Get rid of nptl/sysdeps/ entirely!

1 files changed, 196 insertions, 0 deletions

diff --git a/sysdeps/unix/sysv/linux/timer_routines.c b/sysdeps/unix/sysv/linux/timer_routines.c
new file mode 100644
index 0000000000..4ac9bbe896
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/timer_routines.c
@@ -0,0 +1,196 @@
+/* Copyright (C) 2003-2014 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+   Contributed by Ulrich Drepper <drepper@redhat.com>, 2003.
+
+   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 <errno.h>
+#include <setjmp.h>
+#include <signal.h>
+#include <stdbool.h>
+#include <sysdep.h>
+#include <nptl/pthreadP.h>
+#include "kernel-posix-timers.h"
+
+
+/* List of active SIGEV_THREAD timers.  */
+struct timer *__active_timer_sigev_thread;
+/* Lock for the __active_timer_sigev_thread.  */
+pthread_mutex_t __active_timer_sigev_thread_lock = PTHREAD_MUTEX_INITIALIZER;
+
+
+struct thread_start_data
+{
+  void (*thrfunc) (sigval_t);
+  sigval_t sival;
+};
+
+
+/* Helper thread to call the user-provided function.  */
+static void *
+timer_sigev_thread (void *arg)
+{
+  /* The parent thread has all signals blocked.  This is a bit
+     surprising for user code, although valid.  We unblock all
+     signals.  */
+  sigset_t ss;
+  sigemptyset (&ss);
+  INTERNAL_SYSCALL_DECL (err);
+  INTERNAL_SYSCALL (rt_sigprocmask, err, 4, SIG_SETMASK, &ss, NULL, _NSIG / 8);
+
+  struct thread_start_data *td = (struct thread_start_data *) arg;
+
+  void (*thrfunc) (sigval_t) = td->thrfunc;
+  sigval_t sival = td->sival;
+
+  /* The TD object was allocated in timer_helper_thread.  */
+  free (td);
+
+  /* Call the user-provided function.  */
+  thrfunc (sival);
+
+  return NULL;
+}
+
+
+/* Helper function to support starting threads for SIGEV_THREAD.  */
+static void *
+timer_helper_thread (void *arg)
+{
+  /* Wait for the SIGTIMER signal, allowing the setXid signal, and
+     none else.  */
+  sigset_t ss;
+  sigemptyset (&ss);
+  __sigaddset (&ss, SIGTIMER);
+
+  /* Endless loop of waiting for signals.  The loop is only ended when
+     the thread is canceled.  */
+  while (1)
+    {
+      siginfo_t si;
+
+      /* sigwaitinfo cannot be used here, since it deletes
+	 SIGCANCEL == SIGTIMER from the set.  */
+
+      int oldtype = LIBC_CANCEL_ASYNC ();
+
+      /* XXX The size argument hopefully will have to be changed to the
+	 real size of the user-level sigset_t.  */
+      int result = INLINE_SYSCALL (rt_sigtimedwait, 4, &ss, &si, NULL,
+				   _NSIG / 8);
+
+      LIBC_CANCEL_RESET (oldtype);
+
+      if (result > 0)
+	{
+	  if (si.si_code == SI_TIMER)
+	    {
+	      struct timer *tk = (struct timer *) si.si_ptr;
+
+	      /* Check the timer is still used and will not go away
+		 while we are reading the values here.  */
+	      pthread_mutex_lock (&__active_timer_sigev_thread_lock);
+
+	      struct timer *runp = __active_timer_sigev_thread;
+	      while (runp != NULL)
+		if (runp == tk)
+		  break;
+		else
+		  runp = runp->next;
+
+	      if (runp != NULL)
+		{
+		  struct thread_start_data *td = malloc (sizeof (*td));
+
+		  /* There is not much we can do if the allocation fails.  */
+		  if (td != NULL)
+		    {
+		      /* This is the signal we are waiting for.  */
+		      td->thrfunc = tk->thrfunc;
+		      td->sival = tk->sival;
+
+		      pthread_t th;
+		      (void) pthread_create (&th, &tk->attr,
+					     timer_sigev_thread, td);
+		    }
+		}
+
+	      pthread_mutex_unlock (&__active_timer_sigev_thread_lock);
+	    }
+	  else if (si.si_code == SI_TKILL)
+	    /* The thread is canceled.  */
+	    pthread_exit (NULL);
+	}
+    }
+}
+
+
+/* Control variable for helper thread creation.  */
+pthread_once_t __helper_once attribute_hidden;
+
+
+/* TID of the helper thread.  */
+pid_t __helper_tid attribute_hidden;
+
+
+/* Reset variables so that after a fork a new helper thread gets started.  */
+static void
+reset_helper_control (void)
+{
+  __helper_once = PTHREAD_ONCE_INIT;
+  __helper_tid = 0;
+}
+
+
+void
+attribute_hidden
+__start_helper_thread (void)
+{
+  /* The helper thread needs only very little resources
+     and should go away automatically when canceled.  */
+  pthread_attr_t attr;
+  (void) pthread_attr_init (&attr);
+  (void) pthread_attr_setstacksize (&attr, __pthread_get_minstack (&attr));
+
+  /* Block all signals in the helper thread but SIGSETXID.  To do this
+     thoroughly we temporarily have to block all signals here.  The
+     helper can lose wakeups if SIGCANCEL is not blocked throughout,
+     but sigfillset omits it SIGSETXID.  So, we add SIGCANCEL back
+     explicitly here.  */
+  sigset_t ss;
+  sigset_t oss;
+  sigfillset (&ss);
+  __sigaddset (&ss, SIGCANCEL);
+  INTERNAL_SYSCALL_DECL (err);
+  INTERNAL_SYSCALL (rt_sigprocmask, err, 4, SIG_SETMASK, &ss, &oss, _NSIG / 8);
+
+  /* Create the helper thread for this timer.  */
+  pthread_t th;
+  int res = pthread_create (&th, &attr, timer_helper_thread, NULL);
+  if (res == 0)
+    /* We managed to start the helper thread.  */
+    __helper_tid = ((struct pthread *) th)->tid;
+
+  /* Restore the signal mask.  */
+  INTERNAL_SYSCALL (rt_sigprocmask, err, 4, SIG_SETMASK, &oss, NULL,
+		    _NSIG / 8);
+
+  /* No need for the attribute anymore.  */
+  (void) pthread_attr_destroy (&attr);
+
+  /* We have to make sure that after fork()ing a new helper thread can
+     be created.  */
+  pthread_atfork (NULL, NULL, reset_helper_control);
+}