diff --git a/ext/io/event/selector/epoll.c b/ext/io/event/selector/epoll.c
index 62fd850e..68769e4c 100644
--- a/ext/io/event/selector/epoll.c
+++ b/ext/io/event/selector/epoll.c
@@ -590,36 +590,29 @@ struct io_read_arguments {
 	
 	int descriptor;
 	
-	VALUE buffer;
+	// The remaining writable buffer region after applying the requested offset.
+	void *base;
+	size_t size;
+	
+	// The minimum number of bytes requested by the caller.
 	size_t length;
-	size_t offset;
 };
 
 static
 VALUE io_read_loop(VALUE _arguments) {
 	struct io_read_arguments *arguments = (struct io_read_arguments *)_arguments;
 	
-	void *base;
-	size_t size;
-	rb_io_buffer_get_bytes_for_writing(arguments->buffer, &base, &size);
-	
 	size_t length = arguments->length;
-	size_t offset = arguments->offset;
 	size_t total = 0;
 	
-	// Ensure offset is within the bounds of the buffer to avoid size_t underflow and out-of-bounds pointer arithmetic on (char *)base + offset.
-	if (offset > size) {
-		return rb_fiber_scheduler_io_result(-1, EINVAL);
-	}
-	
-	size_t maximum_size = size - offset;
+	size_t maximum_size = arguments->size;
 	while (maximum_size) {
-		ssize_t result = read(arguments->descriptor, (char*)base+offset, maximum_size);
+		ssize_t result = read(arguments->descriptor, (char*)arguments->base+total, maximum_size);
 		
 		if (result > 0) {
 			total += result;
-			offset += result;
 			if ((size_t)result >= length) break;
+			maximum_size -= result;
 			length -= result;
 		} else if (result == 0) {
 			break;
@@ -628,8 +621,6 @@ VALUE io_read_loop(VALUE _arguments) {
 		} else {
 			return rb_fiber_scheduler_io_result(-1, errno);
 		}
-		
-		maximum_size = size - offset;
 	}
 	
 	return rb_fiber_scheduler_io_result(total, 0);
@@ -645,11 +636,24 @@ VALUE io_read_ensure(VALUE _arguments) {
 }
 
 VALUE IO_Event_Selector_EPoll_io_read(VALUE self, VALUE fiber, VALUE io, VALUE buffer, VALUE _length, VALUE _offset) {
-	int descriptor = IO_Event_Selector_io_descriptor(io);
-	
 	size_t offset = NUM2SIZET(_offset);
 	size_t length = NUM2SIZET(_length);
 	
+	void *base;
+	size_t size;
+	rb_io_buffer_get_bytes_for_writing(buffer, &base, &size);
+	
+	if (offset > size) {
+		return rb_fiber_scheduler_io_result(-1, EINVAL);
+	} else if (offset == size) {
+		return rb_fiber_scheduler_io_result(0, 0);
+	}
+	
+	base = (char*)base + offset;
+	size -= offset;
+	
+	int descriptor = IO_Event_Selector_io_descriptor(io);
+	
 	struct io_read_arguments io_read_arguments = {
 		.self = self,
 		.fiber = fiber,
@@ -657,9 +661,9 @@ VALUE IO_Event_Selector_EPoll_io_read(VALUE self, VALUE fiber, VALUE io, VALUE b
 		
 		.flags = IO_Event_Selector_nonblock_set(descriptor),
 		.descriptor = descriptor,
-		.buffer = buffer,
+		.base = base,
+		.size = size,
 		.length = length,
-		.offset = offset,
 	};
 	
 	RB_OBJ_WRITTEN(self, Qundef, fiber);
@@ -689,40 +693,29 @@ struct io_write_arguments {
 	
 	int descriptor;
 	
-	VALUE buffer;
+	// The remaining readable buffer region after applying the requested offset.
+	const void *base;
+	size_t size;
+	
+	// The minimum number of bytes requested by the caller.
 	size_t length;
-	size_t offset;
 };
 
 static
 VALUE io_write_loop(VALUE _arguments) {
 	struct io_write_arguments *arguments = (struct io_write_arguments *)_arguments;
 	
-	const void *base;
-	size_t size;
-	rb_io_buffer_get_bytes_for_reading(arguments->buffer, &base, &size);
-	
 	size_t length = arguments->length;
-	size_t offset = arguments->offset;
 	size_t total = 0;
 	
