We would like some linked list macros which are (a) well known to be
sane and (b) typesafe. BSD's queue.h meets these criteria.
We also provide some simple perlery to arrange to add the libxl_
namespace prefix to the macros. This will allow us to #include
_libxl_list.h in our public header file without clashing with anyone
else who is also using another version of queue.h.
Signed-off-by: Ian Jackson <ian.jackson@xxxxxxxxxxxxx>
---
Changes since v1:
- use move-if-changed to install _libxl_list.h
- mention bsd-queue.3's 4-clause BSD licence in COPYING
- explictly call the perl script from the Makefile with "perl"
- move the imported files into external/ and provide a README there
- sed out the include of sys/cdefs.h
- improved commit message
COPYING | 8 +
tools/libxl/Makefile | 10 +-
tools/libxl/bsd-sys-queue-h-seddery | 70 +++
tools/libxl/external/README | 13 +
tools/libxl/external/bsd-queue.3 | 1044 ++++++++++++++++++++++++++++++++++
tools/libxl/external/bsd-sys-queue.h | 637 +++++++++++++++++++++
6 files changed, 1779 insertions(+), 3 deletions(-)
diff --git a/COPYING b/COPYING
index 07535ad..524542d 100644
--- a/COPYING
+++ b/COPYING
@@ -18,6 +18,14 @@ GPLv2. See the FSF's definition of GPL compatibility:
And how this applies to a range of open source licenses:
http://www.gnu.org/licenses/license-list.html
+Additionally, the documentation file tools/libxl/external/bsd-queue.3
+has the 4-clause BSD licence. It is present in the Xen source tree
+for reference purposes for people developing Xen. It is not installed
+by "make install" and is bundled in the source only for convenience of
+distribution. We do not intend that we or Xen users or distributors
+should make any reference to "features or use" of that manpage.
+
+
Licensing Exceptions (the relaxed BSD-style license)
----------------------------------------------------
diff --git a/tools/libxl/Makefile b/tools/libxl/Makefile
index 51e5132..f23661a 100644
--- a/tools/libxl/Makefile
+++ b/tools/libxl/Makefile
@@ -42,7 +42,7 @@ LIBXL_OBJS += _libxl_types.o libxl_flask.o
_libxl_types_internal.o
$(LIBXL_OBJS): CFLAGS += $(CFLAGS_libxenctrl) $(CFLAGS_libxenguest)
$(CFLAGS_libxenstore) $(CFLAGS_libblktapctl)
-AUTOINCS= libxlu_cfg_y.h libxlu_cfg_l.h
+AUTOINCS= libxlu_cfg_y.h libxlu_cfg_l.h _libxl_list.h
AUTOSRCS= libxlu_cfg_y.c libxlu_cfg_l.c
LIBXLU_OBJS = libxlu_cfg_y.o libxlu_cfg_l.o libxlu_cfg.o \
libxlu_disk_l.o libxlu_disk.o
@@ -55,7 +55,7 @@ $(XL_OBJS): CFLAGS += $(CFLAGS_libxenctrl) # For xentoollog.h
$(XL_OBJS): CFLAGS += $(CFLAGS_libxenlight)
testidl.o: CFLAGS += $(CFLAGS_libxenctrl) $(CFLAGS_libxenlight)
-testidl.c: libxl_types.idl gentest.py libxl.h
+testidl.c: libxl_types.idl gentest.py libxl.h $(AUTOINCS)
$(PYTHON) gentest.py libxl_types.idl testidl.c.new
mv testidl.c.new testidl.c
@@ -63,7 +63,7 @@ testidl.c: libxl_types.idl gentest.py libxl.h
all: $(CLIENTS) libxenlight.so libxenlight.a libxlutil.so libxlutil.a \
$(AUTOSRCS) $(AUTOINCS)
-$(LIBXLU_OBJS): $(AUTOINCS)
+$(LIBXL_OBJS) $(LIBXLU_OBJS) $(XL_OBJS): $(AUTOINCS)
%.c %.h: %.y
@rm -f $*.[ch]
@@ -81,6 +81,10 @@ _libxl_paths.h: genpath
rm -f $@.tmp
$(call move-if-changed,$@.2.tmp,$@)
+_libxl_list.h: bsd-sys-queue-h-seddery external/bsd-sys-queue.h
+ perl ./$^ --prefix=libxl >$@.new
+ $(call move-if-changed,$@.new,$@)
+
libxl_paths.c: _libxl_paths.h
libxl.h: _libxl_types.h
diff --git a/tools/libxl/bsd-sys-queue-h-seddery
b/tools/libxl/bsd-sys-queue-h-seddery
new file mode 100755
index 0000000..c0aa079
--- /dev/null
+++ b/tools/libxl/bsd-sys-queue-h-seddery
@@ -0,0 +1,70 @@
+#!/usr/bin/perl -p
+#
+# This script is part of the Xen build system. It has a very
+# permissive licence to avoid complicating the licence of the
+# generated header file and to allow this seddery to be reused by
+# other projects.
+#
+# Permission is hereby granted, free of charge, to any person
+# obtaining a copy of this individual file (the "Software"), to deal
+# in the Software without restriction, including without limitation
+# the rights to use, copy, modify, merge, publish, distribute,
+# sublicense, and/or sell copies of the Software, and to permit
+# persons to whom the Software is furnished to do so, subject to the
+# following conditions:
+#
+# The above copyright notice and this permission notice shall be
+# included in all copies or substantial portions of the Software.
+#
+# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+# EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+# MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+# NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
+# BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
+# ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+# CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+# SOFTWARE.
+#
+# Copyright (C) 2011 Citrix Ltd
+
+our $namespace, $ucnamespace;
+
+BEGIN {
+ die unless @ARGV;
+ $namespace = pop @ARGV;
+ $namespace =~ s/^--prefix=// or die;
+ $ucnamespace = uc $namespace;
+
+ print <<END or die $!;
+/*
+ * DO NOT EDIT THIS FILE
+ *
+ * Generated automatically by bsd-sys-queue-h-seddery to
+ * - introduce ${ucnamespace}_ and ${namespace}_ namespace prefixes
+ * - turn "struct type" into "type" so that type arguments
+ * to the macros are type names not struct tags
+ * - remove the reference to sys/cdefs.h, which is not needed
+ *
+ * The purpose of this seddery is to allow the resulting file to be
+ * freely included by software which might also want to include other
+ * list macros; to make it usable when struct tags are not being used
+ * or not known; to make it more portable.
+ */
+END
+}
+
+s/\b( _SYS_QUEUE |
+ SLIST | LIST | STAILQ | TAILQ | QUEUE
+ )/${ucnamespace}_$1/xg;
+
+s/\b( TRACEBUF | TRASHIT |
+ QMD_
+ )/${ucnamespace}__$1/xg;
+
+s/\b(
+ qm_
+ )/${namespace}__$1/xg;
+
+s/\b struct \s+ type \b/type/xg;
+
+s,^\#include.*sys/cdefs.*,/* $& */,xg;
diff --git a/tools/libxl/external/README b/tools/libxl/external/README
new file mode 100644
index 0000000..f3a3ac4
--- /dev/null
+++ b/tools/libxl/external/README
@@ -0,0 +1,13 @@
+WARNING - DO NOT EDIT THINGS IN THIS DIRECTORY (apart from this README)
+-----------------------------------------------------------------------
+
+These files were obtained elsewhere and should only be updated by
+copying new versions from the source location, as documented below:
+
+bsd-sys-queue.h
+bsd-queue.3
+
+ Obtained from the FreeBSD SVN using the following commands:
+ svn co -r 221843 svn://svn.freebsd.org/base/head/sys/sys/
+ svn co -r 221843 svn://svn.freebsd.org/base/head/share/man/man3
+
diff --git a/tools/libxl/external/bsd-queue.3 b/tools/libxl/external/bsd-queue.3
new file mode 100644
index 0000000..007ca5c
--- /dev/null
+++ b/tools/libxl/external/bsd-queue.3
@@ -0,0 +1,1044 @@
+.\" Copyright (c) 1993
+.\" The Regents of the University of California. 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.
+.\" 3. All advertising materials mentioning features or use of this software
+.\" must display the following acknowledgement:
+.\" This product includes software developed by the University of
+.\" California, Berkeley and its contributors.
+.\" 4. Neither the name of the University nor the names of its contributors
+.\" may be used to endorse or promote products derived from this software
+.\" without specific prior written permission.
+.\"
+.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS 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 REGENTS 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.
