diff options
Diffstat (limited to 'sys/kern/subr_taskqueue.c')
| -rw-r--r-- | sys/kern/subr_taskqueue.c | 203 |
1 files changed, 203 insertions, 0 deletions
diff --git a/sys/kern/subr_taskqueue.c b/sys/kern/subr_taskqueue.c new file mode 100644 index 0000000..ab47b4f --- /dev/null +++ b/sys/kern/subr_taskqueue.c @@ -0,0 +1,203 @@ +/*- + * Copyright (c) 2000 Doug Rabson + * All rights reserved. + * + * 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. + * + * THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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. + * + * $FreeBSD$ + */ + +#include <sys/param.h> +#include <sys/queue.h> +#include <sys/systm.h> +#include <sys/kernel.h> +#include <sys/taskqueue.h> +#include <sys/interrupt.h> +#include <sys/malloc.h> +#include <machine/ipl.h> + +MALLOC_DEFINE(M_TASKQUEUE, "taskqueue", "Task Queues"); + +static STAILQ_HEAD(taskqueue_list, taskqueue) taskqueue_queues; + +struct taskqueue { + STAILQ_ENTRY(taskqueue) tq_link; + STAILQ_HEAD(, task) tq_queue; + const char *tq_name; + taskqueue_enqueue_fn tq_enqueue; + void *tq_context; + int tq_draining; +}; + +struct taskqueue * +taskqueue_create(const char *name, int mflags, + taskqueue_enqueue_fn enqueue, void *context) +{ + struct taskqueue *queue; + static int once = 1; + int s; + + queue = malloc(sizeof(struct taskqueue), M_TASKQUEUE, mflags); + if (!queue) + return 0; + STAILQ_INIT(&queue->tq_queue); + queue->tq_name = name; + queue->tq_enqueue = enqueue; + queue->tq_context = context; + queue->tq_draining = 0; + + s = splhigh(); + if (once) { + STAILQ_INIT(&taskqueue_queues); + once = 0; + } + STAILQ_INSERT_TAIL(&taskqueue_queues, queue, tq_link); + splx(s); + + return queue; +} + +void +taskqueue_free(struct taskqueue *queue) +{ + int s = splhigh(); + queue->tq_draining = 1; + splx(s); + + taskqueue_run(queue); + + s = splhigh(); + STAILQ_REMOVE(&taskqueue_queues, queue, taskqueue, tq_link); + splx(s); + + free(queue, M_TASKQUEUE); +} + +struct taskqueue * +taskqueue_find(const char *name) +{ + struct taskqueue *queue; + int s; + + s = splhigh(); + STAILQ_FOREACH(queue, &taskqueue_queues, tq_link) + if (!strcmp(queue->tq_name, name)) { + splx(s); + return queue; + } + splx(s); + return 0; +} + +int +taskqueue_enqueue(struct taskqueue *queue, struct task *task) +{ + struct task *ins; + struct task *prev; + + int s = splhigh(); + + /* + * Don't allow new tasks on a queue which is being freed. + */ + if (queue->tq_draining) { + splx(s); + return EPIPE; + } + + /* + * Count multiple enqueues. + */ + if (task->ta_pending) { + task->ta_pending++; + splx(s); + return 0; + } + + /* + * Optimise the case when all tasks have the same priority. + */ + prev = STAILQ_LAST(&queue->tq_queue); + if (!prev || prev->ta_priority >= task->ta_priority) { + STAILQ_INSERT_TAIL(&queue->tq_queue, task, ta_link); + } else { + prev = 0; + for (ins = STAILQ_FIRST(&queue->tq_queue); ins; + prev = ins, ins = STAILQ_NEXT(ins, ta_link)) + if (ins->ta_priority < task->ta_priority) + break; + + if (prev) + STAILQ_INSERT_AFTER(&queue->tq_queue, prev, task, ta_link); + else + STAILQ_INSERT_HEAD(&queue->tq_queue, task, ta_link); + } + + task->ta_pending = 1; + if (queue->tq_enqueue) + queue->tq_enqueue(queue->tq_context); + + splx(s); + + return 0; +} + +void +taskqueue_run(struct taskqueue *queue) +{ + int s; + struct task *task; + int pending; + + s = splhigh(); + while (STAILQ_FIRST(&queue->tq_queue)) { + /* + * Carefully remove the first task from the queue and + * zero its pending count. + */ + task = STAILQ_FIRST(&queue->tq_queue); + STAILQ_REMOVE_HEAD(&queue->tq_queue, ta_link); + pending = task->ta_pending; + task->ta_pending = 0; + splx(s); + + task->ta_func(task->ta_context, pending); + + s = splhigh(); + } + splx(s); +} + +static void +taskqueue_swi_enqueue(void *context) +{ + setsofttq(); +} + +static void +taskqueue_swi_run(void) +{ + taskqueue_run(taskqueue_swi); +} + +TASKQUEUE_DEFINE(swi, taskqueue_swi_enqueue, 0, + register_swi(SWI_TQ, taskqueue_swi_run)); |
