/* $Id: timer.c 4359 2013-02-21 11:18:36Z bennylp $ */ /* * The PJLIB's timer heap is based (or more correctly, copied and modied) * from ACE library by Douglas C. Schmidt. ACE is an excellent OO framework * that implements many core patterns for concurrent communication software. * If you're looking for C++ alternative of PJLIB, then ACE is your best * solution. * * You may use this file according to ACE open source terms or PJLIB open * source terms. You can find the fine ACE library at: * http://www.cs.wustl.edu/~schmidt/ACE.html * * ACE is Copyright (C)1993-2006 Douglas C. Schmidt * * GNU Public License: * 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 */ #include #include #include #include #include #include #include #include #include #define THIS_FILE "timer.c" #define HEAP_PARENT(X) (X == 0 ? 0 : (((X) - 1) / 2)) #define HEAP_LEFT(X) (((X)+(X))+1) #define DEFAULT_MAX_TIMED_OUT_PER_POLL (64) /** * The implementation of timer heap. */ struct pj_timer_heap_t { /** Pool from which the timer heap resize will get the storage from */ pj_pool_t *pool; /** Maximum size of the heap. */ pj_size_t max_size; /** Current size of the heap. */ pj_size_t cur_size; /** Max timed out entries to process per poll. */ unsigned max_entries_per_poll; /** Lock object. */ pj_lock_t *lock; /** Autodelete lock. */ pj_bool_t auto_delete_lock; /** * Current contents of the Heap, which is organized as a "heap" of * pj_timer_entry *'s. In this context, a heap is a "partially * ordered, almost complete" binary tree, which is stored in an * array. */ pj_timer_entry **heap; /** * An array of "pointers" that allows each pj_timer_entry in the * to be located in O(1) time. Basically, * contains the slot in the array where an pj_timer_entry * with timer id resides. Thus, the timer id passed back from * is really an slot into the array. The * array serves two purposes: negative values are * treated as "pointers" for the , whereas positive * values are treated as "pointers" into the array. */ pj_timer_id_t *timer_ids; /** * "Pointer" to the first element in the freelist contained within * the array, which is organized as a stack. */ pj_timer_id_t timer_ids_freelist; /** Callback to be called when a timer expires. */ pj_timer_heap_callback *callback; }; PJ_INLINE(void) lock_timer_heap( pj_timer_heap_t *ht ) { if (ht->lock) { pj_lock_acquire(ht->lock); } } PJ_INLINE(void) unlock_timer_heap( pj_timer_heap_t *ht ) { if (ht->lock) { pj_lock_release(ht->lock); } } static void copy_node( pj_timer_heap_t *ht, int slot, pj_timer_entry *moved_node ) { PJ_CHECK_STACK(); // Insert into its new location in the heap. ht->heap[slot] = moved_node; // Update the corresponding slot in the parallel array. ht->timer_ids[moved_node->_timer_id] = slot; } static pj_timer_id_t pop_freelist( pj_timer_heap_t *ht ) { // We need to truncate this to for backwards compatibility. pj_timer_id_t new_id = ht->timer_ids_freelist; PJ_CHECK_STACK(); // The freelist values in the are negative, so we need // to negate them to get the next freelist "pointer." ht->timer_ids_freelist = -ht->timer_ids[ht->timer_ids_freelist]; return new_id; } static void push_freelist (pj_timer_heap_t *ht, pj_timer_id_t old_id) { PJ_CHECK_STACK(); // The freelist values in the are negative, so we need // to negate them to get the next freelist "pointer." ht->timer_ids[old_id] = -ht->timer_ids_freelist; ht->timer_ids_freelist = old_id; } static void reheap_down(pj_timer_heap_t *ht, pj_timer_entry *moved_node, size_t slot, size_t child) { PJ_CHECK_STACK(); // Restore the heap property after a deletion. while (child < ht->cur_size) { // Choose the smaller of the two children. if (child + 1 < ht->cur_size && PJ_TIME_VAL_LT(ht->heap[child + 