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-rw-r--r--src/Makefile.am4
-rw-r--r--src/rbtree.c389
-rw-r--r--src/timer.c176
3 files changed, 486 insertions, 83 deletions
diff --git a/src/Makefile.am b/src/Makefile.am
index df104ac3..89b8138f 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -2,7 +2,7 @@ SUBDIRS=. vty codec gsm
# This is _NOT_ the library release version, it's an API version.
# Please read Chapter 6 "Library interface versions" of the libtool documentation before making any modification
-LIBVERSION=2:1:0
+LIBVERSION=3:0:0
INCLUDES = $(all_includes) -I$(top_srcdir)/include
AM_CFLAGS = -fPIC -Wall
@@ -14,7 +14,7 @@ libosmocore_la_SOURCES = timer.c select.c signal.c msgb.c bits.c \
write_queue.c utils.c socket.c \
logging.c logging_syslog.c rate_ctr.c \
gsmtap_util.c crc16.c panic.c backtrace.c \
- conv.c application.c \
+ conv.c application.c rbtree.c \
crc8gen.c crc16gen.c crc32gen.c crc64gen.c
if ENABLE_PLUGIN
diff --git a/src/rbtree.c b/src/rbtree.c
new file mode 100644
index 00000000..07e1041a
--- /dev/null
+++ b/src/rbtree.c
@@ -0,0 +1,389 @@
+/*
+ Red Black Trees
+ (C) 1999 Andrea Arcangeli <andrea@suse.de>
+ (C) 2002 David Woodhouse <dwmw2@infradead.org>
+
+ 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
+
+ linux/lib/rbtree.c
+*/
+
+#include <osmocom/core/linuxrbtree.h>
+
+static void __rb_rotate_left(struct rb_node *node, struct rb_root *root)
+{
+ struct rb_node *right = node->rb_right;
+ struct rb_node *parent = rb_parent(node);
+
+ if ((node->rb_right = right->rb_left))
+ rb_set_parent(right->rb_left, node);
+ right->rb_left = node;
+
+ rb_set_parent(right, parent);
+
+ if (parent)
+ {
+ if (node == parent->rb_left)
+ parent->rb_left = right;
+ else
+ parent->rb_right = right;
+ }
+ else
+ root->rb_node = right;
+ rb_set_parent(node, right);
+}
+
+static void __rb_rotate_right(struct rb_node *node, struct rb_root *root)
+{
+ struct rb_node *left = node->rb_left;
+ struct rb_node *parent = rb_parent(node);
+
+ if ((node->rb_left = left->rb_right))
+ rb_set_parent(left->rb_right, node);
+ left->rb_right = node;
+
+ rb_set_parent(left, parent);
+
+ if (parent)
+ {
+ if (node == parent->rb_right)
+ parent->rb_right = left;
+ else
+ parent->rb_left = left;
+ }
+ else
+ root->rb_node = left;
+ rb_set_parent(node, left);
+}
+
+void rb_insert_color(struct rb_node *node, struct rb_root *root)
+{
+ struct rb_node *parent, *gparent;
+
+ while ((parent = rb_parent(node)) && rb_is_red(parent))
+ {
+ gparent = rb_parent(parent);
+
+ if (parent == gparent->rb_left)
+ {
+ {
+ register struct rb_node *uncle = gparent->rb_right;
+ if (uncle && rb_is_red(uncle))
+ {
+ rb_set_black(uncle);
+ rb_set_black(parent);
+ rb_set_red(gparent);
+ node = gparent;
+ continue;
+ }
+ }
+
+ if (parent->rb_right == node)
+ {
+ register struct rb_node *tmp;
+ __rb_rotate_left(parent, root);
+ tmp = parent;
+ parent = node;
+ node = tmp;
+ }
+
+ rb_set_black(parent);
+ rb_set_red(gparent);
+ __rb_rotate_right(gparent, root);
+ } else {
+ {
+ register struct rb_node *uncle = gparent->rb_left;
+ if (uncle && rb_is_red(uncle))
+ {
+ rb_set_black(uncle);
+ rb_set_black(parent);
+ rb_set_red(gparent);
+ node = gparent;
+ continue;
+ }
+ }
+
+ if (parent->rb_left == node)
+ {
+ register struct rb_node *tmp;
+ __rb_rotate_right(parent, root);
+ tmp = parent;
+ parent = node;
+ node = tmp;
+ }
+
+ rb_set_black(parent);
