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Diffstat (limited to 'sysdeps/pthread/posix-timer.h')
| -rw-r--r-- | sysdeps/pthread/posix-timer.h | 196 |
1 files changed, 196 insertions, 0 deletions
diff --git a/sysdeps/pthread/posix-timer.h b/sysdeps/pthread/posix-timer.h new file mode 100644 index 0000000000..1076110344 --- /dev/null +++ b/sysdeps/pthread/posix-timer.h @@ -0,0 +1,196 @@ +/* Definitions for POSIX timer implementation on top of NPTL. + Copyright (C) 2000-2014 Free Software Foundation, Inc. + This file is part of the GNU C Library. + Contributed by Kaz Kylheku <kaz@ashi.footprints.net>. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public License as + published by the Free Software Foundation; either version 2.1 of the + License, or (at your option) any later version. + + The GNU C Library 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 + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; see the file COPYING.LIB. If + not, see <http://www.gnu.org/licenses/>. */ + +#include <limits.h> +#include <signal.h> + +/* Double linked list. */ +struct list_links +{ + struct list_links *next; + struct list_links *prev; +}; + + +/* Forward declaration. */ +struct timer_node; + + +/* Definitions for an internal thread of the POSIX timer implementation. */ +struct thread_node +{ + struct list_links links; + pthread_attr_t attr; + pthread_t id; + unsigned int exists; + struct list_links timer_queue; + pthread_cond_t cond; + struct timer_node *current_timer; + pthread_t captured; + clockid_t clock_id; +}; + + +/* Internal representation of a timer. */ +struct timer_node +{ + struct list_links links; + struct sigevent event; + clockid_t clock; + struct itimerspec value; + struct timespec expirytime; + pthread_attr_t attr; + unsigned int abstime; + unsigned int armed; + enum { + TIMER_FREE, TIMER_INUSE, TIMER_DELETED + } inuse; + struct thread_node *thread; + pid_t creator_pid; + int refcount; + int overrun_count; +}; + + +/* The limit is not published if we are compiled with kernel timer support. + But we still compiled in this implementation with its limit unless built + to require the kernel support. */ +#ifndef TIMER_MAX +# define TIMER_MAX 256 +#endif + +/* Static array with the structures for all the timers. */ +extern struct timer_node __timer_array[TIMER_MAX]; + +/* Global lock to protect operation on the lists. */ +extern pthread_mutex_t __timer_mutex; + +/* Variable to protext initialization. */ +extern pthread_once_t __timer_init_once_control; + +/* Nonzero if initialization of timer implementation failed. */ +extern int __timer_init_failed; + +/* Node for the thread used to deliver signals. */ +extern struct thread_node __timer_signal_thread_rclk; + + +/* Return pointer to timer structure corresponding to ID. */ +#define timer_id2ptr(timerid) ((struct timer_node *) timerid) +#define timer_ptr2id(timerid) ((void *) timerid) + +/* Check whether timer is valid; global mutex must be held. */ +static inline int +timer_valid (struct timer_node *timer) +{ + return timer && timer->inuse == TIMER_INUSE; +} + +/* Timer refcount functions; need global mutex. */ +extern void __timer_dealloc (struct timer_node *timer); + +static inline void +timer_addref (struct timer_node *timer) +{ + timer->refcount++; +} + +static inline void +timer_delref (struct timer_node *timer) +{ + if (--timer->refcount == 0) + __timer_dealloc (timer); +} + +/* Timespec helper routines. */ +static inline int +__attribute ((always_inline)) +timespec_compare (const struct timespec *left, const struct timespec *right) +{ + if (left->tv_sec < right->tv_sec) + return -1; + if (left->tv_sec > right->tv_sec) + return 1; + + if (left->tv_nsec < right->tv_nsec) + return -1; + if (left->tv_nsec > right->tv_nsec) + return 1; + + return 0; +} + +static inline void +timespec_add (struct timespec *sum, const struct timespec *left, + const struct timespec *right) +{ + sum->tv_sec = left->tv_sec + right->tv_sec; + sum->tv_nsec = left->tv_nsec + right->tv_nsec; + + if (sum->tv_nsec >= 1000000000) + { + ++sum->tv_sec; + sum->tv_nsec -= 1000000000; + } +} + +static inline void +timespec_sub (struct timespec *diff, const struct timespec *left, + const struct timespec *right) +{ + diff->tv_sec = left->tv_sec - right->tv_sec; + diff->tv_nsec = left->tv_nsec - right->tv_nsec; + + if (diff->tv_nsec < 0) + { + --diff->tv_sec; + diff->tv_nsec += 1000000000; + } +} + + +/* We need one of the list functions in the other modules. */ +static inline void +list_unlink_ip (struct list_links *list) +{ + struct list_links *lnext = list->next, *lprev = list->prev; + + lnext->prev = lprev; + lprev->next = lnext; + + /* The suffix ip means idempotent; list_unlink_ip can be called + * two or more times on the same node. + */ + + list->next = list; + list->prev = list; +} + + +/* Functions in the helper file. */ +extern void __timer_mutex_cancel_handler (void *arg); +extern void __timer_init_once (void); +extern struct timer_node *__timer_alloc (void); +extern int __timer_thread_start (struct thread_node *thread); +extern struct thread_node *__timer_thread_find_matching (const pthread_attr_t *desired_attr, clockid_t); +extern struct thread_node *__timer_thread_alloc (const pthread_attr_t *desired_attr, clockid_t); +extern void __timer_thread_dealloc (struct thread_node *thread); +extern int __timer_thread_queue_timer (struct thread_node *thread, + struct timer_node *insert); +extern void __timer_thread_wakeup (struct thread_node *thread); |