From ea87228a267417a28988d1d1753f1d6c44da55af Mon Sep 17 00:00:00 2001 From: Sebastian Huber Date: Mon, 28 Oct 2013 10:45:22 +0100 Subject: TASKQUEUE(9): Use FreeBSD implementation --- Makefile | 2 +- freebsd-to-rtems.py | 3 +- freebsd/sys/kern/subr_taskqueue.c | 509 +++++++++++++++++++++++++++++++++++ libbsd.txt | 4 +- rtemsbsd/rtems/rtems-bsd-taskqueue.c | 349 ------------------------ 5 files changed, 514 insertions(+), 353 deletions(-) create mode 100644 freebsd/sys/kern/subr_taskqueue.c delete mode 100644 rtemsbsd/rtems/rtems-bsd-taskqueue.c diff --git a/Makefile b/Makefile index 2d7d113f..11f44de2 100644 --- a/Makefile +++ b/Makefile @@ -83,7 +83,6 @@ LIB_C_FILES += rtemsbsd/rtems/rtems-bsd-syscall-api.c LIB_C_FILES += rtemsbsd/rtems/rtems-bsd-sysctlbyname.c LIB_C_FILES += rtemsbsd/rtems/rtems-bsd-sysctl.c LIB_C_FILES += rtemsbsd/rtems/rtems-bsd-sysctlnametomib.c -LIB_C_FILES += rtemsbsd/rtems/rtems-bsd-taskqueue.c LIB_C_FILES += rtemsbsd/rtems/rtems-bsd-thread.c LIB_C_FILES += rtemsbsd/rtems/rtems-bsd-timesupport.c LIB_C_FILES += rtemsbsd/rtems/rtems-kvm.c @@ -144,6 +143,7 @@ LIB_C_FILES += freebsd/sys/kern/subr_kobj.c LIB_C_FILES += freebsd/sys/kern/subr_module.c LIB_C_FILES += freebsd/sys/kern/subr_rman.c LIB_C_FILES += freebsd/sys/kern/subr_sbuf.c +LIB_C_FILES += freebsd/sys/kern/subr_taskqueue.c LIB_C_FILES += freebsd/sys/kern/subr_unit.c LIB_C_FILES += freebsd/sys/kern/sys_generic.c LIB_C_FILES += freebsd/sys/kern/uipc_accf.c diff --git a/freebsd-to-rtems.py b/freebsd-to-rtems.py index ebb1c1e9..953bb6d9 100755 --- a/freebsd-to-rtems.py +++ b/freebsd-to-rtems.py @@ -640,7 +640,6 @@ rtems.addRTEMSSourceFiles( 'rtems/rtems-bsd-sysctlbyname.c', 'rtems/rtems-bsd-sysctl.c', 'rtems/rtems-bsd-sysctlnametomib.c', - 'rtems/rtems-bsd-taskqueue.c', 'rtems/rtems-bsd-thread.c', 'rtems/rtems-bsd-timesupport.c', 'rtems/rtems-kvm.c', @@ -804,6 +803,7 @@ base.addSourceFiles( 'sys/kern/subr_module.c', 'sys/kern/subr_rman.c', 'sys/kern/subr_sbuf.c', + 'sys/kern/subr_taskqueue.c', 'sys/kern/subr_unit.c', 'sys/kern/sys_generic.c', 'sys/kern/uipc_accf.c', @@ -1175,7 +1175,6 @@ devNet.addSourceFiles( devNic = Module('dev_nic') devNic.addHeaderFiles( [ - # 'sys/taskqueue.h', 'sys/sys/pciio.h', 'sys/dev/random/randomdev_soft.h', 'sys/sys/eventvar.h', diff --git a/freebsd/sys/kern/subr_taskqueue.c b/freebsd/sys/kern/subr_taskqueue.c new file mode 100644 index 00000000..bbfe69e4 --- /dev/null +++ b/freebsd/sys/kern/subr_taskqueue.c @@ -0,0 +1,509 @@ +#include + +/*- + * 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. + */ + +#include +__FBSDID("$FreeBSD$"); + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +static MALLOC_DEFINE(M_TASKQUEUE, "taskqueue", "Task Queues"); +#ifndef __rtems__ +static void *taskqueue_giant_ih; +#endif /* __rtems__ */ +static void *taskqueue_ih; + +struct taskqueue_busy { + struct task *tb_running; + TAILQ_ENTRY(taskqueue_busy) tb_link; +}; + +struct