IO::Buffer for scheduler interface.

Merged: https://github.com/ruby/ruby/pull/4621

test/ruby/test_io_buffer.rb

@@ -0,0 +1,131 @@
+# frozen_string_literal: false
+
+class TestIOBuffer < Test::Unit::TestCase
+  def assert_negative(value)
+    assert(value < 0, "Expected #{value} to be negative!")
+  end
+
+  def assert_positive(value)
+    assert(value > 0, "Expected #{value} to be positive!")
+  end
+
+  def test_flags
+    assert_equal 0, IO::Buffer::EXTERNAL
+    assert_equal 1, IO::Buffer::INTERNAL
+    assert_equal 2, IO::Buffer::MAPPED
+
+    assert_equal 16, IO::Buffer::LOCKED
+    assert_equal 32, IO::Buffer::PRIVATE
+
+    assert_equal 64, IO::Buffer::IMMUTABLE
+  end
+
+  def test_endian
+    assert_equal 4, IO::Buffer::LITTLE_ENDIAN
+    assert_equal 8, IO::Buffer::BIG_ENDIAN
+    assert_equal 8, IO::Buffer::NETWORK_ENDIAN
+
+    assert_include [IO::Buffer::LITTLE_ENDIAN, IO::Buffer::BIG_ENDIAN], IO::Buffer::HOST_ENDIAN
+  end
+
+  def test_new_internal
+    buffer = IO::Buffer.new(1024, IO::Buffer::INTERNAL)
+    assert_equal 1024, buffer.size
+    refute buffer.external?
+    assert buffer.internal?
+    refute buffer.mapped?
+  end
+
+  def test_new_mapped
+    buffer = IO::Buffer.new(1024, IO::Buffer::MAPPED)
+    assert_equal 1024, buffer.size
+    refute buffer.external?
+    refute buffer.internal?
+    assert buffer.mapped?
+  end
+
+  def test_file_mapped
+    buffer = File.open(__FILE__) {|file| IO::Buffer.map(file)}
+    assert_include buffer.to_str, "Hello World"
+  end
+
+  def test_resize
+    buffer = IO::Buffer.new(1024, IO::Buffer::MAPPED)
+    buffer.resize(2048, 0)
+    assert_equal 2048, buffer.size
+  end
+
+  def test_resize_preserve
+    message = "Hello World"
+    buffer = IO::Buffer.new(1024, IO::Buffer::MAPPED)
+    buffer.copy(message, 0)
+    buffer.resize(2048, 1024)
+    assert_equal message, buffer.to_str(0, message.bytesize)
+  end
+
+  def test_compare_same_size
+    buffer1 = IO::Buffer.new(1)
+    assert_equal buffer1, buffer1
+
+    buffer2 = IO::Buffer.new(1)
+    buffer1.set(:U8, 0, 0x10)
+    buffer2.set(:U8, 0, 0x20)
+
+    assert_negative buffer1 <=> buffer2
+    assert_positive buffer2 <=> buffer1
+  end
+
+  def test_compare_different_size
+    buffer1 = IO::Buffer.new(3)
+    buffer2 = IO::Buffer.new(5)
+
+    assert_negative buffer1 <=> buffer2
+    assert_positive buffer2 <=> buffer1
+  end
+
+  def test_slice
+    buffer = IO::Buffer.new(128)
+    slice = buffer.slice(8, 32)
+    slice.copy("Hello World", 0)
+    assert_equal("Hello World", buffer.to_str(8, 11))
+  end
+
+  def test_slice_bounds
+    buffer = IO::Buffer.new(128)
+
+    # What is best exception class?
+    assert_raise RuntimeError do
+      buffer.slice(128, 10)
+    end
+
+    # assert_raise RuntimeError do
+    #   pp buffer.slice(-10, 10)
+    # end
+  end
+
+  def test_invalidation
+    input, output = IO.pipe
+
+    # (1) rb_write_internal creates IO::Buffer object,
+    buffer = IO::Buffer.new(128)
+
+    # (2) it is passed to (malicious) scheduler
+    # (3) scheduler starts a thread which call system call with the buffer object
+    thread = Thread.new{buffer.locked{input.read}}
+
+    Thread.pass until thread.stop?
+
+    # (4) scheduler returns
+    # (5) rb_write_internal invalidate the buffer object
+    assert_raise RuntimeError do
+      buffer.free
+    end
+
+    # (6) the system call access the memory area after invalidation
+    output.write("Hello World")
+    output.close
+    thread.join
+
+    input.close
+  end
+end