From f962f4301c41514d140e303f0052e18a4a622022 Mon Sep 17 00:00:00 2001
From: James Bursa <james@netsurf-browser.org>
Date: Sun, 21 Mar 2004 12:46:56 +0000
Subject: [project @ 2004-03-21 12:46:56 by bursa] Implement scheduled
 callbacks.

svn path=/import/netsurf/; revision=640
---
 riscos/schedule.c | 135 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 135 insertions(+)
 create mode 100644 riscos/schedule.c

(limited to 'riscos/schedule.c')

diff --git a/riscos/schedule.c b/riscos/schedule.c
new file mode 100644
index 000000000..a33b45ed6
--- /dev/null
+++ b/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;
+}
-- 
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