taskqueue { + STAILQ_HEAD(, task) tq_queue; + const char *tq_name; + taskqueue_enqueue_fn tq_enqueue; + void *tq_context; + TAILQ_HEAD(, taskqueue_busy) tq_active; + struct mtx tq_mutex; + struct thread **tq_threads; + int tq_tcount; +#ifndef __rtems__ + int tq_spin; +#endif /* __rtems__ */ + int tq_flags; +}; + +#define TQ_FLAGS_ACTIVE (1 << 0) +#define TQ_FLAGS_BLOCKED (1 << 1) +#define TQ_FLAGS_PENDING (1 << 2) + +static void taskqueue_run_locked(struct taskqueue *); + +static __inline void +TQ_LOCK(struct taskqueue *tq) +{ +#ifndef __rtems__ + if (tq->tq_spin) + mtx_lock_spin(&tq->tq_mutex); + else +#endif /* __rtems__ */ + mtx_lock(&tq->tq_mutex); +} + +static __inline void +TQ_UNLOCK(struct taskqueue *tq) +{ +#ifndef __rtems__ + if (tq->tq_spin) + mtx_unlock_spin(&tq->tq_mutex); + else +#endif /* __rtems__ */ + mtx_unlock(&tq->tq_mutex); +} + +static __inline int +TQ_SLEEP(struct taskqueue *tq, void *p, struct mtx *m, int pri, const char *wm, + int t) +{ +#ifndef __rtems__ + if (tq->tq_spin) + return (msleep_spin(p, m, wm, t)); +#endif /* __rtems__ */ + return (msleep(p, m, pri, wm, t)); +} + +static struct taskqueue * +_taskqueue_create(const char *name, int mflags, + taskqueue_enqueue_fn enqueue, void *context, + int mtxflags, const char *mtxname) +{ + struct taskqueue *queue; + + queue = malloc(sizeof(struct taskqueue), M_TASKQUEUE, mflags | M_ZERO); + if (!queue) + return NULL; + + STAILQ_INIT(&queue->tq_queue); + TAILQ_INIT(&queue->tq_active); + queue->tq_name = name; + queue->tq_enqueue = enqueue; + queue->tq_context = context; +#ifndef __rtems__ + queue->tq_spin = (mtxflags & MTX_SPIN) != 0; +#else /* __rtems__ */ + /* + * FIXME: Here is a potential performance optimization. Maybe also an + * issue for correctness. + */ +#endif /* __rtems__ */ + queue->tq_flags |= TQ_FLAGS_ACTIVE; + mtx_init(&queue->tq_mutex, mtxname, NULL, mtxflags); + + return queue; +} + +struct taskqueue * +taskqueue_create(const char *name, int mflags, + taskqueue_enqueue_fn enqueue, void *context) +{ + return _taskqueue_create(name, mflags, enqueue, context, + MTX_DEF, "taskqueue"); +} + +/* + * Signal a taskqueue thread to terminate. + */ +static void +taskqueue_terminate(struct thread **pp, struct taskqueue *tq) +{ + + while (tq->tq_tcount > 0) { + wakeup(tq); + TQ_SLEEP(tq, pp, &tq->tq_mutex, PWAIT, "taskqueue_destroy", 0); + } +} + +void +taskqueue_free(struct taskqueue *queue) +{ + + TQ_LOCK(queue); + queue->tq_flags &= ~TQ_FLAGS_ACTIVE; + taskqueue_run_locked(queue); + taskqueue_terminate(queue->tq_threads, queue); + KASSERT(TAILQ_EMPTY(&queue->tq_active), ("Tasks still running?")); + mtx_destroy(&queue->tq_mutex); + free(queue->tq_threads, M_TASKQUEUE); + free(queue, M_TASKQUEUE); +} + +int +taskqueue_enqueue(struct taskqueue *queue, struct task *task) +{ + struct task *ins; + struct task *prev; + + TQ_LOCK(queue); + + /* + * Count