1 files changed, 28 insertions, 0 deletions
diff --git a/benchmark/io_copy_stream_write.yml b/benchmark/io_copy_stream_write.yml
new file mode 100644
index 0000000000..32fa920951
--- /dev/null
+++ b/benchmark/io_copy_stream_write.yml
@@ -0,0 +1,28 @@
+prelude: |
+  # The goal of this is to use a synthetic (non-IO) reader
+  # to trigger the read/write loop of IO.copy_stream,
+  # bypassing in-kernel mechanisms like sendfile for zero copy,
+  # so we wrap the /dev/zero IO object:
+benchmark:
+  io_copy_stream_write: |
+
+    class Zero
+      def initialize
+        @n = 100000
+        @in = File.open('/dev/zero', 'rb')
+      end
+
+      def read(len, buf)
+        return if (@n -= 1) == 0
+        @in.read(len, buf)
+      end
+    end
+
+    begin
+      src = Zero.new
+      dst = File.open(IO::NULL, 'wb')
+      n = IO.copy_stream(src, dst)
+    rescue Errno::ENOENT
+      # not *nix
+    end if IO.respond_to?(:copy_stream) && IO.const_defined?(:NULL)
+loop_count: 1