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wait_queue.c
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/*
* Copyright (c) 2000-2009 Apple Inc. All rights reserved.
*
* @APPLE_OSREFERENCE_LICENSE_HEADER_START@
*
* This file contains Original Code and/or Modifications of Original Code
* as defined in and that are subject to the Apple Public Source License
* Version 2.0 (the 'License'). You may not use this file except in
* compliance with the License. The rights granted to you under the License
* may not be used to create, or enable the creation or redistribution of,
* unlawful or unlicensed copies of an Apple operating system, or to
* circumvent, violate, or enable the circumvention or violation of, any
* terms of an Apple operating system software license agreement.
*
* Please obtain a copy of the License at
* http://www.opensource.apple.com/apsl/ and read it before using this file.
*
* The Original Code and all software distributed under the License are
* distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
* EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
* INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
* Please see the License for the specific language governing rights and
* limitations under the License.
*
* @APPLE_OSREFERENCE_LICENSE_HEADER_END@
*/
/*
* @OSF_FREE_COPYRIGHT@
*/
/*
* Mach Operating System
* Copyright (c) 1991,1990,1989,1988,1987 Carnegie Mellon University
* All Rights Reserved.
*
* Permission to use, copy, modify and distribute this software and its
* documentation is hereby granted, provided that both the copyright
* notice and this permission notice appear in all copies of the
* software, derivative works or modified versions, and any portions
* thereof, and that both notices appear in supporting documentation.
*
* CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
* CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
* ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
*
* Carnegie Mellon requests users of this software to return to
*
* Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU
* School of Computer Science
* Carnegie Mellon University
* Pittsburgh PA 15213-3890
*
* any improvements or extensions that they make and grant Carnegie Mellon
* the rights to redistribute these changes.
*/
/*
*/
/*
* File: wait_queue.c (adapted from sched_prim.c)
* Author: Avadis Tevanian, Jr.
* Date: 1986
*
* Primitives for manipulating wait queues: either global
* ones from sched_prim.c, or private ones associated with
* particular structures(pots, semaphores, etc..).
*/
#include <kern/kern_types.h>
#include <kern/simple_lock.h>
#include <kern/zalloc.h>
#include <kern/queue.h>
#include <kern/spl.h>
#include <mach/sync_policy.h>
#include <kern/mach_param.h>
#include <kern/sched_prim.h>
#include <kern/wait_queue.h>
#include <vm/vm_kern.h>
/* forward declarations */
static boolean_t wait_queue_member_locked(
wait_queue_t wq,
wait_queue_set_t wq_set);
static void wait_queues_init(void);
#define WAIT_QUEUE_MAX thread_max
#define WAIT_QUEUE_SET_MAX task_max * 3
#define WAIT_QUEUE_LINK_MAX PORT_MAX / 2 + (WAIT_QUEUE_MAX * WAIT_QUEUE_SET_MAX) / 64
static zone_t _wait_queue_link_zone;
static zone_t _wait_queue_set_zone;
static zone_t _wait_queue_zone;
/* see rdar://6737748&5561610; we need an unshadowed
* definition of a WaitQueueLink for debugging,
* but it needs to be used somewhere to wind up in
* the dSYM file. */
volatile WaitQueueLink *unused_except_for_debugging;
/*
* Waiting protocols and implementation:
*
* Each thread may be waiting for exactly one event; this event
* is set using assert_wait(). That thread may be awakened either
* by performing a thread_wakeup_prim() on its event,
* or by directly waking that thread up with clear_wait().
*
* The implementation of wait events uses a hash table. Each
* bucket is queue of threads having the same hash function
* value; the chain for the queue (linked list) is the run queue
* field. [It is not possible to be waiting and runnable at the
* same time.]
*
* Locks on both the thread and on the hash buckets govern the
* wait event field and the queue chain field. Because wakeup
* operations only have the event as an argument, the event hash
* bucket must be locked before any thread.