1]->_timer_value, ht->heap[child]->_timer_value)) child++; // Perform a if the child has a larger timeout value than // the . if (PJ_TIME_VAL_LT(ht->heap[child]->_timer_value, moved_node->_timer_value)) { copy_node( ht, slot, ht->heap[child]); slot = child; child = HEAP_LEFT(child); } else // We've found our location in the heap. break; } copy_node( ht, slot, moved_node); } static void reheap_up( pj_timer_heap_t *ht, pj_timer_entry *moved_node, size_t slot, size_t parent) { // Restore the heap property after an insertion. while (slot > 0) { // If the parent node is greater than the we need // to copy it down. if (PJ_TIME_VAL_LT(moved_node->_timer_value, ht->heap[parent]->_timer_value)) { copy_node(ht, slot, ht->heap[parent]); slot = parent; parent = HEAP_PARENT(slot); } else break; } // Insert the new node into its proper resting place in the heap and // update the corresponding slot in the parallel array. copy_node(ht, slot, moved_node); } static pj_timer_entry * remove_node( pj_timer_heap_t *ht, size_t slot) { pj_timer_entry *removed_node = ht->heap[slot]; // Return this timer id to the freelist. push_freelist( ht, removed_node->_timer_id ); // Decrement the size of the heap by one since we're removing the // "slot"th node. ht->cur_size--; // Set the ID removed_node->_timer_id = -1; // Only try to reheapify if we're not deleting the last entry. if (slot < ht->cur_size) { int parent; pj_timer_entry *moved_node = ht->heap[ht->cur_size]; // Move the end node to the location being removed and update // the corresponding slot in the parallel array. copy_node( ht, slot, moved_node); // If the time_value_> is great than or equal its // parent it needs be moved down the heap. parent = HEAP_PARENT (slot); if (PJ_TIME_VAL_GTE(moved_node->_timer_value, ht->heap[parent]->_timer_value)) reheap_down( ht, moved_node, slot, HEAP_LEFT(slot)); else reheap_up( ht, moved_node, slot, parent); } return removed_node; } static void grow_heap(pj_timer_heap_t *ht) { // All the containers will double in size from max_size_ size_t new_size = ht->max_size * 2; pj_timer_id_t *new_timer_ids; pj_size_t i; // First grow the heap itself. pj_timer_entry **new_heap = 0; new_heap = (pj_timer_entry**) pj_pool_alloc(ht->pool, sizeof(pj_timer_entry*) * new_size); memcpy(new_heap, ht->heap, ht->max_size * sizeof(pj_timer_entry*)); //delete [] this->heap_; ht->heap = new_heap; // Grow the array of timer ids. new_timer_ids = 0; new_timer_ids = (pj_timer_id_t*) pj_pool_alloc(ht->pool, new_size * sizeof(pj_timer_id_t)); memcpy( new_timer_ids, ht->timer_ids, ht->max_size * sizeof(pj_timer_id_t)); //delete [] timer_ids_; ht->timer_ids = new_timer_ids; // And add the new elements to the end of the "freelist". for (i = ht->max_size; i < new_size; i++) ht->timer_ids[i] = -((pj_timer_id_t) (i + 1)); ht->max_size = new_size; } static void insert_node(pj_timer_heap_t *ht, pj_timer_entry *new_node) { if (ht->cur_size + 2 >= ht->max_size) grow_heap(ht); reheap_up( ht, new_node, ht->cur_size, HEAP_PARENT(ht->cur_size)); ht->cur_size++; } static pj_status_t schedule_entry( pj_timer_heap_t *ht, pj_timer_entry *entry, const pj_time_val *future_time ) { if (ht->cur_size < ht->max_size) { // Obtain the next unique sequence number. // Set the entry entry->_timer_id = pop_freelist(ht); entry->_timer_value = *future_time; insert_node( ht, entry); return 0; } else return -1; } static int cancel( pj_timer_heap_t *ht, pj_timer_entry *entry, int dont_call) { long timer_node_slot; PJ_CHECK_STACK(); // Check to see if the timer_id is out of range if (entry->_timer_id < 0 || (pj_size_t)entry->_timer_id > ht->max_size) return 0; timer_node_slot = ht->timer_ids[entry->_timer_id]; if (timer_node_slot < 0) // Check to see if timer_id is still valid. return 0; if (entry != ht->heap[timer_node_slot]) { pj_assert(entry == ht->heap[timer_node_slot]); return 0; } else { remove_node( ht, timer_node_slot); if (dont_call == 0) // Call the close hook. (*ht->callback)(ht, entry); return 1; } } /* * Calculate memory size required to create a timer heap. */ PJ_DEF(pj_size_t) pj_timer_heap_mem_size(pj_size_t count) { return /* size of the timer heap itself: */ sizeof(pj_timer_heap_t) + /* size of each entry: */ (count+2) * (sizeof(pj_timer_entry*)+sizeof(pj_timer_id_t)) + /* lock, pool etc: */ 132; } /* * Create a new timer heap. */ PJ_DEF(pj_status_t) pj_timer_heap_create( pj_pool_t *pool, pj_size_t size, pj_timer_heap_t **p_heap) { pj_timer_heap_t *ht; pj_size_t i; PJ_ASSERT_RETURN(pool && p_heap, PJ_EINVAL); *p_heap = NULL; /* Magic? */ size += 2; /* Allocate timer heap data structure from the pool */ ht = PJ_POOL_ALLOC_T(pool, pj_timer_heap_t); if (!ht) return PJ_ENOMEM; /* Initialize timer heap sizes */ ht->max_size = size; ht->cur_size = 0; ht->max_entries_per_poll = DEFAULT_MAX_TIMED_OUT_PER_POLL; ht->timer_ids_freelist = 1; ht->pool = pool; /* Lock. */ ht->lock = NULL; ht->auto_delete_lock = 0; // Create the heap array. ht->heap = (pj_timer_entry**) pj_pool_alloc(pool, sizeof(pj_timer_entry*) * size); if (!ht->heap) return PJ_ENOMEM; // Create the parallel ht->timer_ids = (pj_timer_id_t *) pj_pool_alloc( pool, sizeof(pj_timer_id_t) * size); if (!ht->timer_ids) return PJ_ENOMEM; // Initialize the "freelist," which uses negative values to // distinguish freelist elements from "pointers" into the // array. for (i=0; itimer_ids[i] = -((pj_timer_id_t) (i + 1)); *p_heap = ht; return PJ_SUCCESS; } PJ_DEF(void) pj_timer_heap_destroy( pj_timer_heap_t *ht ) { if (ht->lock && ht->auto_delete_lock) { pj_lock_destroy(ht->lock); ht->lock = NULL; } } PJ_DEF(void) pj_timer_heap_set_lock( pj_timer_heap_t *ht, pj_lock_t *lock, pj_bool_t auto_del ) { if (ht->lock && ht->auto_delete_lock) pj_lock_destroy(ht->lock); ht->lock = lock; ht->auto_delete_lock = auto_del; } PJ_DEF(unsigned) pj_timer_heap_set_max_timed_out_per_poll(pj_timer_heap_t *ht, unsigned count ) { unsigned old_count = ht->max_entries_per_poll; ht->max_entries_per_poll = count; return old_count; } PJ_DEF(pj_timer_entry*) pj_timer_entry_init( pj_timer_entry *entry, int id, void *user_data, pj_timer_heap_callback *cb ) { pj_assert(entry && cb); entry->_timer_id = -1; entry->id = id; entry->user_data = user_data; entry->cb = cb; entry->_grp_lock = NULL; return entry; } #if PJ_TIMER_DEBUG static pj_status_t schedule_w_grp_lock_dbg(pj_timer_heap_t *ht, pj_timer_entry *entry, const pj_time_val *delay, pj_bool_t set_id, int id_val, pj_grp_lock_t *grp_lock, const char *src_file, int src_line) #else static pj_status_t schedule_w_grp_lock(pj_timer_heap_t *ht, pj_timer_entry *entry, const pj_time_val *delay, pj_bool_t set_id, int id_val, pj_grp_lock_t *grp_lock) #endif { pj_status_t status; pj_time_val expires; PJ_ASSERT_RETURN(ht && entry && delay, PJ_EINVAL); PJ_ASSERT_RETURN(entry->cb != NULL, PJ_EINVAL); /* Prevent same entry from being scheduled more than once */ PJ_ASSERT_RETURN(entry->_timer_id < 1, PJ_EINVALIDOP); #if PJ_TIMER_DEBUG entry->src_file = src_file; entry->src_line = src_line; #endif pj_gettickcount(&expires); PJ_TIME_VAL_ADD(expires, *delay); lock_timer_heap(ht); status = schedule_entry(ht, entry, &expires); if (status == PJ_SUCCESS) { if (set_id) entry->id = id_val; entry->_grp_lock = grp_lock; if (entry->_grp_lock) { pj_grp_lock_add_ref(entry->_grp_lock); } } unlock_timer_heap(ht); return status; } #if PJ_TIMER_DEBUG PJ_DEF(pj_status_t) pj_timer_heap_schedule_dbg( pj_timer_heap_t *ht, pj_timer_entry *entry, const pj_time_val *delay, const char *src_file, int src_line) { return