io/uring: basic Linux io_uring support

2020-05-05 14:28:15 +02:00
parent 935e622915
commit 62d0ceabcc
11 changed files with 638 additions and 0 deletions
--- a/src/io/uring/Queue.cxx
+++ b/src/io/uring/Queue.cxx
@@ -0,0 +1,97 @@
+/*
+ * Copyright 2020 CM4all GmbH
+ * All rights reserved.
+ *
+ * author: Max Kellermann <mk@cm4all.com>
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * - Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *
+ * - Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the
+ * distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE
+ * FOUNDATION OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+ * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
+ * OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include "Queue.hxx"
+#include "CancellableOperation.hxx"
+#include "Operation.hxx"
+#include "util/DeleteDisposer.hxx"
+
+#include <cassert>
+
+namespace Uring {
+
+Queue::Queue(unsigned entries, unsigned flags)
+	:ring(entries, flags)
+{
+}
+
+Queue::~Queue() noexcept
+{
+	operations.clear_and_dispose(DeleteDisposer{});
+}
+
+void
+Queue::AddPending(struct io_uring_sqe &sqe,
+		  Operation &operation) noexcept
+{
+	auto *c = new CancellableOperation(operation);
+	operations.push_back(*c);
+	io_uring_sqe_set_data(&sqe, c);
+}
+
+void
+Queue::DispatchOneCompletion(struct io_uring_cqe &cqe) noexcept
+{
+	void *data = io_uring_cqe_get_data(&cqe);
+	if (data != nullptr) {
+		auto *c = (CancellableOperation *)data;
+		c->OnUringCompletion(cqe.res);
+		operations.erase_and_dispose(operations.iterator_to(*c),
+					     DeleteDisposer{});
+	}
+
+	ring.SeenCompletion(cqe);
+}
+
+bool
+Queue::DispatchOneCompletion()
+{
+	auto *cqe = ring.PeekCompletion();
+	if (cqe == nullptr)
+		return false;
+
+	DispatchOneCompletion(*cqe);
+	return true;
+}
+
+bool
+Queue::WaitDispatchOneCompletion()
+{
+	auto *cqe = ring.WaitCompletion();
+	if (cqe == nullptr)
+		return false;
+
+	DispatchOneCompletion(*cqe);
+	return true;
+}
+
+} // namespace Uring