multiple enqueues. + */ + if (task->ta_pending) { + task->ta_pending++; + TQ_UNLOCK(queue); + return 0; + } + + /* + * Optimise the case when all tasks have the same priority. + */ + prev = STAILQ_LAST(&queue->tq_queue, task, ta_link); + if (!prev || prev->ta_priority >= task->ta_priority) { + STAILQ_INSERT_TAIL(&queue->tq_queue, task, ta_link); + } else { + prev = NULL; + 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_flags & TQ_FLAGS_BLOCKED) == 0) + queue->tq_enqueue(queue->tq_context); + else + queue->tq_flags |= TQ_FLAGS_PENDING; + + TQ_UNLOCK(queue); + + return 0; +} + +void +taskqueue_block(struct taskqueue *queue) +{ + + TQ_LOCK(queue); + queue->tq_flags |= TQ_FLAGS_BLOCKED; + TQ_UNLOCK(queue); +} + +void +taskqueue_unblock(struct taskqueue *queue) +{ + + TQ_LOCK(queue); + queue->tq_flags &= ~TQ_FLAGS_BLOCKED; + if (queue->tq_flags & TQ_FLAGS_PENDING) { + queue->tq_flags &= ~TQ_FLAGS_PENDING; + queue->tq_enqueue(queue->tq_context); + } + TQ_UNLOCK(queue); +} + +static void +taskqueue_run_locked(struct taskqueue *queue) +{ + struct taskqueue_busy tb; + struct task *task; + int pending; + + mtx_assert(&queue->tq_mutex, MA_OWNED); + tb.tb_running = NULL; + TAILQ_INSERT_TAIL(&queue->tq_active, &tb, tb_link); + + 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; + tb.tb_running = task; + TQ_UNLOCK(queue); + + task->ta_func(task->ta_context, pending); + + TQ_LOCK(queue); + tb.tb_running = NULL; + wakeup(task); + } + TAILQ_REMOVE(&queue->tq_active, &tb, tb_link); +} + +void +taskqueue_run(struct taskqueue *queue) +{ + + TQ_LOCK(queue); + taskqueue_run_locked(queue); + TQ_UNLOCK(queue); +} + +static int +task_is_running(struct taskqueue *queue, struct task *task) +{ + struct taskqueue_busy *tb; + + mtx_assert(&queue->tq_mutex, MA_OWNED); + TAILQ_FOREACH(tb, &queue->tq_active, tb_link) { + if (tb->tb_running == task) + return (1); + } + return (0); +} + +void +taskqueue_drain(struct taskqueue *queue, struct task *task) +{ +#ifndef __rtems__ + if (queue->tq_spin) { /* XXX */ + mtx_lock_spin(&queue->tq_mutex); + while (task->ta_pending != 0 || task_is_running(queue, task)) + msleep_spin(task, &queue->tq_mutex, "-", 0); + mtx_unlock_spin(&queue->tq_mutex); + } else { +#endif /* __rtems__ */ + WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL, __func__); + + mtx_lock(&queue->tq_mutex); + while (task->ta_pending != 0 || task_is_running(queue, task)) + msleep(task, &queue->tq_mutex, PWAIT, "-", 0); + mtx_unlock(&queue->tq_mutex); +#ifndef __rtems__ + } +#endif /* __rtems__ */ +} + +static void +taskqueue_swi_enqueue(void *context) +{ + swi_sched(taskqueue_ih, 0); +} + +static void +taskqueue_swi_run(void *dummy) +{ + taskqueue_run(taskqueue_swi); +} + +#ifndef __rtems__ +static void +taskqueue_swi_giant_enqueue(void *context) +{ + swi_sched(taskqueue_giant_ih, 0); +} + +static void +taskqueue_swi_giant_run(void *dummy) +{ + taskqueue_run(taskqueue_swi_giant); +} +#endif /* __rtems__ */ + +int +taskqueue_start_threads(struct taskqueue **tqp, int count, int pri, + const char *name, ...) +{ + va_list ap; + struct thread *td; + struct taskqueue *tq; + int i, error; + char ktname[MAXCOMLEN + 1]; + + if (count <= 0) + return (EINVAL); + + tq = *tqp; + + va_start(ap, name); + vsnprintf(ktname, sizeof(ktname), name, ap); + va_end(ap); + + tq->tq_threads = malloc(sizeof(struct thread *) * count, M_TASKQUEUE, + M_NOWAIT | M_ZERO); + if (tq->tq_threads == NULL) { + printf("%s: no memory for %s threads\n", __func__, ktname); + return (ENOMEM); + } + + for (i = 0; i < count; i++) { + if (count == 1) + error = kthread_add(taskqueue_thread_loop, tqp, NULL, + &tq->tq_threads[i], RFSTOPPED, 0, "%s", ktname); + else + error = kthread_add(taskqueue_thread_loop, tqp, NULL, + &tq->tq_threads[i], RFSTOPPED, 0, + "%s_%d", ktname, i); + if (error) { + /* should be ok to continue, taskqueue_free will dtrt */ + printf("%s: kthread_add(%s): error %d", __func__, + ktname, error); + tq->tq_threads[i] = NULL; /* paranoid */ + } else + tq->tq_tcount++; + } +#ifndef __rtems__ + for (i = 0; i < count; i++) { + if (tq->tq_threads[i] == NULL) + continue; + td = tq->tq_threads[i]; + thread_lock(td); + sched_prio(td, pri); + sched_add(td, SRQ_BORING); + thread_unlock(td); + } +#else /* __rtems__ */ + (void) td; +#endif /* __rtems__ */ + + return (0); +} + +void +taskqueue_thread_loop(void *arg) +{ + struct taskqueue **tqp, *tq; + + tqp = arg; + tq = *tqp; + TQ_LOCK(tq); + while ((tq->tq_flags & TQ_FLAGS_ACTIVE) != 0) { + taskqueue_run_locked(tq); + /* + * Because taskqueue_run() can drop tq_mutex, we need to + * check if the TQ_FLAGS_ACTIVE flag wasn't removed in the + * meantime, which means we missed a wakeup. + */ + if ((tq->tq_flags & TQ_FLAGS_ACTIVE) == 0) + break; + TQ_SLEEP(tq, tq, &tq->tq_mutex, 0, "-", 0); + } + + /* rendezvous with thread that asked us to terminate */ + tq->tq_tcount--; + wakeup_one(tq->tq_threads); + TQ_UNLOCK(tq); + kthread_exit(); +} + +void +taskqueue_thread_enqueue(void *context) +{ + struct taskqueue **tqp, *tq; + + tqp = context; + tq = *tqp; + + mtx_assert(&tq->tq_mutex, MA_OWNED); + wakeup_one(tq); +} + +TASKQUEUE_DEFINE(swi, taskqueue_swi_enqueue, NULL, + swi_add(NULL, "task queue", taskqueue_swi_run, NULL, SWI_TQ, + INTR_MPSAFE, &taskqueue_ih)); + +#ifndef __rtems__ +TASKQUEUE_DEFINE(swi_giant, taskqueue_swi_giant_enqueue, NULL, + swi_add(NULL, "Giant taskq", taskqueue_swi_giant_run, + NULL, SWI_TQ_GIANT, 0, &taskqueue_giant_ih)); +#endif /* __rtems__ */ + +TASKQUEUE_DEFINE_THREAD(thread); + +struct taskqueue * +taskqueue_create_fast(const char *name, int mflags, + taskqueue_enqueue_fn enqueue, void *context) +{ + return _taskqueue_create(name, mflags, enqueue, context, + MTX_SPIN, "fast_taskqueue"); +} + +/* NB: for backwards compatibility */ +int +taskqueue_enqueue_fast(struct