+.\"
+.\" @(#)queue.3 8.2 (Berkeley) 1/24/94
+.\" $FreeBSD$
+.\"
+.Dd May 13, 2011
+.Dt QUEUE 3
+.Os
+.Sh NAME
+.Nm SLIST_EMPTY ,
+.Nm SLIST_ENTRY ,
+.Nm SLIST_FIRST ,
+.Nm SLIST_FOREACH ,
+.Nm SLIST_FOREACH_SAFE ,
+.Nm SLIST_HEAD ,
+.Nm SLIST_HEAD_INITIALIZER ,
+.Nm SLIST_INIT ,
+.Nm SLIST_INSERT_AFTER ,
+.Nm SLIST_INSERT_HEAD ,
+.Nm SLIST_NEXT ,
+.Nm SLIST_REMOVE_AFTER ,
+.Nm SLIST_REMOVE_HEAD ,
+.Nm SLIST_REMOVE ,
+.Nm SLIST_SWAP ,
+.Nm STAILQ_CONCAT ,
+.Nm STAILQ_EMPTY ,
+.Nm STAILQ_ENTRY ,
+.Nm STAILQ_FIRST ,
+.Nm STAILQ_FOREACH ,
+.Nm STAILQ_FOREACH_SAFE ,
+.Nm STAILQ_HEAD ,
+.Nm STAILQ_HEAD_INITIALIZER ,
+.Nm STAILQ_INIT ,
+.Nm STAILQ_INSERT_AFTER ,
+.Nm STAILQ_INSERT_HEAD ,
+.Nm STAILQ_INSERT_TAIL ,
+.Nm STAILQ_LAST ,
+.Nm STAILQ_NEXT ,
+.Nm STAILQ_REMOVE_AFTER ,
+.Nm STAILQ_REMOVE_HEAD ,
+.Nm STAILQ_REMOVE ,
+.Nm STAILQ_SWAP ,
+.Nm LIST_EMPTY ,
+.Nm LIST_ENTRY ,
+.Nm LIST_FIRST ,
+.Nm LIST_FOREACH ,
+.Nm LIST_FOREACH_SAFE ,
+.Nm LIST_HEAD ,
+.Nm LIST_HEAD_INITIALIZER ,
+.Nm LIST_INIT ,
+.Nm LIST_INSERT_AFTER ,
+.Nm LIST_INSERT_BEFORE ,
+.Nm LIST_INSERT_HEAD ,
+.Nm LIST_NEXT ,
+.Nm LIST_REMOVE ,
+.Nm LIST_SWAP ,
+.Nm TAILQ_CONCAT ,
+.Nm TAILQ_EMPTY ,
+.Nm TAILQ_ENTRY ,
+.Nm TAILQ_FIRST ,
+.Nm TAILQ_FOREACH ,
+.Nm TAILQ_FOREACH_SAFE ,
+.Nm TAILQ_FOREACH_REVERSE ,
+.Nm TAILQ_FOREACH_REVERSE_SAFE ,
+.Nm TAILQ_HEAD ,
+.Nm TAILQ_HEAD_INITIALIZER ,
+.Nm TAILQ_INIT ,
+.Nm TAILQ_INSERT_AFTER ,
+.Nm TAILQ_INSERT_BEFORE ,
+.Nm TAILQ_INSERT_HEAD ,
+.Nm TAILQ_INSERT_TAIL ,
+.Nm TAILQ_LAST ,
+.Nm TAILQ_NEXT ,
+.Nm TAILQ_PREV ,
+.Nm TAILQ_REMOVE ,
+.Nm TAILQ_SWAP
+.Nd implementations of singly-linked lists, singly-linked tail queues,
+lists and tail queues
+.Sh SYNOPSIS
+.In sys/queue.h
+.\"
+.Fn SLIST_EMPTY "SLIST_HEAD *head"
+.Fn SLIST_ENTRY "TYPE"
+.Fn SLIST_FIRST "SLIST_HEAD *head"
+.Fn SLIST_FOREACH "TYPE *var" "SLIST_HEAD *head" "SLIST_ENTRY NAME"
+.Fn SLIST_FOREACH_SAFE "TYPE *var" "SLIST_HEAD *head" "SLIST_ENTRY NAME" "TYPE
*temp_var"
+.Fn SLIST_HEAD "HEADNAME" "TYPE"
+.Fn SLIST_HEAD_INITIALIZER "SLIST_HEAD head"
+.Fn SLIST_INIT "SLIST_HEAD *head"
+.Fn SLIST_INSERT_AFTER "TYPE *listelm" "TYPE *elm" "SLIST_ENTRY NAME"
+.Fn SLIST_INSERT_HEAD "SLIST_HEAD *head" "TYPE *elm" "SLIST_ENTRY NAME"
+.Fn SLIST_NEXT "TYPE *elm" "SLIST_ENTRY NAME"
+.Fn SLIST_REMOVE_AFTER "TYPE *elm" "SLIST_ENTRY NAME"
+.Fn SLIST_REMOVE_HEAD "SLIST_HEAD *head" "SLIST_ENTRY NAME"
+.Fn SLIST_REMOVE "SLIST_HEAD *head" "TYPE *elm" "TYPE" "SLIST_ENTRY NAME"
+.Fn SLIST_SWAP "SLIST_HEAD *head1" "SLIST_HEAD *head2" "SLIST_ENTRY NAME"
+.\"
+.Fn STAILQ_CONCAT "STAILQ_HEAD *head1" "STAILQ_HEAD *head2"
+.Fn STAILQ_EMPTY "STAILQ_HEAD *head"
+.Fn STAILQ_ENTRY "TYPE"
+.Fn STAILQ_FIRST "STAILQ_HEAD *head"
+.Fn STAILQ_FOREACH "TYPE *var" "STAILQ_HEAD *head" "STAILQ_ENTRY NAME"
+.Fn STAILQ_FOREACH_SAFE "TYPE *var" "STAILQ_HEAD *head" "STAILQ_ENTRY NAME"
"TYPE *temp_var"
+.Fn STAILQ_HEAD "HEADNAME" "TYPE"
+.Fn STAILQ_HEAD_INITIALIZER "STAILQ_HEAD head"
+.Fn STAILQ_INIT "STAILQ_HEAD *head"
+.Fn STAILQ_INSERT_AFTER "STAILQ_HEAD *head" "TYPE *listelm" "TYPE *elm"
"STAILQ_ENTRY NAME"
+.Fn STAILQ_INSERT_HEAD "STAILQ_HEAD *head" "TYPE *elm" "STAILQ_ENTRY NAME"
+.Fn STAILQ_INSERT_TAIL "STAILQ_HEAD *head" "TYPE *elm" "STAILQ_ENTRY NAME"
+.Fn STAILQ_LAST "STAILQ_HEAD *head" "TYPE" "STAILQ_ENTRY NAME"
+.Fn STAILQ_NEXT "TYPE *elm" "STAILQ_ENTRY NAME"
+.Fn STAILQ_REMOVE_AFTER "STAILQ_HEAD *head" "TYPE *elm" "STAILQ_ENTRY NAME"
+.Fn STAILQ_REMOVE_HEAD "STAILQ_HEAD *head" "STAILQ_ENTRY NAME"
+.Fn STAILQ_REMOVE "STAILQ_HEAD *head" "TYPE *elm" "TYPE" "STAILQ_ENTRY NAME"
+.Fn STAILQ_SWAP "STAILQ_HEAD *head1" "STAILQ_HEAD *head2" "STAILQ_ENTRY NAME"
+.\"
+.Fn LIST_EMPTY "LIST_HEAD *head"
+.Fn LIST_ENTRY "TYPE"
+.Fn LIST_FIRST "LIST_HEAD *head"
+.Fn LIST_FOREACH "TYPE *var" "LIST_HEAD *head" "LIST_ENTRY NAME"
+.Fn LIST_FOREACH_SAFE "TYPE *var" "LIST_HEAD *head" "LIST_ENTRY NAME" "TYPE
*temp_var"
+.Fn LIST_HEAD "HEADNAME" "TYPE"
+.Fn LIST_HEAD_INITIALIZER "LIST_HEAD head"
+.Fn LIST_INIT "LIST_HEAD *head"
+.Fn LIST_INSERT_AFTER "TYPE *listelm" "TYPE *elm" "LIST_ENTRY NAME"
+.Fn LIST_INSERT_BEFORE "TYPE *listelm" "TYPE *elm" "LIST_ENTRY NAME"
+.Fn LIST_INSERT_HEAD "LIST_HEAD *head" "TYPE *elm" "LIST_ENTRY NAME"
+.Fn LIST_NEXT "TYPE *elm" "LIST_ENTRY NAME"
+.Fn LIST_REMOVE "TYPE *elm" "LIST_ENTRY NAME"
+.Fn LIST_SWAP "LIST_HEAD *head1" "LIST_HEAD *head2" "TYPE" "LIST_ENTRY NAME"
+.\"
+.Fn TAILQ_CONCAT "TAILQ_HEAD *head1" "TAILQ_HEAD *head2" "TAILQ_ENTRY NAME"
+.Fn TAILQ_EMPTY "TAILQ_HEAD *head"
+.Fn TAILQ_ENTRY "TYPE"
+.Fn TAILQ_FIRST "TAILQ_HEAD *head"
+.Fn TAILQ_FOREACH "TYPE *var" "TAILQ_HEAD *head" "TAILQ_ENTRY NAME"
+.Fn TAILQ_FOREACH_SAFE "TYPE *var" "TAILQ_HEAD *head" "TAILQ_ENTRY NAME" "TYPE
*temp_var"
+.Fn TAILQ_FOREACH_REVERSE "TYPE *var" "TAILQ_HEAD *head" "HEADNAME"
"TAILQ_ENTRY NAME"
+.Fn TAILQ_FOREACH_REVERSE_SAFE "TYPE *var" "TAILQ_HEAD *head" "HEADNAME"
"TAILQ_ENTRY NAME" "TYPE *temp_var"
+.Fn TAILQ_HEAD "HEADNAME" "TYPE"
+.Fn TAILQ_HEAD_INITIALIZER "TAILQ_HEAD head"
+.Fn TAILQ_INIT "TAILQ_HEAD *head"
+.Fn TAILQ_INSERT_AFTER "TAILQ_HEAD *head" "TYPE *listelm" "TYPE *elm"
"TAILQ_ENTRY NAME"
+.Fn TAILQ_INSERT_BEFORE "TYPE *listelm" "TYPE *elm" "TAILQ_ENTRY NAME"
+.Fn TAILQ_INSERT_HEAD "TAILQ_HEAD *head" "TYPE *elm" "TAILQ_ENTRY NAME"
+.Fn TAILQ_INSERT_TAIL "TAILQ_HEAD *head" "TYPE *elm" "TAILQ_ENTRY NAME"
+.Fn TAILQ_LAST "TAILQ_HEAD *head" "HEADNAME"
+.Fn TAILQ_NEXT "TYPE *elm" "TAILQ_ENTRY NAME"
+.Fn TAILQ_PREV "TYPE *elm" "HEADNAME" "TAILQ_ENTRY NAME"
+.Fn TAILQ_REMOVE "TAILQ_HEAD *head" "TYPE *elm" "TAILQ_ENTRY NAME"
+.Fn TAILQ_SWAP "TAILQ_HEAD *head1" "TAILQ_HEAD *head2" "TYPE" "TAILQ_ENTRY
NAME"
+.\"
+.Sh DESCRIPTION
+These macros define and operate on four types of data structures:
+singly-linked lists, singly-linked tail queues, lists, and tail queues.