*
* Scheduling operations may also occur at interrupt level; therefore,
* interrupts below splsched() must be prevented when holding
* thread or hash bucket locks.
*
* The wait event hash table declarations are as follows:
*/
struct wait_queue boot_wait_queue[1];
__private_extern__ struct wait_queue *wait_queues = &boot_wait_queue[0];
__private_extern__ uint32_t num_wait_queues = 1;
#define P2ROUNDUP(x, align) (-(-((uint32_t)(x)) & -(align)))
#define ROUNDDOWN(x,y) (((x)/(y))*(y))
static uint32_t
compute_wait_hash_size(void)
{
uint32_t hsize, queues;
if (PE_parse_boot_argn("wqsize", &hsize, sizeof(hsize)))
return (hsize);
queues = thread_max / 11;
hsize = P2ROUNDUP(queues * sizeof(struct wait_queue), PAGE_SIZE);
return hsize;
}
static void
wait_queues_init(void)
{
uint32_t i, whsize, qsz;
kern_return_t kret;
/*
* Determine the amount of memory we're willing to reserve for
* the waitqueue hash table
*/
whsize = compute_wait_hash_size();
/* Determine the number of waitqueues we can fit. */
qsz = sizeof (struct wait_queue);
whsize = ROUNDDOWN(whsize, qsz);
num_wait_queues = whsize / qsz;
/*
* The hash algorithm requires that this be a power of 2, so we
* just mask off all the low-order bits.
*/
for (i = 0; i < 31; i++) {
uint32_t bit = (1 << i);
if ((num_wait_queues & bit) == num_wait_queues)
break;
num_wait_queues &= ~bit;
}
assert(num_wait_queues > 0);
/* Now determine how much memory we really need. */
whsize = P2ROUNDUP(num_wait_queues * qsz, PAGE_SIZE);
kret = kernel_memory_allocate(kernel_map, (vm_offset_t *) &wait_queues,
whsize, 0, KMA_KOBJECT|KMA_NOPAGEWAIT);
if (kret != KERN_SUCCESS || wait_queues == NULL)
panic("kernel_memory_allocate() failed to allocate wait queues, error: %d, whsize: 0x%x", kret, whsize);
for (i = 0; i < num_wait_queues; i++) {
wait_queue_init(&wait_queues[i], SYNC_POLICY_FIFO);
}
}
void
wait_queue_bootstrap(void)
{
wait_queues_init();
_wait_queue_zone = zinit(sizeof(struct wait_queue),
WAIT_QUEUE_MAX * sizeof(struct wait_queue),
sizeof(struct wait_queue),
"wait queues");
zone_change(_wait_queue_zone, Z_NOENCRYPT, TRUE);
_wait_queue_set_zone = zinit(sizeof(struct wait_queue_set),
WAIT_QUEUE_SET_MAX * sizeof(struct wait_queue_set),
sizeof(struct wait_queue_set),
"wait queue sets");
zone_change(_wait_queue_set_zone, Z_NOENCRYPT, TRUE);
_wait_queue_link_zone = zinit(sizeof(struct _wait_queue_link),
WAIT_QUEUE_LINK_MAX * sizeof(struct _wait_queue_link),
sizeof(struct _wait_queue_link),
"wait queue links");
zone_change(_wait_queue_link_zone, Z_NOENCRYPT, TRUE);
}
/*
* Routine: wait_queue_init
* Purpose:
* Initialize a previously allocated wait queue.
* Returns:
* KERN_SUCCESS - The wait_queue_t was initialized
* KERN_INVALID_ARGUMENT - The policy parameter was invalid
*/
kern_return_t
wait_queue_init(
wait_queue_t wq,
int policy)
{
/* only FIFO and LIFO for now */
if ((policy & SYNC_POLICY_FIXED_PRIORITY) != 0)
return KERN_INVALID_ARGUMENT;
wq->wq_fifo = ((policy & SYNC_POLICY_REVERSED) == 0);
wq->wq_type = _WAIT_QUEUE_inited;
wq->wq_eventmask = 0;
queue_init(&wq->wq_queue);
hw_lock_init(&wq->wq_interlock);
return KERN_SUCCESS;
}
/*
* Routine: wait_queue_alloc
* Purpose:
* Allocate and initialize a wait queue for use outside of
* of the mach part of the kernel.
