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Diffstat (limited to 'pjlib/include/pj/timer.h')
| -rw-r--r-- | pjlib/include/pj/timer.h | 297 |
1 files changed, 297 insertions, 0 deletions
diff --git a/pjlib/include/pj/timer.h b/pjlib/include/pj/timer.h new file mode 100644 index 0000000..1cc11cf --- /dev/null +++ b/pjlib/include/pj/timer.h @@ -0,0 +1,297 @@ +/* $Id: timer.h 4154 2012-06-05 10:41:17Z bennylp $ */ +/* + * 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 + */ + +#ifndef __PJ_TIMER_H__ +#define __PJ_TIMER_H__ + +/** + * @file timer.h + * @brief Timer Heap + */ + +#include <pj/types.h> + +PJ_BEGIN_DECL + +/** + * @defgroup PJ_TIMER Timer Heap Management. + * @ingroup PJ_MISC + * @brief + * The timer scheduling implementation here is based on ACE library's + * ACE_Timer_Heap, with only little modification to suit our library's style + * (I even left most of the comments in the original source). + * + * To quote the original quote in ACE_Timer_Heap_T class: + * + * This implementation uses a heap-based callout queue of + * absolute times. Therefore, in the average and worst case, + * scheduling, canceling, and expiring timers is O(log N) (where + * N is the total number of timers). In addition, we can also + * preallocate as many \a ACE_Timer_Nodes as there are slots in + * the heap. This allows us to completely remove the need for + * dynamic memory allocation, which is important for real-time + * systems. + * + * 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> + * + * @{ + * + * \section pj_timer_examples_sec Examples + * + * For some examples on how to use the timer heap, please see the link below. + * + * - \ref page_pjlib_timer_test + */ + + +/** + * The type for internal timer ID. + */ +typedef int pj_timer_id_t; + +/** + * Forward declaration for pj_timer_entry. + */ +struct pj_timer_entry; + +/** + * The type of callback function to be called by timer scheduler when a timer + * has expired. + * + * @param timer_heap The timer heap. + * @param entry Timer entry which timer's has expired. + */ +typedef void pj_timer_heap_callback(pj_timer_heap_t *timer_heap, + struct pj_timer_entry *entry); + + +/** + * This structure represents an entry to the timer. + */ +typedef struct pj_timer_entry +{ + /** + * User data to be associated with this entry. + * Applications normally will put the instance of object that + * owns the timer entry in this field. + */ + void *user_data; + + /** + * Arbitrary ID assigned by the user/owner of this entry. + * Applications can use this ID to distinguish multiple + * timer entries that share the same callback and user_data. + */ + int id; + + /** + * Callback to be called when the timer expires. + */ + pj_timer_heap_callback *cb; + + /** + * Internal unique timer ID, which is assigned by the timer heap. + * Application should not touch this ID. + */ + pj_timer_id_t _timer_id; + + /** + * The future time when the timer expires, which the value is updated + * by timer heap when the timer is scheduled. + */ + pj_time_val _timer_value; + +#if PJ_TIMER_DEBUG + const char *src_file; + int src_line; +#endif +} pj_timer_entry; + + +/** + * Calculate memory size required to create a timer heap. + * + * @param count Number of timer entries to be supported. + * @return Memory size requirement in bytes. + */ +PJ_DECL(pj_size_t) pj_timer_heap_mem_size(pj_size_t count); + +/** + * Create a timer heap. + * + * @param pool The pool where allocations in the timer heap will be + * allocated. The timer heap will dynamicly allocate + * more storate from the pool if the number of timer + * entries registered is more than the size originally + * requested when calling this function. + * @param count The maximum number of timer entries to be supported + * initially. If the application registers more entries + * during runtime, then the timer heap will resize. + * @param ht Pointer to receive the created timer heap. + * + * @return PJ_SUCCESS, or the appropriate error code. + */ +PJ_DECL(pj_status_t) pj_timer_heap_create( pj_pool_t *pool, + pj_size_t count, + pj_timer_heap_t **ht); + +/** + * Destroy the