1 files changed, 87 insertions, 0 deletions
diff --git a/libs/pbd3/base_ui.cc b/libs/pbd3/base_ui.cc
new file mode 100644
index 0000000000..5598b20021
--- /dev/null
+++ b/libs/pbd3/base_ui.cc
@@ -0,0 +1,87 @@
+#include <stdint.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <errno.h>
+
+#include <pbd/base_ui.h>
+#include <pbd/error.h>
+#include <pbd/compose.h>
+#include <pbd/failed_constructor.h>
+
+#include "i18n.h"
+
+using namespace std;
+	
+uint32_t BaseUI::rt_bit = 1;
+BaseUI::RequestType BaseUI::CallSlot = BaseUI::new_request_type();
+
+BaseUI::BaseUI (string str, bool with_signal_pipe)
+	: _name (str)
+{
+	/* odd pseudo-singleton semantics */
+
+	base_ui_instance = this;
+
+	signal_pipe[0] = -1;
+	signal_pipe[1] = -1;
+
+	if (with_signal_pipe) {
+		if (setup_signal_pipe ()) {
+			throw failed_constructor ();
+		}
+	}
+}
+
+BaseUI::~BaseUI()
+{
+	if (signal_pipe[0] >= 0) {
+		close (signal_pipe[0]);
+	} 
+
+	if (signal_pipe[1] >= 0) {
+		close (signal_pipe[1]);
+	} 
+}
+
+BaseUI::RequestType
+BaseUI::new_request_type ()
+{
+	RequestType rt;
+
+	/* XXX catch out-of-range */
+
+	rt = RequestType (rt_bit);
+	rt_bit <<= 1;
+
+	return rt;
+}
+
+int
+BaseUI::setup_signal_pipe ()
+{
+	/* setup the pipe that other threads send us notifications/requests
+	   through.
+	*/
+
+	if (pipe (signal_pipe)) {
+		error << string_compose (_("%1-UI: cannot create error signal pipe (%2)"), _name, std::strerror (errno))
+		      << endmsg;
+
+		return -1;
+	}
+
+	if (fcntl (signal_pipe[0], F_SETFL, O_NONBLOCK)) {
+		error << string_compose (_("%1-UI: cannot set O_NONBLOCK on signal read pipe (%2)"), _name, std::strerror (errno))
+		      << endmsg;
+		return -1;
+	}
+
+	if (fcntl (signal_pipe[1], F_SETFL, O_NONBLOCK)) {
+		error << string_compose (_("%1-UI: cannot set O_NONBLOCK on signal write pipe (%2)"), _name, std::strerror (errno))
+		      << endmsg;
+		return -1;
+	}
+
+	return 0;
+}
+