+All four structures support the following functionality:
+.Bl -enum -compact -offset indent
+.It
+Insertion of a new entry at the head of the list.
+.It
+Insertion of a new entry after any element in the list.
+.It
+O(1) removal of an entry from the head of the list.
+.It
+Forward traversal through the list.
+.It
+Swawpping the contents of two lists.
+.El
+.Pp
+Singly-linked lists are the simplest of the four data structures
+and support only the above functionality.
+Singly-linked lists are ideal for applications with large datasets
+and few or no removals,
+or for implementing a LIFO queue.
+Singly-linked lists add the following functionality:
+.Bl -enum -compact -offset indent
+.It
+O(n) removal of any entry in the list.
+.El
+.Pp
+Singly-linked tail queues add the following functionality:
+.Bl -enum -compact -offset indent
+.It
+Entries can be added at the end of a list.
+.It
+O(n) removal of any entry in the list.
+.It
+They may be concatenated.
+.El
+However:
+.Bl -enum -compact -offset indent
+.It
+All list insertions must specify the head of the list.
+.It
+Each head entry requires two pointers rather than one.
+.It
+Code size is about 15% greater and operations run about 20% slower
+than singly-linked lists.
+.El
+.Pp
+Singly-linked tailqs are ideal for applications with large datasets and
+few or no removals,
+or for implementing a FIFO queue.
+.Pp
+All doubly linked types of data structures (lists and tail queues)
+additionally allow:
+.Bl -enum -compact -offset indent
+.It
+Insertion of a new entry before any element in the list.
+.It
+O(1) removal of any entry in the list.
+.El
+However:
+.Bl -enum -compact -offset indent
+.It
+Each element requires two pointers rather than one.
+.It
+Code size and execution time of operations (except for removal) is about
+twice that of the singly-linked data-structures.
+.El
+.Pp
+Linked lists are the simplest of the doubly linked data structures and support
+only the above functionality over singly-linked lists.
+.Pp
+Tail queues add the following functionality:
+.Bl -enum -compact -offset indent
+.It
+Entries can be added at the end of a list.
+.It
+They may be traversed backwards, from tail to head.
+.It
+They may be concatenated.
+.El
+However:
+.Bl -enum -compact -offset indent
+.It
+All list insertions and removals must specify the head of the list.
+.It
+Each head entry requires two pointers rather than one.
+.It
+Code size is about 15% greater and operations run about 20% slower
+than singly-linked lists.
+.El
+.Pp
+In the macro definitions,
+.Fa TYPE
+is the name of a user defined structure,
+that must contain a field of type
+.Li SLIST_ENTRY ,
+.Li STAILQ_ENTRY ,
+.Li LIST_ENTRY ,
+or
+.Li TAILQ_ENTRY ,
+named
+.Fa NAME .
+The argument
+.Fa HEADNAME
+is the name of a user defined structure that must be declared
+using the macros
+.Li SLIST_HEAD ,
+.Li STAILQ_HEAD ,
+.Li LIST_HEAD ,
+or
+.Li TAILQ_HEAD .
+See the examples below for further explanation of how these
+macros are used.
+.Sh SINGLY-LINKED LISTS
+A singly-linked list is headed by a structure defined by the
+.Nm SLIST_HEAD
+macro.
+This structure contains a single pointer to the first element
+on the list.
+The elements are singly linked for minimum space and pointer manipulation
+overhead at the expense of O(n) removal for arbitrary elements.
+New elements can be added to the list after an existing element or
+at the head of the list.
+An
+.Fa SLIST_HEAD
+structure is declared as follows:
+.Bd -literal -offset indent
+SLIST_HEAD(HEADNAME, TYPE) head;
+.Ed
+.Pp
+where
+.Fa HEADNAME
+is the name of the structure to be defined, and
+.Fa TYPE
+is the type of the elements to be linked into the list.
+A pointer to the head of the list can later be declared as:
+.Bd -literal -offset indent
+struct HEADNAME *headp;
+.Ed
+.Pp
+(The names
+.Li head
+and
+.Li headp
+are user selectable.)
+.Pp
+The macro
+.Nm SLIST_HEAD_INITIALIZER
+evaluates to an initializer for the list
+.Fa head .
+.Pp
+The macro
+.Nm SLIST_EMPTY
+evaluates to true if there are no elements in the list.
+.Pp
+The macro
+.Nm SLIST_ENTRY
+declares a structure that connects the elements in
+the list.
+.Pp
+The macro
+.Nm SLIST_FIRST
+returns the first element in the list or NULL if the list is empty.
+.Pp
+The macro
+.Nm SLIST_FOREACH
+traverses the list referenced by
+.Fa head
+in the forward direction, assigning each element in
+turn to
+.Fa var .
+.Pp
+The macro
+.Nm SLIST_FOREACH_SAFE
+traverses the list referenced by
+.Fa head
+in the forward direction, assigning each element in
+turn to
+.Fa var .
+However, unlike
+.Fn SLIST_FOREACH
+here it is permitted to both remove
+.Fa var
+as well as free it from within the loop safely without interfering with the
+traversal.
+.Pp
+The macro
+.Nm SLIST_INIT
+initializes the list referenced by
+.Fa head .
+.Pp
+The macro
+.Nm SLIST_INSERT_HEAD
+inserts the new element
+.Fa elm
+at the head of the list.
+.Pp
+The macro
+.Nm SLIST_INSERT_AFTER
+inserts the new element
+.Fa elm
+after the element
+.Fa listelm .
+.Pp
+The macro
+.Nm SLIST_NEXT
+returns the next element in the list.
+.Pp
+The macro
+.Nm SLIST_REMOVE_AFTER
+removes the element after
+.Fa elm
+from the list. Unlike
+.Fa SLIST_REMOVE ,
+this macro does not traverse the entire list.
+.Pp
+The macro
+.Nm SLIST_REMOVE_HEAD
+removes the element
+.Fa elm
+from the head of the list.
+For optimum efficiency,
+elements being removed from the head of the list should explicitly use
+this macro instead of the generic
+.Fa SLIST_REMOVE
+macro.
+.Pp
+The macro
+.Nm SLIST_REMOVE
+removes the element
+.Fa elm
+from the list.
+.Pp
+The macro
+.Nm SLIST_SWAP
+swaps the contents of
+.Fa head1
+and
+.Fa head2 .
+.Sh SINGLY-LINKED LIST EXAMPLE
+.Bd -literal
+SLIST_HEAD(slisthead, entry) head =
+ SLIST_HEAD_INITIALIZER(head);
+struct slisthead *headp; /* Singly-linked List head. */
+struct entry {
+ ...
+ SLIST_ENTRY(entry) entries; /* Singly-linked List. */
+ ...
+} *n1, *n2, *n3, *np;
+
+SLIST_INIT(&head); /* Initialize the list. */
+
+n1 = malloc(sizeof(struct entry)); /* Insert at the head. */
+SLIST_INSERT_HEAD(&head, n1, entries);
+
+n2 = malloc(sizeof(struct entry)); /* Insert after. */
+SLIST_INSERT_AFTER(n1, n2, entries);
+
+SLIST_REMOVE(&head, n2, entry, entries);/* Deletion. */
+free(n2);
+
+n3 = SLIST_FIRST(&head);
+SLIST_REMOVE_HEAD(&head, entries); /* Deletion from the head. */
+free(n3);
+ /* Forward traversal. */
+SLIST_FOREACH(np, &head, entries)
+ np-> ...