taskqueue *queue, struct task *task) +{ + return taskqueue_enqueue(queue, task); +} + +static void *taskqueue_fast_ih; + +static void +taskqueue_fast_enqueue(void *context) +{ + swi_sched(taskqueue_fast_ih, 0); +} + +static void +taskqueue_fast_run(void *dummy) +{ + taskqueue_run(taskqueue_fast); +} + +TASKQUEUE_FAST_DEFINE(fast, taskqueue_fast_enqueue, NULL, + swi_add(NULL, "Fast task queue", taskqueue_fast_run, NULL, + SWI_TQ_FAST, INTR_MPSAFE, &taskqueue_fast_ih)); + +int +taskqueue_member(struct taskqueue *queue, struct thread *td) +{ + int i, j, ret = 0; + + TQ_LOCK(queue); + for (i = 0, j = 0; ; i++) { + if (queue->tq_threads[i] == NULL) + continue; + if (queue->tq_threads[i] == td) { + ret = 1; + break; + } + if (++j >= queue->tq_tcount) + break; + } + TQ_UNLOCK(queue); + return (ret); +} diff --git a/libbsd.txt b/libbsd.txt index 65b1dbc7..caacf1ee 100644 --- a/libbsd.txt +++ b/libbsd.txt @@ -92,7 +92,9 @@ the current Git submodule commit is this * get_cyclecount(): The implementation is a security problem. * What to do with the priority parameter present in the FreeBSD synchronization - primitives? + primitives and the thread creation functions? + +* TASKQUEUE(9): Support spin mutexes. * ZONE(9): Review allocator lock usage in rtems-bsd-chunk.c. diff --git a/rtemsbsd/rtems/rtems-bsd-taskqueue.c b/rtemsbsd/rtems/rtems-bsd-taskqueue.c deleted file mode 100644 index 58959df2..00000000 --- a/rtemsbsd/rtems/rtems-bsd-taskqueue.c +++ /dev/null @@ -1,349 +0,0 @@ -/** - * @file - * - * @ingroup rtems_bsd_rtems - * - * @brief TODO. - */ - -/* - * COPYRIGHT (c) 2012. - * On-Line Applications Research Corporation (OAR). - * 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. - */ - -#include -__FBSDID("$FreeBSD$"); - -#include -#include -#include - -/* -#define STATIC static -*/ -#undef DEBUG - -#ifdef DEBUG -#include -#ifndef STATIC -#define STATIC -#endif -#else -#ifndef STATIC -#define STATIC static -#endif -#endif - -#define TQ_WAKE_EVENT RTEMS_EVENT_0 - -/* This implementation is extremely simple; we assume - * that all taskqueues (and as a matter of fact there is - * only a single one) are manipulated with the rtems - * bsdnet semaphore held. I.e., - * taskqueue_enqueue() - * taskqueue_drain() - * etc. - * are called from an environment that holds the - * bsdnet semaphore. - * Likewise, the thread that works the taskqueue - * holds the semaphore while doing so. - * - */ - -/* use single-linked list; 'drain' which would benefit from - * double-linked list is seldom used and performance doesn't - * matter much there. OTOH, the frequent case of working - * the list + enqueueing is more efficient for the single-linked - * list. -struct task { - struct task *ta_next; - int ta_pending; - int ta_priority; - task_fn ta_fn; - void *ta_fn_arg; -}; - */ - -struct taskqueue { - struct task anchor; - struct task *tail; - tq_enq_fn enq_fn; - void *enq_fn_arg; - rtems_id tid; -}; - - -STATIC struct taskqueue the_taskqueue = { - { 0, 0, 0, 0, 0 }, - &the_taskqueue.anchor, - taskqueue_thread_enqueue, - &taskqueue_fast, - 0 -}; - -struct taskqueue *taskqueue_fast = &the_taskqueue; -struct taskqueue *taskqueue_swi = NULL; - -struct taskqueue * -taskqueue_create(const char *name, int mflags, tq_enq_fn enq_fn, void *arg) -{ - if ( enq_fn != taskqueue_thread_enqueue ) - rtems_panic("rtems_taskqueue: attempt to create non-standard TQ; implementation needs to be modified\n"); - return &the_taskqueue; -} - -struct taskqueue * -taskqueue_create_fast(const char *name, int mflags, tq_enq_fn enq_fn, void *arg) -{ - return taskqueue_create(name, mflags, enq_fn, arg); -} - -/* taskqueue_enqueue must be allowed from an ISR; - * hence, all critical list manipulation must lock out - * interrupts... - */ -int -taskqueue_enqueue(struct taskqueue *tq, struct task *ta) -{ -rtems_interrupt_level l; - -rtems_interrupt_disable(l); - if ( 0 == ta->ta_pending ++ ) { - /* hook into list */ - ta->ta_next = 0; - tq->tail->ta_next = ta; - tq->tail = ta; - } - tq->enq_fn(tq->enq_fn_arg); -rtems_interrupt_enable(l); - return 0; -} - -int -taskqueue_enqueue_fast(struct taskqueue *queue, struct task *task) -{ - return taskqueue_enqueue(queue, task); -} - -void -taskqueue_thread_enqueue(void *ctxt) -{ -int dopost; -/* pointer-to-pointer is what bsd provides; we currently - * follow the scheme even we don't directly use the argument - * passed to taskqueue_create... - */ -struct taskqueue *tq = *(struct taskqueue **)ctxt; - /* If this is the first entry on the list then the - * task needs to be notified... - */ - dopost = ( tq->anchor.ta_next == tq->tail && 1 == tq->tail->ta_pending ); - - if ( dopost ) - rtems_event_send(tq->tid, TQ_WAKE_EVENT); -} - -/* Returns 0 on success */ -int -taskqueue_start_threads(struct taskqueue **ptq, int count, int prio, const char *fmt, ...) -{ - if ( count != 1 ) - rtems_panic("rtems_taskqueue: taskqueue_start_threads cannot currently deal with count != 1\n"); - - /* Do (non thread-safe) lazy init as a fallback */ - if ( ! the_taskqueue.tid ) - rtems_taskqueue_initialize(); - return 0; -} - -void -taskqueue_drain(struct taskqueue *tq, struct task *ta) -{ -rtems_interrupt_level l; -struct task *p, *q; -int i; - - /* find predecessor; searching the list should be - * safe; an ISR might append a new record to the tail - * while we are working but that should be OK. - */ - for ( p = &tq->anchor; (q = p->ta_next); p=q ) { - if ( q == ta ) { - rtems_interrupt_disable(l); - /* found; do work */ - /* remember 'pending' count and extract */ - i = ta->ta_pending; - ta->ta_pending = 0; - p->ta_next = ta->ta_next; - ta->ta_next = 0; - /* adjust tail */ - if ( tq->tail == q ) - tq->tail = p; - rtems_interrupt_enable(l); - for ( ; i>0; i-- ) { - ta->ta_fn(ta->ta_fn_arg, i); - } - return; - } - } -} - -/* work