From c38e02285fda1fd7966c9e4ad85994445247e6a6 Mon Sep 17 00:00:00 2001
From: Paul Davis <paul@linuxaudiosystems.com>
Date: Wed, 9 Dec 2009 03:05:14 +0000
Subject: major design changes: use glib event loop for MIDI thread/UI; rework
 design of BaseUI and AbstractUI; solo & mute are both temporarily broken; OSC
 control up next; may segfault during exit

git-svn-id: svn://localhost/ardour2/branches/3.0@6328 d708f5d6-7413-0410-9779-e7cbd77b26cf
---
 libs/pbd/base_ui.cc | 85 +++++++++++++++++++++++++++++------------------------
 1 file changed, 47 insertions(+), 38 deletions(-)

(limited to 'libs/pbd/base_ui.cc')

diff --git a/libs/pbd/base_ui.cc b/libs/pbd/base_ui.cc
index 015951f118..259a51d954 100644
--- a/libs/pbd/base_ui.cc
+++ b/libs/pbd/base_ui.cc
@@ -33,36 +33,24 @@
 
 using namespace std;
 using namespace PBD;
+using namespace Glib;
 	
-uint32_t BaseUI::rt_bit = 1;
+uint64_t BaseUI::rt_bit = 1;
 BaseUI::RequestType BaseUI::CallSlot = BaseUI::new_request_type();
 
-BaseUI::BaseUI (string str, bool with_signal_pipe)
-	: _name (str)
+BaseUI::BaseUI (const string& str)
+	: run_loop_thread (0)
+	, _name (str)
 {
-	/* odd pseudo-singleton semantics */
-
 	base_ui_instance = this;
 
-	signal_pipe[0] = -1;
-	signal_pipe[1] = -1;
+	request_channel.ios()->connect (sigc::mem_fun (*this, &BaseUI::request_handler));
 
-	if (with_signal_pipe) {
-		if (setup_signal_pipe ()) {
-			throw failed_constructor ();
-		}
-	}
+	/* derived class must set _ok */
 }
 
 BaseUI::~BaseUI()
 {
-	if (signal_pipe[0] >= 0) {
-		close (signal_pipe[0]);
-	} 
-
-	if (signal_pipe[1] >= 0) {
-		close (signal_pipe[1]);
-	} 
 }
 
 BaseUI::RequestType
@@ -78,32 +66,53 @@ BaseUI::new_request_type ()
 	return rt;
 }
 
-int
-BaseUI::setup_signal_pipe ()
+void
+BaseUI::main_thread ()
+{
+	thread_init ();
+	_main_loop->run ();
+}
+
+void
+BaseUI::run ()
 {
-	/* setup the pipe that other threads send us notifications/requests
-	   through.
+	/* to be called by UI's that need/want their own distinct, self-created event loop thread.
+	   Derived classes should have set up a handler for IO on request_channel.ios()
 	*/
 
-	if (pipe (signal_pipe)) {
-		error << string_compose (_("%1-UI: cannot create error signal pipe (%2)"), _name, ::strerror (errno))
-		      << endmsg;
+	_main_loop = MainLoop::create (MainContext::create());
+	request_channel.ios()->attach (_main_loop->get_context());
+	run_loop_thread = Thread::create (mem_fun (*this, &BaseUI::main_thread), true);
+}
 
-		return -1;
-	}
+void
+BaseUI::quit ()
+{
+	_main_loop->quit ();
+	run_loop_thread->join ();
+}
+
+bool
+BaseUI::request_handler (Glib::IOCondition ioc)
+{
+	/* check the transport request pipe */
 
-	if (fcntl (signal_pipe[0], F_SETFL, O_NONBLOCK)) {
-		error << string_compose (_("%1-UI: cannot set O_NONBLOCK on signal read pipe (%2)"), _name, ::strerror (errno))
-		      << endmsg;
-		return -1;
+	if (ioc & ~IO_IN) {
+		_main_loop->quit ();
 	}
 
-	if (fcntl (signal_pipe[1], F_SETFL, O_NONBLOCK)) {
-		error << string_compose (_("%1-UI: cannot set O_NONBLOCK on signal write pipe (%2)"), _name, ::strerror (errno))
-		      << endmsg;
-		return -1;
+	if (ioc & IO_IN) {
+		request_channel.drain ();
+		
+		/* there may been an error. we'd rather handle requests first,
+		   and then get IO_HUP or IO_ERR on the next loop.
+		*/
+
+		/* handle requests */
+
+		handle_ui_requests ();
 	}
 
-	return 0;
+	return true;
 }
-
+	
-- 
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