| /* 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 */ |
| |
| /* Waiting queues are represented by lists of thread descriptors |
| linked through their p_nextwaiting field. The lists are kept |
| sorted by decreasing priority, and then decreasing waiting time. */ |
| |
| static __inline__ void enqueue(pthread_descr * q, pthread_descr th) |
| { |
| int prio = th->p_priority; |
| ASSERT(th->p_nextwaiting == NULL); |
| for (; *q != NULL; q = &((*q)->p_nextwaiting)) { |
| if (prio > (*q)->p_priority) { |
| th->p_nextwaiting = *q; |
| *q = th; |
| return; |
| } |
| } |
| *q = th; |
| } |
| |
| static __inline__ pthread_descr dequeue(pthread_descr * q) |
| { |
| pthread_descr th; |
| th = *q; |
| if (th != NULL) { |
| *q = th->p_nextwaiting; |
| th->p_nextwaiting = NULL; |
| } |
| return th; |
| } |
| |
| static __inline__ int remove_from_queue(pthread_descr * q, pthread_descr th) |
| { |
| for (; *q != NULL; q = &((*q)->p_nextwaiting)) { |
| if (*q == th) { |
| *q = th->p_nextwaiting; |
| th->p_nextwaiting = NULL; |
| return 1; |
| } |
| } |
| return 0; |
| } |
| |
| static __inline__ int queue_is_empty(pthread_descr * q) |
| { |
| return *q == NULL; |
| } |