| /* $Id$ */ |
| /* |
| * 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 <d.schmidt@vanderbilt.edu> |
| * |
| * 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 <pj/timer.h> |
| #include <pj/pool.h> |
| #include <pj/os.h> |
| #include <pj/string.h> |
| #include <pj/assert.h> |
| #include <pj/errno.h> |
| #include <pj/lock.h> |
| |
| #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 |
| * <heap_> to be located in O(1) time. Basically, <timer_id_[i]> |
| * contains the slot in the <heap_> array where an pj_timer_entry |
| * with timer id <i> resides. Thus, the timer id passed back from |
| * <schedule_entry> is really an slot into the <timer_ids> array. The |
| * <timer_ids_> array serves two purposes: negative values are |
| * treated as "pointers" for the <freelist_>, whereas positive |
| * values are treated as "pointers" into the <heap_> array. |
| */ |
| pj_timer_id_t *timer_ids; |
| |
| /** |
| * "Pointer" to the first element in the freelist contained within |
| * the <timer_ids_> 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 <moved_node> into its new location in the heap. |
| ht->heap[slot] = moved_node; |
| |
| // Update the corresponding slot in the parallel <timer_ids_> 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 <int> for backwards compatibility. |
| pj_timer_id_t new_id = ht->timer_ids_freelist; |
| |
| PJ_CHECK_STACK(); |
| |
| // The freelist values in the <timer_ids_> 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 <timer_ids_> 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 <copy> if the child has a larger timeout value than |
| // the <moved_node>. |
| 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 <moved_node> 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 <timer_ids> 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 <timer_ids> array. |
| copy_node( ht, slot, moved_node); |
| |
| // If the <moved_node->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_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_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(pool, sizeof(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_pool_alloc(pool, sizeof(pj_timer_entry*) * size); |
| if (!ht->heap) |
| return PJ_ENOMEM; |
| |
| // Create the parallel |
| ht->timer_ids = 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 <heap_> |
| // array. |
| for (i=0; i<size; ++i) |
| ht->timer_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->id = id; |
| entry->user_data = user_data; |
| entry->cb = cb; |
| |
| return entry; |
| } |
| |
| PJ_DEF(pj_status_t) pj_timer_heap_schedule( pj_timer_heap_t *ht, |
| pj_timer_entry *entry, |
| const pj_time_val *delay) |
| { |
| 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); |
| |
| pj_gettimeofday(&expires); |
| PJ_TIME_VAL_ADD(expires, *delay); |
| |
| lock_timer_heap(ht); |
| status = schedule_entry(ht, entry, &expires); |
| unlock_timer_heap(ht); |
| |
| return status; |
| } |
| |
| PJ_DEF(int) pj_timer_heap_cancel( pj_timer_heap_t *ht, |
| pj_timer_entry *entry) |
| { |
| int count; |
| |
| PJ_ASSERT_RETURN(ht && entry, PJ_EINVAL); |
| |
| lock_timer_heap(ht); |
| count = cancel(ht, entry, 1); |
| unlock_timer_heap(ht); |
| |
| return count; |
| } |
| |
| 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); |
| |
| if (!ht->cur_size && next_delay) { |
| next_delay->sec = next_delay->msec = PJ_MAXINT32; |
| return 0; |
| } |
| |
| count = 0; |
| pj_gettimeofday(&now); |
| |
| lock_timer_heap(ht); |
| 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); |
| ++count; |
| |
| unlock_timer_heap(ht); |
| if (node->cb) |
| (*node->cb)(ht, node); |
| 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; |
| } |
| |