[src/trunk]: src/sys - Change selremove_knote() from returning void to bool, ...

[thorpej <thorpej%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/57e3071c4717
branches:  trunk
changeset: 987495:57e3071c4717
user:      thorpej <thorpej%NetBSD.org@localhost>
date:      Wed Sep 29 02:47:22 2021 +0000

description:
- Change selremove_knote() from returning void to bool, and return
  true if the last knote was removed and there are no more knotes
  on the selinfo.
- Use this new return value in filt_sordetach(), filt_sowdetach(),
  filt_fifordetach(), and filt_fifowdetach() to know when to clear
  SB_KOTE without having to know select/kqueue implementation details.

diffstat:

 sys/kern/sys_select.c          |  10 +++++++---
 sys/kern/uipc_socket.c         |  14 ++++++--------
 sys/miscfs/fifofs/fifo_vnops.c |  14 ++++++--------
 sys/sys/select.h               |   4 ++--
 4 files changed, 21 insertions(+), 21 deletions(-)

diffs (137 lines):

diff -r a63b6e5d938e -r 57e3071c4717 sys/kern/sys_select.c
--- a/sys/kern/sys_select.c     Tue Sep 28 15:35:44 2021 +0000
+++ b/sys/kern/sys_select.c     Wed Sep 29 02:47:22 2021 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: sys_select.c,v 1.55 2020/12/11 01:25:29 thorpej Exp $  */
+/*     $NetBSD: sys_select.c,v 1.56 2021/09/29 02:47:22 thorpej Exp $  */
 
 /*-
  * Copyright (c) 2007, 2008, 2009, 2010, 2019, 2020 The NetBSD Foundation, Inc.
@@ -84,7 +84,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: sys_select.c,v 1.55 2020/12/11 01:25:29 thorpej Exp $");
+__KERNEL_RCSID(0, "$NetBSD: sys_select.c,v 1.56 2021/09/29 02:47:22 thorpej Exp $");
 
 #include <sys/param.h>
 #include <sys/systm.h>
@@ -682,11 +682,15 @@
  * Remove a knote.
  *
  * The caller holds the same lock as for selrecord().
+ *
+ * Returns true if the last knote was removed and the list
+ * is now empty.
  */
-void
+bool
 selremove_knote(struct selinfo *sip, struct knote *kn)
 {
        SLIST_REMOVE(&sip->sel_klist, kn, knote, kn_selnext);
+       return SLIST_EMPTY(&sip->sel_klist);
 }
 
 /*
diff -r a63b6e5d938e -r 57e3071c4717 sys/kern/uipc_socket.c
--- a/sys/kern/uipc_socket.c    Tue Sep 28 15:35:44 2021 +0000
+++ b/sys/kern/uipc_socket.c    Wed Sep 29 02:47:22 2021 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: uipc_socket.c,v 1.296 2021/09/26 01:16:10 thorpej Exp $        */
+/*     $NetBSD: uipc_socket.c,v 1.297 2021/09/29 02:47:22 thorpej Exp $        */
 
 /*
  * Copyright (c) 2002, 2007, 2008, 2009 The NetBSD Foundation, Inc.
@@ -71,7 +71,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: uipc_socket.c,v 1.296 2021/09/26 01:16:10 thorpej Exp $");
+__KERNEL_RCSID(0, "$NetBSD: uipc_socket.c,v 1.297 2021/09/29 02:47:22 thorpej Exp $");
 
 #ifdef _KERNEL_OPT
 #include "opt_compat_netbsd.h"
@@ -2225,9 +2225,8 @@
 
        so = ((file_t *)kn->kn_obj)->f_socket;
        solock(so);
-       selremove_knote(&so->so_rcv.sb_sel, kn);
-       if (SLIST_EMPTY(&so->so_rcv.sb_sel.sel_klist))  /* XXX select/kqueue */
-               so->so_rcv.sb_flags &= ~SB_KNOTE;       /* XXX internals */
+       if (selremove_knote(&so->so_rcv.sb_sel, kn))
+               so->so_rcv.sb_flags &= ~SB_KNOTE;
        sounlock(so);
 }
 
