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+/* POSIX compatible write() function.
+ Copyright (C) 2008-2020 Free Software Foundation, Inc.
+ Written by Bruno Haible <bruno@clisp.org>, 2008.
+
+ This program is free software: you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation; either version 3 of the License, or
+ (at your option) any later version.
+
+ This program 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 General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with this program. If not, see <https://www.gnu.org/licenses/>. */
+
+#include <config.h>
+
+/* Specification. */
+#include <unistd.h>
+
+/* On native Windows platforms, SIGPIPE does not exist. When write() is
+ called on a pipe with no readers, WriteFile() fails with error
+ GetLastError() = ERROR_NO_DATA, and write() in consequence fails with
+ error EINVAL. */
+
+#if defined _WIN32 && ! defined __CYGWIN__
+
+# include <errno.h>
+# include <signal.h>
+# include <io.h>
+
+# define WIN32_LEAN_AND_MEAN /* avoid including junk */
+# include <windows.h>
+
+# if HAVE_MSVC_INVALID_PARAMETER_HANDLER
+# include "msvc-inval.h"
+# endif
+# if GNULIB_MSVC_NOTHROW
+# include "msvc-nothrow.h"
+# else
+# include <io.h>
+# endif
+
+/* Don't assume that UNICODE is not defined. */
+# undef GetNamedPipeHandleState
+# define GetNamedPipeHandleState GetNamedPipeHandleStateA
+
+# undef write
+
+# if HAVE_MSVC_INVALID_PARAMETER_HANDLER
+static ssize_t
+write_nothrow (int fd, const void *buf, size_t count)
+{
+ ssize_t result;
+
+ TRY_MSVC_INVAL
+ {
+ result = _write (fd, buf, count);
+ }
+ CATCH_MSVC_INVAL
+ {
+ result = -1;
+ errno = EBADF;
+ }
+ DONE_MSVC_INVAL;
+
+ return result;
+}
+# else
+# define write_nothrow _write
+# endif
+
+ssize_t
+rpl_write (int fd, const void *buf, size_t count)
+{
+ for (;;)
+ {
+ ssize_t ret = write_nothrow (fd, buf, count);
+
+ if (ret < 0)
+ {
+# if GNULIB_NONBLOCKING
+ if (errno == ENOSPC)
+ {
+ HANDLE h = (HANDLE) _get_osfhandle (fd);
+ if (GetFileType (h) == FILE_TYPE_PIPE)
+ {
+ /* h is a pipe or socket. */
+ DWORD state;
+ if (GetNamedPipeHandleState (h, &state, NULL, NULL, NULL,
+ NULL, 0)
+ && (state & PIPE_NOWAIT) != 0)
+ {
+ /* h is a pipe in non-blocking mode.
+ We can get here in four situations:
+ 1. When the pipe buffer is full.
+ 2. When count <= pipe_buf_size and the number of
+ free bytes in the pipe buffer is < count.
+ 3. When count > pipe_buf_size and the number of free
+ bytes in the pipe buffer is > 0, < pipe_buf_size.
+ 4. When count > pipe_buf_size and the pipe buffer is
+ entirely empty.
+ The cases 1 and 2 are POSIX compliant. In cases 3 and
+ 4 POSIX specifies that write() must split the request
+ and succeed with a partial write. We fix case 4.
+ We don't fix case 3 because it is not essential for
+ programs. */
+ DWORD out_size; /* size of the buffer for outgoing data */
+ DWORD in_size; /* size of the buffer for incoming data */
+ if (GetNamedPipeInfo (h, NULL, &out_size, &in_size, NULL))
+ {
+ size_t reduced_count = count;
+ /* In theory we need only one of out_size, in_size.
+ But I don't know which of the two. The description
+ is ambiguous. */
+ if (out_size != 0 && out_size < reduced_count)
+ reduced_count = out_size;
+ if (in_size != 0 && in_size < reduced_count)
+ reduced_count = in_size;
+ if (reduced_count < count)
+ {
+ /* Attempt to write only the first part. */
+ count = reduced_count;
+ continue;
+ }
+ }
+ /* Change errno from ENOSPC to EAGAIN. */
+ errno = EAGAIN;
+ }
+ }
+ }
+ else
+# endif
+ {
+# if GNULIB_SIGPIPE
+ if (GetLastError () == ERROR_NO_DATA
+ && GetFileType ((HANDLE) _get_osfhandle (fd))
+ == FILE_TYPE_PIPE)
+ {
+ /* Try to raise signal SIGPIPE. */
+ raise (SIGPIPE);
+ /* If it is currently blocked or ignored, change errno from
+ EINVAL to EPIPE. */
+ errno = EPIPE;
+ }
+# endif
+ }
+ }
+ return ret;
+ }
+}
+
+#endif