freebsd-skq/sys/kern/uipc_debug.c
Robert Watson 7abab91135 sblock() implements a sleep lock by interlocking SB_WANT and SB_LOCK flags
on each socket buffer with the socket buffer's mutex.  This sleep lock is
used to serialize I/O on sockets in order to prevent I/O interlacing.

This change replaces the custom sleep lock with an sx(9) lock, which
results in marginally better performance, better handling of contention
during simultaneous socket I/O across multiple threads, and a cleaner
separation between the different layers of locking in socket buffers.
Specifically, the socket buffer mutex is now solely responsible for
serializing simultaneous operation on the socket buffer data structure,
and not for I/O serialization.

While here, fix two historic bugs:

(1) a bug allowing I/O to be occasionally interlaced during long I/O
    operations (discovere by Isilon).

(2) a bug in which failed non-blocking acquisition of the socket buffer
    I/O serialization lock might be ignored (discovered by sam).

SCTP portion of this patch submitted by rrs.
2007-05-03 14:42:42 +00:00

523 lines
12 KiB
C

/*-
* Copyright (c) 2007 Robert N. M. Watson
* 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.
*/
/*
* Debugger routines relating to sockets, protocols, etc, for use in DDB.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include "opt_ddb.h"
#include <sys/param.h>
#include <sys/domain.h>
#include <sys/kernel.h>
#include <sys/protosw.h>
#include <sys/socket.h>
#include <sys/socketvar.h>
#ifdef DDB
#include <ddb/ddb.h>
static void
db_print_sotype(short so_type)
{
switch (so_type) {
case SOCK_STREAM:
db_printf("SOCK_STREAM");
break;
case SOCK_DGRAM:
db_printf("SOCK_DGRAM");
break;
case SOCK_RAW:
db_printf("SOCK_RAW");
break;
case SOCK_RDM:
db_printf("SOCK_RDM");
break;
case SOCK_SEQPACKET:
db_printf("SOCK_SEQPACKET");
break;
default:
db_printf("unknown");
break;
}
}
static void
db_print_sooptions(short so_options)
{
int comma;
comma = 0;
if (so_options & SO_DEBUG) {
db_printf("%sSO_DEBUG", comma ? ", " : "");
comma = 1;
}
if (so_options & SO_ACCEPTCONN) {
db_printf("%sSO_ACCEPTCONN", comma ? ", " : "");
comma = 1;
}
if (so_options & SO_REUSEADDR) {
db_printf("%sSO_REUSEADDR", comma ? ", " : "");
comma = 1;
}
if (so_options & SO_KEEPALIVE) {
db_printf("%sSO_KEEPALIVE", comma ? ", " : "");
comma = 1;
}
if (so_options & SO_DONTROUTE) {
db_printf("%sSO_DONTROUTE", comma ? ", " : "");
comma = 1;
}
if (so_options & SO_BROADCAST) {
db_printf("%sSO_BROADCAST", comma ? ", " : "");
comma = 1;
}
if (so_options & SO_USELOOPBACK) {
db_printf("%sSO_USELOOPBACK", comma ? ", " : "");
comma = 1;
}
if (so_options & SO_LINGER) {
db_printf("%sSO_LINGER", comma ? ", " : "");
comma = 1;
}
if (so_options & SO_OOBINLINE) {
db_printf("%sSO_OOBINLINE", comma ? ", " : "");
comma = 1;
}
if (so_options & SO_REUSEPORT) {
db_printf("%sSO_REUSEPORT", comma ? ", " : "");