-	if (length > size) {
-		rb_raise(rb_eRuntimeError, "Length exceeds size of buffer!");
-	}
-	
-	// Ensure offset is within the bounds of the buffer to avoid size_t underflow and out-of-bounds pointer arithmetic on (char *)base + offset.
-	if (offset > size) {
-		return rb_fiber_scheduler_io_result(-1, EINVAL);
-	}
-	
-	size_t maximum_size = size - offset;
+	size_t maximum_size = arguments->size;
 	while (maximum_size) {
-		ssize_t result = write(arguments->descriptor, (char*)base+offset, maximum_size);
+		ssize_t result = write(arguments->descriptor, (char*)arguments->base+total, maximum_size);
 		
 		if (result > 0) {
 			total += result;
-			offset += result;
 			if ((size_t)result >= length) break;
+			maximum_size -= result;
 			length -= result;
 		} else if (result == 0) {
 			break;
@@ -731,8 +724,6 @@ VALUE io_write_loop(VALUE _arguments) {
 		} else {
 			return rb_fiber_scheduler_io_result(-1, errno);
 		}
-		
-		maximum_size = size - offset;
 	}
 	
 	return rb_fiber_scheduler_io_result(total, 0);
@@ -748,11 +739,28 @@ VALUE io_write_ensure(VALUE _arguments) {
 };
 
 VALUE IO_Event_Selector_EPoll_io_write(VALUE self, VALUE fiber, VALUE io, VALUE buffer, VALUE _length, VALUE _offset) {
-	int descriptor = IO_Event_Selector_io_descriptor(io);
-	
 	size_t length = NUM2SIZET(_length);
 	size_t offset = NUM2SIZET(_offset);
 	
+	const void *base;
+	size_t size;
+	rb_io_buffer_get_bytes_for_reading(buffer, &base, &size);
+	
+	if (length > size) {
+		rb_raise(rb_eRuntimeError, "Length exceeds size of buffer!");
+	}
+	
+	if (offset > size) {
+		return rb_fiber_scheduler_io_result(-1, EINVAL);
+	} else if (offset == size) {
+		return rb_fiber_scheduler_io_result(0, 0);
+	}
+	
+	base = (const char*)base + offset;
+	size -= offset;
+	
+	int descriptor = IO_Event_Selector_io_descriptor(io);
+	
 	struct io_write_arguments io_write_arguments = {
 		.self = self,
 		.fiber = fiber,
@@ -760,9 +768,9 @@ VALUE IO_Event_Selector_EPoll_io_write(VALUE self, VALUE fiber, VALUE io, VALUE
 		
 		.flags = IO_Event_Selector_nonblock_set(descriptor),
 		.descriptor = descriptor,
-		.buffer = buffer,
+		.base = base,
+		.size = size,
 		.length = length,
-		.offset = offset,
 	};
 	
 	RB_OBJ_WRITTEN(self, Qundef, fiber);
diff --git a/ext/io/event/selector/kqueue.c b/ext/io/event/selector/kqueue.c
index cca0ec5c..eae21290 100644
--- a/ext/io/event/selector/kqueue.c
+++ b/ext/io/event/selector/kqueue.c
@@ -578,40 +578,33 @@ struct io_read_arguments {
 	
 	int descriptor;
 	
-	VALUE buffer;
+	// The remaining writable buffer region after applying the requested offset.
+	void *base;
+	size_t size;
+	
+	// The minimum number of bytes requested by the caller.
 	size_t length;
-	size_t offset;
 };
 
 static
 VALUE io_read_loop(VALUE _arguments) {
 	struct io_read_arguments *arguments = (struct io_read_arguments *)_arguments;
 	
-	void *base;
-	size_t size;
-	rb_io_buffer_get_bytes_for_writing(arguments->buffer, &base, &size);
-	
 	size_t length = arguments->length;
-	size_t offset = arguments->offset;
 	size_t total = 0;
 	
 	if (DEBUG_IO_READ) fprintf(stderr, "io_read_loop(fd=%d, length=%zu)\n", arguments->descriptor, length);
 	
