3  * 2002-10-15  Posix Clocks & timers
10  * These are all the functions necessary to implement POSIX clocks & timers
25 #include <linux/posix-timers.h>
36 #include "posix-timers.h"
41  * Timers are managed in a hash table for lockless lookup. The hash key is
315  * based timers.
341 			 * For now let timers with an interval less than a  in posix_timer_fn()
356 			 * Only required when high resolution timers are  in posix_timer_fn()
357 			 * enabled as the periodic tick based timers are  in posix_timer_fn()
573 	 * The hash lookup and the timers are RCU protected.  in __lock_timer()
575 	 * Timers are added to the hash in invalid state where  in __lock_timer()
634  *  2) The timer is a SIGEV_NONE timer. These timers are never enqueued
652 		 * SIGEV_NONE oneshot timers are never queued and therefore  in common_timer_get()
656 		 * For all other timers there is nothing to update here, so  in common_timer_get()
679 	 * Consequently all interval timers, i.e. @iv > 0, cannot have a  in common_timer_get()
686 		 * expired! Timers which have a real signal delivery mode  in common_timer_get()
792 	 * Posix magic: Relative CLOCK_REALTIME timers are not affected by  in common_hrtimer_arm()
832  * For POSIX CPU timers with CONFIG_POSIX_CPU_TIMERS_TASK_WORK=n this is
1108  * At that point no other task can access the timers of the dying
1113 	struct hlist_head timers;  in exit_itimers()  local
1118 	/* Protect against concurrent read via /proc/$PID/timers */  in exit_itimers()
1120 	hlist_move_list(&tsk->signal->posix_timers, &timers);  in exit_itimers()
1123 	/* The timers are not longer accessible via tsk::signal */  in exit_itimers()
1124 	while (!hlist_empty(&timers))  in exit_itimers()
1125 		itimer_delete(hlist_entry(timers.first, struct k_itimer, list));  in exit_itimers()
1212  * resolutions for reading the time and for arming timers.
1224  *	  When high resolution timers are disabled at compile or runtime
1226  *	  the precision at which timers expire.
1230  *	  When high resolution timers are enabled the resolution returned