/*
- Copyright (C) 2000-2007 Paul Davis
+ 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
#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__ */
projects / ardour.git / blobdiff