block: introduce aio task pool

Common interface for aio task loops. To be used for improving
performance of synchronous io loops in qcow2, block-stream,
copy-on-read, and may be other places.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-id: 20190916175324.18478-3-vsementsov@virtuozzo.com
Signed-off-by: Max Reitz <mreitz@redhat.com>

1 files changed, 54 insertions, 0 deletions

diff --git a/include/block/aio_task.h b/include/block/aio_task.h
new file mode 100644
index 0000000000..50bc1e1817
--- /dev/null
+++ b/include/block/aio_task.h
@@ -0,0 +1,54 @@
+/*
+ * Aio tasks loops
+ *
+ * Copyright (c) 2019 Virtuozzo International GmbH.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#ifndef BLOCK_AIO_TASK_H
+#define BLOCK_AIO_TASK_H
+
+#include "qemu/coroutine.h"
+
+typedef struct AioTaskPool AioTaskPool;
+typedef struct AioTask AioTask;
+typedef int coroutine_fn (*AioTaskFunc)(AioTask *task);
+struct AioTask {
+    AioTaskPool *pool;
+    AioTaskFunc func;
+    int ret;
+};
+
+AioTaskPool *coroutine_fn aio_task_pool_new(int max_busy_tasks);
+void aio_task_pool_free(AioTaskPool *);
+
+/* error code of failed task or 0 if all is OK */
+int aio_task_pool_status(AioTaskPool *pool);
+
+bool aio_task_pool_empty(AioTaskPool *pool);
+
+/* User provides filled @task, however task->pool will be set automatically */
+void coroutine_fn aio_task_pool_start_task(AioTaskPool *pool, AioTask *task);
+
+void coroutine_fn aio_task_pool_wait_slot(AioTaskPool *pool);
+void coroutine_fn aio_task_pool_wait_one(AioTaskPool *pool);
+void coroutine_fn aio_task_pool_wait_all(AioTaskPool *pool);
+
+#endif /* BLOCK_AIO_TASK_H */