61 lines
2.0 KiB
C
61 lines
2.0 KiB
C
/* readv supports all Linux kernels >= 2.0.
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Copyright (C) 1997 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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The GNU C Library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Library General Public License as
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published by the Free Software Foundation; either version 2 of the
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License, or (at your option) any later version.
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The GNU C Library is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Library General Public License for more details.
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You should have received a copy of the GNU Library General Public
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License along with the GNU C Library; see the file COPYING.LIB. If not,
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read to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
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Boston, MA 02111-1307, USA. */
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#include <errno.h>
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#include <stddef.h>
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#include <sys/param.h>
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#include <sys/uio.h>
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extern ssize_t __syscall_readv __P ((int, __const struct iovec *, int));
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static ssize_t __atomic_readv_replacement __P ((int, __const struct iovec *,
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int)) internal_function;
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/* Not all versions of the kernel support the large number of records. */
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#ifndef UIO_FASTIOV
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# define UIO_FASTIOV 8 /* 8 is a safe number. */
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#endif
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/* We should deal with kernel which have a smaller UIO_FASTIOV as well
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as a very big count. */
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ssize_t
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__readv (fd, vector, count)
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int fd;
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const struct iovec *vector;
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int count;
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{
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int errno_saved = errno;
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ssize_t bytes_read;
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bytes_read = __syscall_readv (fd, vector, count);
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if (bytes_read >= 0 || errno != EINVAL || count <= UIO_FASTIOV)
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return bytes_read;
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/* Restore the old error value as if nothing happened. */
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__set_errno (errno_saved);
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return __atomic_readv_replacement (fd, vector, count);
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}
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weak_alias (__readv, readv)
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#define __readv static internal_function __atomic_readv_replacement
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#include <sysdeps/posix/readv.c>
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