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Diffstat (limited to 'libiberty/insque.c')
-rw-r--r-- | libiberty/insque.c | 50 |
1 files changed, 50 insertions, 0 deletions
diff --git a/libiberty/insque.c b/libiberty/insque.c new file mode 100644 index 0000000..775019f --- /dev/null +++ b/libiberty/insque.c @@ -0,0 +1,50 @@ +/* insque(3C) routines + This file is in the public domain. */ + +/* +NAME + insque, remque -- insert, remove an element from a queue + +SYNOPSIS + struct qelem { + struct qelem *q_forw; + struct qelem *q_back; + char q_data[]; + }; + + void insque (struct qelem *elem, struct qelem *pred) + + void remque (struct qelem *elem) + +DESCRIPTION + Routines to manipulate queues built from doubly linked lists. + The insque routine inserts ELEM in the queue immediately after + PRED. The remque routine removes ELEM from its containing queue. +*/ + + +struct qelem { + struct qelem *q_forw; + struct qelem *q_back; +}; + + +void +insque (elem, pred) + 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 (elem) + struct qelem *elem; +{ + elem -> q_forw -> q_back = elem -> q_back; + elem -> q_back -> q_forw = elem -> q_forw; +} |