freebsd-dev/lib/libpthread/support/thr_support.c
David Xu a772047bc6 o Use a daemon thread to monitor signal events in kernel, if pending
signals were changed in kernel, it will retrieve the pending set and
  try to find a thread to dispatch the signal. The dispatching process
  can be rolled back if the signal is no longer in kernel.

o Create two functions _thr_signal_init() and _thr_signal_deinit(),
  all signal action settings are retrieved from kernel when threading
  mode is turned on, after a fork(), child process will reset them to
  user settings by calling _thr_signal_deinit(). when threading mode
  is not turned on, all signal operations are direct past to kernel.

o When a thread generated a synchoronous signals and its context returned
  from completed list, UTS will retrieve the signal from its mailbox and try
  to deliver the signal to thread.

o Context signal mask is now only used when delivering signals, thread's
  current signal mask is always the one in pthread structure.

o Remove have_signals field in pthread structure, replace it with
  psf_valid in pthread_signal_frame. when psf_valid is true, in context
  switch time, thread will backout itself from some mutex/condition
  internal queues, then begin to process signals. when a thread is not
  at blocked state and running, check_pending indicates there are signals
  for the thread, after preempted and then resumed time, UTS will try to
  deliver signals to the thread.

o At signal delivering time, not only pending signals in thread will be
  scanned, process's pending signals will be scanned too.

o Change sigwait code a bit, remove field sigwait in pthread_wait_data,
  replace it with oldsigmask in pthread structure, when a thread calls
  sigwait(), its current signal mask is backuped to oldsigmask, and waitset
  is copied to its signal mask and when the thread gets a signal in the
  waitset range, its current signal mask is restored from oldsigmask,
  these are done in atomic fashion.

o Two additional POSIX APIs are implemented, sigwaitinfo() and sigtimedwait().

o Signal code locking is better than previous, there is fewer race conditions.

o Temporary disable most of code in _kse_single_thread as it is not safe
  after fork().
2003-06-28 09:55:02 +00:00

62 lines
2.4 KiB
C

/*-
* Copyright 2003 Alexander Kabaev.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
* $FreeBSD$
*/
#include <sys/cdefs.h>
#include <sys/types.h>
#include <sys/time.h>
#include <sys/kse.h>
#include <signal.h>
#include <string.h>
#include "thr_private.h"
__strong_reference(clock_gettime, _thr_clock_gettime);
__strong_reference(kse_exit, _thr_kse_exit);
__strong_reference(kse_wakeup, _thr_kse_wakeup);
__strong_reference(kse_create, _thr_kse_create);
__strong_reference(kse_thr_interrupt, _thr_kse_thr_interrupt);
__strong_reference(kse_release, _thr_kse_release);
__strong_reference(sigaction, _thr_sigaction);
__strong_reference(sigprocmask, _thr_sigprocmask);
__strong_reference(sigemptyset, _thr_sigemptyset);
__strong_reference(sigaddset, _thr_sigaddset);
__strong_reference(sigfillset, _thr_sigfillset);
__strong_reference(sigismember, _thr_sigismember);
__strong_reference(sigdelset, _thr_sigdelset);
__strong_reference(memset, _thr_memset);
__strong_reference(memcpy, _thr_memcpy);
__strong_reference(strcpy, _thr_strcpy);
__strong_reference(strlen, _thr_strlen);
__strong_reference(bzero, _thr_bzero);
__strong_reference(bcopy, _thr_bcopy);
__strong_reference(__sys_write, _thr__sys_write);
__strong_reference(__sys_sigtimedwait, _thr__sys_sigtimedwait);