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glibc  2.9
Functions
sigsuspend.c File Reference
#include <errno.h>
#include <hurd.h>
#include <hurd/signal.h>
#include <hurd/msg.h>

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Functions

int __sigsuspend (sigset_t *set) const

Function Documentation

int __sigsuspend ( sigset_t set) const

Definition at line 29 of file sigsuspend.c.

{
  struct hurd_sigstate *ss;
  sigset_t newmask, oldmask, pending;
  mach_port_t wait;
  mach_msg_header_t msg;

  if (set != NULL)
    /* Crash before locking.  */
    newmask = *set;

  /* Get a fresh port we will wait on.  */
  wait = __mach_reply_port ();

  ss = _hurd_self_sigstate ();

  __spin_lock (&ss->lock);

  oldmask = ss->blocked;
  if (set != NULL)
    /* Change to the new blocked signal mask.  */
    ss->blocked = newmask & ~_SIG_CANT_MASK;

  /* Notice if any pending signals just became unblocked.  */
  pending = ss->pending & ~ss->blocked;

  /* Tell the signal thread to message us when a signal arrives.  */
  ss->suspended = wait;
  __spin_unlock (&ss->lock);

  if (pending)
    /* Tell the signal thread to check for pending signals.  */
    __msg_sig_post (_hurd_msgport, 0, 0, __mach_task_self ());

  /* Wait for the signal thread's message.  */
  __mach_msg (&msg, MACH_RCV_MSG, 0, sizeof (msg), wait,
             MACH_MSG_TIMEOUT_NONE, MACH_PORT_NULL);
  __mach_port_destroy (__mach_task_self (), wait);

  __spin_lock (&ss->lock);
  ss->blocked = oldmask;    /* Restore the old mask.  */
  pending = ss->pending & ~ss->blocked;   /* Again check for pending signals.  */
  __spin_unlock (&ss->lock);

  if (pending)
    /* Tell the signal thread to check for pending signals.  */
    __msg_sig_post (_hurd_msgport, 0, 0, __mach_task_self ());

  /* We've been interrupted!  And a good thing, too.
     Otherwise we'd never return.
     That's right; this function always returns an error.  */
  errno = EINTR;
  return -1;
}

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