X-Git-Url: https://git.saurik.com/apple/xnu.git/blobdiff_plain/3903760236c30e3b5ace7a4eefac3a269d68957c..bca245acd4c03fd752d1a45f011ad495e60fe53d:/bsd/sys/eventvar.h diff --git a/bsd/sys/eventvar.h b/bsd/sys/eventvar.h index 8d47aad64..62387f2b6 100644 --- a/bsd/sys/eventvar.h +++ b/bsd/sys/eventvar.h @@ -2,7 +2,7 @@ * 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 @@ -11,10 +11,10 @@ * 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, @@ -22,10 +22,10 @@ * 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 * All rights reserved. * @@ -63,10 +63,89 @@ #if defined(XNU_KERNEL_PRIVATE) +typedef int (*kevent_callback_t)(struct kevent_qos_s *, struct kevent_ctx_s *); + +#include #include #include +#include + +/* + * 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 -> workq lock -> 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 + * + * WorkQ/WorkLoop kqueues (from below): + * XXX lock -> kq lock -> workq lock -> thread lock + */ + +#define KQEXTENT 256 /* linear growth by this amount */ + +struct knote_lock_ctx { + struct knote *knlc_knote; + thread_t knlc_thread; + uintptr_t knlc_waiters; + LIST_ENTRY(knote_lock_ctx) knlc_link; +#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); -#define KQEXTENT 256 /* linear growth by this amount */ +#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. + */ +static inline void +knote_lock_ctx_chk(struct knote_lock_ctx *knlc) +{ + /* evil hackery to make sure no one forgets to unlock */ + assert(knlc->knlc_state == KNOTE_LOCK_CTX_UNLOCKED); +} +#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 + + +__options_decl(kq_state_t, uint16_t, { + KQ_SEL = 0x0001, /* select was recorded for kq */ + KQ_SLEEP = 0x0002, /* thread is waiting for events */ + KQ_PROCWAIT = 0x0004, /* thread waiting for processing */ + KQ_KEV32 = 0x0008, /* kq is used with 32-bit events */ + KQ_KEV64 = 0x0010, /* kq is used with 64-bit events */ + KQ_KEV_QOS = 0x0020, /* kq events carry QoS info */ + KQ_WORKQ = 0x0040, /* KQ is bound to process workq */ + KQ_WORKLOOP = 0x0080, /* KQ is part of a workloop */ + KQ_PROCESSING = 0x0100, /* KQ is being processed */ + KQ_DRAIN = 0x0200, /* kq is draining */ + KQ_WAKEUP = 0x0400, /* kq awakened while processing */ + KQ_DYNAMIC = 0x0800, /* kqueue is dynamically managed */ + KQ_R2K_ARMED = 0x1000, /* ast notification armed */ + KQ_HAS_TURNSTILE = 0x2000, /* this kqueue has a turnstile */ +}); /* * kqueue - common core definition of a kqueue @@ -76,26 +155,21 @@ * derived from this definition. */ struct kqueue { - 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 kqtailq kq_queue[1]; /* variable array of kqtailq structs */ + struct { + struct waitq_set kq_wqs; /* private waitq set */ + lck_spin_t kq_lock; /* kqueue lock */ + kq_state_t kq_state; /* state of the kq */ + union { + uint16_t kq_waitq_hook;/* prepost hook (kqwl/kqwq) */ + 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 */ + }; /* 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 bould to process workq */ -#define KQ_PROCESSING 0x080 /* KQ is being processed */ -#define KQ_DRAIN 0x100 /* kq is draining */ -#define KQ_WAKEUP 0x200 /* kq awakened while processing */ - /* * kqfile - definition of a typical kqueue opened as a file descriptor * via the kqueue() system call. @@ -105,17 +179,16 @@ struct kqueue { */ 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 kqf_queue kqf_kqueue.kq_queue +}; #define QOS_INDEX_KQFILE 0 /* number of qos levels in a file kq */ @@ -132,101 +205,165 @@ struct kqfile { #define KQWQ_QOS_MANAGER (THREAD_QOS_LAST) #endif -#if !defined(KQWQ_NQOS) -#define KQWQ_NQOS (KQWQ_QOS_MANAGER + 1) +#if !defined(KQWQ_NBUCKETS) +#define KQWQ_NBUCKETS (KQWQ_QOS_MANAGER + 1) #endif - /* - * kqrequest - per-QoS thread request status + * 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 kqrequest { - struct kqtailq kqr_suppressed; /* Per-QoS suppression queues */ - thread_t kqr_thread; /* thread to satisfy request */ - uint8_t kqr_state; /* KQ/workq interaction state */ - uint8_t kqr_override_delta; /* current override delta */ +struct kqworkq { + struct kqueue kqwq_kqueue; + struct kqtailq kqwq_queue[KQWQ_NBUCKETS]; /* array of queues */ + struct kqtailq kqwq_suppressed[KQWQ_NBUCKETS]; /* Per-QoS suppression queues */ + workq_threadreq_s 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_waitq_hook kqwq_kqueue.kq_waitq_hook +#define kqwq_count kqwq_kqueue.kq_count +#define kqwq_p kqwq_kqueue.kq_p + /* - * Workq thread start out a particular effective-requested-QoS, but - * additional events processed by the filters may represent - * backlogged events that may themselves have a higher requested-QoS. - * To represent this, the filter may apply an override to a knote's - * requested QoS. - * - * We further segregate these overridden knotes into different buckets - * by grouping. This allows easy matching