1 files changed, 29 insertions, 0 deletions
diff --git a/gl/m4/nonblocking.m4 b/gl/m4/nonblocking.m4
new file mode 100644
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+++ b/gl/m4/nonblocking.m4
@@ -0,0 +1,29 @@
+# nonblocking.m4 serial 3
+dnl Copyright (C) 2011-2023 Free Software Foundation, Inc.
+dnl This file is free software; the Free Software Foundation
+dnl gives unlimited permission to copy and/or distribute it,
+dnl with or without modifications, as long as this notice is preserved.
+
+dnl Tests whether non-blocking I/O is natively supported by read(), write().
+dnl Sets gl_cv_have_nonblocking.
+dnl Also tests whether open() supports O_NONBLOCK.
+dnl Sets gl_cv_have_open_O_NONBLOCK.
+AC_DEFUN([gl_NONBLOCKING_IO],
+[
+  dnl Ensure to expand the default settings once only, before all statements
+  dnl that occur in other macros.
+  AC_REQUIRE([gl_NONBLOCKING_IO_BODY])
+])
+
+AC_DEFUN([gl_NONBLOCKING_IO_BODY],
+[
+  AC_REQUIRE([AC_CANONICAL_HOST])
+  case "$host_os" in
+    mingw*) gl_cv_have_nonblocking=no ;;
+    *)      gl_cv_have_nonblocking=yes ;;
+  esac
+  case "$host_os" in
+    mingw*) gl_cv_have_open_O_NONBLOCK=no ;;
+    *)      gl_cv_have_open_O_NONBLOCK=yes ;;
+  esac
+])