1 files changed, 39 insertions, 0 deletions
diff --git a/benchmark/io_copy_stream_write_socket.yml b/benchmark/io_copy_stream_write_socket.yml
new file mode 100644
index 0000000000..2207eca8c6
--- /dev/null
+++ b/benchmark/io_copy_stream_write_socket.yml
@@ -0,0 +1,39 @@
+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_socket: |
+    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
+      require 'socket'
+      src = Zero.new
+      rd, wr = UNIXSocket.pair
+      pid = fork do
+        wr.close
+        buf = String.new
+        while rd.read(16384, buf)
+        end
+      end
+      rd.close
+      IO.copy_stream(src, wr)
+    rescue Errno::ENOENT, NotImplementedError, NameError
+      # not *nix: missing /dev/zero, fork, or UNIXSocket
+    rescue LoadError # no socket?
+    ensure
+      wr.close if wr
+      Process.waitpid(pid) if pid
+    end if IO.respond_to?(:copy_stream)
+loop_count: 1