+ rb_set_red(gparent);
+ __rb_rotate_left(gparent, root);
+ }
+ }
+
+ rb_set_black(root->rb_node);
+}
+
+static void __rb_erase_color(struct rb_node *node, struct rb_node *parent,
+ struct rb_root *root)
+{
+ struct rb_node *other;
+
+ while ((!node || rb_is_black(node)) && node != root->rb_node)
+ {
+ if (parent->rb_left == node)
+ {
+ other = parent->rb_right;
+ if (rb_is_red(other))
+ {
+ rb_set_black(other);
+ rb_set_red(parent);
+ __rb_rotate_left(parent, root);
+ other = parent->rb_right;
+ }
+ if ((!other->rb_left || rb_is_black(other->rb_left)) &&
+ (!other->rb_right || rb_is_black(other->rb_right)))
+ {
+ rb_set_red(other);
+ node = parent;
+ parent = rb_parent(node);
+ }
+ else
+ {
+ if (!other->rb_right || rb_is_black(other->rb_right))
+ {
+ struct rb_node *o_left;
+ if ((o_left = other->rb_left))
+ rb_set_black(o_left);
+ rb_set_red(other);
+ __rb_rotate_right(other, root);
+ other = parent->rb_right;
+ }
+ rb_set_color(other, rb_color(parent));
+ rb_set_black(parent);
+ if (other->rb_right)
+ rb_set_black(other->rb_right);
+ __rb_rotate_left(parent, root);
+ node = root->rb_node;
+ break;
+ }
+ }
+ else
+ {
+ other = parent->rb_left;
+ if (rb_is_red(other))
+ {
+ rb_set_black(other);
+ rb_set_red(parent);
+ __rb_rotate_right(parent, root);
+ other = parent->rb_left;
+ }
+ if ((!other->rb_left || rb_is_black(other->rb_left)) &&
+ (!other->rb_right || rb_is_black(other->rb_right)))
+ {
+ rb_set_red(other);
+ node = parent;
+ parent = rb_parent(node);
+ }
+ else
+ {
+ if (!other->rb_left || rb_is_black(other->rb_left))
+ {
+ register struct rb_node *o_right;
+ if ((o_right = other->rb_right))
+ rb_set_black(o_right);
+ rb_set_red(other);
+ __rb_rotate_left(other, root);
+ other = parent->rb_left;
+ }
+ rb_set_color(other, rb_color(parent));
+ rb_set_black(parent);
+ if (other->rb_left)
+ rb_set_black(other->rb_left);
+ __rb_rotate_right(parent, root);
+ node = root->rb_node;
+ break;
+ }
+ }
+ }
+ if (node)
+ rb_set_black(node);
+}
+
+void rb_erase(struct rb_node *node, struct rb_root *root)
+{
+ struct rb_node *child, *parent;
+ int color;
+
+ if (!node->rb_left)
+ child = node->rb_right;
+ else if (!node->rb_right)
+ child = node->rb_left;
+ else
+ {
+ struct rb_node *old = node, *left;
+
+ node = node->rb_right;
+ while ((left = node->rb_left) != NULL)
+ node = left;
+ child = node->rb_right;
+ parent = rb_parent(node);
+ color = rb_color(node);
+
+ if (child)
+ rb_set_parent(child, parent);
+ if (parent == old) {
+ parent->rb_right = child;
+ parent = node;
+ } else
+ parent->rb_left = child;
+
+ node->rb_parent_color = old->rb_parent_color;
+ node->rb_right = old->rb_right;
+ node->rb_left = old->rb_left;
+
+ if (rb_parent(old))
+ {
+ if (rb_parent(old)->rb_left == old)
+ rb_parent(old)->rb_left = node;
+ else
+ rb_parent(old)->rb_right = node;
+ } else
+ root->rb_node = node;
+
+ rb_set_parent(old->rb_left, node);
+ if (old->rb_right)
+ rb_set_parent(old->rb_right, node);
+ goto color;
+ }
+
+ parent = rb_parent(node);
+ color = rb_color(node);
+
+ if (child)
+ rb_set_parent(child, parent);
+ if (parent)
+ {
+ if (parent->rb_left == node)
+ parent->rb_left = child;
+ else
+ parent->rb_right = child;
+ }
+ else
+ root->rb_node = child;
+
+ color:
+ if (color == RB_BLACK)
+ __rb_erase_color(child, parent, root);
+}
+
+/*
+ * This function returns the first node (in sort order) of the tree.
