/* * Copyright (c) 2003 Apple Computer, 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@ */ /* * Copyright (c) 1999,2000 Jonathan Lemon <jlemon@FreeBSD.org> * 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: src/sys/sys/eventvar.h,v 1.1.2.2 2000/07/18 21:49:12 jlemon Exp $ */ #ifndef _SYS_EVENTVAR_H_ #define _SYS_EVENTVAR_H_ #include <sys/event.h> #include <sys/select.h> #include <kern/kern_types.h> #include <kern/waitq.h> #if defined(XNU_KERNEL_PRIVATE) typedef int (*kevent_callback_t)(struct kqueue *, struct kevent_internal_s *, void *); typedef void (*kqueue_continue_t)(struct kqueue *, void *, int); #include <stdint.h> #include <kern/locks.h> #include <mach/thread_policy.h> #include <pthread/workqueue_internal.h> /* * Lock ordering: * * The kqueue locking order can follow a few different patterns: * * Standard file-based kqueues (from above): * proc fd lock -> kq lock -> kq-waitq-set lock -> thread lock * * WorkQ/WorkLoop kqueues (from above): * proc fd lock -> kq lock -> kq-request lock -> pthread kext locks -> thread lock * * Whenever kqueues interact with source locks, it drops all of its own * locks in exchange for a use-reference on the knote used to synchronize * with the source code. When those sources post events from below, they * have the following lock hierarchy. * * Standard file-based kqueues (from below): * XXX lock -> kq lock -> kq-waitq-set lock -> thread lock * Standard file-based kqueues with non-kq-aware sources (from below): * XXX lock -> kq-waitq-set lock -> thread lock * * WorkQ/WorkLoop kqueues (from below): * XXX lock -> kq lock -> kq-request lock -> pthread kext locks -> thread lock * WorkQ/WorkLoop kqueues with non-kq-aware sources (from below): * XXX -> kq-waitq-set lock -> kq-request lock -> pthread kext locks -> thread lock */ #define KQEXTENT 256 /* linear growth by this amount */ struct knote_lock_ctx { struct knote *knlc_knote; thread_t knlc_thread; // TODO: knlc_turnstile TAILQ_HEAD(, knote_lock_ctx) knlc_head; union { LIST_ENTRY(knote_lock_ctx) knlc_le; TAILQ_ENTRY(knote_lock_ctx) knlc_tqe; }; #if DEBUG || DEVELOPMENT #define KNOTE_LOCK_CTX_UNLOCKED 0 #define KNOTE_LOCK_CTX_LOCKED 1 #define KNOTE_LOCK_CTX_WAITING 2 int knlc_state; #endif }; LIST_HEAD(knote_locks, knote_lock_ctx); #if DEBUG || DEVELOPMENT /* * KNOTE_LOCK_CTX(name) is a convenience macro to define a knote lock context on * the stack named `name`. In development kernels, it uses tricks to make sure * not locks was still held when exiting the C-scope that contains this context. */ __attribute__((noinline,not_tail_called)) void knote_lock_ctx_chk(struct knote_lock_ctx *ctx); #define KNOTE_LOCK_CTX(n) \ struct knote_lock_ctx n __attribute__((cleanup(knote_lock_ctx_chk))); \ n.knlc_state = KNOTE_LOCK_CTX_UNLOCKED #else #define KNOTE_LOCK_CTX(n) \ struct knote_lock_ctx n #endif /* * kqueue - common core definition of a kqueue * * No real structures are allocated of this type. They are * either kqfile objects or kqworkq objects - each of which is * derived from this definition. */ struct kqueue { struct { struct waitq_set kq_wqs; /* private waitq set */ lck_spin_t kq_lock; /* kqueue lock */ uint16_t kq_state; /* state of the kq */ uint16_t kq_level; /* nesting level of the kq */ uint32_t kq_count; /* number of queued events */ struct proc *kq_p; /* process containing kqueue */ struct knote_locks kq_knlocks; /* list of knote locks held */ lck_spin_t kq_reqlock; /* kqueue request lock */ }; /* make sure struct padding is put before kq_queue */ struct kqtailq kq_queue[0]; /* variable array of queues */ }; #define KQ_SEL 0x001 /* select was recorded for kq */ #define KQ_SLEEP 0x002 /* thread is waiting for events */ #define KQ_PROCWAIT 0x004 /* thread waiting for processing */ #define KQ_KEV32 0x008 /* kq is used with 32-bit events */ #define KQ_KEV64 0x010 /* kq is used with 64-bit events */ #define KQ_KEV_QOS 0x020 /* kq events carry QoS info */ #define KQ_WORKQ 