* Conditions:
* Nothing locked - can block.
* Returns:
* The allocated and initialized wait queue
* WAIT_QUEUE_NULL if there is a resource shortage
*/
wait_queue_t
wait_queue_alloc(
int policy)
{
wait_queue_t wq;
kern_return_t ret;
wq = (wait_queue_t) zalloc(_wait_queue_zone);
if (wq != WAIT_QUEUE_NULL) {
ret = wait_queue_init(wq, policy);
if (ret != KERN_SUCCESS) {
zfree(_wait_queue_zone, wq);
wq = WAIT_QUEUE_NULL;
}
}
return wq;
}
/*
* Routine: wait_queue_free
* Purpose:
* Free an allocated wait queue.
* Conditions:
* May block.
*/
kern_return_t
wait_queue_free(
wait_queue_t wq)
{
if (!wait_queue_is_queue(wq))
return KERN_INVALID_ARGUMENT;
if (!queue_empty(&wq->wq_queue))
return KERN_FAILURE;
zfree(_wait_queue_zone, wq);
return KERN_SUCCESS;
}
/*
* Routine: wait_queue_set_init
* Purpose:
* Initialize a previously allocated wait queue set.
* Returns:
* KERN_SUCCESS - The wait_queue_set_t was initialized
* KERN_INVALID_ARGUMENT - The policy parameter was invalid
*/
kern_return_t
wait_queue_set_init(
wait_queue_set_t wqset,
int policy)
{
kern_return_t ret;
ret = wait_queue_init(&wqset->wqs_wait_queue, policy);
if (ret != KERN_SUCCESS)
return ret;
wqset->wqs_wait_queue.wq_type = _WAIT_QUEUE_SET_inited;
if (policy & SYNC_POLICY_PREPOST)
wqset->wqs_wait_queue.wq_prepost = TRUE;
else
wqset->wqs_wait_queue.wq_prepost = FALSE;
queue_init(&wqset->wqs_setlinks);
queue_init(&wqset->wqs_preposts);
return KERN_SUCCESS;
}
kern_return_t
wait_queue_sub_init(
wait_queue_set_t wqset,
int policy)
{
return wait_queue_set_init(wqset, policy);
}
kern_return_t
wait_queue_sub_clearrefs(
wait_queue_set_t wq_set)
{
wait_queue_link_t wql;
queue_t q;
spl_t s;
if (!wait_queue_is_set(wq_set))
return KERN_INVALID_ARGUMENT;
s = splsched();
wqs_lock(wq_set);
q = &wq_set->wqs_preposts;
while (!queue_empty(q)) {
queue_remove_first(q, wql, wait_queue_link_t, wql_preposts);
assert(!wql_is_preposted(wql));
}
wqs_unlock(wq_set);
splx(s);
return KERN_SUCCESS;
}
/*
* Routine: wait_queue_set_alloc
* Purpose:
* Allocate and initialize a wait queue set for
* use outside of the mach part of the kernel.
* Conditions:
* May block.
* Returns:
* The allocated and initialized wait queue set
* WAIT_QUEUE_SET_NULL if there is a resource shortage
*/
wait_queue_set_t
wait_queue_set_alloc(
int policy)
{
wait_queue_set_t wq_set;
wq_set = (wait_queue_set_t) zalloc(_wait_queue_set_zone);
if (wq_set != WAIT_QUEUE_SET_NULL) {
kern_return_t ret;
ret = wait_queue_set_init(wq_set, policy);
if (ret != KERN_SUCCESS) {
zfree(_wait_queue_set_zone, wq_set);
wq_set = WAIT_QUEUE_SET_NULL;
}
}
return wq_set;
}
/*
* Routine: wait_queue_set_free
* Purpose:
* Free an allocated wait queue set
* Conditions:
* May block.
