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-rw-r--r--gl/lib/nonblocking.c163
1 files changed, 163 insertions, 0 deletions
diff --git a/gl/lib/nonblocking.c b/gl/lib/nonblocking.c
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+++ b/gl/lib/nonblocking.c
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+/* Non-blocking I/O for pipe or socket descriptors.
+ Copyright (C) 2011-2022 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