-	// Ensure offset is within the bounds of the buffer to avoid size_t underflow and out-of-bounds pointer arithmetic on (char *)base + offset.
-	if (offset > size) {
-		return rb_fiber_scheduler_io_result(-1, EINVAL);
-	}
-	
-	size_t maximum_size = size - offset;
+	size_t maximum_size = arguments->size;
 	while (maximum_size) {
-		if (DEBUG_IO_READ) fprintf(stderr, "read(%d, +%ld, %ld)\n", arguments->descriptor, offset, maximum_size);
-		ssize_t result = read(arguments->descriptor, (char*)base+offset, maximum_size);
-		if (DEBUG_IO_READ) fprintf(stderr, "read(%d, +%ld, %ld) -> %zd\n", arguments->descriptor, offset, maximum_size, result);
+		if (DEBUG_IO_READ) fprintf(stderr, "read(%d, +%ld, %ld)\n", arguments->descriptor, total, maximum_size);
+		ssize_t result = read(arguments->descriptor, (char*)arguments->base+total, maximum_size);
+		if (DEBUG_IO_READ) fprintf(stderr, "read(%d, +%ld, %ld) -> %zd\n", arguments->descriptor, total, maximum_size, result);
 		
 		if (result > 0) {
 			total += result;
-			offset += result;
 			if ((size_t)result >= length) break;
+			maximum_size -= result;
 			length -= result;
 		} else if (result == 0) {
 			break;
@@ -622,11 +615,9 @@ VALUE io_read_loop(VALUE _arguments) {
 			if (DEBUG_IO_READ) fprintf(stderr, "io_read_loop(fd=%d, length=%zu) -> errno=%d\n", arguments->descriptor, length, errno);
 			return rb_fiber_scheduler_io_result(-1, errno);
 		}
-		
-		maximum_size = size - offset;
 	}
 	
-	if (DEBUG_IO_READ) fprintf(stderr, "io_read_loop(fd=%d, length=%zu) -> %zu\n", arguments->descriptor, length, offset);
+	if (DEBUG_IO_READ) fprintf(stderr, "io_read_loop(fd=%d, length=%zu) -> %zu\n", arguments->descriptor, length, total);
 	return rb_fiber_scheduler_io_result(total, 0);
 }
 
@@ -643,11 +634,24 @@ VALUE IO_Event_Selector_KQueue_io_read(VALUE self, VALUE fiber, VALUE io, VALUE
 	struct IO_Event_Selector_KQueue *selector = NULL;
 	TypedData_Get_Struct(self, struct IO_Event_Selector_KQueue, &IO_Event_Selector_KQueue_Type, selector);
 	
-	int descriptor = IO_Event_Selector_io_descriptor(io);
-	
 	size_t length = NUM2SIZET(_length);
 	size_t offset = NUM2SIZET(_offset);
 	
+	void *base;
+	size_t size;
+	rb_io_buffer_get_bytes_for_writing(buffer, &base, &size);
+	
+	if (offset > size) {
+		return rb_fiber_scheduler_io_result(-1, EINVAL);
+	} else if (offset == size) {
+		return rb_fiber_scheduler_io_result(0, 0);
+	}
+	
+	base = (char*)base + offset;
+	size -= offset;
+	
+	int descriptor = IO_Event_Selector_io_descriptor(io);
+	
 	struct io_read_arguments io_read_arguments = {
 		.self = self,
 		.fiber = fiber,
@@ -655,9 +659,9 @@ VALUE IO_Event_Selector_KQueue_io_read(VALUE self, VALUE fiber, VALUE io, VALUE
 		
 		.flags = IO_Event_Selector_nonblock_set(descriptor),
 		.descriptor = descriptor,
-		.buffer = buffer,
+		.base = base,
+		.size = size,
 		.length = length,
-		.offset = offset,
 	};
 	
 	RB_OBJ_WRITTEN(self, Qundef, fiber);
@@ -687,44 +691,33 @@ struct io_write_arguments {
 	
 	int descriptor;
 	
-	VALUE buffer;
+	// The remaining readable buffer region after applying the requested offset.
+	const void *base;
+	size_t size;
+	
+	// The minimum number of bytes requested by the caller.
 	size_t length;
-	size_t offset;
 };
 
 static
 VALUE io_write_loop(VALUE _arguments) {
 	struct io_write_arguments *arguments = (struct io_write_arguments *)_arguments;
 	
-	const void *base;
-	size_t size;
-	rb_io_buffer_get_bytes_for_reading(arguments->buffer, &base, &size);
-	
 	size_t length = arguments->length;
-	size_t offset = arguments->offset;
 	size_t total = 0;
 	