*/
kern_return_t
wait_queue_set_free(
wait_queue_set_t wq_set)
{
if (!wait_queue_is_set(wq_set))
return KERN_INVALID_ARGUMENT;
if (!queue_empty(&wq_set->wqs_wait_queue.wq_queue))
return KERN_FAILURE;
zfree(_wait_queue_set_zone, wq_set);
return KERN_SUCCESS;
}
/*
*
* Routine: wait_queue_set_size
* Routine: wait_queue_link_size
* Purpose:
* Return the size of opaque wait queue structures
*/
unsigned int wait_queue_set_size(void) { return sizeof(WaitQueueSet); }
unsigned int wait_queue_link_size(void) { return sizeof(WaitQueueLink); }
/* declare a unique type for wait queue link structures */
static unsigned int _wait_queue_link;
static unsigned int _wait_queue_link_noalloc;
static unsigned int _wait_queue_unlinked;
#define WAIT_QUEUE_LINK ((void *)&_wait_queue_link)
#define WAIT_QUEUE_LINK_NOALLOC ((void *)&_wait_queue_link_noalloc)
#define WAIT_QUEUE_UNLINKED ((void *)&_wait_queue_unlinked)
#define WAIT_QUEUE_ELEMENT_CHECK(wq, wqe) \
WQASSERT(((wqe)->wqe_queue == (wq) && \
queue_next(queue_prev((queue_t) (wqe))) == (queue_t)(wqe)), \
"wait queue element list corruption: wq=%#x, wqe=%#x", \
(wq), (wqe))
#define WQSPREV(wqs, wql) ((wait_queue_link_t)queue_prev( \
((&(wqs)->wqs_setlinks == (queue_t)(wql)) ? \
(queue_t)(wql) : &(wql)->wql_setlinks)))
#define WQSNEXT(wqs, wql) ((wait_queue_link_t)queue_next( \
((&(wqs)->wqs_setlinks == (queue_t)(wql)) ? \
(queue_t)(wql) : &(wql)->wql_setlinks)))
#define WAIT_QUEUE_SET_LINK_CHECK(wqs, wql) \
WQASSERT(((((wql)->wql_type == WAIT_QUEUE_LINK) || \
((wql)->wql_type == WAIT_QUEUE_LINK_NOALLOC)) && \
((wql)->wql_setqueue == (wqs)) && \
(((wql)->wql_queue->wq_type == _WAIT_QUEUE_inited) || \
((wql)->wql_queue->wq_type == _WAIT_QUEUE_SET_inited)) && \
(WQSNEXT((wqs), WQSPREV((wqs),(wql))) == (wql))), \
"wait queue set links corruption: wqs=%#x, wql=%#x", \
(wqs), (wql))
#if defined(_WAIT_QUEUE_DEBUG_)
#define WQASSERT(e, s, p0, p1) ((e) ? 0 : panic(s, p0, p1))
#define WAIT_QUEUE_CHECK(wq) \
MACRO_BEGIN \
queue_t q2 = &(wq)->wq_queue; \
wait_queue_element_t wqe2 = (wait_queue_element_t) queue_first(q2); \
while (!queue_end(q2, (queue_entry_t)wqe2)) { \
WAIT_QUEUE_ELEMENT_CHECK((wq), wqe2); \
wqe2 = (wait_queue_element_t) queue_next((queue_t) wqe2); \
} \
MACRO_END
#define WAIT_QUEUE_SET_CHECK(wqs) \
MACRO_BEGIN \
queue_t q2 = &(wqs)->wqs_setlinks; \
wait_queue_link_t wql2 = (wait_queue_link_t) queue_first(q2); \
while (!queue_end(q2, (queue_entry_t)wql2)) { \
WAIT_QUEUE_SET_LINK_CHECK((wqs), wql2); \
wql2 = (wait_queue_link_t) wql2->wql_setlinks.next; \
} \
MACRO_END
#else /* !_WAIT_QUEUE_DEBUG_ */
#define WQASSERT(e, s, p0, p1) assert(e)
#define WAIT_QUEUE_CHECK(wq)
#define WAIT_QUEUE_SET_CHECK(wqs)
#endif /* !_WAIT_QUEUE_DEBUG_ */
/*
* Routine: wait_queue_global
* Purpose:
* Indicate if this wait queue is a global wait queue or not.