+ /* Safe forward traversal. */
+SLIST_FOREACH_SAFE(np, &head, entries, np_temp) {
+ np->do_stuff();
+ ...
+ SLIST_REMOVE(&head, np, entry, entries);
+ free(np);
+}
+
+while (!SLIST_EMPTY(&head)) { /* List Deletion. */
+ n1 = SLIST_FIRST(&head);
+ SLIST_REMOVE_HEAD(&head, entries);
+ free(n1);
+}
+.Ed
+.Sh SINGLY-LINKED TAIL QUEUES
+A singly-linked tail queue is headed by a structure defined by the
+.Nm STAILQ_HEAD
+macro.
+This structure contains a pair of pointers,
+one to the first element in the tail queue and the other to
+the last element in the tail queue.
+The elements are singly linked for minimum space and pointer
+manipulation overhead at the expense of O(n) removal for arbitrary
+elements.
+New elements can be added to the tail queue after an existing element,
+at the head of the tail queue, or at the end of the tail queue.
+A
+.Fa STAILQ_HEAD
+structure is declared as follows:
+.Bd -literal -offset indent
+STAILQ_HEAD(HEADNAME, TYPE) head;
+.Ed
+.Pp
+where
+.Li HEADNAME
+is the name of the structure to be defined, and
+.Li TYPE
+is the type of the elements to be linked into the tail queue.
+A pointer to the head of the tail queue can later be declared as:
+.Bd -literal -offset indent
+struct HEADNAME *headp;
+.Ed
+.Pp
+(The names
+.Li head
+and
+.Li headp
+are user selectable.)
+.Pp
+The macro
+.Nm STAILQ_HEAD_INITIALIZER
+evaluates to an initializer for the tail queue
+.Fa head .
+.Pp
+The macro
+.Nm STAILQ_CONCAT
+concatenates the tail queue headed by
+.Fa head2
+onto the end of the one headed by
+.Fa head1
+removing all entries from the former.
+.Pp
+The macro
+.Nm STAILQ_EMPTY
+evaluates to true if there are no items on the tail queue.
+.Pp
+The macro
+.Nm STAILQ_ENTRY
+declares a structure that connects the elements in
+the tail queue.
+.Pp
+The macro
+.Nm STAILQ_FIRST
+returns the first item on the tail queue or NULL if the tail queue
+is empty.
+.Pp
+The macro
+.Nm STAILQ_FOREACH
+traverses the tail queue referenced by
+.Fa head
+in the forward direction, assigning each element
+in turn to
+.Fa var .
+.Pp
+The macro
+.Nm STAILQ_FOREACH_SAFE
+traverses the tail queue referenced by
+.Fa head
+in the forward direction, assigning each element
+in turn to
+.Fa var .
+However, unlike
+.Fn STAILQ_FOREACH
+here it is permitted to both remove
+.Fa var
+as well as free it from within the loop safely without interfering with the
+traversal.
+.Pp
+The macro
+.Nm STAILQ_INIT
+initializes the tail queue referenced by
+.Fa head .
+.Pp
+The macro
+.Nm STAILQ_INSERT_HEAD
+inserts the new element
+.Fa elm
+at the head of the tail queue.
+.Pp
+The macro
+.Nm STAILQ_INSERT_TAIL
+inserts the new element
+.Fa elm
+at the end of the tail queue.
+.Pp
+The macro
+.Nm STAILQ_INSERT_AFTER
+inserts the new element
+.Fa elm
+after the element
+.Fa listelm .
+.Pp
+The macro
+.Nm STAILQ_LAST
+returns the last item on the tail queue.
+If the tail queue is empty the return value is
+.Dv NULL .
+.Pp
+The macro
+.Nm STAILQ_NEXT
+returns the next item on the tail queue, or NULL this item is the last.
+.Pp
+The macro
+.Nm STAILQ_REMOVE_AFTER
+removes the element after
+.Fa elm
+from the tail queue. Unlike
+.Fa STAILQ_REMOVE ,
+this macro does not traverse the entire tail queue.
+.Pp
+The macro
+.Nm STAILQ_REMOVE_HEAD
+removes the element at the head of the tail queue.
+For optimum efficiency,
+elements being removed from the head of the tail queue should
+use this macro explicitly rather than the generic
+.Fa STAILQ_REMOVE
+macro.
+.Pp
+The macro
+.Nm STAILQ_REMOVE
+removes the element
+.Fa elm
+from the tail queue.
+.Pp
+The macro
+.Nm STAILQ_SWAP
+swaps the contents of
+.Fa head1
+and
+.Fa head2 .
+.Sh SINGLY-LINKED TAIL QUEUE EXAMPLE
+.Bd -literal
+STAILQ_HEAD(stailhead, entry) head =
+ STAILQ_HEAD_INITIALIZER(head);
+struct stailhead *headp; /* Singly-linked tail queue head. */
+struct entry {
+ ...
+ STAILQ_ENTRY(entry) entries; /* Tail queue. */
+ ...
+} *n1, *n2, *n3, *np;
+
+STAILQ_INIT(&head); /* Initialize the queue. */
+
+n1 = malloc(sizeof(struct entry)); /* Insert at the head. */
+STAILQ_INSERT_HEAD(&head, n1, entries);
+
+n1 = malloc(sizeof(struct entry)); /* Insert at the tail. */
+STAILQ_INSERT_TAIL(&head, n1, entries);
+
+n2 = malloc(sizeof(struct entry)); /* Insert after. */
+STAILQ_INSERT_AFTER(&head, n1, n2, entries);
+ /* Deletion. */
+STAILQ_REMOVE(&head, n2, entry, entries);
+free(n2);
+ /* Deletion from the head. */
+n3 = STAILQ_FIRST(&head);
+STAILQ_REMOVE_HEAD(&head, entries);
+free(n3);
+ /* Forward traversal. */
+STAILQ_FOREACH(np, &head, entries)
+ np-> ...
+ /* Safe forward traversal. */
+STAILQ_FOREACH_SAFE(np, &head, entries, np_temp) {
+ np->do_stuff();
+ ...
+ STAILQ_REMOVE(&head, np, entry, entries);
+ free(np);
+}
+ /* TailQ Deletion. */
+while (!STAILQ_EMPTY(&head)) {
+ n1 = STAILQ_FIRST(&head);
+ STAILQ_REMOVE_HEAD(&head, entries);
+ free(n1);
+}
+ /* Faster TailQ Deletion. */
+n1 = STAILQ_FIRST(&head);
+while (n1 != NULL) {
+ n2 = STAILQ_NEXT(n1, entries);
+ free(n1);
+ n1 = n2;
+}
+STAILQ_INIT(&head);
+.Ed
+.Sh LISTS
+A list is headed by a structure defined by the
+.Nm LIST_HEAD
+macro.
+This structure contains a single pointer to the first element
+on the list.
+The elements are doubly linked so that an arbitrary element can be
+removed without traversing the list.
+New elements can be added to the list after an existing element,
+before an existing element, or at the head of the list.
+A
+.Fa LIST_HEAD
+structure is declared as follows:
+.Bd -literal -offset indent
+LIST_HEAD(HEADNAME, TYPE) head;
+.Ed
+.Pp
+where
+.Fa HEADNAME
+is the name of the structure to be defined, and
+.Fa TYPE
+is the type of the elements to be linked into the list.
+A pointer to the head of the list can later be declared as:
+.Bd -literal -offset indent
+struct HEADNAME *headp;
+.Ed
+.Pp
+(The names
+.Li head
+and
+.Li headp
+are user selectable.)
+.Pp
+The macro
+.Nm LIST_HEAD_INITIALIZER
+evaluates to an initializer for the list
+.Fa head .
+.Pp
+The macro
+.Nm LIST_EMPTY
+evaluates to true if there are no elements in the list.
+.Pp
+The macro
+.Nm LIST_ENTRY
+declares a structure that connects the elements in
+the list.
+.Pp
+The macro
+.Nm LIST_FIRST
+returns the first element in the list or NULL if the list
+is empty.
+.Pp
+The macro
+.Nm LIST_FOREACH
+traverses the list referenced by
+.Fa head
+in the forward direction, assigning each element in turn to
+.Fa var .
+.Pp
+The macro
+.Nm LIST_FOREACH_SAFE
+traverses the list referenced by
+.Fa head
+in the forward direction, assigning each element in turn to
+.Fa var .
+However, unlike
+.Fn LIST_FOREACH
+here it is permitted to both remove
+.Fa var
+as well as free it from within the loop safely without interfering with the
+traversal.
+.Pp
+The macro
+.Nm LIST_INIT
+initializes the list referenced by
+.Fa head .
+.Pp
+The macro
+.Nm LIST_INSERT_HEAD
+inserts the new element
+.Fa elm
+at the head of the list.
+.Pp
+The macro
+.Nm LIST_INSERT_AFTER
+inserts the new element
+.Fa elm
+after the element
+.Fa listelm .
+.Pp
+The macro
+.Nm LIST_INSERT_BEFORE
+inserts the new element
+.Fa elm
+before the element
+.Fa listelm .
+.Pp
+The macro
+.Nm LIST_NEXT
+returns the next element in the list, or NULL if this is the last.
