NPTL specific definitions for async name lookup.

nptl/sysdeps/pthread/gai_misc.h

@@ -0,0 +1,119 @@
+/* Copyright (C) 2006 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   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; if not, write to the Free
+   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+   02111-1307 USA.  */
+
+/* We define a special synchronization primitive for AIO.  POSIX
+   conditional variables would be ideal but the pthread_cond_*wait
+   operations do not return on EINTR.  This is a requirement for
+   correct aio_suspend and lio_listio implementations.  */
+
+#include <assert.h>
+#include <signal.h>
+#include <pthreadP.h>
+#include <lowlevellock.h>
+
+#define DONT_NEED_GAI_MISC_COND	1
+
+#define GAI_MISC_NOTIFY(waitlist) \
+  do {									      \
+    if (--*waitlist->counterp == 0)					      \
+      lll_futex_wake (waitlist->counterp, 1);				      \
+  } while (0)
+
+#define GAI_MISC_WAIT(result, futex, timeout, cancel) \
+  do {									      \
+    volatile int *futexaddr = &futex;					      \
+    int oldval = futex;							      \
+									      \
+    if (oldval != 0)							      \
+      {									      \
+	pthread_mutex_unlock (&__gai_requests_mutex);			      \
+									      \
+	int oldtype;							      \
+	if (cancel)							      \
+	  oldtype = LIBC_CANCEL_ASYNC ();				      \
+									      \
+	int status;							      \
+	do								      \
+	  {								      \
+	    status = lll_futex_timed_wait (futexaddr, oldval, timeout);	      \
+	    if (status != -EWOULDBLOCK)					      \
+	      break;							      \
+									      \
+	    oldval = *futexaddr;					      \
+	  }								      \
+	while (oldval != 0);						      \
+									      \
+	if (cancel)							      \
+	  LIBC_CANCEL_RESET (oldtype);					      \
+									      \
+	if (status == -EINTR)						      \
+	  result = EINTR;						      \
+	else if (status == -ETIMEDOUT)					      \
+	  result = EAGAIN;						      \
+	else								      \
+	  assert (status == 0 || status == -EWOULDBLOCK);		      \
+									      \
+	pthread_mutex_lock (&__gai_requests_mutex);			      \
+      }									      \
+  } while (0)
+
+
+#define gai_start_notify_thread __gai_start_notify_thread
+#define gai_create_helper_thread __gai_create_helper_thread
+
+extern inline void
+__gai_start_notify_thread (void)
+{
+  sigset_t ss;
+  sigemptyset (&ss);
+  INTERNAL_SYSCALL_DECL (err);
+  INTERNAL_SYSCALL (rt_sigprocmask, err, 4, SIG_SETMASK, &ss, NULL, _NSIG / 8);
+}
+
+extern inline int
+__gai_create_helper_thread (pthread_t *threadp, void *(*tf) (void *),
+			    void *arg)
+{
+  pthread_attr_t attr;
+
+  /* Make sure the thread is created detached.  */
+  pthread_attr_init (&attr);
+  pthread_attr_setdetachstate (&attr, PTHREAD_CREATE_DETACHED);
+
+  /* The helper thread needs only very little resources.  */
+  (void) pthread_attr_setstacksize (&attr, PTHREAD_STACK_MIN);
+
+  /* Block all signals in the helper thread.  To do this thoroughly we
+     temporarily have to block all signals here.  */
+  sigset_t ss;
+  sigset_t oss;
+  sigfillset (&ss);
+  INTERNAL_SYSCALL_DECL (err);
+  INTERNAL_SYSCALL (rt_sigprocmask, err, 4, SIG_SETMASK, &ss, &oss, _NSIG / 8);
+
+  int ret = pthread_create (threadp, &attr, tf, arg);
+
+  /* Restore the signal mask.  */
+  INTERNAL_SYSCALL (rt_sigprocmask, err, 4, SIG_SETMASK, &oss, NULL,
+		    _NSIG / 8);
+
+  (void) pthread_attr_destroy (&attr);
+  return ret;
+}
+
+#include_next <gai_misc.h>