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-rw-r--r--sysdeps/unix/sysv/linux/futex-internal.h251
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diff --git a/sysdeps/unix/sysv/linux/futex-internal.h b/sysdeps/unix/sysv/linux/futex-internal.h
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+++ b/sysdeps/unix/sysv/linux/futex-internal.h
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+/* futex operations for glibc-internal use.  Linux version.
+   Copyright (C) 2014-2015 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, see
+   <http://www.gnu.org/licenses/>.  */
+
+#ifndef FUTEX_INTERNAL_H
+#define FUTEX_INTERNAL_H
+
+#include <sysdeps/nptl/futex-internal.h>
+#include <errno.h>
+#include <lowlevellock-futex.h>
+#include <nptl/pthreadP.h>
+
+/* See sysdeps/nptl/futex-internal.h for documentation; this file only
+   contains Linux-specific comments.
+
+   The Linux kernel treats provides absolute timeouts based on the
+   CLOCK_REALTIME clock and relative timeouts measured against the
+   CLOCK_MONOTONIC clock.
+
+   We expect a Linux kernel version of 2.6.22 or more recent (since this
+   version, EINTR is not returned on spurious wake-ups anymore).  */
+
+/* FUTEX_SHARED is always supported by the Linux kernel.  */
+static __always_inline int
+futex_supports_pshared (int pshared)
+{
+  if (__glibc_likely (pshared == PTHREAD_PROCESS_PRIVATE))
+    return 0;
+  else if (pshared == PTHREAD_PROCESS_SHARED)
+    return 0;
+  else
+    return EINVAL;
+}
+
+/* The Linux kernel supports relative timeouts measured against the
+   CLOCK_MONOTONIC clock.  */
+static __always_inline bool
+futex_supports_exact_relative_timeouts (void)
+{
+  return true;
+}
+
+/* See sysdeps/nptl/futex-internal.h for details.  */
+static __always_inline int
+futex_wait (unsigned int *futex_word, unsigned int expected, int private)
+{
+  int err = lll_futex_timed_wait (futex_word, expected, NULL, private);
+  switch (err)
+    {
+    case 0:
+    case -EAGAIN:
+    case -EINTR:
+      return -err;
+
+    case -ETIMEDOUT: /* Cannot have happened as we provided no timeout.  */
+    case -EFAULT: /* Must have been caused by a glibc or application bug.  */
+    case -EINVAL: /* Either due to wrong alignment or due to the timeout not
+		     being normalized.  Must have been caused by a glibc or
+		     application bug.  */
+    case -ENOSYS: /* Must have been caused by a glibc bug.  */
+    /* No other errors are documented at this time.  */
+    default:
+      futex_fatal_error ();
+    }
+}
+
+/* See sysdeps/nptl/futex-internal.h for details.  */
+static __always_inline int
+futex_wait_cancelable (unsigned int *futex_word, unsigned int expected,
+		       int private)
+{
+  int oldtype;
+  oldtype = __pthread_enable_asynccancel ();
+  int err = lll_futex_timed_wait (futex_word, expected, NULL, private);
+  __pthread_disable_asynccancel (oldtype);
+  switch (err)
+    {
+    case 0:
+    case -EAGAIN:
+    case -EINTR:
+      return -err;
+
+    case -ETIMEDOUT: /* Cannot have happened as we provided no timeout.  */
+    case -EFAULT: /* Must have been caused by a glibc or application bug.  */
+    case -EINVAL: /* Either due to wrong alignment or due to the timeout not
+		     being normalized.  Must have been caused by a glibc or
+		     application bug.  */
+    case -ENOSYS: /* Must have been caused by a glibc bug.  */
+    /* No other errors are documented at this time.  */
+    default:
+      futex_fatal_error ();
+    }
+}
+
+/* See sysdeps/nptl/futex-internal.h for details.  */
+static __always_inline int
+futex_reltimed_wait (unsigned int *futex_word, unsigned int expected,
+		     const struct timespec *reltime, int private)
+{
+  int err = lll_futex_timed_wait (futex_word, expected, reltime, private);
+  switch (err)
+    {
+    case 0:
+    case -EAGAIN:
+    case -EINTR:
+    case -ETIMEDOUT:
+      return -err;
+
+    case -EFAULT: /* Must have been caused by a glibc or application bug.  */
+    case -EINVAL: /* Either due to wrong alignment or due to the timeout not
+		     being normalized.  Must have been caused by a glibc or
+		     application bug.  */
+    case -ENOSYS: /* Must have been caused by a glibc bug.  */