+.Pp
+The macro
+.Nm LIST_REMOVE
+removes the element
+.Fa elm
+from the list.
+.Pp
+The macro
+.Nm LIST_SWAP
+swaps the contents of
+.Fa head1
+and
+.Fa head2 .
+.Sh LIST EXAMPLE
+.Bd -literal
+LIST_HEAD(listhead, entry) head =
+ LIST_HEAD_INITIALIZER(head);
+struct listhead *headp; /* List head. */
+struct entry {
+ ...
+ LIST_ENTRY(entry) entries; /* List. */
+ ...
+} *n1, *n2, *n3, *np, *np_temp;
+
+LIST_INIT(&head); /* Initialize the list. */
+
+n1 = malloc(sizeof(struct entry)); /* Insert at the head. */
+LIST_INSERT_HEAD(&head, n1, entries);
+
+n2 = malloc(sizeof(struct entry)); /* Insert after. */
+LIST_INSERT_AFTER(n1, n2, entries);
+
+n3 = malloc(sizeof(struct entry)); /* Insert before. */
+LIST_INSERT_BEFORE(n2, n3, entries);
+
+LIST_REMOVE(n2, entries); /* Deletion. */
+free(n2);
+ /* Forward traversal. */
+LIST_FOREACH(np, &head, entries)
+ np-> ...
+
+ /* Safe forward traversal. */
+LIST_FOREACH_SAFE(np, &head, entries, np_temp) {
+ np->do_stuff();
+ ...
+ LIST_REMOVE(np, entries);
+ free(np);
+}
+
+while (!LIST_EMPTY(&head)) { /* List Deletion. */
+ n1 = LIST_FIRST(&head);
+ LIST_REMOVE(n1, entries);
+ free(n1);
+}
+
+n1 = LIST_FIRST(&head); /* Faster List Deletion. */
+while (n1 != NULL) {
+ n2 = LIST_NEXT(n1, entries);
+ free(n1);
+ n1 = n2;
+}
+LIST_INIT(&head);
+.Ed
+.Sh TAIL QUEUES
+A tail queue is headed by a structure defined by the
+.Nm TAILQ_HEAD
+macro.
+This structure contains a pair of pointers,
+one to the first element in the tail queue and the other to
+the last element in the tail queue.
+The elements are doubly linked so that an arbitrary element can be
+removed without traversing the tail queue.
+New elements can be added to the tail queue after an existing element,
+before an existing element, at the head of the tail queue,
+or at the end of the tail queue.
+A
+.Fa TAILQ_HEAD
+structure is declared as follows:
+.Bd -literal -offset indent
+TAILQ_HEAD(HEADNAME, TYPE) head;
+.Ed
+.Pp
+where
+.Li HEADNAME
+is the name of the structure to be defined, and
+.Li TYPE
+is the type of the elements to be linked into the tail queue.
+A pointer to the head of the tail queue can later be declared as:
+.Bd -literal -offset indent
+struct HEADNAME *headp;
+.Ed
+.Pp
+(The names
+.Li head
+and
+.Li headp
+are user selectable.)
+.Pp
+The macro
+.Nm TAILQ_HEAD_INITIALIZER
+evaluates to an initializer for the tail queue
+.Fa head .
+.Pp
+The macro
+.Nm TAILQ_CONCAT
+concatenates the tail queue headed by
+.Fa head2
+onto the end of the one headed by
+.Fa head1
+removing all entries from the former.
+.Pp
+The macro
+.Nm TAILQ_EMPTY
+evaluates to true if there are no items on the tail queue.
+.Pp
+The macro
+.Nm TAILQ_ENTRY
+declares a structure that connects the elements in
+the tail queue.
+.Pp
+The macro
+.Nm TAILQ_FIRST
+returns the first item on the tail queue or NULL if the tail queue
+is empty.
+.Pp
+The macro
+.Nm TAILQ_FOREACH
+traverses the tail queue referenced by
+.Fa head
+in the forward direction, assigning each element in turn to
+.Fa var .
+.Fa var
+is set to
+.Dv NULL
+if the loop completes normally, or if there were no elements.
+.Pp
+The macro
+.Nm TAILQ_FOREACH_REVERSE
+traverses the tail queue referenced by
+.Fa head
+in the reverse direction, assigning each element in turn to
+.Fa var .
+.Pp
+The macros
+.Nm TAILQ_FOREACH_SAFE
+and
+.Nm TAILQ_FOREACH_REVERSE_SAFE
+traverse the list referenced by
+.Fa head
+in the forward or reverse direction respectively,
+assigning each element in turn to
+.Fa var .
+However, unlike their unsafe counterparts,
+.Nm TAILQ_FOREACH
+and
+.Nm TAILQ_FOREACH_REVERSE
+permit to both remove
+.Fa var
+as well as free it from within the loop safely without interfering with the
+traversal.
+.Pp
+The macro
+.Nm TAILQ_INIT
+initializes the tail queue referenced by
+.Fa head .
+.Pp
+The macro
+.Nm TAILQ_INSERT_HEAD
+inserts the new element
+.Fa elm
+at the head of the tail queue.
+.Pp
+The macro
+.Nm TAILQ_INSERT_TAIL
+inserts the new element
+.Fa elm
+at the end of the tail queue.
+.Pp
+The macro
+.Nm TAILQ_INSERT_AFTER
+inserts the new element
+.Fa elm
+after the element
+.Fa listelm .
+.Pp
+The macro
+.Nm TAILQ_INSERT_BEFORE
+inserts the new element
+.Fa elm
+before the element
+.Fa listelm .
+.Pp
+The macro
+.Nm TAILQ_LAST
+returns the last item on the tail queue.
+If the tail queue is empty the return value is
+.Dv NULL .
+.Pp
+The macro
+.Nm TAILQ_NEXT
+returns the next item on the tail queue, or NULL if this item is the last.
+.Pp
+The macro
+.Nm TAILQ_PREV
+returns the previous item on the tail queue, or NULL if this item
+is the first.
+.Pp
+The macro
+.Nm TAILQ_REMOVE
+removes the element
+.Fa elm
+from the tail queue.
+.Pp
+The macro
+.Nm TAILQ_SWAP
+swaps the contents of
+.Fa head1
+and
+.Fa head2 .
+.Sh TAIL QUEUE EXAMPLE
+.Bd -literal
+TAILQ_HEAD(tailhead, entry) head =
+ TAILQ_HEAD_INITIALIZER(head);
+struct tailhead *headp; /* Tail queue head. */
+struct entry {
+ ...
+ TAILQ_ENTRY(entry) entries; /* Tail queue. */
+ ...
+} *n1, *n2, *n3, *np;
+
+TAILQ_INIT(&head); /* Initialize the queue. */
+
+n1 = malloc(sizeof(struct entry)); /* Insert at the head. */
+TAILQ_INSERT_HEAD(&head, n1, entries);
+
+n1 = malloc(sizeof(struct entry)); /* Insert at the tail. */
+TAILQ_INSERT_TAIL(&head, n1, entries);
+
+n2 = malloc(sizeof(struct entry)); /* Insert after. */
+TAILQ_INSERT_AFTER(&head, n1, n2, entries);
+
+n3 = malloc(sizeof(struct entry)); /* Insert before. */
+TAILQ_INSERT_BEFORE(n2, n3, entries);
+
+TAILQ_REMOVE(&head, n2, entries); /* Deletion. */
+free(n2);
+ /* Forward traversal. */
+TAILQ_FOREACH(np, &head, entries)
+ np-> ...
+ /* Safe forward traversal. */
+TAILQ_FOREACH_SAFE(np, &head, entries, np_temp) {
+ np->do_stuff();
+ ...
+ TAILQ_REMOVE(&head, np, entries);
+ free(np);
+}
+ /* Reverse traversal. */
+TAILQ_FOREACH_REVERSE(np, &head, tailhead, entries)
+ np-> ...
+ /* TailQ Deletion. */
+while (!TAILQ_EMPTY(&head)) {
+ n1 = TAILQ_FIRST(&head);
+ TAILQ_REMOVE(&head, n1, entries);
+ free(n1);
+}
+ /* Faster TailQ Deletion. */
+n1 = TAILQ_FIRST(&head);
+while (n1 != NULL) {
+ n2 = TAILQ_NEXT(n1, entries);
+ free(n1);
+ n1 = n2;
+}
+TAILQ_INIT(&head);
+.Ed
+.Sh SEE ALSO
+.Xr tree 3
+.Sh HISTORY
+The
+.Nm queue
+functions first appeared in
+.Bx 4.4 .
diff --git a/tools/libxl/external/bsd-sys-queue.h
b/tools/libxl/external/bsd-sys-queue.h
new file mode 100644
index 0000000..274e636
--- /dev/null
+++ b/tools/libxl/external/bsd-sys-queue.h
@@ -0,0 +1,637 @@
+/*-
+ * Copyright (c) 1991, 1993
+ * The Regents of the University of California. 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.
+ * 4. Neither the name of the University nor the names of its contributors
+ * may be used to endorse or promote products derived from this software
+ * without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS 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 REGENTS 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.