*/
static boolean_t
wait_queue_global(
wait_queue_t wq)
{
if ((wq >= wait_queues) && (wq <= (wait_queues + num_wait_queues))) {
return TRUE;
}
return FALSE;
}
/*
* Routine: wait_queue_member_locked
* Purpose:
* Indicate if this set queue is a member of the queue
* Conditions:
* The wait queue is locked
* The set queue is just that, a set queue
*/
static boolean_t
wait_queue_member_locked(
wait_queue_t wq,
wait_queue_set_t wq_set)
{
wait_queue_element_t wq_element;
queue_t q;
assert(wait_queue_held(wq));
assert(wait_queue_is_set(wq_set));
q = &wq->wq_queue;
wq_element = (wait_queue_element_t) queue_first(q);
while (!queue_end(q, (queue_entry_t)wq_element)) {
WAIT_QUEUE_ELEMENT_CHECK(wq, wq_element);
if ((wq_element->wqe_type == WAIT_QUEUE_LINK) ||
(wq_element->wqe_type == WAIT_QUEUE_LINK_NOALLOC)) {
wait_queue_link_t wql = (wait_queue_link_t)wq_element;
if (wql->wql_setqueue == wq_set)
return TRUE;
}
wq_element = (wait_queue_element_t)
queue_next((queue_t) wq_element);
}
return FALSE;
}
/*
* Routine: wait_queue_member
* Purpose:
* Indicate if this set queue is a member of the queue
* Conditions:
* The set queue is just that, a set queue
*/
boolean_t
wait_queue_member(
wait_queue_t wq,
wait_queue_set_t wq_set)
{
boolean_t ret;
spl_t s;
if (!wait_queue_is_set(wq_set))
return FALSE;
s = splsched();
wait_queue_lock(wq);
ret = wait_queue_member_locked(wq, wq_set);
wait_queue_unlock(wq);
splx(s);
return ret;
}
/*
* Routine: wait_queue_link_internal
* Purpose:
* Insert a set wait queue into a wait queue. This
* requires us to link the two together using a wait_queue_link
* structure that was provided.
* Conditions:
* The wait queue being inserted must be inited as a set queue
* The wait_queue_link structure must already be properly typed
*/
static
kern_return_t
wait_queue_link_internal(
wait_queue_t wq,
wait_queue_set_t wq_set,
wait_queue_link_t wql)
{
wait_queue_element_t wq_element;
queue_t q;
spl_t s;
if (!wait_queue_is_valid(wq) || !wait_queue_is_set(wq_set))
return KERN_INVALID_ARGUMENT;
/*
* There are probably fewer threads and sets associated with
* the wait queue than there are wait queues associated with
* the set. So let's validate it that way.
*/
s = splsched();
wait_queue_lock(wq);
q = &wq->wq_queue;
wq_element = (wait_queue_element_t) queue_first(q);
while (!queue_end(q, (queue_entry_t)wq_element)) {
WAIT_QUEUE_ELEMENT_CHECK(wq, wq_element);
if ((wq_element->wqe_type == WAIT_QUEUE_LINK ||
wq_element->wqe_type == WAIT_QUEUE_LINK_NOALLOC) &&
((wait_queue_link_t)wq_element)->wql_setqueue == wq_set) {
wait_queue_unlock(wq);
splx(s);
return KERN_ALREADY_IN_SET;
}
wq_element = (wait_queue_element_t)
queue_next((queue_t) wq_element);
}
/*
* Not already a member, so we can add it.
