2 * Copyright (c) 1996 Regents of the University of Michigan.
5 * Redistribution and use in source and binary forms are permitted
6 * provided that this notice is preserved and that due credit is given
7 * to the University of Michigan at Ann Arbor. The name of the University
8 * may not be used to endorse or promote products derived from this
9 * software without specific prior written permission. This software
10 * is provided ``as is'' without express or implied warranty.
14 * tsleep.c - allow a thread to sleep without putting the whole process
15 * (e.g. pod under lwp) to sleep. Contains platform-specific code to
18 * Under non-preemptive threads packages like SunOS lwp, tsleep() adds
19 * the thread to a list of sleepers. The lwp_scheduler process takes
20 * care of resuming suspended threads.
22 * Under a fully-preemptive threads package, like Solaris threads,
23 * tsleep just calls sleep(), and there is no scheduler thread. Life
24 * is so much simpler...
34 #if defined( THREAD_SUNOS4_LWP )
36 extern stkalign_t *get_stack( int * );
37 extern void free_stack( int );
49 if ( lwp_self( &mylwp ) < 0 ) {
54 mon_enter( &sglob->tsl_mon );
55 if ( sglob->tsl_list != NULL ) {
56 for ( t = sglob->tsl_list; t != NULL; t = t->tl_next ) {
57 if ( SAMETHREAD( t->tl_tid, mylwp )) {
58 /* We're already sleeping? */
59 t->tl_wake = now + (time_t) interval;
60 mon_exit( &sglob->tsl_mon );
66 nt = (tl_t *) malloc( sizeof( tl_t ));
68 nt->tl_next = sglob->tsl_list;
69 nt->tl_wake = now + (time_t) interval;
72 mon_exit( &sglob->tsl_mon );
78 * The lwp_scheduler thread periodically checks to see if any threads
79 * are due to be resumed. If there are, it resumes them. Otherwise,
80 * it computes the lesser of ( 1 second ) or ( the minimum time until
81 * a thread need to be resumed ) and puts itself to sleep for that amount
90 struct timeval interval;
93 while ( !sglob->slurpd_shutdown ) {
94 mon_enter( &sglob->tsl_mon );
97 if ( sglob->tsl_list != NULL ) {
98 for ( t = sglob->tsl_list; t != NULL; t = t->tl_next ) {
99 if (( t->tl_wake > 0L ) && ( t->tl_wake < now )) {
100 lwp_resume( t->tl_tid );
103 if (( t->tl_wake > now ) && ( t->tl_wake < min )) {
108 mon_exit( &sglob->tsl_mon );
109 interval.tv_usec = 0L;
111 interval.tv_sec = 1L;
113 interval.tv_sec = min;
115 lwp_sleep( &interval );
117 mon_enter( &sglob->tsl_mon );
118 for ( t = sglob->tsl_list; t != NULL; t = t->tl_next ) {
119 lwp_resume( t->tl_tid );
121 mon_exit( &sglob->tsl_mon );
122 free_stack( stackno );
127 * Create the lwp_scheduler thread.
130 start_lwp_scheduler()
136 if (( stack = get_stack( &stackno )) == NULL ) {
139 lwp_create( &tid, lwp_scheduler, MINPRIO, 0, stack, 1, stackno );
144 #else /* THREAD_SUNOS4_LWP */
147 * Here we assume we have fully preemptive threads, and that sleep()
148 * does the right thing.
157 #endif /* THREAD_SUNOS4_LWP */