schedule_w_grp_lock_dbg(ht, entry, delay, PJ_FALSE, 1, NULL, src_file, src_line); } PJ_DEF(pj_status_t) pj_timer_heap_schedule_w_grp_lock_dbg( pj_timer_heap_t *ht, pj_timer_entry *entry, const pj_time_val *delay, int id_val, pj_grp_lock_t *grp_lock, const char *src_file, int src_line) { return schedule_w_grp_lock_dbg(ht, entry, delay, PJ_TRUE, id_val, grp_lock, src_file, src_line); } #else PJ_DEF(pj_status_t) pj_timer_heap_schedule( pj_timer_heap_t *ht, pj_timer_entry *entry, const pj_time_val *delay) { return schedule_w_grp_lock(ht, entry, delay, PJ_FALSE, 1, NULL); } PJ_DEF(pj_status_t) pj_timer_heap_schedule_w_grp_lock(pj_timer_heap_t *ht, pj_timer_entry *entry, const pj_time_val *delay, int id_val, pj_grp_lock_t *grp_lock) { return schedule_w_grp_lock(ht, entry, delay, PJ_TRUE, id_val, grp_lock); } #endif static int cancel_timer(pj_timer_heap_t *ht, pj_timer_entry *entry, pj_bool_t set_id, int id_val) { int count; PJ_ASSERT_RETURN(ht && entry, PJ_EINVAL); lock_timer_heap(ht); count = cancel(ht, entry, 1); if (set_id) { entry->id = id_val; } if (entry->_grp_lock) { pj_grp_lock_t *grp_lock = entry->_grp_lock; entry->_grp_lock = NULL; pj_grp_lock_dec_ref(grp_lock); } unlock_timer_heap(ht); return count; } PJ_DEF(int) pj_timer_heap_cancel( pj_timer_heap_t *ht, pj_timer_entry *entry) { return cancel_timer(ht, entry, PJ_FALSE, 0); } PJ_DEF(int) pj_timer_heap_cancel_if_active(pj_timer_heap_t *ht, pj_timer_entry *entry, int id_val) { return cancel_timer(ht, entry, PJ_TRUE, id_val); } PJ_DEF(unsigned) pj_timer_heap_poll( pj_timer_heap_t *ht, pj_time_val *next_delay ) { pj_time_val now; unsigned count; PJ_ASSERT_RETURN(ht, 0); lock_timer_heap(ht); if (!ht->cur_size && next_delay) { next_delay->sec = next_delay->msec = PJ_MAXINT32; unlock_timer_heap(ht); return 0; } count = 0; pj_gettickcount(&now); while ( ht->cur_size && PJ_TIME_VAL_LTE(ht->heap[0]->_timer_value, now) && count < ht->max_entries_per_poll ) { pj_timer_entry *node = remove_node(ht, 0); pj_grp_lock_t *grp_lock; ++count; grp_lock = node->_grp_lock; node->_grp_lock = NULL; unlock_timer_heap(ht); PJ_RACE_ME(5); if (node->cb) (*node->cb)(ht, node); if (grp_lock) pj_grp_lock_dec_ref(grp_lock); lock_timer_heap(ht); } if (ht->cur_size && next_delay) { *next_delay = ht->heap[0]->_timer_value; PJ_TIME_VAL_SUB(*next_delay, now); if (next_delay->sec < 0 || next_delay->msec < 0) next_delay->sec = next_delay->msec = 0; } else if (next_delay) { next_delay->sec = next_delay->msec = PJ_MAXINT32; } unlock_timer_heap(ht); return count; } PJ_DEF(pj_size_t) pj_timer_heap_count( pj_timer_heap_t *ht ) { PJ_ASSERT_RETURN(ht, 0); return ht->cur_size; } PJ_DEF(pj_status_t) pj_timer_heap_earliest_time( pj_timer_heap_t * ht, pj_time_val *timeval) { pj_assert(ht->cur_size != 0); if (ht->cur_size == 0) return PJ_ENOTFOUND; lock_timer_heap(ht); *timeval = ht->heap[0]->_timer_value; unlock_timer_heap(ht); return PJ_SUCCESS; } #if PJ_TIMER_DEBUG PJ_DEF(void) pj_timer_heap_dump(pj_timer_heap_t *ht) { lock_timer_heap(ht); PJ_LOG(3,(THIS_FILE, "Dumping timer heap:")); PJ_LOG(3,(THIS_FILE, " Cur size: %d entries, max: %d", (int)ht->cur_size, (int)ht->max_size)); if (ht->cur_size) { unsigned i; pj_time_val now; PJ_LOG(3,(THIS_FILE, " Entries: ")); PJ_LOG(3,(THIS_FILE, " _id\tId\tElapsed\tSource")); PJ_LOG(3,(THIS_FILE, " ----------------------------------")); pj_gettickcount(&now); for (i=0; i<(unsigned)ht->cur_size; ++i) { pj_timer_entry *e = ht->heap[i]; pj_time_val delta; if (PJ_TIME_VAL_LTE(e->_timer_value, now)) delta.sec = delta.msec = 0; else { delta = e->_timer_value; PJ_TIME_VAL_SUB(delta, now); } PJ_LOG(3,(THIS_FILE, " %d\t%d\t%d.%03d\t%s:%d", e->_timer_id, e->id, (int)delta.sec, (int)delta.msec, e->src_file, e->src_line)); } } unlock_timer_heap(ht); } #endif