of - * knotes to process vs. the highest workq thread override applied. - * - * Only certain override patterns need to be supported. A knote - * cannot have an effective-requested-QoS of UNSPECIFIED - because - * the kevent->qos (when canonicalized) will always be above that - * or indicate manager. And we don't allow an override to specify - * manager. This results in the following buckets being needed: - * - * Effective-Requested QoS - * MAINT BG UTIL DEFAULT UINIT UINTER MANAGER - * override: - * MAINT 0 - * BG 1 6 - * UTILITY 2 7 11 - * DEFAULT 3 8 12 15 - * UINIT 4 9 13 16 18 - * UINTER 5 10 14 17 19 20 - * 21 + * 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. */ -#if !defined(KQWQ_NBUCKETS) -#define KQWQ_NBUCKETS 22 + +/* + * "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 /* - * kqworkq - definition of a private kqueue used to coordinate event - * handling for pthread work queues. + * kqworkloop - definition of a private kqueue used to coordinate event + * handling for pthread workloops. * - * These have per-qos processing queues and state to coordinate with - * the pthread kext to ask for threads at corresponding pthread priority - * values. + * 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 kqworkq { - struct kqueue kqwq_kqueue; - struct kqtailq kqwq_queuecont[KQWQ_NBUCKETS-1]; /* continue array of queues */ - struct kqrequest kqwq_request[KQWQ_NQOS]; /* per-QoS request states */ - lck_spin_t kqwq_reqlock; /* kqueue request lock */ +struct kqworkloop { + struct kqueue kqwl_kqueue; /* queue of events */ + struct kqtailq kqwl_queue[KQWL_NBUCKETS]; /* array of queues */ + struct kqtailq kqwl_suppressed; /* Per-QoS suppression queues */ + workq_threadreq_s kqwl_request; /* thread request state */ + lck_spin_t kqwl_statelock; /* state/debounce lock */ + thread_t kqwl_owner; /* current [sync] owner thread */ + uint32_t kqwl_retains; /* retain references */ +#define KQWL_STAYACTIVE_FIRED_BIT (1 << 0) + uint8_t kqwl_wakeup_indexes; /* QoS/override levels that woke */ + kq_index_t kqwl_stayactive_qos; /* max QoS of statyactive knotes */ + struct turnstile *kqwl_turnstile; /* turnstile for sync IPC/waiters */ + kqueue_id_t kqwl_dynamicid; /* dynamic identity */ + uint64_t kqwl_params; /* additional parameters */ + LIST_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 }; +LIST_HEAD(kqwllist, kqworkloop); -#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 -#define kqwq_queue kqwq_kqueue.kq_queue - -#define kqwq_req_lock(kqwq) (lck_spin_lock(&kqwq->kqwq_reqlock)) -#define kqwq_req_unlock(kqwq) (lck_spin_unlock(&kqwq->kqwq_reqlock)) -#define kqwq_req_held(kqwq) (lck_spin_held(&kqwq->kqwq_reqlock)) - -#define KQWQ_PROCESSING 0x01 /* running the kq in workq mode */ -#define KQWQ_THREQUESTED 0x02 /* thread requested from workq */ -#define KQWQ_THMANAGER 0x04 /* expect manager thread to run the queue */ -#define KQWQ_HOOKCALLED 0x10 /* hook called during processing */ -#define KQWQ_WAKEUP 0x20 /* wakeup called during processing */ - -extern struct kqueue *kqueue_alloc(struct proc *, unsigned int); -extern void kqueue_dealloc(struct kqueue *); +typedef union { + struct kqueue *kq; + struct kqworkq *kqwq; + struct kqfile *kqf; + struct kqworkloop *kqwl; +} __attribute__((transparent_union)) kqueue_t; -typedef int (*kevent_callback_t)(struct kqueue *, struct kevent_internal_s *, void *); -typedef void (*kqueue_continue_t)(struct kqueue *, void *, int); -extern void kevent_register(struct kqueue *, struct kevent_internal_s *, struct proc *); -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); +#define kqwl_wqs kqwl_kqueue.kq_wqs +#define kqwl_lock kqwl_kqueue.kq_lock +#define kqwl_state kqwl_kqueue.kq_state +#define kqwl_waitq_hook kqwl_kqueue.kq_waitq_hook +#define kqwl_count kqwl_kqueue.kq_count +#define kqwl_p kqwl_kqueue.kq_p -#endif /* XNU_KERNEL_PRIVATE */ +#define KQ_WORKLOOP_RETAINS_MAX UINT32_MAX -#endif /* !_SYS_EVENTVAR_H_ */ +extern void kqueue_threadreq_unbind(struct proc *p, workq_threadreq_t); + +// 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); + +struct turnstile *kqueue_threadreq_get_turnstile(workq_threadreq_t kqr); + +// called with the wq lock held +extern void kqueue_threadreq_bind_prepost(struct proc *p, workq_threadreq_t req, + struct uthread *uth); +// 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 *); +extern void kqueue_dealloc(struct kqueue *); +extern void kqworkq_dealloc(struct kqworkq *kqwq); + +extern void knotes_dealloc(struct proc *); +extern void kqworkloops_dealloc(struct proc *); + +extern int kevent_register(struct kqueue *, struct kevent_qos_s *, + struct knote **); +extern int kqueue_scan(struct kqueue *, int flags, + struct kevent_ctx_s *, kevent_callback_t); +extern int kqueue_stat(struct kqueue *, void *, int, proc_t); + +#endif /* XNU_KERNEL_PRIVATE */ + +#endif /* !_SYS_EVENTVAR_H_ */