move everything to src/ subdirectory

The code corresponds to commit a9aa4777cc1144897a77dfb6c5c3d7325705251e
in openbts-p2.8.git (Tue Jun 12 18:14:49 2012 +0400)

1 files changed, 226 insertions, 0 deletions

diff --git a/src/gsm_timer.cpp b/src/gsm_timer.cpp
new file mode 100644
index 00000000..95513b47
--- /dev/null
+++ b/src/gsm_timer.cpp
@@ -0,0 +1,226 @@
+/* gsm_timer.cpp
+ *
+ * Copyright (C) 2012 Ivan Klyuchnikov
+ *
+ * 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., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
+ */
+ 
+/* These store the amount of frame number that we wait until next timer expires. */
+static int nearest;
+static int *nearest_p;
+
+/*! \addtogroup gsm_timer
+ *  @{
+ */
+
+/*! \file gsm_timer.cpp
+ */
+
+#include <assert.h>
+#include <string.h>
+#include <limits.h>
+#include <gsm_timer.h>
+#include <pcu_l1_if.h>
+
+static struct rb_root timer_root = RB_ROOT;
+
+static void __add_gsm_timer(struct osmo_gsm_timer_list *timer)
+{
+	struct rb_node **new_node = &(timer_root.rb_node);
+	struct rb_node *parent = NULL;
+
+	while (*new_node) {
+		struct osmo_gsm_timer_list *this_timer;
+
+		this_timer = container_of(*new_node, struct osmo_gsm_timer_list, node);
+
+		parent = *new_node;
+		if (timer->fn < this_timer->fn)
+			new_node = &((*new_node)->rb_left);
+		else
+			new_node = &((*new_node)->rb_right);
+		}
+
+		rb_link_node(&timer->node, parent, new_node);
+		rb_insert_color(&timer->node, &timer_root);
+}
+
+/*! \brief add a new timer to the timer management
+ *  \param[in] timer the timer that should be added
+ */
+void osmo_gsm_timer_add(struct osmo_gsm_timer_list *timer)
+{
+	osmo_gsm_timer_del(timer);
+	timer->active = 1;
+	INIT_LLIST_HEAD(&timer->list);
+	__add_gsm_timer(timer);
+}
+
+/*! \brief schedule a gsm timer at a given future relative time
+ *  \param[in] timer the to-be-added timer
+ *  \param[in] number of frames from now
+ *
+ * This function can be used to (re-)schedule a given timer at a
+ * specified number of frames in the future.  It will
+ * internally add it to the timer management data structures, thus
+ * osmo_timer_add() is automatically called.
+ */
+void
+osmo_gsm_timer_schedule(struct osmo_gsm_timer_list *timer, int fn)
+{
+	int current_fn;
+
+	current_fn = get_current_fn();
+	timer->fn = current_fn + fn;
+	osmo_gsm_timer_add(timer);
+}
+
+/*! \brief delete a gsm timer from timer management
+ *  \param[in] timer the to-be-deleted timer
+ *
+ * This function can be used to delete a previously added/scheduled
+ * timer from the timer management code.
+ */
+void osmo_gsm_timer_del(struct osmo_gsm_timer_list *timer)
+{
+	if (timer->active) {
+		timer->active = 0;
+		rb_erase(&timer->node, &timer_root);
+		/* make sure this is not already scheduled for removal. */
+		if (!llist_empty(&timer->list))
+			llist_del_init(&timer->list);
+	}
+}
+
+/*! \brief check if given timer is still pending
+ *  \param[in] timer the to-be-checked timer
+ *  \return 1 if pending, 0 otherwise
+ *
+ * This function can be used to determine whether a given timer
+ * has alredy expired (returns 0) or is still pending (returns 1)
+ */
+int osmo_gsm_timer_pending(struct osmo_gsm_timer_list *timer)
+{
+	return timer->active;
+}
+
+/*
+ * if we have a nearest frame number return the delta between the current
+ * FN and the FN of the nearest timer.
+ * If the nearest timer timed out return NULL and then we will
+ * dispatch everything after the select
+ */
+int *osmo_gsm_timers_nearest(void)
+{
+	/* nearest_p is exactly what we need already: NULL if nothing is
+	 * waiting, {0,0} if we must dispatch immediately, and the correct
+	 * delay if we need to wait */
+	return nearest_p;
+}
+
+static void update_nearest(int *cand, int *current)
+{
+	if (*cand != LONG_MAX) {
+		if (*cand > *current)
+			nearest = *cand - *current;
+		else {
+			/* loop again inmediately */
+			nearest = 0;
+		}
+		nearest_p = &nearest;
+	} else {
+		nearest_p = NULL;
+	}
+}
+
+/*
+ * Find the nearest FN and update s_nearest_time
+ */
+void osmo_gsm_timers_prepare(void)
+{
+	struct rb_node *node;
+	int current_fn;
+
+	current_fn = get_current_fn();
+
+	node = rb_first(&timer_root);
+	if (node) {
+		struct osmo_gsm_timer_list *this_timer;
+		this_timer = container_of(node, struct osmo_gsm_timer_list, node);
+		update_nearest(&this_timer->fn, &current_fn);
+	} else {
+		nearest_p = NULL;
+	}
+}
+
+/*
+ * fire all timers... and remove them
+ */
+int osmo_gsm_timers_update(void)
+{
+	int current_fn;
+	struct rb_node *node;
+	struct llist_head timer_eviction_list;
+	struct osmo_gsm_timer_list *this_timer;
+	int work = 0;
+
+	current_fn = get_current_fn();
+
+	INIT_LLIST_HEAD(&timer_eviction_list);
+	for (node = rb_first(&timer_root); node; node = rb_next(node)) {
+		this_timer = container_of(node, struct osmo_gsm_timer_list, node);
+
+		if (this_timer->fn > current_fn)
+			break;
+
+		llist_add(&this_timer->list, &timer_eviction_list);
+	}
+
+	/*
+	 * The callbacks might mess with our list and in this case
+	 * even llist_for_each_entry_safe is not safe to use. To allow
+	 * osmo_gsm_timer_del to be called from within the callback we need
+	 * to restart the iteration for each element scheduled for removal.
+	 *
+	 * The problematic scenario is the following: Given two timers A
+	 * and B that have expired at the same time. Thus, they are both
+	 * in the eviction list in this order: A, then B. If we remove
+	 * timer B from the A's callback, we continue with B in the next
+	 * iteration step, leading to an access-after-release.
+	 */
+restart:
+	llist_for_each_entry(this_timer, &timer_eviction_list, list) {
+		osmo_gsm_timer_del(this_timer);
+		this_timer->cb(this_timer->data);
+		work = 1;
+		goto restart;
+	}
+
+	return work;
+}
+
+int osmo_gsm_timers_check(void)
+{
+	struct rb_node *node;
+	int i = 0;
+
+	for (node = rb_first(&timer_root); node; node = rb_next(node)) {
+		i++;
+	}
+	return i;
+}
+
+/*! }@ */
+