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/*
* Declarations for long-running block device operations
*
* Copyright (c) 2011 IBM Corp.
* Copyright (c) 2012 Red Hat, Inc.
*
* 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 BLOCKJOB_H
#define BLOCKJOB_H 1
#include "block.h"
/**
* BlockJobType:
*
* A class type for block job objects.
*/
typedef struct BlockJobType {
/** Derived BlockJob struct size */
size_t instance_size;
/** String describing the operation, part of query-block-jobs QMP API */
const char *job_type;
/** Optional callback for job types that support setting a speed limit */
void (*set_speed)(BlockJob *job, int64_t speed, Error **errp);
} BlockJobType;
/**
* BlockJob:
*
* Long-running operation on a BlockDriverState.
*/
struct BlockJob {
/** The job type, including the job vtable. */
const BlockJobType *job_type;
/** The block device on which the job is operating. */
BlockDriverState *bs;
/**
* The coroutine that executes the job. If not NULL, it is
* reentered when busy is false and the job is cancelled.
*/
Coroutine *co;
/**
* Set to true if the job should cancel itself. The flag must
* always be tested just before toggling the busy flag from false
* to true. After a job has been cancelled, it should only yield
* if #qemu_aio_wait will ("sooner or later") reenter the coroutine.
*/
bool cancelled;
/**
* Set to false by the job while it is in a quiescent state, where
* no I/O is pending and the job has yielded on any condition
* that is not detected by #qemu_aio_wait, such as a timer.
*/
bool busy;
/** Offset that is published by the query-block-jobs QMP API */
int64_t offset;
/** Length that is published by the query-block-jobs QMP API */
int64_t len;
/** Speed that was set with @block_job_set_speed. */
int64_t speed;
/** The completion function that will be called when the job completes. */
BlockDriverCompletionFunc *cb;
/** The opaque value that is passed to the completion function. */
void *opaque;
};
/**
* block_job_create:
* @job_type: The class object for the newly-created job.
* @bs: The block
* @speed: The maximum speed, in bytes per second, or 0 for unlimited.
* @cb: Completion function for the job.
* @opaque: Opaque pointer value passed to @cb.
* @errp: Error object.
*
* Create a new long-running block device job and return it. The job
* will call @cb asynchronously when the job completes. Note that
* @bs may have been closed at the time the @cb it is called. If
* this is the case, the job may be reported as either cancelled or
* completed.
*
* This function is not part of the public job interface; it should be
* called from a wrapper that is specific to the job type.
*/
void *block_job_create(const BlockJobType *job_type, BlockDriverState *bs,
int64_t speed, BlockDriverCompletionFunc *cb,
void *opaque, Error **errp);
/**
* block_job_sleep_ns:
* @job: The job that calls the function.
* @clock: The clock to sleep on.
* @ns: How many nanoseconds to stop for.
*
* Put the job to sleep (assuming that it wasn't canceled) for @ns
* nanoseconds. Canceling the job will interrupt the wait immediately.
*/
void block_job_sleep_ns(BlockJob *job, QEMUClock *clock, int64_t ns);
/**
* block_job_complete:
* @job: The job being completed.
* @ret: The status code.
*
* Call the completion function that was registered at creation time, and
* free @job.
*/
void block_job_complete(BlockJob *job, int ret);
/**
* block_job_set_speed:
* @job: The job to set the speed for.
* @speed: The new value
* @errp: Error object.
*
* Set a rate-limiting parameter for the job; the actual meaning may
* vary depending on the job type.
*/
void block_job_set_speed(BlockJob *job, int64_t speed, Error **errp);
/**
* block_job_cancel:
* @job: The job to be canceled.
*
* Asynchronously cancel the specified job.
*/
void block_job_cancel(BlockJob *job);
/**
* block_job_is_cancelled:
* @job: The job being queried.
*
* Returns whether the job is scheduled for cancellation.
*/
bool block_job_is_cancelled(BlockJob *job);
/**
* block_job_cancel_sync:
* @job: The job to be canceled.
*
* Synchronously cancel the job. The completion callback is called
* before the function returns. The job may actually complete
* instead of canceling itself; the circumstances under which this
* happens depend on the kind of job that is active.
*
* Returns the return value from the job if the job actually completed
* during the call, or -ECANCELED if it was canceled.
*/
int block_job_cancel_sync(BlockJob *job);
#endif
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