1 76193d7c 2003-09-30 devnull #include <signal.h>
  2 cd7ddc9b 2003-11-23 devnull #include "threadimpl.h"
  3 76193d7c 2003-09-30 devnull 
  4 76193d7c 2003-09-30 devnull //static Thread	*runthread(Proc*);
  5 76193d7c 2003-09-30 devnull 
  6 76193d7c 2003-09-30 devnull static char *_psstate[] = {
  7 76193d7c 2003-09-30 devnull 	"Dead",
  8 76193d7c 2003-09-30 devnull 	"Running",
  9 76193d7c 2003-09-30 devnull 	"Ready",
 10 76193d7c 2003-09-30 devnull 	"Rendezvous",
 11 76193d7c 2003-09-30 devnull };
 12 76193d7c 2003-09-30 devnull 
 13 76193d7c 2003-09-30 devnull static char*
 14 76193d7c 2003-09-30 devnull psstate(int s)
 15 76193d7c 2003-09-30 devnull {
 16 76193d7c 2003-09-30 devnull 	if(s < 0 || s >= nelem(_psstate))
 17 76193d7c 2003-09-30 devnull 		return "unknown";
 18 76193d7c 2003-09-30 devnull 	return _psstate[s];
 19 76193d7c 2003-09-30 devnull }
 20 76193d7c 2003-09-30 devnull 
 21 76193d7c 2003-09-30 devnull void
 22 76193d7c 2003-09-30 devnull _schedinit(void *arg)
 23 76193d7c 2003-09-30 devnull {
 24 76193d7c 2003-09-30 devnull 	Proc *p;
 25 76193d7c 2003-09-30 devnull 	Thread *t;
 26 76193d7c 2003-09-30 devnull 	extern void ignusr1(void), _threaddie(int);
 27 76193d7c 2003-09-30 devnull 	ignusr1();
 28 76193d7c 2003-09-30 devnull 	signal(SIGTERM, _threaddie);
 29 76193d7c 2003-09-30 devnull   
 30 76193d7c 2003-09-30 devnull 	p = arg;
 31 cd7ddc9b 2003-11-23 devnull 	lock(&p->lock);
 32 76193d7c 2003-09-30 devnull 	p->pid = _threadgetpid();
 33 76193d7c 2003-09-30 devnull 	_threadsetproc(p);
 34 cd7ddc9b 2003-11-23 devnull 	unlock(&p->lock);
 35 76193d7c 2003-09-30 devnull 	while(_setlabel(&p->sched))
 36 76193d7c 2003-09-30 devnull 		;
 37 76193d7c 2003-09-30 devnull 	_threaddebug(DBGSCHED, "top of schedinit, _threadexitsallstatus=%p", _threadexitsallstatus);
 38 76193d7c 2003-09-30 devnull 	if(_threadexitsallstatus)
 39 76193d7c 2003-09-30 devnull 		exits(_threadexitsallstatus);
 40 76193d7c 2003-09-30 devnull 	lock(&p->lock);
 41 76193d7c 2003-09-30 devnull 	if((t=p->thread) != nil){
 42 76193d7c 2003-09-30 devnull 		p->thread = nil;
 43 76193d7c 2003-09-30 devnull 		if(t->moribund){
 44 76193d7c 2003-09-30 devnull 			assert(t->moribund == 1);
 45 76193d7c 2003-09-30 devnull 			t->state = Dead;
 46 76193d7c 2003-09-30 devnull 			if(t->prevt)
 47 76193d7c 2003-09-30 devnull 				t->prevt->nextt = t->nextt;
 48 76193d7c 2003-09-30 devnull 			else
 49 76193d7c 2003-09-30 devnull 				p->threads.head = t->nextt;
 50 76193d7c 2003-09-30 devnull 			if(t->nextt)
 51 76193d7c 2003-09-30 devnull 				t->nextt->prevt = t->prevt;
 52 76193d7c 2003-09-30 devnull 			else
 53 76193d7c 2003-09-30 devnull 				p->threads.tail = t->prevt;
 54 76193d7c 2003-09-30 devnull 			unlock(&p->lock);
 55 76193d7c 2003-09-30 devnull 			if(t->inrendez){
 56 76193d7c 2003-09-30 devnull 				_threadflagrendez(t);
 57 76193d7c 2003-09-30 devnull 				_threadbreakrendez();
 58 76193d7c 2003-09-30 devnull 			}
 59 76193d7c 2003-09-30 devnull 			_stackfree(t->stk);
 60 76193d7c 2003-09-30 devnull 			free(t->cmdname);
 61 76193d7c 2003-09-30 devnull 			free(t);	/* XXX how do we know there are no references? */
 62 cd7ddc9b 2003-11-23 devnull 			p->nthreads--;
 63 76193d7c 2003-09-30 devnull 			t = nil;
 64 76193d7c 2003-09-30 devnull 			_sched();
