kamailio/timer_proc.h

/* 
 * Copyright (C) 2009 iptelorg GmbH
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

/*
 * History:
 * --------
 *  2009-03-10  initial version (andrei)
*/

/**
 * @file
 * @brief SIP-router core :: timer_proc.h - separate process timers
 *
 * (unrelated to the main fast and slow timers)
 * @ingroup core
 * Module: @ref core
 */

#ifndef __timer_proc_h
#define __timer_proc_h

#include "local_timer.h"

/**
 * \brief update internal counters for running new dummy timers
 * @param timers number of dummy timer processes
 * @return 0 on success; -1 on error
 */
int register_dummy_timers(int timers);


/**
 * \brief Forks a separate simple sleep() periodic timer
 * 
 * Forks a very basic periodic timer process, that just sleep()s for 
 * the specified interval and then calls the timer function.
 * The new "dummy timer" process execution start immediately, the sleep()
 * is called first (so the first call to the timer function will happen
 * \<interval\> seconds after the call to fork_dummy_timer)
 * @param child_id  @see fork_process()
 * @param desc      @see fork_process()
 * @param make_sock @see fork_process()
 * @param f         timer function/callback
 * @param param     parameter passed to the timer function
 * @param interval  interval in seconds.
 * @return pid of the new process on success, -1 on error
 * (doesn't return anything in the child process)
 */
int fork_dummy_timer(int child_id, char* desc, int make_sock,
						timer_function* f, void* param, int interval);


/**
 * \brief Forks a timer process based on the local timer
 * 
 * Forks a separate timer process running a local_timer.h type of timer
 * A pointer to the local_timer handle (allocated in shared memory) is
 * returned in lt_h. It can be used to add/delete more timers at runtime
 * (via local_timer_add()/local_timer_del() a.s.o).
 * If timers are added from separate processes, some form of locking must be
 * used (all the calls to local_timer* must be enclosed by locks if it
 * cannot be guaranteed that they cannot execute in the same time)
 * The timer "engine" must be run manually from the child process. For
 * example a very simple local timer process that just runs a single 
 * periodic timer can be started in the following way:
 * struct local_timer* lt_h;
 * 
 * pid=fork_local_timer_process(...., &lt_h);
 * if (pid==0){
 *          timer_init(&my_timer, my_timer_f, 0, 0);
 *          local_timer_add(&lt_h, &my_timer, S_TO_TICKS(10), get_ticks_raw());
 *          while(1) { sleep(1); local_timer_run(lt, get_ticks_raw()); }
 * }
 *
 * @param child_id  @see fork_process()
 * @param desc      @see fork_process()
 * @param make_sock @see fork_process()
 * @param lt_h      local_timer handler
 * @return pid to the parent, 0 to the child, -1 if error.
 */
int fork_local_timer_process(int child_id, char* desc, int make_sock,
						struct local_timer** lt_h);

#endif /*__timer_proc_h*/

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