timer heap. + * + * @param ht The timer heap. + */ +PJ_DECL(void) pj_timer_heap_destroy( pj_timer_heap_t *ht ); + + +/** + * Set lock object to be used by the timer heap. By default, the timer heap + * uses dummy synchronization. + * + * @param ht The timer heap. + * @param lock The lock object to be used for synchronization. + * @param auto_del If nonzero, the lock object will be destroyed when + * the timer heap is destroyed. + */ +PJ_DECL(void) pj_timer_heap_set_lock( pj_timer_heap_t *ht, + pj_lock_t *lock, + pj_bool_t auto_del ); + +/** + * Set maximum number of timed out entries to process in a single poll. + * + * @param ht The timer heap. + * @param count Number of entries. + * + * @return The old number. + */ +PJ_DECL(unsigned) pj_timer_heap_set_max_timed_out_per_poll(pj_timer_heap_t *ht, + unsigned count ); + +/** + * Initialize a timer entry. Application should call this function at least + * once before scheduling the entry to the timer heap, to properly initialize + * the timer entry. + * + * @param entry The timer entry to be initialized. + * @param id Arbitrary ID assigned by the user/owner of this entry. + * Applications can use this ID to distinguish multiple + * timer entries that share the same callback and user_data. + * @param user_data User data to be associated with this entry. + * Applications normally will put the instance of object that + * owns the timer entry in this field. + * @param cb Callback function to be called when the timer elapses. + * + * @return The timer entry itself. + */ +PJ_DECL(pj_timer_entry*) pj_timer_entry_init( pj_timer_entry *entry, + int id, + void *user_data, + pj_timer_heap_callback *cb ); + +/** + * Schedule a timer entry which will expire AFTER the specified delay. + * + * @param ht The timer heap. + * @param entry The entry to be registered. + * @param delay The interval to expire. + * @return PJ_SUCCESS, or the appropriate error code. + */ +#if PJ_TIMER_DEBUG +# define pj_timer_heap_schedule(ht,e,d) \ + pj_timer_heap_schedule_dbg(ht,e,d,__FILE__,__LINE__) + + PJ_DECL(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); +#else +PJ_DECL(pj_status_t) pj_timer_heap_schedule( pj_timer_heap_t *ht, + pj_timer_entry *entry, + const pj_time_val *delay); +#endif /* PJ_TIMER_DEBUG */ + +/** + * Cancel a previously registered timer. + * + * @param ht The timer heap. + * @param entry The entry to be cancelled. + * @return The number of timer cancelled, which should be one if the + * entry has really been registered, or zero if no timer was + * cancelled. + */ +PJ_DECL(int) pj_timer_heap_cancel( pj_timer_heap_t *ht, + pj_timer_entry *entry); + +/** + * Get the number of timer entries. + * + * @param ht The timer heap. + * @return The number of timer entries. + */ +PJ_DECL(pj_size_t) pj_timer_heap_count( pj_timer_heap_t *ht ); + +/** + * Get the earliest time registered in the timer heap. The timer heap + * MUST have at least one timer being scheduled (application should use + * #pj_timer_heap_count() before calling this function). + * + * @param ht The timer heap. + * @param timeval The time deadline of the earliest timer entry. + * + * @return PJ_SUCCESS, or PJ_ENOTFOUND if no entry is scheduled. + */ +PJ_DECL(pj_status_t) pj_timer_heap_earliest_time( pj_timer_heap_t *ht, + pj_time_val *timeval); + +/** + * Poll the timer heap, check for expired timers and call the callback for + * each of the expired timers. + * + * Note: polling the timer heap is not necessary in Symbian. Please see + * @ref PJ_SYMBIAN_OS for more info. + * + * @param ht The timer heap. + * @param next_delay If this parameter is not NULL, it will be filled up with + * the time delay until the next timer elapsed, or + * PJ_MAXINT32 in the sec part if no entry exist. + * + * @return The number of timers expired. + */ +PJ_DECL(unsigned) pj_timer_heap_poll( pj_timer_heap_t *ht, + pj_time_val *next_delay); + +#if PJ_TIMER_DEBUG +/** + * Dump timer heap entries. + * + * @param ht The timer heap. + */ +PJ_DECL(void) pj_timer_heap_dump(pj_timer_heap_t *ht); +#endif + +/** + * @} + */ + +PJ_END_DECL + +#endif /* __PJ_TIMER_H__ */ + |