 65 76193d7c 2003-09-30 devnull 		}
 66 76193d7c 2003-09-30 devnull 		if(p->needexec){
 67 76193d7c 2003-09-30 devnull 			t->ret = _schedexec(&p->exec);
 68 76193d7c 2003-09-30 devnull 			p->needexec = 0;
 69 76193d7c 2003-09-30 devnull 		}
 70 76193d7c 2003-09-30 devnull 		if(p->newproc){
 71 76193d7c 2003-09-30 devnull 			t->ret = _schedfork(p->newproc);
 72 76193d7c 2003-09-30 devnull 			if(t->ret < 0){
 73 76193d7c 2003-09-30 devnull //fprint(2, "_schedfork: %r\n");
 74 76193d7c 2003-09-30 devnull 				abort();
 75 76193d7c 2003-09-30 devnull }
 76 76193d7c 2003-09-30 devnull 			p->newproc = nil;
 77 76193d7c 2003-09-30 devnull 		}
 78 76193d7c 2003-09-30 devnull 		t->state = t->nextstate;
 79 76193d7c 2003-09-30 devnull 		if(t->state == Ready)
 80 76193d7c 2003-09-30 devnull 			_threadready(t);
 81 76193d7c 2003-09-30 devnull 	}
 82 76193d7c 2003-09-30 devnull 	unlock(&p->lock);
 83 76193d7c 2003-09-30 devnull 	_sched();
 84 76193d7c 2003-09-30 devnull }
 85 76193d7c 2003-09-30 devnull 
 86 76193d7c 2003-09-30 devnull static inline Thread*
 87 76193d7c 2003-09-30 devnull runthread(Proc *p)
 88 76193d7c 2003-09-30 devnull {
 89 76193d7c 2003-09-30 devnull 	Thread *t;
 90 76193d7c 2003-09-30 devnull 	Tqueue *q;
 91 76193d7c 2003-09-30 devnull 
 92 76193d7c 2003-09-30 devnull 	if(p->nthreads==0)
 93 76193d7c 2003-09-30 devnull 		return nil;
 94 76193d7c 2003-09-30 devnull 	q = &p->ready;
 95 76193d7c 2003-09-30 devnull 	lock(&p->readylock);
 96 76193d7c 2003-09-30 devnull 	if(q->head == nil){
 97 76193d7c 2003-09-30 devnull 		q->asleep = 1;
 98 cd7ddc9b 2003-11-23 devnull 		_threaddebug(DBGSCHED, "sleeping for more work (%d threads)", p->nthreads);
 99 76193d7c 2003-09-30 devnull 		unlock(&p->readylock);
100 76193d7c 2003-09-30 devnull 		while(rendezvous((ulong)q, 0) == ~0){
101 76193d7c 2003-09-30 devnull 			if(_threadexitsallstatus)
102 76193d7c 2003-09-30 devnull 				exits(_threadexitsallstatus);
103 76193d7c 2003-09-30 devnull 		}
104 76193d7c 2003-09-30 devnull 		/* lock picked up from _threadready */
105 76193d7c 2003-09-30 devnull 	}
106 76193d7c 2003-09-30 devnull 	t = q->head;
107 76193d7c 2003-09-30 devnull 	q->head = t->next;
108 76193d7c 2003-09-30 devnull 	unlock(&p->readylock);
109 76193d7c 2003-09-30 devnull 	return t;
110 76193d7c 2003-09-30 devnull }
111 76193d7c 2003-09-30 devnull 
112 76193d7c 2003-09-30 devnull void
113 76193d7c 2003-09-30 devnull _sched(void)
114 76193d7c 2003-09-30 devnull {
115 76193d7c 2003-09-30 devnull 	Proc *p;
116 76193d7c 2003-09-30 devnull 	Thread *t;
117 76193d7c 2003-09-30 devnull 
118 76193d7c 2003-09-30 devnull Resched:
119 76193d7c 2003-09-30 devnull 	p = _threadgetproc();
120 76193d7c 2003-09-30 devnull //fprint(2, "p %p\n", p);
121 76193d7c 2003-09-30 devnull 	if((t = p->thread) != nil){
122 76193d7c 2003-09-30 devnull 		if((ulong)&p < (ulong)t->stk){	/* stack overflow */
123 76193d7c 2003-09-30 devnull 			fprint(2, "stack overflow %lux %lux\n", (ulong)&p, (ulong)t->stk);
124 76193d7c 2003-09-30 devnull 			abort();
125 76193d7c 2003-09-30 devnull 		}
126 76193d7c 2003-09-30 devnull 	//	_threaddebug(DBGSCHED, "pausing, state=%s set %p goto %p",
127 76193d7c 2003-09-30 devnull 	//		psstate(t->state), &t->sched, &p->sched);
128 76193d7c 2003-09-30 devnull 		if(_setlabel(&t->sched)==0)
