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-rw-r--r--nptl/sysdeps/pthread/aio_misc.h74
1 files changed, 74 insertions, 0 deletions
diff --git a/nptl/sysdeps/pthread/aio_misc.h b/nptl/sysdeps/pthread/aio_misc.h
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+/* 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 <pthreadP.h>
+#include <lowlevellock.h>
+
+#define DONT_NEED_AIO_MISC_COND	1
+
+#define AIO_MISC_NOTIFY(waitlist) \
+  do {									      \
+    if (*waitlist->counterp > 0 && --*waitlist->counterp == 0)		      \
+      lll_futex_wake (waitlist->counterp, 1);				      \
+  } while (0)
+
+#define AIO_MISC_WAIT(result, futex, timeout, cancel)			      \
+  do {									      \
+    volatile int *futexaddr = &futex;					      \
+    int oldval = futex;							      \
+									      \
+    if (oldval != 0)							      \
+      {									      \
+	pthread_mutex_unlock (&__aio_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 (&__aio_requests_mutex);			      \
+      }									      \
+  } while (0)
+
+#include_next <aio_misc.h>