@@ -2264,9 +2263,8 @@
 
        so = ((file_t *)kn->kn_obj)->f_socket;
        solock(so);
-       selremove_knote(&so->so_snd.sb_sel, kn);
-       if (SLIST_EMPTY(&so->so_snd.sb_sel.sel_klist))  /* XXX select/kqueue */
-               so->so_snd.sb_flags &= ~SB_KNOTE;       /* XXX internals */
+       if (selremove_knote(&so->so_snd.sb_sel, kn))
+               so->so_snd.sb_flags &= ~SB_KNOTE;
        sounlock(so);
 }
 
diff -r a63b6e5d938e -r 57e3071c4717 sys/miscfs/fifofs/fifo_vnops.c
--- a/sys/miscfs/fifofs/fifo_vnops.c    Tue Sep 28 15:35:44 2021 +0000
+++ b/sys/miscfs/fifofs/fifo_vnops.c    Wed Sep 29 02:47:22 2021 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: fifo_vnops.c,v 1.84 2021/09/26 01:16:10 thorpej Exp $  */
+/*     $NetBSD: fifo_vnops.c,v 1.85 2021/09/29 02:47:22 thorpej Exp $  */
 
 /*-
  * Copyright (c) 2008 The NetBSD Foundation, Inc.
@@ -58,7 +58,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: fifo_vnops.c,v 1.84 2021/09/26 01:16:10 thorpej Exp $");
+__KERNEL_RCSID(0, "$NetBSD: fifo_vnops.c,v 1.85 2021/09/29 02:47:22 thorpej Exp $");
 
 #include <sys/param.h>
 #include <sys/systm.h>
@@ -516,9 +516,8 @@
 
        so = (struct socket *)kn->kn_hook;
        solock(so);
-       selremove_knote(&so->so_rcv.sb_sel, kn);
-       if (SLIST_EMPTY(&so->so_rcv.sb_sel.sel_klist))  /* XXX select/kqueue */
-               so->so_rcv.sb_flags &= ~SB_KNOTE;       /* XXX internals */
+       if (selremove_knote(&so->so_rcv.sb_sel, kn))
+               so->so_rcv.sb_flags &= ~SB_KNOTE;
        sounlock(so);
 }
 
@@ -551,9 +550,8 @@
 
        so = (struct socket *)kn->kn_hook;
        solock(so);
-       selremove_knote(&so->so_snd.sb_sel, kn);
-       if (SLIST_EMPTY(&so->so_snd.sb_sel.sel_klist))  /* XXX select/kqueue */
-               so->so_snd.sb_flags &= ~SB_KNOTE;       /* XXX internals */
+       if (selremove_knote(&so->so_snd.sb_sel, kn))
+               so->so_snd.sb_flags &= ~SB_KNOTE;
        sounlock(so);
 }
 
diff -r a63b6e5d938e -r 57e3071c4717 sys/sys/select.h
--- a/sys/sys/select.h  Tue Sep 28 15:35:44 2021 +0000
+++ b/sys/sys/select.h  Wed Sep 29 02:47:22 2021 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: select.h,v 1.38 2020/12/11 01:25:29 thorpej Exp $      */
+/*     $NetBSD: select.h,v 1.39 2021/09/29 02:47:22 thorpej Exp $      */
 
 /*-
  * Copyright (c) 1992, 1993
@@ -53,7 +53,7 @@
     struct timespec *, sigset_t *);
 void   selrecord(struct lwp *selector, struct selinfo *);
 void   selrecord_knote(struct selinfo *, struct knote *);
-void   selremove_knote(struct selinfo *, struct knote *);
+bool   selremove_knote(struct selinfo *, struct knote *);
 void   selnotify(struct selinfo *, int, long);
 void   selsysinit(struct cpu_info *);
 void   selinit(struct selinfo *);