comma = 1;
}
if (so_options & SO_TIMESTAMP) {
db_printf("%sSO_TIMESTAMP", comma ? ", " : "");
comma = 1;
}
if (so_options & SO_NOSIGPIPE) {
db_printf("%sSO_NOSIGPIPE", comma ? ", " : "");
comma = 1;
}
if (so_options & SO_ACCEPTFILTER) {
db_printf("%sSO_ACCEPTFILTER", comma ? ", " : "");
comma = 1;
}
if (so_options & SO_BINTIME) {
db_printf("%sSO_BINTIME", comma ? ", " : "");
comma = 1;
}
}
static void
db_print_sostate(short so_state)
{
int comma;
comma = 0;
if (so_state & SS_NOFDREF) {
db_printf("%sSS_FDREF", comma ? ", " : "");
comma = 1;
}
if (so_state & SS_ISCONNECTED) {
db_printf("%sSS_ISCONNECTED", comma ? ", " : "");
comma = 1;
}
if (so_state & SS_ISCONNECTING) {
db_printf("%sSS_ISCONNECTING", comma ? ", " : "");
comma = 1;
}
if (so_state & SS_ISDISCONNECTING) {
db_printf("%sSS_ISDISCONNECTING", comma ? ", " : "");
comma = 1;
}
if (so_state & SS_NBIO) {
db_printf("%sSS_NBIO", comma ? ", " : "");
comma = 1;
}
if (so_state & SS_ASYNC) {
db_printf("%sSS_ASYNC", comma ? ", " : "");
comma = 1;
}
if (so_state & SS_ISCONFIRMING) {
db_printf("%sSS_ISCONFIRMING", comma ? ", " : "");
comma = 1;
}
comma = 0;
if (so_state & SS_PROTOREF) {
db_printf("%sSS_PROTOREF", comma ? ", " : "");
comma = 1;
}
}
static void
db_print_soqstate(int so_qstate)
{
int comma;
comma = 0;
if (so_qstate & SQ_INCOMP) {
db_printf("%sSQ_INCOMP", comma ? ", " : "");
comma = 1;
}
if (so_qstate & SQ_COMP) {
db_printf("%sSQ_COMP", comma ? ", " : "");
comma = 1;
}
}
static void
db_print_sbstate(short sb_state)
{
int comma;
comma = 0;
if (sb_state & SBS_CANTSENDMORE) {
db_printf("%sSS_CANTSENDMORE", comma ? ", " : "");
comma = 1;
}
if (sb_state & SBS_CANTRCVMORE) {
db_printf("%sSS_CANTRCVMORE", comma ? ", " : "");
comma = 1;
}
if (sb_state & SBS_RCVATMARK) {
db_printf("%sSS_RCVATMARK", comma ? ", " : "");
comma = 1;
}
}
static void
db_print_indent(int indent)
{
int i;
for (i = 0; i < indent; i++)
db_printf(" ");
}
static void
db_print_domain(struct domain *d, const char *domainname, int indent)
{
db_print_indent(indent);
db_printf("%s at %p\n", domainname, d);
indent += 2;
db_print_indent(indent);
db_printf("dom_family: %d ", d->dom_family);
db_printf("dom_name: %s\n", d->dom_name);
db_print_indent(indent);
db_printf("dom_init: %p ", d->dom_init);
db_printf("dom_externalize: %p ", d->dom_externalize);
db_printf("dom_dispose: %p\n", d->dom_dispose);
db_print_indent(indent);
db_printf("dom_protosw: %p ", d->dom_protosw);
db_printf("dom_next: %p\n", d->dom_next);
db_print_indent(indent);
db_printf("dom_rtattach: %p ", d->dom_rtattach);
db_printf("dom_rtoffset: %d ", d->dom_rtoffset);
db_printf("dom_maxrtkey: %d\n", d->dom_maxrtkey);
db_print_indent(indent);
db_printf("dom_ifattach: %p ", d->dom_ifattach);
db_printf("dom_ifdetach: %p\n", d->dom_ifdetach);
}
static void
db_print_prflags(short pr_flags)
{
int comma;
comma = 0;
if (pr_flags & PR_ATOMIC) {
