| /* $Id$ |
| * |
| */ |
| /* (C)1993-2003 Douglas C. Schmidt |
| * |
| * This file is originaly from ACE library by Doug Schmidt |
| * ACE(TM), TAO(TM) and CIAO(TM) are copyrighted by Douglas C. Schmidt and his research |
| * group at Washington University, University of California, Irvine, and Vanderbilt |
| * University Copyright (c) 1993-2003, all rights reserved. |
| * |
| */ |
| |
| #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. |
| * @{ |
| * |
| * \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. |
| */ |
| 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; |
| }; |
| |
| |
| /** |
| * Default flag for timer heap, indicates that synchronization will be |
| * used. |
| */ |
| #define PJ_TIMER_HEAP_SYNCHRONIZE (0) |
| |
| /** |
| * Flag to indicate that thread synchronization is NOT needed for the |
| * timer heap. |
| */ |
| #define PJ_TIMER_HEAP_NO_SYNCHRONIZE (1) |
| |
| /** |
| * 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 flag Creation flag, currently only PJ_TIMER_HEAP_NO_SYNCHRONIZE |
| * is recognized.. |
| * @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, |
| unsigned flag, |
| pj_timer_heap_t **ht); |
| |
| /** |
| * 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. |
| */ |
| PJ_DECL(pj_status_t) pj_timer_heap_schedule( pj_timer_heap_t *ht, |
| pj_timer_entry *entry, |
| const pj_time_val *delay); |
| |
| /** |
| * 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. |
| * |
| * @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 -1 in |
| * the sec part if no entry exist. |
| * @return The number of timers expired. |
| */ |
| PJ_DECL(int) pj_timer_heap_poll( pj_timer_heap_t *ht, pj_time_val *next_delay); |
| |
| /** |
| * @} |
| */ |
| |
| PJ_END_DECL |
| |
| #endif /* __PJ_TIMER_H__ */ |
| |