libxnvme_queue.h#

Enums#

xnvme_queue_opts#

enum xnvme_queue_opts#

Command Queue initialization options.

Values:

enumerator XNVME_QUEUE_IOPOLL#

XNVME_QUEUE_IOPOLL: queue. is polled for completions.

enumerator XNVME_QUEUE_SQPOLL#

XNVME_QUEUE_SQPOLL: queue. is polled for submissions.

Functions#

xnvme_queue_drain#

int xnvme_queue_drain(struct xnvme_queue *queue)#

Process outstanding commands on the given xnvme_queue until it is empty.

Parameters:

  • queue – Pointer to the xnvme_queue to wait/process commands on

Returns:

On success, number of commands processed, may be 0. On error, negative errno is returned.

xnvme_queue_get_capacity#

uint32_t xnvme_queue_get_capacity(struct xnvme_queue *queue)#

Get the capacity of the given xnvme_queue.

Parameters:

  • queue – Pointer to the xnvme_queue to query for capacity

Returns:

On success, capacity of given xnvme_queue text is returned. On error, 0 is returned e.g. errors are silent

xnvme_queue_get_cmd_ctx#

struct xnvme_cmd_ctx *xnvme_queue_get_cmd_ctx(struct xnvme_queue *queue)#

Retrieve a command-context from the given queue for async.

command execution with the queue

Note

The command-context is managed by the queue, thus, return it to the queue via xnvme_queue_put_cmd_ctx

Note

This is not thread-safe

Parameters:

  • queue – Pointer to the xnvme_queue to retrieve a command-context for

Returns:

On success, a command-context is returned. On error, NULL is returned and errno is set to indicate the error.

xnvme_queue_get_completion_fd#

int xnvme_queue_get_completion_fd(struct xnvme_queue *queue)#

Get the completion event fd on the given xnvme_queue.

Parameters:

  • queue – Pointer to the xnvme_queue to query for outstanding commands

Returns:

On success, an eventfd() file descriptor is returned. On error, negative errno is returned.

xnvme_queue_get_outstanding#

uint32_t xnvme_queue_get_outstanding(struct xnvme_queue *queue)#

Get the number of outstanding commands on the given xnvme_queue.

Parameters:

  • queue – Pointer to the xnvme_queue to query for outstanding commands

Returns:

On success, number of outstanding commands are returned. On error, 0 is returned e.g. errors are silent

xnvme_queue_init#

int xnvme_queue_init(struct xnvme_dev *dev, uint16_t capacity, int opts, struct xnvme_queue **queue)#

Allocate a Command Queue for asynchronous command submission and completion.

Parameters:

  • dev – Device handle (xnvme_dev) obtained with xnvme_dev_open()

  • capacity – Maximum number of outstanding commands on the initialized queue, note that it must be a power of 2 within the range [1,4096]

  • opts – Queue options

  • queue – Pointer-pointer to the xnvme_queue to initialize

Returns:

On success, 0 is returned. On error, negative errno is returned.

xnvme_queue_poke#

int xnvme_queue_poke(struct xnvme_queue *queue, uint32_t max)#

Process completions of commands on the given xnvme_queue.

Set process ‘max’ to limit number of completions, 0 means no max.

Parameters:

  • queue – Pointer to the xnvme_queue to poke for completions

  • max – The max number of completions to complete

Returns:

On success, number of completions processed, may be 0. On error, negative errno is returned.

xnvme_queue_put_cmd_ctx#

int xnvme_queue_put_cmd_ctx(struct xnvme_queue *queue, struct xnvme_cmd_ctx *ctx)#

Hand back a command-context previously retrieve using xnvme_queue_get_cmd_ctx.

Note

This function is not thread-safe

Parameters:

  • queue – Pointer to the xnvme_queue to hand back the command-context to

  • ctx – Pointer to command context (xnvme_cmd_ctx)

Returns:

On success, 0 is returned. On error, negative errno is returned.

xnvme_queue_set_cb#

int xnvme_queue_set_cb(struct xnvme_queue *queue, xnvme_queue_cb cb, void *cb_arg)#

Assign a callback-function and argument to be used with the xnvme_cmd_ctx of the queue.

Parameters:

  • queue – The xnvme_queue to assign default callback function for

  • cb – The callback function to use

  • cb_arg – The callback argument to use

Returns:

On success, 0 is returned. On error, negative errno is returned.

xnvme_queue_term#

int xnvme_queue_term(struct xnvme_queue *queue)#

Tear down the given xnvme_queue.

Parameters:

  • queue – Pointer to the xnvme_queue to tear down

Returns:

On success, 0 is returned. On error, negative errno is returned.

xnvme_queue_wait#

int xnvme_queue_wait(struct xnvme_queue *queue)#

DEPRECATED: expect that this function will be removed in an upcoming release.

Parameters:

  • queue – Pointer to the xnvme_queue to wait/process commands on

Returns:

On success, number of commands processed, may be 0. On error, negative errno is returned.

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