Mercurial > hg > CbC > CbC_gcc
diff libiberty/insque.c @ 0:a06113de4d67
first commit
author | kent <kent@cr.ie.u-ryukyu.ac.jp> |
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date | Fri, 17 Jul 2009 14:47:48 +0900 |
parents | |
children | f6334be47118 |
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--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/libiberty/insque.c Fri Jul 17 14:47:48 2009 +0900 @@ -0,0 +1,50 @@ +/* insque(3C) routines + This file is in the public domain. */ + +/* + +@deftypefn Supplemental void insque (struct qelem *@var{elem}, struct qelem *@var{pred}) +@deftypefnx Supplemental void remque (struct qelem *@var{elem}) + +Routines to manipulate queues built from doubly linked lists. The +@code{insque} routine inserts @var{elem} in the queue immediately +after @var{pred}. The @code{remque} routine removes @var{elem} from +its containing queue. These routines expect to be passed pointers to +structures which have as their first members a forward pointer and a +back pointer, like this prototype (although no prototype is provided): + +@example +struct qelem @{ + struct qelem *q_forw; + struct qelem *q_back; + char q_data[]; +@}; +@end example + +@end deftypefn + +*/ + + +struct qelem { + struct qelem *q_forw; + struct qelem *q_back; +}; + + +void +insque (struct qelem *elem, struct qelem *pred) +{ + elem -> q_forw = pred -> q_forw; + pred -> q_forw -> q_back = elem; + elem -> q_back = pred; + pred -> q_forw = elem; +} + + +void +remque (struct qelem *elem) +{ + elem -> q_forw -> q_back = elem -> q_back; + elem -> q_back -> q_forw = elem -> q_forw; +}