IO#nread compatibility for Rubinius (Linux-only)

We don't deal with user-space buffers, so we should be fine
using this compatibility layer and only checking the kernel
buffers (until rbx implements a proper solution).

1 files changed, 12 insertions, 0 deletions

diff --git a/lib/dtas/compat_rbx.rb b/lib/dtas/compat_rbx.rb
new file mode 100644
index 0000000..a64bf78
--- /dev/null
+++ b/lib/dtas/compat_rbx.rb
@@ -0,0 +1,12 @@
+# Copyright (C) 2013, Eric Wong <normalperson@yhbt.net> and all contributors
+# License: GPLv3 or later (https://www.gnu.org/licenses/gpl-3.0.txt)
+
+# ref: https://github.com/rubysl/rubysl-io-wait/issues/1
+# this ignores buffers and is Linux-only
+class IO
+  def nread
+    buf = "\0" * 8
+    ioctl(0x541B, buf)
+    buf.unpack("l_")[0]
+  end
+end if ! IO.method_defined?(:nread) && RUBY_PLATFORM =~ /linux/