*/
wqs_lock(wq_set);
WAIT_QUEUE_SET_CHECK(wq_set);
assert(wql->wql_type == WAIT_QUEUE_LINK ||
wql->wql_type == WAIT_QUEUE_LINK_NOALLOC);
wql->wql_queue = wq;
wql_clear_prepost(wql);
queue_enter(&wq->wq_queue, wql, wait_queue_link_t, wql_links);
wql->wql_setqueue = wq_set;
queue_enter(&wq_set->wqs_setlinks, wql, wait_queue_link_t, wql_setlinks);
wqs_unlock(wq_set);
wait_queue_unlock(wq);
splx(s);
return KERN_SUCCESS;
}
/*
* Routine: wait_queue_link_noalloc
* Purpose:
* Insert a set wait queue into a wait queue. This
* requires us to link the two together using a wait_queue_link
* structure that we allocate.
* Conditions:
* The wait queue being inserted must be inited as a set queue
*/
kern_return_t
wait_queue_link_noalloc(
wait_queue_t wq,
wait_queue_set_t wq_set,
wait_queue_link_t wql)
{
wql->wql_type = WAIT_QUEUE_LINK_NOALLOC;
return wait_queue_link_internal(wq, wq_set, wql);
}
/*
* Routine: wait_queue_link
* Purpose:
* Insert a set wait queue into a wait queue. This
* requires us to link the two together using a wait_queue_link
* structure that we allocate.
* Conditions:
* The wait queue being inserted must be inited as a set queue
*/
kern_return_t
wait_queue_link(
wait_queue_t wq,
wait_queue_set_t wq_set)
{
wait_queue_link_t wql;
kern_return_t ret;
wql = (wait_queue_link_t) zalloc(_wait_queue_link_zone);
if (wql == WAIT_QUEUE_LINK_NULL)
return KERN_RESOURCE_SHORTAGE;
wql->wql_type = WAIT_QUEUE_LINK;
ret = wait_queue_link_internal(wq, wq_set, wql);
if (ret != KERN_SUCCESS)
zfree(_wait_queue_link_zone, wql);
return ret;
}
wait_queue_link_t
wait_queue_link_allocate(void)
{
wait_queue_link_t wql;
wql = zalloc(_wait_queue_link_zone); /* Can't fail */
bzero(wql, sizeof(*wql));
wql->wql_type = WAIT_QUEUE_UNLINKED;
return wql;
}
kern_return_t
wait_queue_link_free(wait_queue_link_t wql)
{
zfree(_wait_queue_link_zone, wql);
return KERN_SUCCESS;
}
/*
* Routine: wait_queue_unlink_locked
* Purpose:
* Undo the linkage between a wait queue and a set.
*/
static void
wait_queue_unlink_locked(
wait_queue_t wq,
wait_queue_set_t wq_set,
wait_queue_link_t wql)
{
assert(wait_queue_held(wq));
assert(wait_queue_held(&wq_set->wqs_wait_queue));
wql->wql_queue = WAIT_QUEUE_NULL;
queue_remove(&wq->wq_queue, wql, wait_queue_link_t, wql_links);
wql->wql_setqueue = WAIT_QUEUE_SET_NULL;
queue_remove(&wq_set->wqs_setlinks, wql, wait_queue_link_t, wql_setlinks);
if (wql_is_preposted(wql)) {
queue_t ppq = &wq_set->wqs_preposts;
queue_remove(ppq, wql, wait_queue_link_t, wql_preposts);
}
wql->wql_type = WAIT_QUEUE_UNLINKED;
WAIT_QUEUE_CHECK(wq);
WAIT_QUEUE_SET_CHECK(wq_set);
}
/*
* Routine: wait_queue_unlink_nofree
* Purpose:
* Remove the linkage between a wait queue and a set,
* returning the linkage structure to the caller to
* free later.