the task queue and return - * nonzero if the list is not empty - * (which means that some callback has - * rescheduled itself) - */ -static void * -taskqueue_work(struct taskqueue *tq) -{ -rtems_interrupt_level l; -struct task *p, *q; -task_fn f; -void *arg; -int i; - -/* work off a temporary list in case any callback reschedules - * itself or if new tasks are queued from an ISR. - */ -rtems_interrupt_disable(l); - p = tq->anchor.ta_next; - - tq->anchor.ta_next = 0; - tq->tail = &tq->anchor; -rtems_interrupt_enable(l); - - while ( (q=p) ) { - rtems_interrupt_disable(l); - i = q->ta_pending; - q->ta_pending = 0; - /* extract */ - p = q->ta_next; - q->ta_next = 0; - f = q->ta_fn; - arg = q->ta_fn_arg; - rtems_interrupt_enable(l); - for ( ; i>0; i-- ) { - f(arg, i); - } - } - return tq->anchor.ta_next; -} - -void -taskqueue_free(struct taskqueue *tq) -{ - taskqueue_work(tq); -} - -static void -taskqueueDoWork(void *arg) -{ -struct taskqueue *tq = arg; -rtems_event_set evs; -rtems_status_code sc; - while ( 1 ) { - sc = rtems_event_receive(TQ_WAKE_EVENT, RTEMS_EVENT_ANY | RTEMS_WAIT, RTEMS_NO_TIMEOUT, &evs); - if ( RTEMS_SUCCESSFUL != sc ) { - rtems_error(sc,"rtems_taskqueue: taskqueueDoWork() unable to receive wakup event\n"); - rtems_panic("Can't proceed\n"); - } - if ( taskqueue_work(tq) ) { -#if 0 - /* chance to reschedule */ - rtems_bsdnet_semaphore_release(); - rtems_task_wake_after(0); - rtems_bsdnet_semaphore_obtain(); -#else - /* hopefully, releasing the semaphore (as part of bsdnet_event_receive) - * and obtaining the event (which has been posted already) - * yields the CPU if necessary... - */ -#endif - } - } -} - -#ifdef DEBUG -struct task_dbg { - struct task t; - char *nm; -}; - -struct task_dbg taskA = { - {0}, - "taskA" -}; - -struct task_dbg taskB = { - {0}, - "taskB" -}; - -struct task_dbg taskC = { - {0}, - "taskC" -}; - -static void the_task_fn(void *arg, int pending) -{ -struct task_dbg *td = arg; - printf("%s (pending: %i)\n", td->nm, pending); - /* Test rescheduling */ - if ( pending > 3 ) - taskqueue_enqueue(&the_taskqueue,&td->t); -} - -void taskqueue_dump() -{ -struct task *p; - printf("Anchor %p, Tail %p\n", &the_taskqueue.anchor, the_taskqueue.tail); - for ( p = the_taskqueue.anchor.ta_next; p; p=p->ta_next ) { - printf("%p: (pending %2i, next %p)\n", - p, p->ta_pending, p->ta_next); - } -} -#endif - -rtems_id -rtems_taskqueue_initialize() -{ -#ifdef DEBUG - TASK_INIT( &taskA.t, 0, the_task_fn, &taskA ); - TASK_INIT( &taskB.t, 0, the_task_fn, &taskB ); - TASK_INIT( &taskC.t, 0, the_task_fn, &taskC ); -#endif - if ( ! the_taskqueue.tid ) - the_taskqueue.tid = rtems_bsdnet_newproc("tskq", 10000, taskqueueDoWork, &the_taskqueue); - return the_taskqueue.tid; -} - -#ifdef DEBUG -void -_cexpModuleInitialize(void *u) -{ - rtems_bsdnet_initialize_network(); - the_taskqueue.tid = rtems_taskqueue_initialize(); -} -#endif -- cgit v1.2.3