62 lines
2.0 KiB
C
62 lines
2.0 KiB
C
/* 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;
|
|
}
|