+ *
+ * @(#)queue.h 8.5 (Berkeley) 8/20/94
+ * $FreeBSD$
+ */
+
+#ifndef _SYS_QUEUE_H_
+#define _SYS_QUEUE_H_
+
+#include <sys/cdefs.h>
+
+/*
+ * This file defines four types of data structures: singly-linked lists,
+ * singly-linked tail queues, lists and tail queues.
+ *
+ * A singly-linked list is headed by a single forward pointer. The elements
+ * are singly linked for minimum space and pointer manipulation overhead at
+ * the expense of O(n) removal for arbitrary elements. New elements can be
+ * added to the list after an existing element or at the head of the list.
+ * Elements being removed from the head of the list should use the explicit
+ * macro for this purpose for optimum efficiency. A singly-linked list may
+ * only be traversed in the forward direction. Singly-linked lists are ideal
+ * for applications with large datasets and few or no removals or for
+ * implementing a LIFO queue.
+ *
+ * A singly-linked tail queue is headed by a pair of pointers, one to the
+ * head of the list and the other to the tail of the list. The elements are
+ * singly linked for minimum space and pointer manipulation overhead at the
+ * expense of O(n) removal for arbitrary elements. New elements can be added
+ * to the list after an existing element, at the head of the list, or at the
+ * end of the list. Elements being removed from the head of the tail queue
+ * should use the explicit macro for this purpose for optimum efficiency.
+ * A singly-linked tail queue may only be traversed in the forward direction.
+ * Singly-linked tail queues are ideal for applications with large datasets
+ * and few or no removals or for implementing a FIFO queue.
+ *
+ * A list is headed by a single forward pointer (or an array of forward
+ * pointers for a hash table header). The elements are doubly linked
+ * so that an arbitrary element can be removed without a need to
+ * traverse the list. New elements can be added to the list before
+ * or after an existing element or at the head of the list. A list
+ * may only be traversed in the forward direction.
+ *
+ * A tail queue is headed by a pair of pointers, one to the head of the
+ * list and the other to the tail of the list. The elements are doubly
+ * linked so that an arbitrary element can be removed without a need to
+ * traverse the list. New elements can be added to the list before or
+ * after an existing element, at the head of the list, or at the end of
+ * the list. A tail queue may be traversed in either direction.
+ *
+ * For details on the use of these macros, see the queue(3) manual page.
+ *
+ *
+ * SLIST LIST STAILQ TAILQ
+ * _HEAD + + + +
+ * _HEAD_INITIALIZER + + + +
+ * _ENTRY + + + +
+ * _INIT + + + +
+ * _EMPTY + + + +
+ * _FIRST + + + +
+ * _NEXT + + + +
+ * _PREV - - - +
+ * _LAST - - + +
+ * _FOREACH + + + +
+ * _FOREACH_SAFE + + + +
+ * _FOREACH_REVERSE - - - +
+ * _FOREACH_REVERSE_SAFE - - - +
+ * _INSERT_HEAD + + + +
+ * _INSERT_BEFORE - + - +
+ * _INSERT_AFTER + + + +
+ * _INSERT_TAIL - - + +
+ * _CONCAT - - + +
+ * _REMOVE_AFTER + - + -
+ * _REMOVE_HEAD + - + -
+ * _REMOVE + + + +
+ * _SWAP + + + +
+ *
+ */
+#ifdef QUEUE_MACRO_DEBUG
+/* Store the last 2 places the queue element or head was altered */
+struct qm_trace {
+ char * lastfile;
+ int lastline;
+ char * prevfile;
+ int prevline;
+};
+
+#define TRACEBUF struct qm_trace trace;
+#define TRASHIT(x) do {(x) = (void *)-1;} while (0)
+#define QMD_SAVELINK(name, link) void **name = (void *)&(link)
+
+#define QMD_TRACE_HEAD(head) do {
\
+ (head)->trace.prevline = (head)->trace.lastline; \
+ (head)->trace.prevfile = (head)->trace.lastfile; \
+ (head)->trace.lastline = __LINE__; \
+ (head)->trace.lastfile = __FILE__; \
+} while (0)
+
+#define QMD_TRACE_ELEM(elem) do {
\
+ (elem)->trace.prevline = (elem)->trace.lastline; \
+ (elem)->trace.prevfile = (elem)->trace.lastfile; \
+ (elem)->trace.lastline = __LINE__; \
+ (elem)->trace.lastfile = __FILE__; \
+} while (0)
+
+#else
+#define QMD_TRACE_ELEM(elem)
+#define QMD_TRACE_HEAD(head)
+#define QMD_SAVELINK(name, link)
+#define TRACEBUF
+#define TRASHIT(x)
+#endif /* QUEUE_MACRO_DEBUG */
+
+/*
+ * Singly-linked List declarations.
+ */
+#define SLIST_HEAD(name, type)
\
+struct name { \
+ struct type *slh_first; /* first element */ \
+}
+
+#define SLIST_HEAD_INITIALIZER(head)
\
+ { NULL }
+
+#define SLIST_ENTRY(type)
\
+struct { \
+ struct type *sle_next; /* next element */ \
+}
+
+/*
+ * Singly-linked List functions.
+ */
+#define SLIST_EMPTY(head) ((head)->slh_first == NULL)
+
+#define SLIST_FIRST(head) ((head)->slh_first)
+
+#define SLIST_FOREACH(var, head, field)
\
+ for ((var) = SLIST_FIRST((head)); \
+ (var); \
+ (var) = SLIST_NEXT((var), field))
+
+#define SLIST_FOREACH_SAFE(var, head, field, tvar)
\
+ for ((var) = SLIST_FIRST((head)); \
+ (var) && ((tvar) = SLIST_NEXT((var), field), 1); \
+ (var) = (tvar))
+
+#define SLIST_FOREACH_PREVPTR(var, varp, head, field)
\
+ for ((varp) = &SLIST_FIRST((head)); \
+ ((var) = *(varp)) != NULL; \
+ (varp) = &SLIST_NEXT((var), field))
+
+#define SLIST_INIT(head) do {
\
+ SLIST_FIRST((head)) = NULL; \
+} while (0)
+
+#define SLIST_INSERT_AFTER(slistelm, elm, field) do {
\
+ SLIST_NEXT((elm), field) = SLIST_NEXT((slistelm), field); \
+ SLIST_NEXT((slistelm), field) = (elm); \
+} while (0)
+
+#define SLIST_INSERT_HEAD(head, elm, field) do {
\
+ SLIST_NEXT((elm), field) = SLIST_FIRST((head)); \
+ SLIST_FIRST((head)) = (elm); \
+} while (0)
+
+#define SLIST_NEXT(elm, field) ((elm)->field.sle_next)
+
+#define SLIST_REMOVE(head, elm, type, field) do {
\
+ QMD_SAVELINK(oldnext, (elm)->field.sle_next); \
+ if (SLIST_FIRST((head)) == (elm)) { \
+ SLIST_REMOVE_HEAD((head), field); \
+ } \
+ else { \
+ struct type *curelm = SLIST_FIRST((head)); \
+ while (SLIST_NEXT(curelm, field) != (elm)) \
+ curelm = SLIST_NEXT(curelm, field); \
+ SLIST_REMOVE_AFTER(curelm, field); \
+ } \
+ TRASHIT(*oldnext); \
+} while (0)
+
+#define SLIST_REMOVE_AFTER(elm, field) do { \
+ SLIST_NEXT(elm, field) = \
+ SLIST_NEXT(SLIST_NEXT(elm, field), field); \
+} while (0)
+
+#define SLIST_REMOVE_HEAD(head, field) do {
\
+ SLIST_FIRST((head)) = SLIST_NEXT(SLIST_FIRST((head)), field); \
+} while (0)
+
+#define SLIST_SWAP(head1, head2, type) do { \
+ struct type *swap_first = SLIST_FIRST(head1); \
+ SLIST_FIRST(head1) = SLIST_FIRST(head2); \
+ SLIST_FIRST(head2) = swap_first; \
+} while (0)
+
+/*
+ * Singly-linked Tail queue declarations.
+ */
+#define STAILQ_HEAD(name, type)
\
+struct name { \
+ struct type *stqh_first;/* first element */ \
+ struct type **stqh_last;/* addr of last next element */ \
+}
+
+#define STAILQ_HEAD_INITIALIZER(head)
\
+ { NULL, &(head).stqh_first }
+
+#define STAILQ_ENTRY(type)
\
+struct { \
+ struct type *stqe_next; /* next element */ \
+}
+
+/*
+ * Singly-linked Tail queue functions.