+ */
+struct rb_node *rb_first(struct rb_root *root)
+{
+ struct rb_node *n;
+
+ n = root->rb_node;
+ if (!n)
+ return NULL;
+ while (n->rb_left)
+ n = n->rb_left;
+ return n;
+}
+
+struct rb_node *rb_last(struct rb_root *root)
+{
+ struct rb_node *n;
+
+ n = root->rb_node;
+ if (!n)
+ return NULL;
+ while (n->rb_right)
+ n = n->rb_right;
+ return n;
+}
+
+struct rb_node *rb_next(struct rb_node *node)
+{
+ struct rb_node *parent;
+
+ if (rb_parent(node) == node)
+ return NULL;
+
+ /* If we have a right-hand child, go down and then left as far
+ as we can. */
+ if (node->rb_right) {
+ node = node->rb_right;
+ while (node->rb_left)
+ node=node->rb_left;
+ return node;
+ }
+
+ /* No right-hand children. Everything down and left is
+ smaller than us, so any 'next' node must be in the general
+ direction of our parent. Go up the tree; any time the
+ ancestor is a right-hand child of its parent, keep going
+ up. First time it's a left-hand child of its parent, said
+ parent is our 'next' node. */
+ while ((parent = rb_parent(node)) && node == parent->rb_right)
+ node = parent;
+
+ return parent;
+}
+
+struct rb_node *rb_prev(struct rb_node *node)
+{
+ struct rb_node *parent;
+
+ if (rb_parent(node) == node)
+ return NULL;
+
+ /* If we have a left-hand child, go down and then right as far
+ as we can. */
+ if (node->rb_left) {
+ node = node->rb_left;
+ while (node->rb_right)
+ node=node->rb_right;
+ return node;
+ }
+
+ /* No left-hand children. Go up till we find an ancestor which
+ is a right-hand child of its parent */
+ while ((parent = rb_parent(node)) && node == parent->rb_left)
+ node = parent;
+
+ return parent;
+}
+
+void rb_replace_node(struct rb_node *victim, struct rb_node *new,
+ struct rb_root *root)
+{
+ struct rb_node *parent = rb_parent(victim);
+
+ /* Set the surrounding nodes to point to the replacement */
+ if (parent) {
+ if (victim == parent->rb_left)
+ parent->rb_left = new;
+ else
+ parent->rb_right = new;
+ } else {
+ root->rb_node = new;
+ }
+ if (victim->rb_left)
+ rb_set_parent(victim->rb_left, new);
+ if (victim->rb_right)
+ rb_set_parent(victim->rb_right, new);
+
+ /* Copy the pointers/colour from the victim to the replacement */
+ *new = *victim;
+}
diff --git a/src/timer.c b/src/timer.c
index ed2b2963..68529833 100644
--- a/src/timer.c
+++ b/src/timer.c
@@ -1,7 +1,12 @@
/*
* (C) 2008,2009 by Holger Hans Peter Freyther <zecke@selfish.org>
+ * (C) 2011 by Harald Welte <laforge@gnumonks.org>
* All Rights Reserved
*
+ * Authors: Holger Hans Peter Freyther <zecke@selfish.org>
+ * Harald Welte <laforge@gnumonks.org>
+ * Pablo Neira Ayuso <pablo@gnumonks.org>
+ *
* 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
@@ -18,6 +23,10 @@
*
*/
+/* These store the amount of time that we wait until next timer expires. */
+static struct timeval nearest;
+static struct timeval *nearest_p;
+
/*! \addtogroup timer
* @{
*/
@@ -27,35 +36,41 @@
#include <assert.h>
#include <string.h>
+#include <limits.h>
#include <osmocom/core/timer.h>
+#include <osmocom/core/linuxlist.h>
+
+static struct rb_root timer_root = RB_ROOT;
+
+static void __add_timer(struct osmo_timer_list *timer)
+{
+ struct rb_node **new = &(timer_root.rb_node);