* Conditions:
* The wait queue being must be a member set queue
*/
kern_return_t
wait_queue_unlink_nofree(
wait_queue_t wq,
wait_queue_set_t wq_set,
wait_queue_link_t *wqlp)
{
wait_queue_element_t wq_element;
wait_queue_link_t wql;
queue_t q;
spl_t s;
if (!wait_queue_is_valid(wq) || !wait_queue_is_set(wq_set)) {
return KERN_INVALID_ARGUMENT;
}
s = splsched();
wait_queue_lock(wq);
q = &wq->wq_queue;
wq_element = (wait_queue_element_t) queue_first(q);
while (!queue_end(q, (queue_entry_t)wq_element)) {
WAIT_QUEUE_ELEMENT_CHECK(wq, wq_element);
if (wq_element->wqe_type == WAIT_QUEUE_LINK ||
wq_element->wqe_type == WAIT_QUEUE_LINK_NOALLOC) {
wql = (wait_queue_link_t)wq_element;
if (wql->wql_setqueue == wq_set) {
wqs_lock(wq_set);
wait_queue_unlink_locked(wq, wq_set, wql);
wqs_unlock(wq_set);
wait_queue_unlock(wq);
splx(s);
*wqlp = wql;
return KERN_SUCCESS;
}
}
wq_element = (wait_queue_element_t)
queue_next((queue_t) wq_element);
}
wait_queue_unlock(wq);
splx(s);
return KERN_NOT_IN_SET;
}
/*
* Routine: wait_queue_unlink
* Purpose:
* Remove the linkage between a wait queue and a set,
* freeing the linkage structure.
* Conditions:
* The wait queue being must be a member set queue
*/
kern_return_t
wait_queue_unlink(
wait_queue_t wq,
wait_queue_set_t wq_set)
{
wait_queue_element_t wq_element;
wait_queue_link_t wql;
queue_t q;
spl_t s;
if (!wait_queue_is_valid(wq) || !wait_queue_is_set(wq_set)) {
return KERN_INVALID_ARGUMENT;
}
s = splsched();
wait_queue_lock(wq);
q = &wq->wq_queue;
wq_element = (wait_queue_element_t) queue_first(q);
while (!queue_end(q, (queue_entry_t)wq_element)) {
WAIT_QUEUE_ELEMENT_CHECK(wq, wq_element);
if (wq_element->wqe_type == WAIT_QUEUE_LINK ||
wq_element->wqe_type == WAIT_QUEUE_LINK_NOALLOC) {
wql = (wait_queue_link_t)wq_element;
if (wql->wql_setqueue == wq_set) {
boolean_t alloced;
alloced = (wql->wql_type == WAIT_QUEUE_LINK);
wqs_lock(wq_set);
wait_queue_unlink_locked(wq, wq_set, wql);
wqs_unlock(wq_set);
wait_queue_unlock(wq);
splx(s);
if (alloced)
zfree(_wait_queue_link_zone, wql);
return KERN_SUCCESS;
}
}
wq_element = (wait_queue_element_t)
queue_next((queue_t) wq_element);
}
wait_queue_unlock(wq);
splx(s);
return KERN_NOT_IN_SET;
}
/*
* Routine: wait_queue_unlink_all_nofree_locked
* Purpose:
* Remove the linkage between a wait queue and all its sets.
* All the linkage structures are returned to the caller for
* later freeing.
* Conditions:
* Wait queue locked.