+    /* No other errors are documented at this time.  */
+    default:
+      futex_fatal_error ();
+    }
+}
+
+/* See sysdeps/nptl/futex-internal.h for details.  */
+static __always_inline int
+futex_reltimed_wait_cancelable (unsigned int *futex_word,
+				unsigned int expected,
+			        const struct timespec *reltime, int private)
+{
+  int oldtype;
+  oldtype = __pthread_enable_asynccancel ();
+  int err = lll_futex_timed_wait (futex_word, expected, reltime, private);
+  __pthread_disable_asynccancel (oldtype);
+  switch (err)
+    {
+    case 0:
+    case -EAGAIN:
+    case -EINTR:
+    case -ETIMEDOUT:
+      return -err;
+
+    case -EFAULT: /* Must have been caused by a glibc or application bug.  */
+    case -EINVAL: /* Either due to wrong alignment or due to the timeout not
+		     being normalized.  Must have been caused by a glibc or
+		     application bug.  */
+    case -ENOSYS: /* Must have been caused by a glibc bug.  */
+    /* No other errors are documented at this time.  */
+    default:
+      futex_fatal_error ();
+    }
+}
+
+/* See sysdeps/nptl/futex-internal.h for details.  */
+static __always_inline int
+futex_abstimed_wait (unsigned int *futex_word, unsigned int expected,
+		     const struct timespec *abstime, int private)
+{
+  /* Work around the fact that the kernel rejects negative timeout values
+     despite them being valid.  */
+  if (__glibc_unlikely ((abstime != NULL) && (abstime->tv_sec < 0)))
+    return ETIMEDOUT;
+  int err = lll_futex_timed_wait_bitset (futex_word, expected, abstime,
+					 FUTEX_CLOCK_REALTIME, private);
+  switch (err)
+    {
+    case 0:
+    case -EAGAIN:
+    case -EINTR:
+    case -ETIMEDOUT:
+      return -err;
+
+    case -EFAULT: /* Must have been caused by a glibc or application bug.  */
+    case -EINVAL: /* Either due to wrong alignment or due to the timeout not
+		     being normalized.  Must have been caused by a glibc or
+		     application bug.  */
+    case -ENOSYS: /* Must have been caused by a glibc bug.  */
+    /* No other errors are documented at this time.  */
+    default:
+      futex_fatal_error ();
+    }
+}
+
+/* See sysdeps/nptl/futex-internal.h for details.  */
+static __always_inline int
+futex_abstimed_wait_cancelable (unsigned int *futex_word,
+				unsigned int expected,
+			        const struct timespec *abstime, int private)
+{
+  /* Work around the fact that the kernel rejects negative timeout values
+     despite them being valid.  */
+  if (__glibc_unlikely ((abstime != NULL) && (abstime->tv_sec < 0)))
+    return ETIMEDOUT;
+  int oldtype;
+  oldtype = __pthread_enable_asynccancel ();
+  int err = lll_futex_timed_wait_bitset (futex_word, expected, abstime,
+					 FUTEX_CLOCK_REALTIME, private);
+  __pthread_disable_asynccancel (oldtype);
+  switch (err)
+    {
+    case 0:
+    case -EAGAIN:
+    case -EINTR:
+    case -ETIMEDOUT:
+      return -err;
+
+    case -EFAULT: /* Must have been caused by a glibc or application bug.  */
+    case -EINVAL: /* Either due to wrong alignment or due to the timeout not
+		     being normalized.  Must have been caused by a glibc or
+		     application bug.  */
+    case -ENOSYS: /* Must have been caused by a glibc bug.  */
+    /* No other errors are documented at this time.  */
+    default:
+      futex_fatal_error ();
+    }
+}
+
+/* See sysdeps/nptl/futex-internal.h for details.  */
+static __always_inline void
+futex_wake (unsigned int *futex_word, int processes_to_wake, int private)
+{
+  int res = lll_futex_wake (futex_word, processes_to_wake, private);
+  /* No error.  Ignore the number of woken processes.  */
+  if (res >= 0)
+    return;
+  switch (res)
+    {
+    case -EFAULT: /* Could have happened due to memory reuse.  */
+    case -EINVAL: /* Could be either due to incorrect alignment (a bug in
+		     glibc or in the application) or due to memory being
+		     reused for a PI futex.  We cannot distinguish between the
+		     two causes, and one of them is correct use, so we do not
+		     act in this case.  */
+      return;
+    case -ENOSYS: /* Must have been caused by a glibc bug.  */
+    /* No other errors are documented at this time.  */
+    default:
+      futex_fatal_error ();
+    }
+}
+
+#endif  /* futex-internal.h */