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Diffstat (limited to 'lib/workqueue.h')
| -rw-r--r-- | lib/workqueue.h | 169 |
1 files changed, 169 insertions, 0 deletions
diff --git a/lib/workqueue.h b/lib/workqueue.h new file mode 100644 index 0000000..5d84739 --- /dev/null +++ b/lib/workqueue.h @@ -0,0 +1,169 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Quagga Work Queues. + * + * Copyright (C) 2005 Sun Microsystems, Inc. + */ + +#ifndef _QUAGGA_WORK_QUEUE_H +#define _QUAGGA_WORK_QUEUE_H + +#include "memory.h" +#include "queue.h" + +#ifdef __cplusplus +extern "C" { +#endif + +DECLARE_MTYPE(WORK_QUEUE); + +/* Hold time for the initial schedule of a queue run, in millisec */ +#define WORK_QUEUE_DEFAULT_HOLD 50 + +/* Retry for queue that is 'blocked' or 'retry later' */ +#define WORK_QUEUE_DEFAULT_RETRY 0 + +/* action value, for use by item processor and item error handlers */ +typedef enum { + WQ_SUCCESS = 0, + WQ_RETRY_NOW, /* retry immediately */ + WQ_RETRY_LATER, /* retry later, cease processing work queue */ + WQ_REQUEUE, /* requeue item, continue processing work queue */ + WQ_QUEUE_BLOCKED, /* Queue cant be processed at this time. + * Similar to WQ_RETRY_LATER, but doesn't penalise + * the particular item.. */ +} wq_item_status; + +/* A single work queue item, unsurprisingly */ +struct work_queue_item { + STAILQ_ENTRY(work_queue_item) wq; + void *data; /* opaque data */ + unsigned short ran; /* # of times item has been run */ +}; + +#define WQ_UNPLUGGED (1 << 0) /* available for draining */ + +struct work_queue { + /* Everything but the specification struct is private + * the following may be read + */ + struct event_loop *master; /* thread master */ + struct event *thread; /* thread, if one is active */ + char *name; /* work queue name */ + + /* Specification for this work queue. + * Public, must be set before use by caller. May be modified at will. + */ + struct { + /* optional opaque user data, global to the queue. */ + void *data; + + /* work function to process items with: + * First argument is the workqueue queue. + * Second argument is the item data + */ + wq_item_status (*workfunc)(struct work_queue *, void *); + + /* callback to delete user specific item data */ + void (*del_item_data)(struct work_queue *, void *); + + /* completion callback, called when queue is emptied, optional + */ + void (*completion_func)(struct work_queue *); + + /* max number of retries to make for item that errors */ + unsigned int max_retries; + + unsigned int hold; /* hold time for first run, in ms */ + + unsigned long + yield; /* yield time in us for associated thread */ + + uint32_t retry; /* Optional retry timeout if queue is blocked */ + } spec; + + /* remaining fields should be opaque to users */ + STAILQ_HEAD(work_queue_items, work_queue_item) + items; /* queue item list */ + int item_count; /* queued items */ + unsigned long runs; /* runs count */ + unsigned long yields; /* yields count */ + + struct { + unsigned int best; + unsigned int granularity; + unsigned long total; + } cycles; /* cycle counts */ + + /* private state */ + uint16_t flags; /* user set flag */ +}; + +/* User API */ + +static inline int work_queue_item_count(struct work_queue *wq) +{ + return wq->item_count; +} + +static inline bool work_queue_empty(struct work_queue *wq) +{ + return (wq->item_count == 0) ? true : false; +} + +static inline struct work_queue_item * +work_queue_last_item(struct work_queue *wq) +{ + return STAILQ_LAST(&wq->items, work_queue_item, wq); +} + +static inline void work_queue_item_enqueue(struct work_queue *wq, + struct work_queue_item *item) +{ + STAILQ_INSERT_TAIL(&wq->items, item, wq); + wq->item_count++; +} + +static inline void work_queue_item_dequeue(struct work_queue *wq, + struct work_queue_item *item) +{ + assert(wq->item_count > 0); + + wq->item_count--; + STAILQ_REMOVE(&wq->items, item, work_queue_item, wq); +} + +/* create a new work queue, of given name. + * user must fill in the spec of the returned work queue before adding + * anything to it + */ +extern struct work_queue *work_queue_new(struct event_loop *m, + const char *queue_name); + +/* destroy work queue */ +/* + * The usage of work_queue_free is being transitioned to pass + * in the double pointer to remove use after free's. + */ +extern void work_queue_free_and_null(struct work_queue **wqp); + +/* Add the supplied data as an item onto the workqueue */ +extern void work_queue_add(struct work_queue *wq, void *item); + +/* plug the queue, ie prevent it from being drained / processed */ +extern void work_queue_plug(struct work_queue *wq); +/* unplug the queue, allow it to be drained again */ +extern void work_queue_unplug(struct work_queue *wq); + +bool work_queue_is_scheduled(struct work_queue *wq); + +/* Helpers, exported for thread.c and command.c */ +extern void work_queue_run(struct event *thread); + +extern void workqueue_cmd_init(void); + +#ifdef __cplusplus +} +#endif + +#endif /* _QUAGGA_WORK_QUEUE_H */ |