libtf: separate scheduler fibre, change the core api

1 files changed, 132 insertions, 0 deletions

diff --git a/src/scheduler.c b/src/scheduler.c
new file mode 100644
index 0000000..d287eca
--- /dev/null
+++ b/src/scheduler.c
@@ -0,0 +1,132 @@
+/* scheduler.c - fiber scheduling
+ *
+ * Copyright (C) 2009-2010 Timo Teräs <timo.teras@iki.fi>
+ * All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 or later as
+ * published by the Free Software Foundation.
+ *
+ * See http://www.gnu.org/ for details.
+ */
+
+#include <time.h>
+#include <libtf/scheduler.h>
+#include <libtf/io.h>
+
+/* FIXME: should be in thread local storage */
+struct tf_scheduler *__tf_scheduler;
+
+static void update_time(struct tf_scheduler *sched)
+{
+	struct timespec ts;
+
+	clock_gettime(CLOCK_MONOTONIC, &ts);
+	sched->scheduler_time = ts.tv_sec * 1000 + ts.tv_nsec / 1000000;
+}
+
+static void process_heap(struct tf_scheduler *sched)
+{
+	struct tf_heap_node *node;
+	tf_mtime_t now = sched->scheduler_time;
+
+	while (!tf_heap_empty(&sched->heap) &&
+	       tf_mtime_diff(now, tf_heap_get_value(&sched->heap)) >= 0) {
+		node = tf_heap_get_node(&sched->heap);
+		tf_heap_delete(node, &sched->heap);
+		__tf_fiber_wakeup_heapnode(node);
+	}
+}
+
+void tf_scheduler_fiber(void *data)
+{
+	struct tf_scheduler *sched = (struct tf_scheduler *) data;
+
+	do {
+		tf_mtime_diff_t timeout;
+
+		update_time(sched);
+		if (!tf_list_empty(&sched->scheduled_q) ||
+		    !tf_list_empty(&sched->running_q)) {
+			timeout = 0;
+		} else if (!tf_heap_empty(&sched->heap)) {
+			timeout = tf_mtime_diff(
+				tf_heap_get_value(&sched->heap),
+				tf_scheduler_get_mtime());
+			if (timeout < 0)
+				timeout = 0;
+		} else {
+			timeout = -1;
+		}
+
+		if (tf_poll(timeout) == TF_WAKEUP_TIMEOUT &&
+		    timeout >= 0) {
+			sched->scheduler_time += timeout;
+			process_heap(sched);
+		}
+
+		if (tf_fiber_yield() == TF_WAKEUP_KILL) {
+			do {
+				tf_fiber_put(sched->active_fiber);
+				sched->active_fiber = sched;
+			} while (__tf_fiber_schedule() == TF_WAKEUP_KILL);
+		}
+	} while (1);
+}
+
+struct tf_scheduler *tf_scheduler_create(void)
+{
+	struct tf_scheduler *sched;
+
+	sched = __tf_fiber_create(tf_scheduler_fiber,
+				  sizeof(struct tf_scheduler));
+
+	*sched = (struct tf_scheduler) {
+		.scheduled_q = TF_LIST_HEAD_INITIALIZER(sched->scheduled_q),
+		.running_q = TF_LIST_HEAD_INITIALIZER(sched->running_q),
+	};
+
+	return sched;
+}
+
+int  tf_scheduler_enable(struct tf_scheduler *sched)
+{
+	struct tf_scheduler *s = sched;
+
+	if (s == NULL) {
+		s = tf_scheduler_create();
+		if (s == NULL)
+			return -ENOMEM;
+	}
+	if (s->main_fiber != NULL)
+		return -EBUSY;
+
+	__tf_fiber_bind_scheduler(s);
+	__tf_scheduler = s;
+	tf_poll_init();
+	update_time(s);
+
+	if (sched != NULL)
+		tf_scheduler_get(sched);
+
+	return 0;
+}
+
+void tf_scheduler_disable(void)
+{
+	struct tf_scheduler *sched = __tf_scheduler;
+
+	if (sched == NULL ||
+	    sched->main_fiber != sched->active_fiber)
+		return;
+
+	/* sleep until no others */
+	while (sched->num_fibers > 1)
+		__tf_fiber_schedule();
+
+	tf_poll_close();
+	__tf_scheduler = NULL;
+	__tf_fiber_release_scheduler(sched);
+	tf_heap_destroy(&sched->heap);
+	tf_fiber_put(sched);
+}