[project @ 2004-03-21 12:46:56 by bursa]

Implement scheduled callbacks.

svn path=/import/netsurf/; revision=640

makefile

@@ -19,7 +19,7 @@ OBJECTS = $(OBJECTS_COMMON) \
 	draw.o gif.o jpeg.o plugin.o png.o sprite.o \
 	about.o filetype.o font.o uri.o url_protocol.o history.o \
 	version.o thumbnail.o \
-	save.o save_complete.o save_draw.o
+	save.o save_complete.o save_draw.o schedule.o
 OBJECTS_DEBUG = $(OBJECTS_COMMON) \
 	netsurfd.o \
 	options.o filetyped.o fontd.o

riscos/gui.c

@@ -306,6 +306,8 @@ void gui_poll(bool active)
 	xhourglass_off();
 	if (active) {
 		event = wimp_poll(mask, &block, 0);
+	} else if (sched_active) {
+		event = wimp_poll_idle(mask, &block, sched_time, 0);
 	} else if (over_window || gui_reformat_pending) {
 		os_t t = os_read_monotonic_time();
 		event = wimp_poll_idle(mask, &block, t + 10, 0);
@@ -314,6 +316,7 @@ void gui_poll(bool active)
 	}
 	xhourglass_on();
 	ro_gui_handle_event(event, &block);
+	schedule_run();
 
         if (gui_reformat_pending && event == wimp_NULL_REASON_CODE) {
 		for (g = window_list; g; g = g->next) {

riscos/gui.h

@@ -162,6 +162,13 @@ void ro_gui_save_datasave_ack(wimp_message *message);
 /* in filetype.c */
 int ro_content_filetype(struct content *content);
 
+/* in schedule.c */
+extern bool sched_active;
+extern os_t sched_time;
+void schedule(int t, void (*callback)(void *p), void *p);
+void schedule_remove(void (*callback)(void *p), void *p);
+void schedule_run(void);
+
 /* icon numbers */
 #define ICON_TOOLBAR_THROBBER 1
 #define ICON_TOOLBAR_URL 2

riscos/schedule.c

@@ -0,0 +1,135 @@
+/*
+ * This file is part of NetSurf, http://netsurf.sourceforge.net/
+ * Licensed under the GNU General Public License,
+ *                http://www.opensource.org/licenses/gpl-license
+ * Copyright 2004 James Bursa <bursa@users.sourceforge.net>
+ */
+
+/** \file
+ * Scheduled callback queue (implementation).
+ *
+ * The queue is simply implemented as a linked list.
+ */
+
+#include <stdbool.h>
+#include <stdlib.h>
+#include "oslib/os.h"
+#include "netsurf/riscos/gui.h"
+#include "netsurf/utils/log.h"
+
+
+/** Entry in the queue of scheduled callbacks. */
+struct sched_entry {
+	/** Preferred time for callback. */
+	os_t time;
+	/** Function to call at the specified time. */
+	void (*callback)(void *p);
+	/** User parameter for callback. */
+	void *p;
+	/** Next (later) entry in queue. */
+	struct sched_entry *next;
+};
+
+/** Queue of scheduled callbacks (sentinel at head). */
+static struct sched_entry sched_queue = { 0, 0, 0, 0 };
+
+/** Items have been scheduled. */
+bool sched_active = false;
+/** Time of soonest scheduled event (valid only if sched_active is true). */
+os_t sched_time;
+
+
+/**
+ * Schedule a callback.
+ *
+ * \param  t         interval before the callback should be made / cs
+ * \param  callback  callback function
+ * \param  p         user parameter, passed to callback function
+ *
+ * The callback function will be called as soon as possible after t cs have
+ * passed.
+ */
+
+void schedule(int t, void (*callback)(void *p), void *p)
+{
+	struct sched_entry *entry;
+	struct sched_entry *queue;
+	os_t time;
+
+	time = os_read_monotonic_time() + t;
+
+	entry = malloc(sizeof *entry);
+	if (!entry) {
+		LOG(("malloc failed"));
+		return;
+	}
+
+	entry->time = time;
+	entry->callback = callback;
+	entry->p = p;
+
+	for (queue = &sched_queue;
+			queue->next && queue->next->time <= time;
+			queue = queue->next)
+		;
+	entry->next = queue->next;
+	queue->next = entry;
+
+	sched_active = true;
+	sched_time = sched_queue.next->time;
+}
+
+
+/**
+ * Unschedule a callback.
+ *
+ * \param  callback  callback function
+ * \param  p         user parameter, passed to callback function
+ *
+ * All scheduled callbacks matching both callback and p are removed.
+ */
+
+void schedule_remove(void (*callback)(void *p), void *p)
+{
+	struct sched_entry *entry, *next;
+
+	for (entry = &sched_queue; entry->next; entry = entry->next) {
+		if (entry->next->callback != callback || entry->next->p != p)
+			continue;
+		next = entry->next;
+		entry->next = entry->next->next;
+		free(next);
+	}
+
+	if (sched_queue.next) {
+		sched_active = true;
+		sched_time = sched_queue.next->time;
+	} else
+		sched_active = false;
+}
+
+
+/**
+ * Process events up to current time.
+ */
+
+void schedule_run(void)
+{
+	struct sched_entry *entry;
+	os_t now;
+
+	now = os_read_monotonic_time();
+
+	while (sched_queue.next && sched_queue.next->time <= now) {
+		entry = sched_queue.next;
+		entry->callback(entry->p);
+		sched_queue.next = entry->next;
+		free(entry);
+	}
+
+	if (sched_queue.next) {
+		sched_active = true;
+		sched_time = sched_queue.next->time;
+	} else
+		sched_active = false;
+}