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/* 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; 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; } |