Add kernel-only per-thread kqueue & helpers to initialize and free it.

This will soon be used by select(2) and poll(2).

ok anton@, visa@

4 files changed, 45 insertions, 5 deletions

diff --git a/sys/kern/kern_event.c b/sys/kern/kern_event.c
index d945c0692d3..9cd7c7dac8f 100644
--- a/sys/kern/kern_event.c
+++ b/sys/kern/kern_event.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: kern_event.c,v 1.146 2020/12/07 11:15:50 mpi Exp $	*/
+/*	$OpenBSD: kern_event.c,v 1.147 2020/12/09 18:58:19 mpi Exp $	*/
 
 /*-
  * Copyright (c) 1999,2000,2001 Jonathan Lemon <jlemon@FreeBSD.org>
@@ -57,6 +57,7 @@
 #include <sys/timeout.h>
 #include <sys/wait.h>
 
+struct	kqueue *kqueue_alloc(struct filedesc *);
 void	kqueue_terminate(struct proc *p, struct kqueue *);
 void	kqueue_free(struct kqueue *);
 void	kqueue_init(void);
@@ -504,6 +505,31 @@ const struct filterops dead_filtops = {
 	.f_event	= filt_dead,
 };
 
+void
+kqpoll_init(void)
+{
+	struct proc *p = curproc;
+
+	if (p->p_kq != NULL)
+		return;
+
+	p->p_kq = kqueue_alloc(p->p_fd);
+	p->p_kq_serial = arc4random();
+}
+
+void
+kqpoll_exit(void)
+{
+	struct proc *p = curproc;
+
+	if (p->p_kq == NULL)
+		return;
+
+	kqueue_terminate(p, p->p_kq);
+	kqueue_free(p->p_kq);
+	p->p_kq = NULL;
+}
+
 struct kqueue *
 kqueue_alloc(struct filedesc *fdp)
 {
@@ -1144,7 +1170,7 @@ kqueue_stat(struct file *fp, struct stat *st, struct proc *p)
 }
 
 void
-kqueue_terminate(struct proc *p, struct kqueue *kq)
+kqueue_purge(struct proc *p, struct kqueue *kq)
 {
 	int i;
 
@@ -1156,6 +1182,12 @@ kqueue_terminate(struct proc *p, struct kqueue *kq)
 		for (i = 0; i < kq->kq_knhashmask + 1; i++)
 			knote_remove(p, &kq->kq_knhash[i]);
 	}
+}
+
+void
+kqueue_terminate(struct proc *p, struct kqueue *kq)
+{
+	kqueue_purge(p, kq);
 	kq->kq_state |= KQ_DYING;
 	kqueue_wakeup(kq);
 
diff --git a/sys/kern/kern_exit.c b/sys/kern/kern_exit.c
index 92bbfe915b5..4738000e10d 100644
--- a/sys/kern/kern_exit.c
+++ b/sys/kern/kern_exit.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: kern_exit.c,v 1.192 2020/12/07 16:55:28 mpi Exp $	*/
+/*	$OpenBSD: kern_exit.c,v 1.193 2020/12/09 18:58:19 mpi Exp $	*/
 /*	$NetBSD: kern_exit.c,v 1.39 1996/04/22 01:38:25 christos Exp $	*/
 
 /*
@@ -185,6 +185,8 @@ exit1(struct proc *p, int xexit, int xsig, int flags)
 	if ((p->p_flag & P_THREAD) == 0)
 		pr->ps_siglist = 0;
 
+	kqpoll_exit();
+
 #if NKCOV > 0
 	kcov_exit(p);
 #endif
diff --git a/sys/sys/event.h b/sys/sys/event.h
index 9534b673836..93cc2200deb 100644
--- a/sys/sys/event.h
+++ b/sys/sys/event.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: event.h,v 1.48 2020/12/07 11:15:50 mpi Exp $	*/
+/*	$OpenBSD: event.h,v 1.49 2020/12/09 18:58:19 mpi Exp $	*/
 
 /*-
  * Copyright (c) 1999,2000,2001 Jonathan Lemon <jlemon@FreeBSD.org>
@@ -215,6 +215,8 @@ struct timespec;
 extern const struct filterops sig_filtops;
 extern const struct filterops dead_filtops;
 
+extern void	kqpoll_init(void);
+extern void	kqpoll_exit(void);
 extern void	knote(struct klist *list, long hint);
 extern void	knote_activate(struct knote *);
 extern void	knote_remove(struct proc *p, struct knlist *list);
@@ -226,6 +228,7 @@ extern int	kqueue_scan(struct kqueue_scan_state *, int, struct kevent *,
 		    struct timespec *, struct proc *, int *);
 extern void	kqueue_scan_setup(struct kqueue_scan_state *, struct kqueue *);
 extern void	kqueue_scan_finish(struct kqueue_scan_state *);
+extern void	kqueue_purge(struct proc *, struct kqueue *);
 extern int	filt_seltrue(struct knote *kn, long hint);
 extern int	seltrue_kqfilter(dev_t, struct knote *);
 extern void	klist_insert(struct klist *, struct knote *);
diff --git a/sys/sys/proc.h b/sys/sys/proc.h
index 6ab055506e9..929691496e7 100644
--- a/sys/sys/proc.h
+++ b/sys/sys/proc.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: proc.h,v 1.302 2020/12/07 16:55:29 mpi Exp $	*/
+/*	$OpenBSD: proc.h,v 1.303 2020/12/09 18:58:19 mpi Exp $	*/
 /*	$NetBSD: proc.h,v 1.44 1996/04/22 01:23:21 christos Exp $	*/
 
 /*-
@@ -324,6 +324,7 @@ struct process {
 
 struct kcov_dev;
 struct lock_list_entry;
+struct kqueue;
 
 struct p_inentry {
 	u_long	 ie_serial;
@@ -390,6 +391,8 @@ struct proc {
 	struct	plimit	*p_limit;	/* [l] read ref. of p_p->ps_limit */
 	struct	kcov_dev *p_kd;		/* kcov device handle */
 	struct	lock_list_entry *p_sleeplocks;	/* WITNESS lock tracking */ 
+	struct	kqueue *p_kq;		/* [o] select/poll queue of evts */
+	unsigned long p_kq_serial;	/* [o] to check against enqueued evts */
 
 	int	 p_siglist;		/* [a] Signals arrived & not delivered*/