mirror of
https://github.com/xemu-project/xemu.git
synced 2024-11-23 19:49:43 +00:00
0c330a734b
aio_co_wake provides the infrastructure to start a coroutine on a "home" AioContext. It will be used by CoMutex and CoQueue, so that coroutines don't jump from one context to another when they go to sleep on a mutex or waitqueue. However, it can also be used as a more efficient alternative to one-shot bottom halves, and saves the effort of tracking which AioContext a coroutine is running on. aio_co_schedule is the part of aio_co_wake that starts a coroutine on a remove AioContext, but it is also useful to implement e.g. bdrv_set_aio_context callbacks. The implementation of aio_co_schedule is based on a lock-free multiple-producer, single-consumer queue. The multiple producers use cmpxchg to add to a LIFO stack. The consumer (a per-AioContext bottom half) grabs all items added so far, inverts the list to make it FIFO, and goes through it one item at a time until it's empty. The data structure was inspired by OSv, which uses it in the very code we'll "port" to QEMU for the thread-safe CoMutex. Most of the new code is really tests. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Fam Zheng <famz@redhat.com> Message-id: 20170213135235.12274-3-pbonzini@redhat.com Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
26 lines
603 B
C
26 lines
603 B
C
/*
|
|
* Event loop thread implementation for unit tests
|
|
*
|
|
* Copyright Red Hat Inc., 2013, 2016
|
|
*
|
|
* Authors:
|
|
* Stefan Hajnoczi <stefanha@redhat.com>
|
|
* Paolo Bonzini <pbonzini@redhat.com>
|
|
*
|
|
* This work is licensed under the terms of the GNU GPL, version 2 or later.
|
|
* See the COPYING file in the top-level directory.
|
|
*/
|
|
#ifndef TEST_IOTHREAD_H
|
|
#define TEST_IOTHREAD_H
|
|
|
|
#include "block/aio.h"
|
|
#include "qemu/thread.h"
|
|
|
|
typedef struct IOThread IOThread;
|
|
|
|
IOThread *iothread_new(void);
|
|
void iothread_join(IOThread *iothread);
|
|
AioContext *iothread_get_aio_context(IOThread *iothread);
|
|
|
|
#endif
|