diff options
Diffstat (limited to 'nptl/sysdeps/pthread/timer_routines.c')
| -rw-r--r-- | nptl/sysdeps/pthread/timer_routines.c | 577 |
1 files changed, 0 insertions, 577 deletions
diff --git a/nptl/sysdeps/pthread/timer_routines.c b/nptl/sysdeps/pthread/timer_routines.c deleted file mode 100644 index ce1aa417cd..0000000000 --- a/nptl/sysdeps/pthread/timer_routines.c +++ /dev/null @@ -1,577 +0,0 @@ -/* Helper code for POSIX timer implementation on 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 <assert.h> -#include <errno.h> -#include <pthread.h> -#include <stddef.h> -#include <stdlib.h> -#include <string.h> -#include <sysdep.h> -#include <time.h> -#include <unistd.h> -#include <sys/syscall.h> - -#include "posix-timer.h" -#include <pthreadP.h> - - -/* Number of threads used. */ -#define THREAD_MAXNODES 16 - -/* Array containing the descriptors for the used threads. */ -static struct thread_node thread_array[THREAD_MAXNODES]; - -/* Static array with the structures for all the timers. */ -struct timer_node __timer_array[TIMER_MAX]; - -/* Global lock to protect operation on the lists. */ -pthread_mutex_t __timer_mutex = PTHREAD_MUTEX_INITIALIZER; - -/* Variable to protext initialization. */ -pthread_once_t __timer_init_once_control = PTHREAD_ONCE_INIT; - -/* Nonzero if initialization of timer implementation failed. */ -int __timer_init_failed; - -/* Node for the thread used to deliver signals. */ -struct thread_node __timer_signal_thread_rclk; - -/* Lists to keep free and used timers and threads. */ -struct list_links timer_free_list; -struct list_links thread_free_list; -struct list_links thread_active_list; - - -#ifdef __NR_rt_sigqueueinfo -extern int __syscall_rt_sigqueueinfo (int, int, siginfo_t *); -#endif - - -/* List handling functions. */ -static inline void -list_init (struct list_links *list) -{ - list->next = list->prev = list; -} - -static inline void -list_append (struct list_links *list, struct list_links *newp) -{ - newp->prev = list->prev; - newp->next = list; - list->prev->next = newp; - list->prev = newp; -} - -static inline void -list_insbefore (struct list_links *list, struct list_links *newp) -{ - list_append (list, newp); -} - -/* - * Like list_unlink_ip, except that calling it on a node that - * is already unlinked is disastrous rather than a noop. - */ - -static inline void -list_unlink (struct list_links *list) -{ - struct list_links *lnext = list->next, *lprev = list->prev; - - lnext->prev = lprev; - lprev->next = lnext; -} - -static inline struct list_links * -list_first (struct list_links *list) -{ - return list->next; -} - -static inline struct list_links * -list_null (struct list_links *list) -{ - return list; -} - -static inline struct list_links * -list_next (struct list_links *list) -{ - return list->next; -} - -static inline int -list_isempty (struct list_links *list) -{ - return list->next == list; -} - - -/* Functions build on top of the list functions. */ -static inline struct thread_node * -thread_links2ptr (struct list_links *list) -{ - return (struct thread_node *) ((char *) list - - offsetof (struct thread_node, links)); -} - -static inline struct timer_node * -timer_links2ptr (struct list_links *list) -{ - return (struct timer_node *) ((char *) list - - offsetof (struct timer_node, links)); -} - - -/* Initialize a newly allocated thread structure. */ -static void -thread_init (struct thread_node *thread, const pthread_attr_t *attr, clockid_t clock_id) -{ - if (attr != NULL) - thread->attr = *attr; - else - { - pthread_attr_init (&thread->attr); - pthread_attr_setdetachstate (&thread->attr, PTHREAD_CREATE_DETACHED); - } - - thread->exists = 0; - list_init (&thread->timer_queue); - pthread_cond_init (&thread->cond, 0); - thread->current_timer = 0; - thread->captured = pthread_self (); - thread->clock_id = clock_id; -} - - -/* Initialize the global lists, and acquire global resources. Error - reporting is done by storing a non-zero value to the global variable - timer_init_failed. */ -static void -init_module (void) -{ - int i; - - list_init (&timer_free_list); - list_init (&thread_free_list); - list_init (&thread_active_list); - - for (i = 0; i < TIMER_MAX; ++i) - { - list_append (&timer_free_list, &__timer_array[i].links); - __timer_array[i].inuse = TIMER_FREE; - } - - for (i = 0; i < THREAD_MAXNODES; ++i) - list_append (&thread_free_list, &thread_array[i].links); - - thread_init (&__timer_signal_thread_rclk, 0, CLOCK_REALTIME); -} - - -/* This is a handler executed in a child process after a fork() - occurs. It reinitializes the module, resetting all of the data - structures to their initial state. The mutex is initialized in - case it was locked in the parent process. */ -static void -reinit_after_fork (void) -{ - init_module (); - pthread_mutex_init (&__timer_mutex, 0); -} - - -/* Called once form pthread_once in timer_init. This initializes the - module and ensures that reinit_after_fork will be executed in any - child process. */ -void -__timer_init_once (void) -{ - init_module (); - pthread_atfork (0, 0, reinit_after_fork); -} - - -/* Deinitialize a thread that is about to be deallocated. */ -static void -thread_deinit (struct thread_node *thread) -{ - assert (list_isempty (&thread->timer_queue)); - pthread_cond_destroy (&thread->cond); -} - - -/* Allocate a thread structure from the global free list. Global - mutex lock must be held by caller. The thread is moved to - the active list. */ -struct thread_node * -__timer_thread_alloc (const pthread_attr_t *desired_attr, clockid_t clock_id) -{ - struct list_links *node = list_first (&thread_free_list); - - if (node != list_null (&thread_free_list)) - { - struct thread_node *thread = thread_links2ptr (node); - list_unlink (node); - thread_init (thread, desired_attr, clock_id); - list_append (&thread_active_list, node); - return thread; - } - - return 0; -} - - -/* Return a thread structure to the global free list. Global lock - must be held by caller. */ -void -__timer_thread_dealloc (struct thread_node *thread) -{ - thread_deinit (thread); - list_unlink (&thread->links); - list_append (&thread_free_list, &thread->links); -} - - -/* Each of our threads which terminates executes this cleanup - handler. We never terminate threads ourselves; if a thread gets here - it means that the evil application has killed it. If the thread has - timers, these require servicing and so we must hire a replacement - thread right away. We must also unblock another thread that may - have been waiting for this thread to finish servicing a timer (see - timer_delete()). */ - -static void -thread_cleanup (void *val) -{ - if (val != NULL) - { - struct thread_node *thread = val; - - /* How did the signal thread get killed? */ - assert (thread != &__timer_signal_thread_rclk); - - pthread_mutex_lock (&__timer_mutex); - - thread->exists = 0; - - /* We are no longer processing a timer event. */ - thread->current_timer = 0; - - if (list_isempty (&thread->timer_queue)) - __timer_thread_dealloc (thread); - else - (void) __timer_thread_start (thread); - - pthread_mutex_unlock (&__timer_mutex); - - /* Unblock potentially blocked timer_delete(). */ - pthread_cond_broadcast (&thread->cond); - } -} - - -/* Handle a timer which is supposed to go off now. */ -static void -thread_expire_timer (struct thread_node *self, struct timer_node *timer) -{ - self->current_timer = timer; /* Lets timer_delete know timer is running. */ - - pthread_mutex_unlock (&__timer_mutex); - - switch (__builtin_expect (timer->event.sigev_notify, SIGEV_SIGNAL)) - { - case SIGEV_NONE: - break; - - case SIGEV_SIGNAL: -#ifdef __NR_rt_sigqueueinfo - { - siginfo_t info; - - /* First, clear the siginfo_t structure, so that we don't pass our - stack content to other tasks. */ - memset (&info, 0, sizeof (siginfo_t)); - /* We must pass the information about the data in a siginfo_t - value. */ - info.si_signo = timer->event.sigev_signo; - info.si_code = SI_TIMER; - info.si_pid = timer->creator_pid; - info.si_uid = getuid (); - info.si_value = timer->event.sigev_value; - - INLINE_SYSCALL (rt_sigqueueinfo, 3, info.si_pid, info.si_signo, &info); - } -#else - if (pthread_kill (self->captured, timer->event.sigev_signo) != 0) - { - if (pthread_kill (self->id, timer->event.sigev_signo) != 0) - abort (); - } -#endif - break; - - case SIGEV_THREAD: - timer->event.sigev_notify_function (timer->event.sigev_value); - break; - - default: - assert (! "unknown event"); - break; - } - - pthread_mutex_lock (&__timer_mutex); - - self->current_timer = 0; - - pthread_cond_broadcast (&self->cond); -} - - -/* Thread function; executed by each timer thread. The job of this - function is to wait on the thread's timer queue and expire the - timers in chronological order as close to their scheduled time as - possible. */ -static void -__attribute__ ((noreturn)) -thread_func (void *arg) -{ - struct thread_node *self = arg; - - /* Register cleanup handler, in case rogue application terminates - this thread. (This cannot happen to __timer_signal_thread, which - doesn't invoke application callbacks). */ - - pthread_cleanup_push (thread_cleanup, self); - - pthread_mutex_lock (&__timer_mutex); - - while (1) - { - struct list_links *first; - struct timer_node *timer = NULL; - - /* While the timer queue is not empty, inspect the first node. */ - first = list_first (&self->timer_queue); - if (first != list_null (&self->timer_queue)) - { - struct timespec now; - - timer = timer_links2ptr (first); - - /* This assumes that the elements of the list of one thread - are all for the same clock. */ - clock_gettime (timer->clock, &now); - - while (1) - { - /* If the timer is due or overdue, remove it from the queue. - If it's a periodic timer, re-compute its new time and - requeue it. Either way, perform the timer expiry. */ - if (timespec_compare (&now, &timer->expirytime) < 0) - break; - - list_unlink_ip (first); - - if (__builtin_expect (timer->value.it_interval.tv_sec, 