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-rw-r--r--nptl/sysdeps/pthread/timer_routines.c592
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diff --git a/nptl/sysdeps/pthread/timer_routines.c b/nptl/sysdeps/pthread/timer_routines.c
new file mode 100644
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+++ b/nptl/sysdeps/pthread/timer_routines.c
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+/* Helper code for POSIX timer implementation on LinuxThreads.
+ Copyright (C) 2000, 2001, 2002 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,
+ write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ Boston, MA 02111-1307, USA. */
+
+#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;
+#ifdef _POSIX_CPUTIME
+struct thread_node __timer_signal_thread_pclk;
+#endif
+#ifdef _POSIX_THREAD_CPUTIME
+struct thread_node __timer_signal_thread_tclk;
+#endif
+
+/* 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);
+#ifdef _POSIX_CPUTIME
+ thread_init (&__timer_signal_thread_pclk, 0, CLOCK_PROCESS_CPUTIME_ID);
+#endif
+#ifdef _POSIX_THREAD_CPUTIME
+ thread_init (&__timer_signal_thread_tclk, 0, CLOCK_THREAD_CPUTIME_ID);
+#endif
+}
+
+
+/* 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);
+#ifdef _POSIX_CPUTIME
+ assert (thread != &__timer_signal_thread_pclk);
+#endif
+#ifdef _POSIX_THREAD_CPUTIME
+ assert (thread != &__timer_signal_thread_tclk);
+#endif
+
+ 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:
+ assert (! "timer_create should never have created such a timer");
+ 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 LinuxThreads-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));
+}
+
+
+/* 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)
+ {
+ list_unlink (iter);
+ 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);
+}
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