-	if (length > size) {
-		rb_raise(rb_eRuntimeError, "Length exceeds size of buffer!");
-	}
-	
 	if (DEBUG_IO_WRITE) fprintf(stderr, "io_write_loop(fd=%d, length=%zu)\n", arguments->descriptor, length);
 	
-	// Ensure offset is within the bounds of the buffer to avoid size_t underflow and out-of-bounds pointer arithmetic on (char *)base + offset.
-	if (offset > size) {
-		return rb_fiber_scheduler_io_result(-1, EINVAL);
-	}
-	
-	size_t maximum_size = size - offset;
+	size_t maximum_size = arguments->size;
 	while (maximum_size) {
-		if (DEBUG_IO_WRITE) fprintf(stderr, "write(%d, +%ld, %ld, length=%zu)\n", arguments->descriptor, offset, maximum_size, length);
-		ssize_t result = write(arguments->descriptor, (char*)base+offset, maximum_size);
-		if (DEBUG_IO_WRITE) fprintf(stderr, "write(%d, +%ld, %ld) -> %zd\n", arguments->descriptor, offset, maximum_size, result);
+		if (DEBUG_IO_WRITE) fprintf(stderr, "write(%d, +%ld, %ld, length=%zu)\n", arguments->descriptor, total, maximum_size, length);
+		ssize_t result = write(arguments->descriptor, (char*)arguments->base+total, maximum_size);
+		if (DEBUG_IO_WRITE) fprintf(stderr, "write(%d, +%ld, %ld) -> %zd\n", arguments->descriptor, total, maximum_size, result);
 		
 		if (result > 0) {
 			total += result;
-			offset += result;
 			if ((size_t)result >= length) break;
+			maximum_size -= result;
 			length -= result;
 		} else if (result == 0) {
 			break;
@@ -735,11 +728,9 @@ VALUE io_write_loop(VALUE _arguments) {
 			if (DEBUG_IO_WRITE) fprintf(stderr, "io_write_loop(fd=%d, length=%zu) -> errno=%d\n", arguments->descriptor, length, errno);
 			return rb_fiber_scheduler_io_result(-1, errno);
 		}
-		
-		maximum_size = size - offset;
 	}
 	
-	if (DEBUG_IO_WRITE) fprintf(stderr, "io_write_loop(fd=%d, length=%zu) -> %zu\n", arguments->descriptor, length, offset);
+	if (DEBUG_IO_WRITE) fprintf(stderr, "io_write_loop(fd=%d, length=%zu) -> %zu\n", arguments->descriptor, length, total);
 	return rb_fiber_scheduler_io_result(total, 0);
 };
 
@@ -756,11 +747,28 @@ VALUE IO_Event_Selector_KQueue_io_write(VALUE self, VALUE fiber, VALUE io, VALUE
 	struct IO_Event_Selector_KQueue *selector = NULL;
 	TypedData_Get_Struct(self, struct IO_Event_Selector_KQueue, &IO_Event_Selector_KQueue_Type, selector);
 	
-	int descriptor = IO_Event_Selector_io_descriptor(io);
-	
 	size_t length = NUM2SIZET(_length);
 	size_t offset = NUM2SIZET(_offset);
 	
+	const void *base;
+	size_t size;
+	rb_io_buffer_get_bytes_for_reading(buffer, &base, &size);
+	
+	if (length > size) {
+		rb_raise(rb_eRuntimeError, "Length exceeds size of buffer!");
+	}
+	
+	if (offset > size) {
+		return rb_fiber_scheduler_io_result(-1, EINVAL);
+	} else if (offset == size) {
+		return rb_fiber_scheduler_io_result(0, 0);
+	}
+	
+	base = (const char*)base + offset;
+	size -= offset;
+	
+	int descriptor = IO_Event_Selector_io_descriptor(io);
+	
 	struct io_write_arguments io_write_arguments = {
 		.self = self,
 		.fiber = fiber,
@@ -768,9 +776,9 @@ VALUE IO_Event_Selector_KQueue_io_write(VALUE self, VALUE fiber, VALUE io, VALUE
 		
 		.flags = IO_Event_Selector_nonblock_set(descriptor),
 		.descriptor = descriptor,
-		.buffer = buffer,
+		.base = base,
+		.size = size,
 		.length = length,
-		.offset = offset,
 	};
 	