0) != 0 - || timer->value.it_interval.tv_nsec != 0) - { - timer->overrun_count = 0; - timespec_add (&timer->expirytime, &timer->expirytime, - &timer->value.it_interval); - while (timespec_compare (&timer->expirytime, &now) < 0) - { - timespec_add (&timer->expirytime, &timer->expirytime, - &timer->value.it_interval); - if (timer->overrun_count < DELAYTIMER_MAX) - ++timer->overrun_count; - } - __timer_thread_queue_timer (self, timer); - } - - thread_expire_timer (self, timer); - - first = list_first (&self->timer_queue); - if (first == list_null (&self->timer_queue)) - break; - - timer = timer_links2ptr (first); - } - } - - /* If the queue is not empty, wait until the expiry time of the - first node. Otherwise wait indefinitely. Insertions at the - head of the queue must wake up the thread by broadcasting - this condition variable. */ - if (timer != NULL) - pthread_cond_timedwait (&self->cond, &__timer_mutex, - &timer->expirytime); - else - pthread_cond_wait (&self->cond, &__timer_mutex); - } - /* This macro will never be executed since the while loop loops - forever - but we have to add it for proper nesting. */ - pthread_cleanup_pop (1); -} - - -/* Enqueue a timer in wakeup order in the thread's timer queue. - Returns 1 if the timer was inserted at the head of the queue, - causing the queue's next wakeup time to change. */ - -int -__timer_thread_queue_timer (struct thread_node *thread, - struct timer_node *insert) -{ - struct list_links *iter; - int athead = 1; - - for (iter = list_first (&thread->timer_queue); - iter != list_null (&thread->timer_queue); - iter = list_next (iter)) - { - struct timer_node *timer = timer_links2ptr (iter); - - if (timespec_compare (&insert->expirytime, &timer->expirytime) < 0) - break; - athead = 0; - } - - list_insbefore (iter, &insert->links); - return athead; -} - - -/* Start a thread and associate it with the given thread node. Global - lock must be held by caller. */ -int -__timer_thread_start (struct thread_node *thread) -{ - int retval = 1; - - assert (!thread->exists); - thread->exists = 1; - - if (pthread_create (&thread->id, &thread->attr, - (void *(*) (void *)) thread_func, thread) != 0) - { - thread->exists = 0; - retval = -1; - } - - return retval; -} - - -void -__timer_thread_wakeup (struct thread_node *thread) -{ - pthread_cond_broadcast (&thread->cond); -} - - -/* Compare two pthread_attr_t thread attributes for exact equality. - Returns 1 if they are equal, otherwise zero if they are not equal - or contain illegal values. This version is NPTL-specific for - performance reason. One could use the access functions to get the - values of all the fields of the attribute structure. */ -static int -thread_attr_compare (const pthread_attr_t *left, const pthread_attr_t *right) -{ - struct pthread_attr *ileft = (struct pthread_attr *) left; - struct pthread_attr *iright = (struct pthread_attr *) right; - - return (ileft->flags == iright->flags - && ileft->schedpolicy == iright->schedpolicy - && (ileft->schedparam.sched_priority - == iright->schedparam.sched_priority) - && ileft->guardsize == iright->guardsize - && ileft->stackaddr == iright->stackaddr - && ileft->stacksize == iright->stacksize - && ((ileft->cpuset == NULL && iright->cpuset == NULL) - || (ileft->cpuset != NULL && iright->cpuset != NULL - && ileft->cpusetsize == iright->cpusetsize - && memcmp (ileft->cpuset, iright->cpuset, - ileft->cpusetsize) == 0))); -} - - -/* Search the list of active threads and find one which has matching - attributes. Global mutex lock must be held by caller. */ -struct thread_node * -__timer_thread_find_matching (const pthread_attr_t *desired_attr, - clockid_t desired_clock_id) -{ - struct list_links *iter = list_first (&thread_active_list); - - while (iter != list_null (&thread_active_list)) - { - struct thread_node *candidate = thread_links2ptr (iter); - - if (thread_attr_compare (desired_attr, &candidate->attr) - && desired_clock_id == candidate->clock_id) - return candidate; - - iter = list_next (iter); - } - - return NULL; -} - - -/* Grab a free timer structure from the global free list. The global - lock must be held by the caller. */ -struct timer_node * -__timer_alloc (void) -{ - struct list_links *node = list_first (&timer_free_list); - - if (node != list_null (&timer_free_list)) - { - struct timer_node *timer = timer_links2ptr (node); - list_unlink_ip (node); - timer->inuse = TIMER_INUSE; - timer->refcount = 1; - return timer; - } - - return NULL; -} - - -/* Return a timer structure to the global free list. The global lock - must be held by the caller. */ -void -__timer_dealloc (struct timer_node *timer) -{ - assert (timer->refcount == 0); - timer->thread = NULL; /* Break association between timer and thread. */ - timer->inuse = TIMER_FREE; - list_append (&timer_free_list, &timer->links); -} - - -/* Thread cancellation handler which unlocks a mutex. */ -void -__timer_mutex_cancel_handler (void *arg) -{ - pthread_mutex_unlock (arg); -} |