diff options
Diffstat (limited to 'linuxthreads/queue.h')
| -rw-r--r-- | linuxthreads/queue.h | 62 |
1 files changed, 62 insertions, 0 deletions
diff --git a/linuxthreads/queue.h b/linuxthreads/queue.h new file mode 100644 index 0000000..60039cc --- /dev/null +++ b/linuxthreads/queue.h @@ -0,0 +1,62 @@ +/* Linuxthreads - a simple clone()-based implementation of Posix */ +/* threads for Linux. */ +/* Copyright (C) 1996 Xavier Leroy (Xavier.Leroy@inria.fr) */ +/* */ +/* This program is free software; you can redistribute it and/or */ +/* modify it under the terms of the GNU Library General Public License */ +/* as published by the Free Software Foundation; either version 2 */ +/* of the License, or (at your option) any later version. */ +/* */ +/* This program is distributed in the hope that it will be useful, */ +/* but WITHOUT ANY WARRANTY; without even the implied warranty of */ +/* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the */ +/* GNU Library General Public License for more details. */ + +/* Waiting queues */ + +typedef struct _pthread_queue pthread_queue; + +static inline void queue_init(pthread_queue * q) +{ + q->head = q->tail = NULL; +} + +static inline void enqueue(pthread_queue * q, pthread_descr th) +{ + int prio; + pthread_descr * elt; + + ASSERT(th->p_nextwaiting == NULL); + if (q->tail == NULL) { + q->head = th; + q->tail = th; + return; + } + prio = th->p_priority; + if (prio > 0) { + /* Insert in queue according to priority order */ + for (elt = &(q->head); *elt != NULL; elt = &((*elt)->p_nextwaiting)) { + if (prio > (*elt)->p_priority) { + th->p_nextwaiting = *elt; + *elt = th; + return; + } + } + } + /* Priority is no greater than any thread in the queue. + Insert at end of queue */ + q->tail->p_nextwaiting = th; + q->tail = th; +} + +static inline pthread_descr dequeue(pthread_queue * q) +{ + pthread_descr th; + th = q->head; + if (th != NULL) { + q->head = th->p_nextwaiting; + if (q->head == NULL) q->tail = NULL; + th->p_nextwaiting = NULL; + } + return th; +} |