 	RB_OBJ_WRITTEN(self, Qundef, fiber);
diff --git a/ext/io/event/selector/uring.c b/ext/io/event/selector/uring.c
index dca77f5b..28128776 100644
--- a/ext/io/event/selector/uring.c
+++ b/ext/io/event/selector/uring.c
@@ -757,8 +757,6 @@ VALUE IO_Event_Selector_URing_io_read(VALUE self, VALUE fiber, VALUE io, VALUE b
 	struct IO_Event_Selector_URing *selector = NULL;
 	TypedData_Get_Struct(self, struct IO_Event_Selector_URing, &IO_Event_Selector_URing_Type, selector);
 	
-	int descriptor = IO_Event_Selector_io_descriptor(io);
-	
 	void *base;
 	size_t size;
 	rb_io_buffer_get_bytes_for_writing(buffer, &base, &size);
@@ -766,13 +764,17 @@ VALUE IO_Event_Selector_URing_io_read(VALUE self, VALUE fiber, VALUE io, VALUE b
 	size_t length = NUM2SIZET(_length);
 	size_t offset = NUM2SIZET(_offset);
 	size_t total = 0;
-	off_t from = io_seekable(descriptor);
 	
 	// Ensure offset is within the bounds of the buffer to avoid size_t underflow and out-of-bounds pointer arithmetic on (char *)base + offset.
 	if (offset > size) {
 		return rb_fiber_scheduler_io_result(-1, EINVAL);
+	} else if (offset == size) {
+		return rb_fiber_scheduler_io_result(0, 0);
 	}
 	
+	int descriptor = IO_Event_Selector_io_descriptor(io);
+	off_t from = io_seekable(descriptor);
+	
 	size_t maximum_size = size - offset;
 	
 	// Are we performing a non-blocking read?
@@ -827,8 +829,6 @@ VALUE IO_Event_Selector_URing_io_pread(VALUE self, VALUE fiber, VALUE io, VALUE
 	struct IO_Event_Selector_URing *selector = NULL;
 	TypedData_Get_Struct(self, struct IO_Event_Selector_URing, &IO_Event_Selector_URing_Type, selector);
 	
-	int descriptor = IO_Event_Selector_io_descriptor(io);
-	
 	void *base;
 	size_t size;
 	rb_io_buffer_get_bytes_for_writing(buffer, &base, &size);
@@ -841,8 +841,12 @@ VALUE IO_Event_Selector_URing_io_pread(VALUE self, VALUE fiber, VALUE io, VALUE
 	// Ensure offset is within the bounds of the buffer to avoid size_t underflow and out-of-bounds pointer arithmetic on (char *)base + offset.
 	if (offset > size) {
 		return rb_fiber_scheduler_io_result(-1, EINVAL);
+	} else if (offset == size) {
+		return rb_fiber_scheduler_io_result(0, 0);
 	}
 	
+	int descriptor = IO_Event_Selector_io_descriptor(io);
+	
 	size_t maximum_size = size - offset;
 	while (maximum_size) {
 		int result = io_read(selector, fiber, descriptor, (char*)base+offset, maximum_size, from);
@@ -945,8 +949,6 @@ VALUE IO_Event_Selector_URing_io_write(VALUE self, VALUE fiber, VALUE io, VALUE
 	struct IO_Event_Selector_URing *selector = NULL;
 	TypedData_Get_Struct(self, struct IO_Event_Selector_URing, &IO_Event_Selector_URing_Type, selector);
 	
-	int descriptor = IO_Event_Selector_io_descriptor(io);
-	
 	const void *base;
 	size_t size;
 	rb_io_buffer_get_bytes_for_reading(buffer, &base, &size);
@@ -954,7 +956,6 @@ VALUE IO_Event_Selector_URing_io_write(VALUE self, VALUE fiber, VALUE io, VALUE
 	size_t length = NUM2SIZET(_length);
 	size_t offset = NUM2SIZET(_offset);
 	size_t total = 0;
-	off_t from = io_seekable(descriptor);
 	