+ */
+#define STAILQ_CONCAT(head1, head2) do {
\
+ if (!STAILQ_EMPTY((head2))) { \
+ *(head1)->stqh_last = (head2)->stqh_first; \
+ (head1)->stqh_last = (head2)->stqh_last; \
+ STAILQ_INIT((head2)); \
+ } \
+} while (0)
+
+#define STAILQ_EMPTY(head) ((head)->stqh_first == NULL)
+
+#define STAILQ_FIRST(head) ((head)->stqh_first)
+
+#define STAILQ_FOREACH(var, head, field)
\
+ for((var) = STAILQ_FIRST((head)); \
+ (var); \
+ (var) = STAILQ_NEXT((var), field))
+
+
+#define STAILQ_FOREACH_SAFE(var, head, field, tvar)
\
+ for ((var) = STAILQ_FIRST((head)); \
+ (var) && ((tvar) = STAILQ_NEXT((var), field), 1); \
+ (var) = (tvar))
+
+#define STAILQ_INIT(head) do {
\
+ STAILQ_FIRST((head)) = NULL; \
+ (head)->stqh_last = &STAILQ_FIRST((head)); \
+} while (0)
+
+#define STAILQ_INSERT_AFTER(head, tqelm, elm, field) do {
\
+ if ((STAILQ_NEXT((elm), field) = STAILQ_NEXT((tqelm), field)) == NULL)\
+ (head)->stqh_last = &STAILQ_NEXT((elm), field); \
+ STAILQ_NEXT((tqelm), field) = (elm); \
+} while (0)
+
+#define STAILQ_INSERT_HEAD(head, elm, field) do {
\
+ if ((STAILQ_NEXT((elm), field) = STAILQ_FIRST((head))) == NULL) \
+ (head)->stqh_last = &STAILQ_NEXT((elm), field); \
+ STAILQ_FIRST((head)) = (elm); \
+} while (0)
+
+#define STAILQ_INSERT_TAIL(head, elm, field) do {
\
+ STAILQ_NEXT((elm), field) = NULL; \
+ *(head)->stqh_last = (elm); \
+ (head)->stqh_last = &STAILQ_NEXT((elm), field); \
+} while (0)
+
+#define STAILQ_LAST(head, type, field)
\
+ (STAILQ_EMPTY((head)) ? \
+ NULL : \
+ ((struct type *)(void *) \
+ ((char *)((head)->stqh_last) - __offsetof(struct type, field))))
+
+#define STAILQ_NEXT(elm, field) ((elm)->field.stqe_next)
+
+#define STAILQ_REMOVE(head, elm, type, field) do {
\
+ QMD_SAVELINK(oldnext, (elm)->field.stqe_next); \
+ if (STAILQ_FIRST((head)) == (elm)) { \
+ STAILQ_REMOVE_HEAD((head), field); \
+ } \
+ else { \
+ struct type *curelm = STAILQ_FIRST((head)); \
+ while (STAILQ_NEXT(curelm, field) != (elm)) \
+ curelm = STAILQ_NEXT(curelm, field); \
+ STAILQ_REMOVE_AFTER(head, curelm, field); \
+ } \
+ TRASHIT(*oldnext); \
+} while (0)
+
+#define STAILQ_REMOVE_AFTER(head, elm, field) do { \
+ if ((STAILQ_NEXT(elm, field) = \
+ STAILQ_NEXT(STAILQ_NEXT(elm, field), field)) == NULL) \
+ (head)->stqh_last = &STAILQ_NEXT((elm), field); \
+} while (0)
+
+#define STAILQ_REMOVE_HEAD(head, field) do {
\
+ if ((STAILQ_FIRST((head)) = \
+ STAILQ_NEXT(STAILQ_FIRST((head)), field)) == NULL) \
+ (head)->stqh_last = &STAILQ_FIRST((head)); \
+} while (0)
+
+#define STAILQ_SWAP(head1, head2, type) do { \
+ struct type *swap_first = STAILQ_FIRST(head1); \
+ struct type **swap_last = (head1)->stqh_last; \
+ STAILQ_FIRST(head1) = STAILQ_FIRST(head2); \
+ (head1)->stqh_last = (head2)->stqh_last; \
+ STAILQ_FIRST(head2) = swap_first; \
+ (head2)->stqh_last = swap_last; \
+ if (STAILQ_EMPTY(head1)) \
+ (head1)->stqh_last = &STAILQ_FIRST(head1); \
+ if (STAILQ_EMPTY(head2)) \
+ (head2)->stqh_last = &STAILQ_FIRST(head2); \
+} while (0)
+
+
+/*
+ * List declarations.
+ */
+#define LIST_HEAD(name, type)
\
+struct name { \
+ struct type *lh_first; /* first element */ \
+}
+
+#define LIST_HEAD_INITIALIZER(head)
\
+ { NULL }
+
+#define LIST_ENTRY(type)
\
+struct { \
+ struct type *le_next; /* next element */ \
+ struct type **le_prev; /* address of previous next element */ \
+}
+
+/*
+ * List functions.
+ */
+
+#if (defined(_KERNEL) && defined(INVARIANTS))
+#define QMD_LIST_CHECK_HEAD(head, field) do {
\
+ if (LIST_FIRST((head)) != NULL && \
+ LIST_FIRST((head))->field.le_prev != \
+ &LIST_FIRST((head))) \
+ panic("Bad list head %p first->prev != head", (head)); \
+} while (0)
+
+#define QMD_LIST_CHECK_NEXT(elm, field) do {
\
+ if (LIST_NEXT((elm), field) != NULL && \
+ LIST_NEXT((elm), field)->field.le_prev != \
+ &((elm)->field.le_next)) \
+ panic("Bad link elm %p next->prev != elm", (elm)); \
+} while (0)
+
+#define QMD_LIST_CHECK_PREV(elm, field) do {
\
+ if (*(elm)->field.le_prev != (elm)) \
+ panic("Bad link elm %p prev->next != elm", (elm)); \
+} while (0)
+#else
+#define QMD_LIST_CHECK_HEAD(head, field)
+#define QMD_LIST_CHECK_NEXT(elm, field)
+#define QMD_LIST_CHECK_PREV(elm, field)
+#endif /* (_KERNEL && INVARIANTS) */
+
+#define LIST_EMPTY(head) ((head)->lh_first == NULL)
+
+#define LIST_FIRST(head) ((head)->lh_first)
+
+#define LIST_FOREACH(var, head, field)
\
+ for ((var) = LIST_FIRST((head)); \
+ (var); \
+ (var) = LIST_NEXT((var), field))
+
+#define LIST_FOREACH_SAFE(var, head, field, tvar)
\
+ for ((var) = LIST_FIRST((head)); \
+ (var) && ((tvar) = LIST_NEXT((var), field), 1); \
+ (var) = (tvar))
+
+#define LIST_INIT(head) do {
\
+ LIST_FIRST((head)) = NULL; \
+} while (0)
+
+#define LIST_INSERT_AFTER(listelm, elm, field) do {
\
+ QMD_LIST_CHECK_NEXT(listelm, field); \
+ if ((LIST_NEXT((elm), field) = LIST_NEXT((listelm), field)) != NULL)\
+ LIST_NEXT((listelm), field)->field.le_prev = \
+ &LIST_NEXT((elm), field); \
+ LIST_NEXT((listelm), field) = (elm); \
+ (elm)->field.le_prev = &LIST_NEXT((listelm), field); \
+} while (0)
+
+#define LIST_INSERT_BEFORE(listelm, elm, field) do {
\
+ QMD_LIST_CHECK_PREV(listelm, field); \
+ (elm)->field.le_prev = (listelm)->field.le_prev; \
+ LIST_NEXT((elm), field) = (listelm); \
+ *(listelm)->field.le_prev = (elm); \
+ (listelm)->field.le_prev = &LIST_NEXT((elm), field); \
+} while (0)
+
+#define LIST_INSERT_HEAD(head, elm, field) do {
\
+ QMD_LIST_CHECK_HEAD((head), field); \
+ if ((LIST_NEXT((elm), field) = LIST_FIRST((head))) != NULL) \
+ LIST_FIRST((head))->field.le_prev = &LIST_NEXT((elm), field);\
+ LIST_FIRST((head)) = (elm); \
+ (elm)->field.le_prev = &LIST_FIRST((head)); \
+} while (0)
+
+#define LIST_NEXT(elm, field) ((elm)->field.le_next)
+
+#define LIST_REMOVE(elm, field) do {
\
+ QMD_SAVELINK(oldnext, (elm)->field.le_next); \
+ QMD_SAVELINK(oldprev, (elm)->field.le_prev); \
+ QMD_LIST_CHECK_NEXT(elm, field); \
+ QMD_LIST_CHECK_PREV(elm, field); \
+ if (LIST_NEXT((elm), field) != NULL) \
+ LIST_NEXT((elm), field)->field.le_prev = \
+ (elm)->field.le_prev; \
+ *(elm)->field.le_prev = LIST_NEXT((elm), field); \
+ TRASHIT(*oldnext); \
+ TRASHIT(*oldprev); \
+} while (0)
+
+#define LIST_SWAP(head1, head2, type, field) do { \
+ struct type *swap_tmp = LIST_FIRST((head1)); \
+ LIST_FIRST((head1)) = LIST_FIRST((head2)); \
+ LIST_FIRST((head2)) = swap_tmp; \
+ if ((swap_tmp = LIST_FIRST((head1))) != NULL) \
+ swap_tmp->field.le_prev = &LIST_FIRST((head1)); \
+ if ((swap_tmp = LIST_FIRST((head2))) != NULL) \
+ swap_tmp->field.le_prev = &LIST_FIRST((head2)); \
+} while (0)
+
+/*
+ * Tail queue declarations.