0x040 /* KQ is bound to process workq */ #define KQ_WORKLOOP 0x080 /* KQ is part of a workloop */ #define KQ_PROCESSING 0x100 /* KQ is being processed */ #define KQ_DRAIN 0x200 /* kq is draining */ #define KQ_WAKEUP 0x400 /* kq awakened while processing */ #define KQ_DYNAMIC 0x800 /* kqueue is dynamically managed */ /* * kqfile - definition of a typical kqueue opened as a file descriptor * via the kqueue() system call. * * Adds selinfo support to the base kqueue definition, as these * fds can be fed into select(). */ struct kqfile { struct kqueue kqf_kqueue; /* common kqueue core */ struct kqtailq kqf_queue; /* queue of woken up knotes */ struct kqtailq kqf_suppressed; /* suppression queue */ struct selinfo kqf_sel; /* parent select/kqueue info */ }; #define kqf_wqs kqf_kqueue.kq_wqs #define kqf_lock kqf_kqueue.kq_lock #define kqf_state kqf_kqueue.kq_state #define kqf_level kqf_kqueue.kq_level #define kqf_count kqf_kqueue.kq_count #define kqf_p kqf_kqueue.kq_p #define QOS_INDEX_KQFILE 0 /* number of qos levels in a file kq */ /* * kqrequest - per-QoS thread request status */ struct kqrequest { struct workq_threadreq_s kqr_req; /* used when request oustanding */ struct kqtailq kqr_suppressed; /* Per-QoS suppression queues */ thread_t kqr_thread; /* thread to satisfy request */ uint8_t kqr_state; /* KQ/workq interaction state */ #define KQWL_STAYACTIVE_FIRED_BIT (1 << 0) uint8_t kqr_wakeup_indexes; /* QoS/override levels that woke */ uint16_t kqr_dsync_waiters; /* number of dispatch sync waiters */ kq_index_t kqr_stayactive_qos; /* max QoS of statyactive knotes */ kq_index_t kqr_override_index; /* highest wakeup override index */ kq_index_t kqr_qos_index; /* QoS for the thread request */ }; #define KQR_WORKLOOP 0x01 /* owner is a workloop */ #define KQR_THREQUESTED 0x02 /* thread has been requested from workq */ #define KQR_WAKEUP 0x04 /* wakeup called during processing */ #define KQR_THOVERCOMMIT 0x08 /* overcommit needed for thread requests */ #define KQR_R2K_NOTIF_ARMED 0x10 /* ast notifications armed */ #define KQR_ALLOCATED_TURNSTILE 0x20 /* kqwl_turnstile is allocated */ /* * WorkQ kqueues need to request threads to service the triggered * knotes in the queue. These threads are brought up on a * effective-requested-QoS basis. Knotes are segregated based on * that value - calculated by computing max(event-QoS, kevent-QoS). * Only one servicing thread is requested at a time for all the * knotes at a given effective-requested-QoS. */ #if !defined(KQWQ_QOS_MANAGER) #define KQWQ_QOS_MANAGER (THREAD_QOS_LAST) #endif #if !defined(KQWQ_NBUCKETS) #define KQWQ_NBUCKETS (KQWQ_QOS_MANAGER + 1) #endif /* * kqworkq - definition of a private kqueue used to coordinate event * handling for pthread work queues. * * These have per-qos processing queues and state to coordinate with * the pthread kext to ask for threads at corresponding pthread priority * values. */ struct kqworkq { struct kqueue kqwq_kqueue; struct kqtailq kqwq_queue[KQWQ_NBUCKETS]; /* array of queues */ struct kqrequest kqwq_request[KQWQ_NBUCKETS]; /* per-QoS request states */ }; #define kqwq_wqs kqwq_kqueue.kq_wqs #define kqwq_lock kqwq_kqueue.kq_lock #define kqwq_state kqwq_kqueue.kq_state #define kqwq_level kqwq_kqueue.kq_level #define kqwq_count kqwq_kqueue.kq_count #define kqwq_p kqwq_kqueue.kq_p /* * WorkLoop kqueues need to request a thread to service the triggered * knotes in the queue. The thread is brought up on a * effective-requested-QoS basis. Knotes are segregated based on * that value. Once a request is made, it cannot be undone. If * events with higher QoS arrive after, they are stored in their * own queues and an override applied to the original request based * on the delta between the two QoS values. */ /* * "Stay-active" knotes are held in a separate bucket that indicates * special handling required. They are kept separate because the * wakeups issued to them don't have context to tell us where