__
+#define __pbd__crossthread_h__
+
+#include <pbd/abstract_ui.h>
+#include <sigc++/sigc++.h>
+#include <pthread.h>
+
+template<class RequestType> 
+void 
+call_slot_from_thread_or_dispatch_it (pthread_t thread_id, AbstractUI<RequestType>& ui, sigc::slot<void> theSlot)
+{
+	/* when called, this function will determine whether the calling thread
+	   is the same as thread specified by the first argument. if it is,
+	   the we execute the slot. if not, we ask the interface given by the second
+	   argument to call the slot.
+	*/
+
+	if (pthread_self() == thread_id) {
+		theSlot ();
+	} else {
+		ui.call_slot (theSlot);
+	}
+}
+
+template<class RequestType> 
+sigc::slot<void>
+crossthread_safe (pthread_t thread_id, AbstractUI<RequestType>& ui, sigc::slot<void> theSlot)
+{
+	/* this function returns a slot that will ensure that theSlot is either
+	   called by the specified thread or passed to the interface via 
+	   AbstractUI::call_slot().
+	*/
+	   
+	return sigc::bind (sigc::ptr_fun (call_slot_from_thread_or_dispatch_it<RequestType>), 
+			   thread_id, ui, theSlot);
+}
+
+#endif /* __pbd__crossthread_h__ */