+ */
+#define TAILQ_HEAD(name, type)
\
+struct name { \
+ struct type *tqh_first; /* first element */ \
+ struct type **tqh_last; /* addr of last next element */ \
+ TRACEBUF \
+}
+
+#define TAILQ_HEAD_INITIALIZER(head)
\
+ { NULL, &(head).tqh_first }
+
+#define TAILQ_ENTRY(type)
\
+struct { \
+ struct type *tqe_next; /* next element */ \
+ struct type **tqe_prev; /* address of previous next element */ \
+ TRACEBUF \
+}
+
+/*
+ * Tail queue functions.
+ */
+#if (defined(_KERNEL) && defined(INVARIANTS))
+#define QMD_TAILQ_CHECK_HEAD(head, field) do {
\
+ if (!TAILQ_EMPTY(head) && \
+ TAILQ_FIRST((head))->field.tqe_prev != \
+ &TAILQ_FIRST((head))) \
+ panic("Bad tailq head %p first->prev != head", (head)); \
+} while (0)
+
+#define QMD_TAILQ_CHECK_TAIL(head, field) do {
\
+ if (*(head)->tqh_last != NULL) \
+ panic("Bad tailq NEXT(%p->tqh_last) != NULL", (head)); \
+} while (0)
+
+#define QMD_TAILQ_CHECK_NEXT(elm, field) do {
\
+ if (TAILQ_NEXT((elm), field) != NULL && \
+ TAILQ_NEXT((elm), field)->field.tqe_prev != \
+ &((elm)->field.tqe_next)) \
+ panic("Bad link elm %p next->prev != elm", (elm)); \
+} while (0)
+
+#define QMD_TAILQ_CHECK_PREV(elm, field) do {
\
+ if (*(elm)->field.tqe_prev != (elm)) \
+ panic("Bad link elm %p prev->next != elm", (elm)); \
+} while (0)
+#else
+#define QMD_TAILQ_CHECK_HEAD(head, field)
+#define QMD_TAILQ_CHECK_TAIL(head, headname)
+#define QMD_TAILQ_CHECK_NEXT(elm, field)
+#define QMD_TAILQ_CHECK_PREV(elm, field)
+#endif /* (_KERNEL && INVARIANTS) */
+
+#define TAILQ_CONCAT(head1, head2, field) do {
\
+ if (!TAILQ_EMPTY(head2)) { \
+ *(head1)->tqh_last = (head2)->tqh_first; \
+ (head2)->tqh_first->field.tqe_prev = (head1)->tqh_last; \
+ (head1)->tqh_last = (head2)->tqh_last; \
+ TAILQ_INIT((head2)); \
+ QMD_TRACE_HEAD(head1); \
+ QMD_TRACE_HEAD(head2); \
+ } \
+} while (0)
+
+#define TAILQ_EMPTY(head) ((head)->tqh_first == NULL)
+
+#define TAILQ_FIRST(head) ((head)->tqh_first)
+
+#define TAILQ_FOREACH(var, head, field)
\
+ for ((var) = TAILQ_FIRST((head)); \
+ (var); \
+ (var) = TAILQ_NEXT((var), field))
+
+#define TAILQ_FOREACH_SAFE(var, head, field, tvar)
\
+ for ((var) = TAILQ_FIRST((head)); \
+ (var) && ((tvar) = TAILQ_NEXT((var), field), 1); \
+ (var) = (tvar))
+
+#define TAILQ_FOREACH_REVERSE(var, head, headname, field)
\
+ for ((var) = TAILQ_LAST((head), headname); \
+ (var); \
+ (var) = TAILQ_PREV((var), headname, field))
+
+#define TAILQ_FOREACH_REVERSE_SAFE(var, head, headname, field, tvar)
\
+ for ((var) = TAILQ_LAST((head), headname); \
+ (var) && ((tvar) = TAILQ_PREV((var), headname, field), 1); \
+ (var) = (tvar))
+
+#define TAILQ_INIT(head) do {
\
+ TAILQ_FIRST((head)) = NULL; \
+ (head)->tqh_last = &TAILQ_FIRST((head)); \
+ QMD_TRACE_HEAD(head); \
+} while (0)
+
+#define TAILQ_INSERT_AFTER(head, listelm, elm, field) do {
\
+ QMD_TAILQ_CHECK_NEXT(listelm, field); \
+ if ((TAILQ_NEXT((elm), field) = TAILQ_NEXT((listelm), field)) != NULL)\
+ TAILQ_NEXT((elm), field)->field.tqe_prev = \
+ &TAILQ_NEXT((elm), field); \
+ else { \
+ (head)->tqh_last = &TAILQ_NEXT((elm), field); \
+ QMD_TRACE_HEAD(head); \
+ } \
+ TAILQ_NEXT((listelm), field) = (elm); \
+ (elm)->field.tqe_prev = &TAILQ_NEXT((listelm), field); \
+ QMD_TRACE_ELEM(&(elm)->field); \
+ QMD_TRACE_ELEM(&listelm->field); \
+} while (0)
+
+#define TAILQ_INSERT_BEFORE(listelm, elm, field) do {
\
+ QMD_TAILQ_CHECK_PREV(listelm, field); \
+ (elm)->field.tqe_prev = (listelm)->field.tqe_prev; \
+ TAILQ_NEXT((elm), field) = (listelm); \
+ *(listelm)->field.tqe_prev = (elm); \
+ (listelm)->field.tqe_prev = &TAILQ_NEXT((elm), field); \
+ QMD_TRACE_ELEM(&(elm)->field); \
+ QMD_TRACE_ELEM(&listelm->field); \
+} while (0)
+
+#define TAILQ_INSERT_HEAD(head, elm, field) do {
\
+ QMD_TAILQ_CHECK_HEAD(head, field); \
+ if ((TAILQ_NEXT((elm), field) = TAILQ_FIRST((head))) != NULL) \
+ TAILQ_FIRST((head))->field.tqe_prev = \
+ &TAILQ_NEXT((elm), field); \
+ else \
+ (head)->tqh_last = &TAILQ_NEXT((elm), field); \
+ TAILQ_FIRST((head)) = (elm); \
+ (elm)->field.tqe_prev = &TAILQ_FIRST((head)); \
+ QMD_TRACE_HEAD(head); \
+ QMD_TRACE_ELEM(&(elm)->field); \
+} while (0)
+
+#define TAILQ_INSERT_TAIL(head, elm, field) do {
\
+ QMD_TAILQ_CHECK_TAIL(head, field); \
+ TAILQ_NEXT((elm), field) = NULL; \
+ (elm)->field.tqe_prev = (head)->tqh_last; \
+ *(head)->tqh_last = (elm); \
+ (head)->tqh_last = &TAILQ_NEXT((elm), field); \
+ QMD_TRACE_HEAD(head); \
+ QMD_TRACE_ELEM(&(elm)->field); \
+} while (0)
+
+#define TAILQ_LAST(head, headname)
\
+ (*(((struct headname *)((head)->tqh_last))->tqh_last))
+
+#define TAILQ_NEXT(elm, field) ((elm)->field.tqe_next)
+
+#define TAILQ_PREV(elm, headname, field)
\
+ (*(((struct headname *)((elm)->field.tqe_prev))->tqh_last))
+
+#define TAILQ_REMOVE(head, elm, field) do {
\
+ QMD_SAVELINK(oldnext, (elm)->field.tqe_next); \
+ QMD_SAVELINK(oldprev, (elm)->field.tqe_prev); \
+ QMD_TAILQ_CHECK_NEXT(elm, field); \
+ QMD_TAILQ_CHECK_PREV(elm, field); \
+ if ((TAILQ_NEXT((elm), field)) != NULL) \
+ TAILQ_NEXT((elm), field)->field.tqe_prev = \
+ (elm)->field.tqe_prev; \
+ else { \
+ (head)->tqh_last = (elm)->field.tqe_prev; \
+ QMD_TRACE_HEAD(head); \
+ } \
+ *(elm)->field.tqe_prev = TAILQ_NEXT((elm), field); \
+ TRASHIT(*oldnext); \
+ TRASHIT(*oldprev); \
+ QMD_TRACE_ELEM(&(elm)->field); \
+} while (0)
+
+#define TAILQ_SWAP(head1, head2, type, field) do { \
+ struct type *swap_first = (head1)->tqh_first; \
+ struct type **swap_last = (head1)->tqh_last; \
+ (head1)->tqh_first = (head2)->tqh_first; \
+ (head1)->tqh_last = (head2)->tqh_last; \
+ (head2)->tqh_first = swap_first; \
+ (head2)->tqh_last = swap_last; \
+ if ((swap_first = (head1)->tqh_first) != NULL) \
+ swap_first->field.tqe_prev = &(head1)->tqh_first; \
+ else \
+ (head1)->tqh_last = &(head1)->tqh_first; \
+ if ((swap_first = (head2)->tqh_first) != NULL) \
+ swap_first->field.tqe_prev = &(head2)->tqh_first; \
+ else \
+ (head2)->tqh_last = &(head2)->tqh_first; \
+} while (0)
+
+#endif /* !_SYS_QUEUE_H_ */
--
tg: (92a50a8..) t/xen/bsd-queue (depends on: t/xen/gitignore)
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