diff options
Diffstat (limited to 'src')
-rw-r--r-- | src/Makefile.am | 4 | ||||
-rw-r--r-- | src/rbtree.c | 389 | ||||
-rw-r--r-- | src/timer.c | 176 |
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(¤t_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, ¤t_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(¤t_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(¤t, 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, ¤t); } 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(¤t_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, ¤t_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; |