db_printf("%sPR_ATOMIC", comma ? ", " : "");
comma = 1;
}
if (pr_flags & PR_ADDR) {
db_printf("%sPR_ADDR", comma ? ", " : "");
comma = 1;
}
if (pr_flags & PR_CONNREQUIRED) {
db_printf("%sPR_CONNREQUIRED", comma ? ", " : "");
comma = 1;
}
if (pr_flags & PR_WANTRCVD) {
db_printf("%sPR_WANTRCVD", comma ? ", " : "");
comma = 1;
}
if (pr_flags & PR_RIGHTS) {
db_printf("%sPR_RIGHTS", comma ? ", " : "");
comma = 1;
}
if (pr_flags & PR_IMPLOPCL) {
db_printf("%sPR_IMPLOPCL", comma ? ", " : "");
comma = 1;
}
if (pr_flags & PR_LASTHDR) {
db_printf("%sPR_LASTHDR", comma ? ", " : "");
comma = 1;
}
}
static void
db_print_protosw(struct protosw *pr, const char *prname, int indent)
{
db_print_indent(indent);
db_printf("%s at %p\n", prname, pr);
indent += 2;
db_print_indent(indent);
db_printf("pr_type: %d ", pr->pr_type);
db_printf("pr_domain: %p\n", pr->pr_domain);
if (pr->pr_domain != NULL)
db_print_domain(pr->pr_domain, "pr_domain", indent);
db_print_indent(indent);
db_printf("pr_protocol: %d\n", pr->pr_protocol);
db_print_indent(indent);
db_printf("pr_flags: %d (", pr->pr_flags);
db_print_prflags(pr->pr_flags);
db_printf(")\n");
db_print_indent(indent);
db_printf("pr_input: %p ", pr->pr_input);
db_printf("pr_output: %p ", pr->pr_output);
db_printf("pr_ctlinput: %p\n", pr->pr_ctlinput);
db_print_indent(indent);
db_printf("pr_ctloutput: %p ", pr->pr_ctloutput);
db_printf("pr_ousrreq: %p ", pr->pr_ousrreq);
db_printf("pr_init: %p\n", pr->pr_init);
db_print_indent(indent);
db_printf("pr_fasttimo: %p ", pr->pr_fasttimo);
db_printf("pr_slowtimo: %p ", pr->pr_slowtimo);
db_printf("pr_drain: %p\n", pr->pr_drain);
db_print_indent(indent);
db_printf("pr_ousrreq: %p\n", pr->pr_ousrreq);
}
static void
db_print_sbflags(short sb_flags)
{
int comma;
comma = 0;
if (sb_flags & SB_WAIT) {
db_printf("%sSB_WAIT", comma ? ", " : "");
comma = 1;
}
if (sb_flags & SB_SEL) {
db_printf("%sSB_SEL", comma ? ", " : "");
comma = 1;
}
if (sb_flags & SB_ASYNC) {
db_printf("%sSB_ASYNC", comma ? ", " : "");
comma = 1;
}
if (sb_flags & SB_UPCALL) {
db_printf("%sSB_UPCALL", comma ? ", " : "");
comma = 1;
}
if (sb_flags & SB_NOINTR) {
db_printf("%sSB_NOINTR", comma ? ", " : "");
comma = 1;
}
if (sb_flags & SB_AIO) {
db_printf("%sSB_AIO", comma ? ", " : "");
comma = 1;
}
if (sb_flags & SB_KNOTE) {
db_printf("%sSB_KNOTE", comma ? ", " : "");
comma = 1;
}
if (sb_flags & SB_AUTOSIZE) {
db_printf("%sSB_AUTOSIZE", comma ? ", " : "");
comma = 1;
}
}
static void
db_print_sockbuf(struct sockbuf *sb, const char *sockbufname, int indent)
{
db_print_indent(indent);
db_printf("%s at %p\n", sockbufname, sb);
indent += 2;
db_print_indent(indent);
db_printf("sb_state: 0x%x (", sb->sb_state);
db_print_sbstate(sb->sb_state);
db_printf(")\n");
db_print_indent(indent);
db_printf("sb_mb: %p ", sb->sb_mb);
db_printf("sb_mbtail: %p ", sb->sb_mbtail);
db_printf("sb_lastrecord: %p\n", sb->sb_lastrecord);