129 76193d7c 2003-09-30 devnull 			_gotolabel(&p->sched);
130 76193d7c 2003-09-30 devnull 		return;
131 76193d7c 2003-09-30 devnull 	}else{
132 76193d7c 2003-09-30 devnull 		t = runthread(p);
133 76193d7c 2003-09-30 devnull 		if(t == nil){
134 76193d7c 2003-09-30 devnull 			_threaddebug(DBGSCHED, "all threads gone; exiting");
135 76193d7c 2003-09-30 devnull 			_threaddelproc();
136 76193d7c 2003-09-30 devnull 			_schedexit(p);
137 76193d7c 2003-09-30 devnull 		}
138 76193d7c 2003-09-30 devnull 	//	_threaddebug(DBGSCHED, "running %d.%d", t->proc->pid, t->id);
139 76193d7c 2003-09-30 devnull 		p->thread = t;
140 76193d7c 2003-09-30 devnull 		if(t->moribund){
141 76193d7c 2003-09-30 devnull 			_threaddebug(DBGSCHED, "%d.%d marked to die");
142 76193d7c 2003-09-30 devnull 			goto Resched;
143 76193d7c 2003-09-30 devnull 		}
144 76193d7c 2003-09-30 devnull 		t->state = Running;
145 76193d7c 2003-09-30 devnull 		t->nextstate = Ready;
146 76193d7c 2003-09-30 devnull 		_gotolabel(&t->sched);
147 76193d7c 2003-09-30 devnull 	}
148 76193d7c 2003-09-30 devnull }
149 76193d7c 2003-09-30 devnull 
150 76193d7c 2003-09-30 devnull long
151 76193d7c 2003-09-30 devnull threadstack(void)
152 76193d7c 2003-09-30 devnull {
153 76193d7c 2003-09-30 devnull 	Proc *p;
154 76193d7c 2003-09-30 devnull 	Thread *t;
155 76193d7c 2003-09-30 devnull 
156 76193d7c 2003-09-30 devnull 	p = _threadgetproc();
157 76193d7c 2003-09-30 devnull 	t = p->thread;
158 76193d7c 2003-09-30 devnull 	return (ulong)&p - (ulong)t->stk;
159 76193d7c 2003-09-30 devnull }
160 76193d7c 2003-09-30 devnull 
161 76193d7c 2003-09-30 devnull void
162 76193d7c 2003-09-30 devnull _threadready(Thread *t)
163 76193d7c 2003-09-30 devnull {
164 76193d7c 2003-09-30 devnull 	Tqueue *q;
165 76193d7c 2003-09-30 devnull 
166 76193d7c 2003-09-30 devnull 	assert(t->state == Ready);
167 76193d7c 2003-09-30 devnull 	_threaddebug(DBGSCHED, "readying %d.%d", t->proc->pid, t->id);
168 76193d7c 2003-09-30 devnull 	q = &t->proc->ready;
169 76193d7c 2003-09-30 devnull 	lock(&t->proc->readylock);
170 76193d7c 2003-09-30 devnull 	t->next = nil;
171 76193d7c 2003-09-30 devnull 	if(q->head==nil)
172 76193d7c 2003-09-30 devnull 		q->head = t;
173 76193d7c 2003-09-30 devnull 	else
174 76193d7c 2003-09-30 devnull 		q->tail->next = t;
175 76193d7c 2003-09-30 devnull 	q->tail = t;
176 76193d7c 2003-09-30 devnull 	if(q->asleep){
177 cd7ddc9b 2003-11-23 devnull 		assert(q->asleep == 1);
178 76193d7c 2003-09-30 devnull 		q->asleep = 0;
179 76193d7c 2003-09-30 devnull 		/* lock passes to runthread */
180 76193d7c 2003-09-30 devnull 		_threaddebug(DBGSCHED, "waking process %d", t->proc->pid);
181 76193d7c 2003-09-30 devnull 		while(rendezvous((ulong)q, 0) == ~0){
182 76193d7c 2003-09-30 devnull 			if(_threadexitsallstatus)
183 76193d7c 2003-09-30 devnull 				exits(_threadexitsallstatus);
184 76193d7c 2003-09-30 devnull 		}
185 76193d7c 2003-09-30 devnull 	}else
186 76193d7c 2003-09-30 devnull 		unlock(&t->proc->readylock);
187 76193d7c 2003-09-30 devnull }
188 76193d7c 2003-09-30 devnull 
189 76193d7c 2003-09-30 devnull void
190 76193d7c 2003-09-30 devnull yield(void)
191 76193d7c 2003-09-30 devnull {
192 76193d7c 2003-09-30 devnull 	_sched();
193 76193d7c 2003-09-30 devnull }
194 76193d7c 2003-09-30 devnull