1 files changed, 163 insertions, 0 deletions
diff --git a/gl/lib/nonblocking.c b/gl/lib/nonblocking.c
new file mode 100644
index 0000000..3a8bb2a
--- /dev/null
+++ b/gl/lib/nonblocking.c
@@ -0,0 +1,163 @@
+/* Non-blocking I/O for pipe or socket descriptors.
+   Copyright (C) 2011-2023 Free Software Foundation, Inc.
+
+   This file 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.
+
+   This file 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 this program.  If not, see <https://www.gnu.org/licenses/>.  */
+
+#include <config.h>
+
+/* Specification.  */
+#include "nonblocking.h"
+
+#include <errno.h>
+
+#if defined _WIN32 && ! defined __CYGWIN__
+/* Native Windows API.  */
+
+# include <sys/ioctl.h>
+# include <sys/socket.h>
+# include <unistd.h>
+
+/* Get declarations of the native Windows API functions.  */
+# define WIN32_LEAN_AND_MEAN
+# include <windows.h>
+
+# 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
+
+int
+get_nonblocking_flag (int desc)
+{
+  HANDLE h = (HANDLE) _get_osfhandle (desc);
+  if (h == INVALID_HANDLE_VALUE)
+    {
+      errno = EBADF;
+      return -1;
+    }
+  if (GetFileType (h) == FILE_TYPE_PIPE)
+    {
+      /* h is a pipe or socket.  */
+      DWORD state;
+      if (GetNamedPipeHandleState (h, &state, NULL, NULL, NULL, NULL, 0))
+        /* h is a pipe.  */
+        return (state & PIPE_NOWAIT) != 0;
+      else
+        /* h is a socket.  */
+        errno = ENOSYS;
+        return -1;
+    }
+  else
+    /* The native Windows API does not support non-blocking on regular
+       files.  */
+    return 0;
+}
+
+int
+set_nonblocking_flag (int desc, bool value)
+{
+  HANDLE h = (HANDLE) _get_osfhandle (desc);
+  if (h == INVALID_HANDLE_VALUE)
+    {
+      errno = EBADF;
+      return -1;
+    }
+  if (GetFileType (h) == FILE_TYPE_PIPE)
+    {
+      /* h is a pipe or socket.  */
+      DWORD state;
+      if (GetNamedPipeHandleState (h, &state, NULL, NULL, NULL, NULL, 0))
+        {
+          /* h is a pipe.  */
+          if ((state & PIPE_NOWAIT) != 0)
+            {
+              if (value)
+                return 0;
+              state &= ~PIPE_NOWAIT;
+            }
+          else
+            {
+              if (!value)
+                return 0;
+              state |= PIPE_NOWAIT;
+            }
+          if (SetNamedPipeHandleState (h, &state, NULL, NULL))
+            return 0;
+          errno = EINVAL;
+          return -1;
+        }
+      else
+        {
+          /* h is a socket.  */
+          int v = value;
+          return ioctl (desc, FIONBIO, &v);
+        }
+    }
+  else
+    {
+      /* The native Windows API does not support non-blocking on regular
+         files.  */
+      if (!value)
+        return 0;
+      errno = ENOTSUP;
+      return -1;
+    }
+}
+
+#else
+/* Unix API.  */
+
+# include <fcntl.h>
+
+# if GNULIB_defined_O_NONBLOCK
+#  error Please port nonblocking to your platform
+# endif
+
+/* We don't need the gnulib replacement of fcntl() here.  */
+# undef fcntl
+
+int
+get_nonblocking_flag (int desc)
+{
+  int fcntl_flags;
+
+  fcntl_flags = fcntl (desc, F_GETFL, 0);
+  if (fcntl_flags < 0)
+    return -1;
+  return (fcntl_flags & O_NONBLOCK) != 0;
+}
+
+int
+set_nonblocking_flag (int desc, bool value)
+{
+  int fcntl_flags;
+
+  fcntl_flags = fcntl (desc, F_GETFL, 0);
+  if (fcntl_flags < 0)
+    return -1;
+  if (((fcntl_flags & O_NONBLOCK) != 0) == value)
+    return 0;
+  if (value)
+    fcntl_flags |= O_NONBLOCK;
+  else
+    fcntl_flags &= ~O_NONBLOCK;
+  return fcntl (desc, F_SETFL, fcntl_flags);
+}
+
+#endif