X-Git-Url: https://main.carlh.net/gitweb/?a=blobdiff_plain;f=libs%2Fpbd%2Fpbd%2Fcrossthread.h;h=e87879e4a31bb9a36698b1f71cc9548919be8c43;hb=569167a603ef812a234d3c02f6a94976571a70ea;hp=413dea024e4c1c54c95795cd01523fab1798dfdd;hpb=7bbf76132164d3bd293c3bfdf2038dd47f1cc63b;p=ardour.git

diff --git a/libs/pbd/pbd/crossthread.h b/libs/pbd/pbd/crossthread.h
index 413dea024e..e87879e4a3 100644
--- a/libs/pbd/pbd/crossthread.h
+++ b/libs/pbd/pbd/crossthread.h
@@ -1,38 +1,108 @@
+/*
+    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);
-}
+#ifdef check
+#undef check
+#endif
+
+#include <glibmm/main.h>
+
+#include "pbd/libpbd_visibility.h"
+
+#ifdef PLATFORM_WINDOWS
+#include <windows.h>
+#endif // PLATFORM_WINDOWS
+
+
+/** A simple abstraction of a mechanism of signalling one thread from another.
+ * The signaller calls ::wakeup() to tell the signalled thread to check for
+ * work to be done.
+ *
+ * This implementation provides both ::selectable() for use in direct
+ * poll/select-based event loops, and a Glib::IOSource via ::ios() for use
+ * in Glib main loop based situations.
+ */
+
+class LIBPBD_API CrossThreadChannel {
+public:
+	/** if @a non_blocking is true, the channel will not cause blocking
+	 * when used in an event loop based on poll/select or the glib main
+	 * loop.
+	 */
+	CrossThreadChannel(bool non_blocking);
+	~CrossThreadChannel();
+
+	/** Tell the listening thread that is has work to do.
+	 */
+	void wakeup();
+
+	/* if the listening thread cares about the precise message
+	 * it is being sent, then ::deliver() can be used to send
+	 * a single byte message rather than a simple wakeup. These
+	 * two mechanisms should not be used on the same CrossThreadChannel
+	 * because there is no way to know which byte value will be used
+	 * for ::wakeup()
+	 */
+	int deliver (char msg);
+
+	/** if using ::deliver() to wakeup the listening thread, then
+	 * the listener should call ::receive() to fetch the message
+	 * type from the channel.
+	 *
+	 * wait = true only make sense for non_blocking channels,
+	 * it polls for data to become available.
+	 */
+	int receive (char& msg, bool wait = false);
+
+	/** empty the channel of all requests.
+	 * Typically this is done as soon as input
+	 * is noticed on the channel, because the
+	 * handler will look at a separately managed work
+	 * queue. The actual number of queued "wakeups"
+	 * in the channel will not be important.
+	 */
+	void drain ();
+
+	void set_receive_handler (sigc::slot<bool,Glib::IOCondition> s);
+	void attach (Glib::RefPtr<Glib::MainContext>);
+
+private:
+	friend gboolean cross_thread_channel_call_receive_slot (GIOChannel*, GIOCondition condition, void *data);
+
+	GIOChannel* receive_channel;
+	GSource*    receive_source;
+	sigc::slot<bool,Glib::IOCondition> receive_slot;
+
+	bool poll_for_request();
+
+#ifndef PLATFORM_WINDOWS
+	int fds[2]; // current implementation uses a pipe/fifo
+#else
+
+	SOCKET send_socket;
+	SOCKET receive_socket;
+	struct sockaddr_in recv_address;
+#endif
+
+};
 
 #endif /* __pbd__crossthread_h__ */