/****************************************************************************
* include/nuttx/wqueue.h
*
* Copyright (C) 2009, 2011-2012 Gregory Nutt. All rights reserved.
* Author: Gregory Nutt <gnutt@nuttx.org>
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
* 3. Neither the name NuttX nor the names of its contributors may be
* used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*
****************************************************************************/
#ifndef __INCLUDE_NUTTX_WQUEUE_H
#define __INCLUDE_NUTTX_WQUEUE_H
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/config.h>
#include <sys/types.h>
#include <stdint.h>
#include <signal.h>
#include <queue.h>
/****************************************************************************
* Pre-Processor Definitions
****************************************************************************/
/* Configuration ************************************************************/
/* CONFIG_SCHED_WORKQUEUE. Create a dedicated "worker" thread to
* handle delayed processing from interrupt handlers. This feature
* is required for some drivers but, if there are not complaints,
* can be safely disabled. The worker thread also performs
* garbage collection -- completing any delayed memory deallocations
* from interrupt handlers. If the worker thread is disabled,
* then that clean will be performed by the IDLE thread instead
* (which runs at the lowest of priority and may not be appropriate
* if memory reclamation is of high priority). If CONFIG_SCHED_WORKQUEUE
* is enabled, then the following options can also be used:
* CONFIG_SCHED_WORKPRIORITY - The execution priority of the worker
* thread. Default: 192
* CONFIG_SCHED_WORKPERIOD - How often the worker thread checks for
* work in units of microseconds. Default: 50*1000 (50 MS).
* CONFIG_SCHED_WORKSTACKSIZE - The stack size allocated for the worker
* thread. Default: CONFIG_IDLETHREAD_STACKSIZE.
* CONFIG_SIG_SIGWORK - The signal number that will be used to wake-up
* the worker thread. Default: 4
*
* CONFIG_SCHED_LPWORK. If CONFIG_SCHED_WORKQUEUE is defined, then a single
* work queue is created by default. If CONFIG_SCHED_LPWORK is also defined
* then an additional, lower-priority work queue will also be created. This
* lower priority work queue is better suited for more extended processing
* (such as file system clean-up operations)
* CONFIG_SCHED_LPWORKPRIORITY - The execution priority of the lower priority
* worker thread. Default: 50
* CONFIG_SCHED_LPWORKPERIOD - How often the lower priority worker thread
* checks for work in units of microseconds. Default: 50*1000 (50 MS).
* CONFIG_SCHED_LPWORKSTACKSIZE - The stack size allocated for the lower
* priority worker thread. Default: CONFIG_IDLETHREAD_STACKSIZE.
*/
#ifndef CONFIG_SCHED_WORKPRIORITY
# define CONFIG_SCHED_WORKPRIORITY 192
#endif
#ifndef CONFIG_SCHED_WORKPERIOD
# define CONFIG_SCHED_WORKPERIOD (50*1000) /* 50 milliseconds */
#endif
#ifndef CONFIG_SCHED_WORKSTACKSIZE
# define CONFIG_SCHED_WORKSTACKSIZE CONFIG_IDLETHREAD_STACKSIZE
#endif
#ifdef CONFIG_SCHED_LPWORK
# ifndef CONFIG_SCHED_LPWORKPRIORITY
# define CONFIG_SCHED_LPWORKPRIORITY 50
# endif
# ifndef CONFIG_SCHED_LPWORKPERIOD
# define CONFIG_SCHED_LPWORKPERIOD (50*1000) /* 50 milliseconds */
# endif
# ifndef CONFIG_SCHED_LPWORKSTACKSIZE
# define CONFIG_SCHED_LPWORKSTACKSIZE CONFIG_IDLETHREAD_STACKSIZE
# endif
#endif
/* Work queue IDs (indices). These are both zero if there is only one work
* queue.
*/
#define HPWORK 0
#ifdef CONFIG_SCHED_LPWORK
# define LPWORK 1
#else
# define LPWORK HPWORK
#endif
/****************************************************************************
* Public Types
****************************************************************************/
#ifndef __ASSEMBLY__
/* Defines the work callback */
typedef void (*worker_t)(FAR void *arg);
/* Defines one entry in the work queue. The user only needs this structure
* in order to declare instances of the work structure. Handling of all
* fields is performed by the work APIs
*/
struct work_s
{
struct dq_entry_s dq; /* Implements a doubly linked list */
worker_t worker; /* Work callback */
FAR void *arg; /* Callback argument */
uint32_t qtime; /* Time work queued */
uint32_t delay; /* Delay until work performed */
};
/****************************************************************************
* Public Data
****************************************************************************/
#ifdef __cplusplus
#define EXTERN extern "C"
extern "C" {
#else
#define EXTERN extern
#endif
/****************************************************************************
* Public Function Prototypes
****************************************************************************/
/****************************************************************************
* Name: work_queue
*
* Description:
* Queue work to be performed at a later time. All queued work will be
* performed on the worker thread of of execution (not the caller's).
*
* The work structure is allocated by caller, but completely managed by
* the work queue logic. The caller should never modify the contents of
* the work queue structure; the caller should not call work_queue()
* again until either (1) the previous work has been performed and removed
* from the queue, or (2) work_cancel() has been called to cancel the work
* and remove it from the work queue.
*
* Input parameters:
* qid - The work queue ID
* work - The work structure to queue
* worker - The worker callback to be invoked. The callback will invoked
* on the worker thread of execution.
* arg - The argument that will be passed to the workder callback when
* int is invoked.
* delay - Delay (in clock ticks) from the time queue until the worker
* is invoked. Zero means to perform the work immediately.
*
* Returned Value:
* Zero on success, a negated errno on failure
*
****************************************************************************/
EXTERN int work_queue(int qid, FAR struct work_s *work, worker_t worker,
FAR void *arg, uint32_t delay);
/****************************************************************************
* Name: work_cancel
*
* Description:
* Cancel previously queued work. This removes work from the work queue.
* After work has been canceled, it may be re-queue by calling work_queue()
* again.
*
* Input parameters:
* qid - The work queue ID
* work - The previously queue work structure to cancel
*
* Returned Value:
* Zero on success, a negated errno on failure
*
****************************************************************************/
EXTERN int work_cancel(int qid, FAR struct work_s *work);
/****************************************************************************
* Name: work_signal
*
* Description:
* Signal the worker thread to process the work queue now. This function
* is used internally by the work logic but could also be used by the
* user to force an immediate re-assessment of pending work.
*
* Input parameters:
* qid - The work queue ID
*
* Returned Value:
* Zero on success, a negated errno on failure
*
****************************************************************************/
EXTERN int work_signal(int qid);
/****************************************************************************
* Name: work_available
*
* Description:
* Check if the work structure is available.
*
* Input parameters:
* None
*
* Returned Value:
* true if available; false if busy (i.e., there is still pending work).
*
****************************************************************************/
#define work_available(work) ((work)->worker == NULL)
#undef EXTERN
#ifdef __cplusplus
}
#endif
#endif /* __ASSEMBLY__ */
#endif /* __INCLUDE_NUTTX_WQUEUE_H */