+ struct rb_node *parent = NULL;
-static LLIST_HEAD(timer_list);
-static struct timeval s_nearest_time;
-static struct timeval s_select_time;
+ while (*new) {
+ struct osmo_timer_list *this;
-#define MICRO_SECONDS 1000000LL
+ this = container_of(*new, struct osmo_timer_list, node);
-#define TIME_SMALLER(left, right) \
- (left.tv_sec*MICRO_SECONDS+left.tv_usec) <= (right.tv_sec*MICRO_SECONDS+right.tv_usec)
+ parent = *new;
+ if (timercmp(&timer->timeout, &this->timeout, <))
+ new = &((*new)->rb_left);
+ else
+ new = &((*new)->rb_right);
+ }
+ rb_link_node(&timer->node, parent, new);
+ 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_timer_add(struct osmo_timer_list *timer)
{
- struct osmo_timer_list *list_timer;
-
- /* TODO: Optimize and remember the closest item... */
timer->active = 1;
-
- /* this might be called from within update_timers */
- llist_for_each_entry(list_timer, &timer_list, entry)
- if (timer == list_timer)
- return;
-
- timer->in_list = 1;
- llist_add(&timer->entry, &timer_list);
+ INIT_LLIST_HEAD(&timer->list);
+ __add_timer(timer);
}
/*! \brief schedule a timer at a given future relative time
@@ -74,10 +89,9 @@ osmo_timer_schedule(struct osmo_timer_list *timer, int seconds, int microseconds
struct timeval current_time;
gettimeofday(&current_time, NULL);
- unsigned long long currentTime = current_time.tv_sec * MICRO_SECONDS + current_time.tv_usec;
- currentTime += seconds * MICRO_SECONDS + microseconds;
- timer->timeout.tv_sec = currentTime / MICRO_SECONDS;
- timer->timeout.tv_usec = currentTime % MICRO_SECONDS;
+ timer->timeout.tv_sec = seconds;
+ timer->timeout.tv_usec = microseconds;
+ timeradd(&timer->timeout, &current_time, &timer->timeout);
osmo_timer_add(timer);
}
@@ -89,10 +103,12 @@ osmo_timer_schedule(struct osmo_timer_list *timer, int seconds, int microseconds
*/
void osmo_timer_del(struct osmo_timer_list *timer)
{
- if (timer->in_list) {
+ if (timer->active) {
timer->active = 0;
- timer->in_list = 0;
- llist_del(&timer->entry);
+ 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);
}
}
@@ -116,26 +132,28 @@ int osmo_timer_pending(struct osmo_timer_list *timer)
*/
struct timeval *osmo_timers_nearest(void)
{
- struct timeval current_time;
-
- if (s_nearest_time.tv_sec == 0 && s_nearest_time.tv_usec == 0)
- return NULL;
-
- if (gettimeofday(&current_time, NULL) == -1)
- return NULL;
+ static struct timeval no_timers = { 0, 0 };
- unsigned long long nearestTime = s_nearest_time.tv_sec * MICRO_SECONDS + s_nearest_time.tv_usec;
- unsigned long long currentTime = current_time.tv_sec * MICRO_SECONDS + current_time.tv_usec;
+ if (nearest_p != NULL && !timerisset(nearest_p))
+ return nearest_p;
+ else
+ return &no_timers;
+}
- if (nearestTime < currentTime) {
- s_select_time.tv_sec = 0;
- s_select_time.tv_usec = 0;
+static void update_nearest(struct timeval *cand, struct timeval *current)
+{
+ if (cand->tv_sec != LONG_MAX) {
+ if (timercmp(cand, current, >))
+ timersub(cand, current, &nearest);
+ else {
+ /* loop again inmediately */
+ nearest.tv_sec = 0;
+ nearest.tv_usec = 0;
+ }
+ nearest_p = &nearest;
} else {
- s_select_time.tv_sec = (nearestTime - currentTime) / MICRO_SECONDS;
