/****************************************************************************
* include/nuttx/wqueue.h
*
* Copyright (C) 2009, 2011-2013 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_HPWORK - Build the high priority work queue. To preserve
* legacy behavior, CONFIG_SCHED_HPWORK is assumed to be true in a flat
* build (CONFIG_SCHED_KERNEL=n) but must be defined in kernel mode
* in order to build the high priority work queue.
* 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: 17
*
* 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.
*/
/* Is this a protected build (CONFIG_BUILD_PROTECTED=y) */
#if defined(CONFIG_BUILD_PROTECTED)
/* Yes.. kernel worker threads are not built in a kernel build when we are
* building the user-space libraries.
*/
# ifndef __KERNEL__
# undef CONFIG_SCHED_HPWORK
# undef CONFIG_SCHED_LPWORK
# ifndef CONFIG_SCHED_USRWORK
# undef CONFIG_SCHED_WORKQUEUE
# endif
/* User-space worker threads are not built in a kernel build when we are
* building the kernel-space libraries (but we still need to know that it
* is configured).
*/
# endif
#elif defined(CONFIG_BUILD_KERNEL)
/* The kernel only build is equivalent to the kernel part of the protected
* build.
*/
#else
/* User-space worker threads are not built in a flat build
* (CONFIG_BUILD_PROTECTED=n && CONFIG_BUILD_KERNEL=n)
*/
#else
/* To preserve legacy behavior, CONFIG_SCHED_HPWORK is assumed to be true
* in a flat build (CONFIG_SCHED_KERNEL=n) but must be defined in kernel
* mode in order to build the high priority work queue.
*
* In the kernel build, it is possible that no kernel work queues will be
* built. But in the flat build, the high priority work queue will always
* be built.
*/
# undef CONFIG_SCHED_HPWORK
# undef CONFIG_SCHED_USRWORK
# define CONFIG_SCHED_HPWORK 1
#endif
/* We never build the low priority work queue without building the high
* priority work queue.
*/
#if defined(CONFIG_SCHED_LPWORK) && !defined(CONFIG_SCHED_HPWORK)
# error "CONFIG_SCHED_LPWORK defined, but CONFIG_SCHED_HPWORK not defined"
# undef CONFIG_SCHED_LPWORK
#endif
#ifdef CONFIG_SCHED_WORKQUEUE
/* We are building work queues... Work queues need signal support */
#ifdef CONFIG_DISABLE_SIGNALS
# warning "Worker thread support requires signals"
#endif
/* High priority, kernel work queue configuration ***************************/
#ifdef CONFIG_SCHED_HPWORK
# 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
/* Low priority kernel work queue configuration *****************************/
#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
/* The high priority worker thread should be higher priority than the low
* priority worker thread.
*/
#if CONFIG_SCHED_LPWORKPRIORITY > CONFIG_SCHED_WORKPRIORITY
# warning "The Lower priority worker thread has the higher priority"
#endif
#endif /* CONFIG_SCHED_LPWORK */
#endif /* CONFIG_SCHED_HPWORK */
/* User space work queue configuration **************************************/
#ifdef CONFIG_SCHED_USRWORK
# ifndef CONFIG_SCHED_USRWORKPRIORITY
# define CONFIG_SCHED_USRWORKPRIORITY 50
# endif
# ifndef CONFIG_SCHED_USRWORKPERIOD
# define CONFIG_SCHED_USRWORKPERIOD (50*1000) /* 50 milliseconds */
# endif
# ifndef CONFIG_SCHED_USRWORKSTACKSIZE
# define CONFIG_SCHED_USRWORKSTACKSIZE CONFIG_IDLETHREAD_STACKSIZE
# endif
#endif /* CONFIG_SCHED_USRWORK */
/* How many worker threads are there? In the user-space phase of a kernel
* build, there will be no more than one.
*
* Work queue IDs (indices):
*
* Kernel Work Queues: There are none and any attempts to use them
* should generate errors.
*
* User Work Queue: Will be available if CONFIG_SCHED_USRWORK is defined
*/
#if defined(CONFIG_BUILD_PROTECTED) && !defined(__KERNEL__)
# ifdef CONFIG_SCHED_USRWORK
# define NWORKERS 1
# define USRWORK 0
# endif
#else
/* In a flat build (CONFIG_BUILD_PROTECTED=n) or during the kernel phase of
* the kernel build, there may be 0, 1, or 2 work queues.