to go * to find and process them. All processing of them happens at the * highest QoS. Unlike WorkQ kqueues, there is no special singular * "manager thread" for a process. We simply request a servicing * thread at the higest known QoS when these are woken (or override * an existing request to that). */ #define KQWL_BUCKET_STAYACTIVE (THREAD_QOS_LAST) #if !defined(KQWL_NBUCKETS) #define KQWL_NBUCKETS (KQWL_BUCKET_STAYACTIVE + 1) #endif /* * kqworkloop - definition of a private kqueue used to coordinate event * handling for pthread workloops. * * Workloops vary from workqs in that only a single thread is ever * requested to service a workloop at a time. But unlike workqs, * workloops may be "owned" by user-space threads that are * synchronously draining an event off the workloop. In those cases, * any overrides have to be applied to the owner until it relinqueshes * ownership. * * NOTE: "lane" support is TBD. */ struct kqworkloop { struct kqueue kqwl_kqueue; /* queue of events */ struct kqtailq kqwl_queue[KQWL_NBUCKETS]; /* array of queues */ struct kqrequest kqwl_request; /* thread request state */ lck_mtx_t kqwl_statelock; /* state/debounce lock */ thread_t kqwl_owner; /* current [sync] owner thread */ uint32_t kqwl_retains; /* retain references */ kqueue_id_t kqwl_dynamicid; /* dynamic identity */ uint64_t kqwl_params; /* additional parameters */ struct turnstile *kqwl_turnstile; /* turnstile for sync IPC/waiters */ SLIST_ENTRY(kqworkloop) kqwl_hashlink; /* linkage for search list */ #if CONFIG_WORKLOOP_DEBUG #define KQWL_HISTORY_COUNT 32 #define KQWL_HISTORY_WRITE_ENTRY(kqwl, ...) ({ \ struct kqworkloop *__kqwl = (kqwl); \ unsigned int __index = os_atomic_inc_orig(&__kqwl->kqwl_index, relaxed); \ __kqwl->kqwl_history[__index % KQWL_HISTORY_COUNT] = \ (struct kqwl_history)__VA_ARGS__; \ }) struct kqwl_history { thread_t updater; /* Note: updates can be reordered */ thread_t servicer; thread_t old_owner; thread_t new_owner; uint64_t kev_ident; int16_t error; uint16_t kev_flags; uint32_t kev_fflags; uint64_t kev_mask; uint64_t kev_value; uint64_t in_value; } kqwl_history[KQWL_HISTORY_COUNT]; unsigned int kqwl_index; #endif // CONFIG_WORKLOOP_DEBUG }; typedef union { struct kqueue *kq; struct kqworkq *kqwq; struct kqfile *kqf; struct kqworkloop *kqwl; } __attribute__((transparent_union)) kqueue_t; SLIST_HEAD(kqlist, kqworkloop); #define kqwl_wqs kqwl_kqueue.kq_wqs #define kqwl_lock kqwl_kqueue.kq_lock #define kqwl_state kqwl_kqueue.kq_state #define kqwl_level kqwl_kqueue.kq_level #define kqwl_count kqwl_kqueue.kq_count #define kqwl_p kqwl_kqueue.kq_p #define KQ_WORKLOOP_RETAINS_MAX UINT32_MAX extern void kqueue_threadreq_unbind(struct proc *p, struct kqrequest *kqr); // called with the kq req held #define KQUEUE_THREADERQ_BIND_NO_INHERITOR_UPDATE 0x1 extern void kqueue_threadreq_bind(struct proc *p, workq_threadreq_t req, thread_t thread, unsigned int flags); // called with the wq lock held extern void kqueue_threadreq_bind_prepost(struct proc *p, workq_threadreq_t req, thread_t thread); // called with no lock held extern void kqueue_threadreq_bind_commit(struct proc *p, thread_t thread); extern void kqueue_threadreq_cancel(struct proc *p, workq_threadreq_t req); // lock not held as kqwl_params is immutable after creation extern workq_threadreq_param_t kqueue_threadreq_workloop_param(workq_threadreq_t req); extern struct kqueue *kqueue_alloc(struct proc *, unsigned int); extern void kqueue_dealloc(struct kqueue *); extern void knotes_dealloc(struct proc *); extern void kqworkloops_dealloc(struct proc *); extern int kevent_register(struct kqueue *, struct kevent_internal_s *, struct knote_lock_ctx *); extern int kqueue_scan(struct kqueue *, kevent_callback_t, kqueue_continue_t, void *, struct filt_process_s *, struct timeval *, struct proc *); extern int kqueue_stat(struct kqueue *, void *, int, proc_t); #endif /* XNU_KERNEL_PRIVATE */ #endif /* !_SYS_EVENTVAR_H_ */