- s_select_time.tv_usec = (nearestTime - currentTime) % MICRO_SECONDS;
+ nearest_p = NULL;
}
-
- return &s_select_time;
}
/*
@@ -143,17 +161,18 @@ struct timeval *osmo_timers_nearest(void)
*/
void osmo_timers_prepare(void)
{
- struct osmo_timer_list *timer, *nearest_timer = NULL;
- llist_for_each_entry(timer, &timer_list, entry) {
- if (!nearest_timer || TIME_SMALLER(timer->timeout, nearest_timer->timeout)) {
- nearest_timer = timer;
- }
- }
+ struct rb_node *node;
+ struct timeval current;
+
+ gettimeofday(&current, NULL);
- if (nearest_timer) {
- s_nearest_time = nearest_timer->timeout;
+ node = rb_first(&timer_root);
+ if (node) {
+ struct osmo_timer_list *this;
+ this = container_of(node, struct osmo_timer_list, node);
+ update_nearest(&this->timeout, &current);
} else {
- memset(&s_nearest_time, 0, sizeof(struct timeval));
+ nearest_p = NULL;
}
}
@@ -163,46 +182,41 @@ void osmo_timers_prepare(void)
int osmo_timers_update(void)
{
struct timeval current_time;
- struct osmo_timer_list *timer, *tmp;
+ struct rb_node *node;
+ struct llist_head timer_eviction_list;
+ struct osmo_timer_list *this;
int work = 0;
gettimeofday(&current_time, NULL);
+ INIT_LLIST_HEAD(&timer_eviction_list);
+ for (node = rb_first(&timer_root); node; node = rb_next(node)) {
+ this = container_of(node, struct osmo_timer_list, node);
+
+ if (timercmp(&this->timeout, &current_time, >))
+ break;
+
+ llist_add(&this->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
- * del_timer, add_timer, schedule_timer to be called from within
- * the callback we jump through some loops.
+ * osmo_timer_del to be called from within the callback we need
+ * to restart the iteration for each element scheduled for removal.
*
- * First we set the handled flag of each active timer to zero,
- * then we iterate over the list and execute the callbacks. As the
- * list might have been changed (specially the next) from within
- * the callback we have to start over again. Once every callback
- * is dispatched we will remove the non-active from the list.
- *
- * TODO: If this is a performance issue we can poison a global
- * variable in add_timer and del_timer and only then restart.
+ * 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.
*/
- llist_for_each_entry(timer, &timer_list, entry) {
- timer->handled = 0;
- }
-
restart:
- llist_for_each_entry(timer, &timer_list, entry) {
- if (!timer->handled && TIME_SMALLER(timer->timeout, current_time)) {
- timer->handled = 1;
- timer->active = 0;
- (*timer->cb)(timer->data);
- work = 1;
- goto restart;
- }
- }
-
- llist_for_each_entry_safe(timer, tmp, &timer_list, entry) {
- timer->handled = 0;
- if (!timer->active) {
- osmo_timer_del(timer);
- }
+ llist_for_each_entry(this, &timer_eviction_list, list) {
+ osmo_timer_del(this);
+ this->cb(this->data);
+ work = 1;
+ goto restart;
}
return work;
@@ -210,10 +224,10 @@ restart:
int osmo_timers_check(void)
{
- struct osmo_timer_list *timer;
+ struct rb_node *node;
int i = 0;
- llist_for_each_entry(timer, &timer_list, entry) {
+ for (node = rb_first(&timer_root); node; node = rb_next(node)) {
i++;
}
return i;
generated by cgit v1.2.3 (git 2.25.1) at 2024-10-30 06:39:23 +0000