 	if (length > size) {
 		rb_raise(rb_eRuntimeError, "Length exceeds size of buffer!");
@@ -963,8 +964,13 @@ VALUE IO_Event_Selector_URing_io_write(VALUE self, VALUE fiber, VALUE io, VALUE
 	// Ensure offset is within the bounds of the buffer to avoid size_t underflow and out-of-bounds pointer arithmetic on (char *)base + offset.
 	if (offset > size) {
 		return rb_fiber_scheduler_io_result(-1, EINVAL);
+	} else if (offset == size) {
+		return rb_fiber_scheduler_io_result(0, 0);
 	}
-
+	
+	int descriptor = IO_Event_Selector_io_descriptor(io);
+	off_t from = io_seekable(descriptor);
+	
 	size_t maximum_size = size - offset;
 	while (maximum_size) {
 		int result = io_write(selector, fiber, descriptor, (char*)base+offset, maximum_size, from);
@@ -1005,8 +1011,6 @@ VALUE IO_Event_Selector_URing_io_pwrite(VALUE self, VALUE fiber, VALUE io, VALUE
 	struct IO_Event_Selector_URing *selector = NULL;
 	TypedData_Get_Struct(self, struct IO_Event_Selector_URing, &IO_Event_Selector_URing_Type, selector);
 	
-	int descriptor = IO_Event_Selector_io_descriptor(io);
-	
 	const void *base;
 	size_t size;
 	rb_io_buffer_get_bytes_for_reading(buffer, &base, &size);
@@ -1023,8 +1027,12 @@ VALUE IO_Event_Selector_URing_io_pwrite(VALUE self, VALUE fiber, VALUE io, VALUE
 	// Ensure offset is within the bounds of the buffer to avoid size_t underflow and out-of-bounds pointer arithmetic on (char *)base + offset.
 	if (offset > size) {
 		return rb_fiber_scheduler_io_result(-1, EINVAL);
+	} else if (offset == size) {
+		return rb_fiber_scheduler_io_result(0, 0);
 	}
-
+	
+	int descriptor = IO_Event_Selector_io_descriptor(io);
+	
 	size_t maximum_size = size - offset;
 	while (maximum_size) {
 		int result = io_write(selector, fiber, descriptor, (char*)base+offset, maximum_size, from);
diff --git a/lib/io/event/selector/select.rb b/lib/io/event/selector/select.rb
index 5968f35a..e9a14213 100644
--- a/lib/io/event/selector/select.rb
+++ b/lib/io/event/selector/select.rb
@@ -199,6 +199,8 @@ def io_read(fiber, io, buffer, length, offset = 0)
 				# Ensure offset is within the bounds of the buffer to avoid ArgumentError
 				if offset > buffer.size
 					return -Errno::EINVAL::Errno
+				elsif offset == buffer.size
+					return 0
 				end
 				
 				total = 0
@@ -234,6 +236,8 @@ def io_write(fiber, io, buffer, length, offset = 0)
 				# Ensure offset is within the bounds of the buffer to avoid ArgumentError
 				if offset > buffer.size
 					return -Errno::EINVAL::Errno
+				elsif offset == buffer.size
+					return 0
 				end
 				
 				total = 0
diff --git a/test/io/event/selector/buffered_io.rb b/test/io/event/selector/buffered_io.rb
index e948c66b..fa5d7c64 100644
--- a/test/io/event/selector/buffered_io.rb
+++ b/test/io/event/selector/buffered_io.rb
@@ -133,6 +133,19 @@ def be_again?
 			selector.select(0)
 		end
 		
+		it "returns zero when read offset equals buffer size" do
+			input.close
+			buffer = IO::Buffer.new(64)
+			
+			reader = Fiber.new do
+				result = selector.io_read(Fiber.current, input, buffer, 1, 64)
+				expect(result).to be == 0
+			end
+			
+			reader.transfer
+			selector.select(0)
+		end
+		
 		it "returns EINVAL when write offset exceeds buffer size" do
 			skip_if_ruby_platform(/mswin|mingw|cygwin/)
 			
@@ -147,6 +160,19 @@ def be_again?
 			writer.transfer
 			selector.select(0)
 		end
+		
+		it "returns zero when write offset equals buffer size" do
+			output.close
+			buffer = IO::Buffer.new(64)
+			
+			writer = Fiber.new do
+				result = selector.io_write(Fiber.current, output, buffer, 1, 64)
+				expect(result).to be == 0
+			end
+			
+			writer.transfer
+			selector.select(0)
+		end
 	end
 end