From f9b99e7eacd72ec2e65ab74b325b7f727ec222eb Mon Sep 17 00:00:00 2001
From: Miguel de Icaza <miguel@gnome.org>
Date: Sat, 17 Aug 2002 19:53:51 +0000
Subject: [PATCH] 2002-08-17  Miguel de Icaza  <miguel@ximian.com>

	* gtk/ThreadNotify.cs: New file, used to notify invoke code in the
	main Gtk thread.

svn path=/trunk/gtk-sharp/; revision=6712
---
 ChangeLog           |  5 +++
 gtk/ThreadNotify.cs | 89 +++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 94 insertions(+)
 create mode 100644 gtk/ThreadNotify.cs

diff --git a/ChangeLog b/ChangeLog
index de98dfd7b..adcf0a1bb 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+2002-08-17  Miguel de Icaza  <miguel@ximian.com>
+
+	* gtk/ThreadNotify.cs: New file, used to notify invoke code in the
+	main Gtk thread.
+
 2002-08-17  Duncan Mak  <duncan@ximian.com>
 
 	* gnome/CanvasProxy.cs:
diff --git a/gtk/ThreadNotify.cs b/gtk/ThreadNotify.cs
new file mode 100644
index 000000000..3301829e6
--- /dev/null
+++ b/gtk/ThreadNotify.cs
@@ -0,0 +1,89 @@
+//
+// ThreadNotify.cs: implements a notification for the thread running the Gtk main
+// loop from another thread
+//
+// Author:
+//    Miguel de Icaza (miguel@ximian.com).
+//
+// (C) 2002 Ximian, Inc.
+//
+
+namespace Gtk {
+	using System.Runtime.InteropServices;
+	using System.Threading;
+	using System;
+
+	// <summary>
+	//    This delegate will be invoked on the main Gtk thread.
+	// </summary>
+	delegate void ReadyEvent ();
+
+	/// <summary>
+	///   Utility class to help writting multi-threaded Gtk applications
+	/// </summary>
+	/// <remarks>
+	///   
+	public class ThreadNotify {
+
+		//
+		// DllImport functions from Gtk
+		//
+		[DllImport ("gtk-x11-2.0")]
+		public static extern int gdk_input_add (int s, int cond, GdkInputFunction f, IntPtr data);
+		public delegate void GdkInputFunction (IntPtr data, int source, int cond);
+
+		//
+		// Libc stuff
+		//
+		[DllImport ("libc.so.6")]
+		public static extern int pipe (int [] fd);
+		
+		[DllImport ("libc.so.6")]
+		public static extern unsafe int read (int fd, byte *b, int count);
+		
+		[DllImport ("libc.so.6")]
+		public static extern unsafe int write (int fd, byte *b, int count);
+
+		
+		GdkInputFunction notify_pipe;
+		int [] pipes;
+
+		ReadyEvent re;
+
+		/// <summary>
+		///   The ReadyEvent delegate will be invoked on the current thread (which should
+		///   be the Gtk thread) when another thread wakes us up by calling WakeupMain
+		/// </summary>
+		public ThreadNotify (ReadyEvent re)
+		{
+			notify_pipe = new GdkInputFunction (NotifyPipe);
+			pipes = new int [2];
+			pipe (pipes);
+			gdk_input_add (pipes [0], 1, notify_pipe, (IntPtr) 0);
+			this.re = re;
+		}
+		
+		void NotifyPipe (IntPtr data, int source, int cond)
+		{
+			byte s;
+			
+			unsafe {
+				read (pipes [0], &s, 1);
+			}
+			
+			re ();
+		}
+
+		/// <summary>
+		///   Invoke this function from a thread to call the `ReadyEvent'
+		///   delegate provided in the constructor on the Main Gtk thread
+		/// </summary>
+		public void WakeupMain ()
+		{
+			unsafe {
+				byte s;
+				write (pipes [1], &s, 1);
+			}
+		}
+	}
+}