db_print_indent(indent);
db_printf("sb_cc: %d ", sb->sb_cc);
db_printf("sb_hiwat: %d ", sb->sb_hiwat);
db_printf("sb_mbcnt: %d ", sb->sb_mbcnt);
db_printf("sb_mbmax: %d\n", sb->sb_mbmax);
db_print_indent(indent);
db_printf("sb_ctl: %d ", sb->sb_ctl);
db_printf("sb_lowat: %d ", sb->sb_lowat);
db_printf("sb_timeo: %d\n", sb->sb_timeo);
db_print_indent(indent);
db_printf("sb_flags: 0x%x (", sb->sb_flags);
db_print_sbflags(sb->sb_flags);
db_printf(")\n");
}
static void
db_print_socket(struct socket *so, const char *socketname, int indent)
{
db_print_indent(indent);
db_printf("%s at %p\n", socketname, so);
indent += 2;
db_print_indent(indent);
db_printf("so_count: %d ", so->so_count);
db_printf("so_type: %d (", so->so_type);
db_print_sotype(so->so_type);
db_printf(")\n");
db_print_indent(indent);
db_printf("so_options: 0x%x (", so->so_options);
db_print_sooptions(so->so_options);
db_printf(")\n");
db_print_indent(indent);
db_printf("so_linger: %d ", so->so_linger);
db_printf("so_state: 0x%x (", so->so_state);
db_print_sostate(so->so_state);
db_printf(")\n");
db_print_indent(indent);
db_printf("so_qstate: 0x%x (", so->so_qstate);
db_print_soqstate(so->so_qstate);
db_printf(") ");
db_printf("so_pcb: %p ", so->so_pcb);
db_printf("so_proto: %p\n", so->so_proto);
if (so->so_proto != NULL)
db_print_protosw(so->so_proto, "so_proto", indent);
db_print_indent(indent);
db_printf("so_head: %p ", so->so_head);
db_printf("so_incomp first: %p ", TAILQ_FIRST(&so->so_incomp));
db_printf("so_comp first: %p\n", TAILQ_FIRST(&so->so_comp));
db_print_indent(indent);
/* so_list skipped */
db_printf("so_qlen: %d ", so->so_qlen);
db_printf("so_incqlen: %d ", so->so_incqlen);
db_printf("so_qlimit: %d ", so->so_qlimit);
db_printf("so_timeo: %d ", so->so_timeo);
db_printf("so_error: %d\n", so->so_error);
db_print_indent(indent);
db_printf("so_sigio: %p ", so->so_sigio);
db_printf("so_oobmark: %lu ", so->so_oobmark);
db_printf("so_aiojobq first: %p\n", TAILQ_FIRST(&so->so_aiojobq));
db_print_sockbuf(&so->so_rcv, "so_rcv", indent);
db_print_sockbuf(&so->so_snd, "so_snd", indent);
}
DB_SHOW_COMMAND(socket, db_show_socket)
{
struct socket *so;
if (!have_addr) {
db_printf("usage: show socket <addr>\n");
return;
}
so = (struct socket *)addr;
db_print_socket(so, "socket", 0);
}
DB_SHOW_COMMAND(sockbuf, db_show_sockbuf)
{
struct sockbuf *sb;
if (!have_addr) {
db_printf("usage: show sockbuf <addr>\n");
return;
}
sb = (struct sockbuf *)addr;
db_print_sockbuf(sb, "sockbuf", 0);
}
DB_SHOW_COMMAND(protosw, db_show_protosw)
{
struct protosw *pr;
if (!have_addr) {
db_printf("usage: show protosw <addr>\n");
return;
}
pr = (struct protosw *)addr;
db_print_protosw(pr, "protosw", 0);
}
DB_SHOW_COMMAND(domain, db_show_domain)
{
struct domain *d;
if (!have_addr) {
db_printf("usage: show protosw <addr>\n");
return;
}
d = (struct domain *)addr;
db_print_domain(d, "domain", 0);
}
#endif