*
* Work queue IDs (indices):
*
* Kernel Work Queues:
* HPWORK: This ID of the high priority work queue that should only be
* used for hi-priority, time-critical, driver bottom-half functions.
*
* LPWORK: This is the ID of the low priority work queue that can be
* used for any purpose. if CONFIG_SCHED_LPWORK is not defined, then
* there is only one kernel work queue and LPWORK == HPWORK.
*
* User Work Queue:
* USRWORK: In the kernel phase a a kernel build, there should be no
* references to user-space work queues. That would be an error.
* Otherwise, in a flat build, user applications will use the lower
* priority work queue (if there is one).
*/
# define HPWORK 0
# ifdef CONFIG_SCHED_LPWORK
# define LPWORK (HPWORK+1)
# define NWORKERS 2
# else
# define LPWORK HPWORK
# define NWORKERS 1
# endif
# if !defined(CONFIG_BUILD_PROTECTED) && !defined(CONFIG_BUILD_KERNEL)
# define USRWORK LPWORK
# endif
#endif /* CONFIG_BUILD_PROTECTED && !__KERNEL__ */
/****************************************************************************
* Public Types
****************************************************************************/
#ifndef __ASSEMBLY__
/* This structure defines the state on one work queue. This structure is
* used internally by the OS and worker queue logic and should not be
* accessed by application logic.
*/
struct wqueue_s
{
pid_t pid; /* The task ID of the worker thread */
struct dq_queue_s q; /* The queue of pending work */
};
/* 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
/* The state of each work queue. This data structure is used internally by
* the OS and worker queue logic and should not be accessed by application
* logic.
*/
#ifdef CONFIG_BUILD_PROTECTED
/* Play some games in the kernel mode build to assure that different
* naming is used for the global work queue data structures. This may
* not be necessary but it safer.
*/
# ifdef __KERNEL__
EXTERN struct wqueue_s g_kernelwork[NWORKERS];
# define g_work g_kernelwork
# else
EXTERN struct wqueue_s g_usrwork[NWORKERS];
# define g_work g_usrwork
# endif
#else /* CONFIG_BUILD_PROTECTED */
EXTERN struct wqueue_s g_work[NWORKERS];
#endif /* CONFIG_BUILD_PROTECTED */
/****************************************************************************
* Public Function Prototypes
****************************************************************************/
/****************************************************************************
* Name: work_hpthread, work_lpthread, and work_usrthread
*
* Description:
* These are the worker threads that performs actions placed on the work
* lists.
*
* work_hpthread and work_lpthread: These are the kernel mode work queues
* (also build in the flat build). One of these threads also performs
* periodic garbage collection (that is otherwise performed by the idle
* thread if CONFIG_SCHED_WORKQUEUE is not defined).
*
* These worker threads are started by the OS during normal bringup.
*
* work_usrthread: This is a user mode work queue. It must be started
* by application code by calling work_usrstart().
*
* All of these entrypoints are referenced by OS internally and should not
* not be accessed by application logic.
*
* Input parameters:
* argc, argv (not used)
*
* Returned Value:
* Does not return
*
****************************************************************************/
#ifdef CONFIG_SCHED_HPWORK
int work_hpthread(int argc, char *argv[]);
#endif
#ifdef CONFIG_SCHED_LPWORK
int work_lpthread(int argc, char *argv[]);
#endif
#if defined(CONFIG_SCHED_USRWORK) && !defined(__KERNEL__)
int work_usrthread(int argc, char *argv[]);
#endif
/****************************************************************************
* Name: work_usrstart
*
* Description:
* Start the user mode work queue.
*
* Input parameters:
* None
*
* Returned Value:
* The task ID of the worker thread is returned on success. A negated
* errno value is returned on failure.
*
****************************************************************************/
#if defined(CONFIG_SCHED_USRWORK) && !defined(__KERNEL__)
int work_usrstart(void);
#endif
/****************************************************************************
* 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 worker callback when
* it 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
*
****************************************************************************/
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
*
****************************************************************************/
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
*
****************************************************************************/
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 /* CONFIG_SCHED_WORKQUEUE */
#endif /* __INCLUDE_NUTTX_WQUEUE_H */
