Imported Upstream version 1.13.4upstream/1.13.4

1 files changed, 123 insertions, 0 deletions

diff --git a/lib/write.c b/lib/write.c
new file mode 100644
index 0000000..b0ffa94
--- /dev/null
+++ b/lib/write.c
@@ -0,0 +1,123 @@
+/* POSIX compatible write() function.
+   Copyright (C) 2008-2011 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 <http://www.gnu.org/licenses/>.  */
+
+#include <config.h>
+
+/* Specification.  */
+#include <unistd.h>
+
+/* Replace this function only if module 'nonblocking' or module 'sigpipe' is
+   requested.  */
+#if GNULIB_NONBLOCKING || GNULIB_SIGPIPE
+
+/* 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 __WIN32__) && ! defined __CYGWIN__
+
+#  include <errno.h>
+#  include <signal.h>
+#  include <io.h>
+
+#  define WIN32_LEAN_AND_MEAN  /* avoid including junk */
+#  include <windows.h>
+
+ssize_t
+rpl_write (int fd, const void *buf, size_t count)
+#undef write
+{
+  for (;;)
+    {
+      ssize_t ret = write (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
+#endif