*/
static void
wait_queue_unlink_all_nofree_locked(
wait_queue_t wq,
queue_t links)
{
wait_queue_element_t wq_element;
wait_queue_element_t wq_next_element;
wait_queue_set_t wq_set;
wait_queue_link_t wql;
queue_t q;
q = &wq->wq_queue;
wq_element = (wait_queue_element_t) queue_first(q);
while (!queue_end(q, (queue_entry_t)wq_element)) {
WAIT_QUEUE_ELEMENT_CHECK(wq, wq_element);
wq_next_element = (wait_queue_element_t)
queue_next((queue_t) wq_element);
if (wq_element->wqe_type == WAIT_QUEUE_LINK ||
wq_element->wqe_type == WAIT_QUEUE_LINK_NOALLOC) {
wql = (wait_queue_link_t)wq_element;
wq_set = wql->wql_setqueue;
wqs_lock(wq_set);
wait_queue_unlink_locked(wq, wq_set, wql);
wqs_unlock(wq_set);
enqueue(links, &wql->wql_links);
}
wq_element = wq_next_element;
}
}
/*
* Routine: wait_queue_unlink_all_nofree
* Purpose:
* Remove the linkage between a wait queue and all its sets.
* All the linkage structures are returned to the caller for
* later freeing.
* Conditions:
* Nothing of interest locked.
*/
kern_return_t
wait_queue_unlink_all_nofree(
wait_queue_t wq,
queue_t links)
{
spl_t s;
if (!wait_queue_is_valid(wq)) {
return KERN_INVALID_ARGUMENT;
}
s = splsched();
wait_queue_lock(wq);
wait_queue_unlink_all_nofree_locked(wq, links);
wait_queue_unlock(wq);
splx(s);
return(KERN_SUCCESS);
}
/*
* Routine: wait_queue_unlink_all_locked
* Purpose:
* Remove the linkage between a locked wait queue and all its
* sets and enqueue the allocated ones onto the links queue
* provided.
* Conditions:
* Wait queue locked.
*/
static void
wait_queue_unlink_all_locked(
wait_queue_t wq,
queue_t links)
{
wait_queue_element_t wq_element;
wait_queue_element_t wq_next_element;
wait_queue_set_t wq_set;
wait_queue_link_t wql;
queue_t q;
q = &wq->wq_queue;
wq_element = (wait_queue_element_t) queue_first(q);
while (!queue_end(q, (queue_entry_t)wq_element)) {
boolean_t alloced;
WAIT_QUEUE_ELEMENT_CHECK(wq, wq_element);
wq_next_element = (wait_queue_element_t)
queue_next((queue_t) wq_element);
alloced = (wq_element->wqe_type == WAIT_QUEUE_LINK);
if (alloced || wq_element->wqe_type == WAIT_QUEUE_LINK_NOALLOC) {
wql = (wait_queue_link_t)wq_element;
wq_set = wql->wql_setqueue;
wqs_lock(wq_set);
wait_queue_unlink_locked(wq, wq_set, wql);
wqs_unlock(wq_set);
if (alloced)
enqueue(links, &wql->wql_links);
}
wq_element = wq_next_element;
}
}
/*
* Routine: wait_queue_unlink_all
* Purpose:
* Remove the linkage between a wait queue and all its sets.
* All the linkage structures that were allocated internally
* are freed. The others are the caller's responsibility.
* Conditions:
* Nothing of interest locked.
*/
kern_return_t
wait_queue_unlink_all(
wait_queue_t wq)
{
wait_queue_link_t wql;
queue_head_t links_queue_head;
queue_t links = &links_queue_head;
spl_t s;
if (!wait_queue_is_valid(wq)) {
return KERN_INVALID_ARGUMENT;
}
queue_init(links);
s = splsched();
wait_queue_lock(wq);
wait_queue_unlink_all_locked(wq, links);
wait_queue_unlock(wq);
splx(s);
while(!queue_empty(links)) {
wql = (wait_queue_link_t) dequeue(links);
zfree(_wait_queue_link_zone, wql);
}
return(KERN_SUCCESS);
}
/* legacy interface naming */
kern_return_t
wait_subqueue_unlink_all(
wait_queue_set_t wq_set)
{
return wait_queue_set_unlink_all(wq_set);
}
/*