1 a0f1e21f 2004-04-20 devnull #include <u.h>
  2 76193d7c 2003-09-30 devnull #include <signal.h>
  3 5a8e63b2 2004-02-29 devnull #include <errno.h>
  4 cd7ddc9b 2003-11-23 devnull #include "threadimpl.h"
  5 76193d7c 2003-09-30 devnull 
  6 76193d7c 2003-09-30 devnull //static Thread	*runthread(Proc*);
  7 76193d7c 2003-09-30 devnull 
  8 76193d7c 2003-09-30 devnull static char *_psstate[] = {
  9 76193d7c 2003-09-30 devnull 	"Dead",
 10 76193d7c 2003-09-30 devnull 	"Running",
 11 76193d7c 2003-09-30 devnull 	"Ready",
 12 76193d7c 2003-09-30 devnull 	"Rendezvous",
 13 76193d7c 2003-09-30 devnull };
 14 76193d7c 2003-09-30 devnull 
 15 76193d7c 2003-09-30 devnull static char*
 16 76193d7c 2003-09-30 devnull psstate(int s)
 17 76193d7c 2003-09-30 devnull {
 18 76193d7c 2003-09-30 devnull 	if(s < 0 || s >= nelem(_psstate))
 19 76193d7c 2003-09-30 devnull 		return "unknown";
 20 76193d7c 2003-09-30 devnull 	return _psstate[s];
 21 76193d7c 2003-09-30 devnull }
 22 76193d7c 2003-09-30 devnull 
 23 76193d7c 2003-09-30 devnull void
 24 76193d7c 2003-09-30 devnull _schedinit(void *arg)
 25 76193d7c 2003-09-30 devnull {
 26 76193d7c 2003-09-30 devnull 	Proc *p;
 27 76193d7c 2003-09-30 devnull 	Thread *t;
 28 76193d7c 2003-09-30 devnull 	extern void ignusr1(void), _threaddie(int);
 29 76193d7c 2003-09-30 devnull 	ignusr1();
 30 76193d7c 2003-09-30 devnull 	signal(SIGTERM, _threaddie);
 31 76193d7c 2003-09-30 devnull   
 32 76193d7c 2003-09-30 devnull 	p = arg;
 33 cd7ddc9b 2003-11-23 devnull 	lock(&p->lock);
 34 76193d7c 2003-09-30 devnull 	p->pid = _threadgetpid();
 35 76193d7c 2003-09-30 devnull 	_threadsetproc(p);
 36 cd7ddc9b 2003-11-23 devnull 	unlock(&p->lock);
 37 76193d7c 2003-09-30 devnull 	while(_setlabel(&p->sched))
 38 76193d7c 2003-09-30 devnull 		;
 39 76193d7c 2003-09-30 devnull 	_threaddebug(DBGSCHED, "top of schedinit, _threadexitsallstatus=%p", _threadexitsallstatus);
 40 76193d7c 2003-09-30 devnull 	if(_threadexitsallstatus)
 41 76193d7c 2003-09-30 devnull 		exits(_threadexitsallstatus);
 42 76193d7c 2003-09-30 devnull 	lock(&p->lock);
 43 76193d7c 2003-09-30 devnull 	if((t=p->thread) != nil){
 44 76193d7c 2003-09-30 devnull 		p->thread = nil;
 45 76193d7c 2003-09-30 devnull 		if(t->moribund){
 46 912fba95 2003-11-24 devnull 			if(t->moribund != 1)
 47 912fba95 2003-11-24 devnull 				fprint(2, "moribund %d\n", t->moribund);
 48 76193d7c 2003-09-30 devnull 			assert(t->moribund == 1);
 49 76193d7c 2003-09-30 devnull 			t->state = Dead;
 50 76193d7c 2003-09-30 devnull 			if(t->prevt)
 51 76193d7c 2003-09-30 devnull 				t->prevt->nextt = t->nextt;
 52 76193d7c 2003-09-30 devnull 			else
 53 76193d7c 2003-09-30 devnull 				p->threads.head = t->nextt;
 54 76193d7c 2003-09-30 devnull 			if(t->nextt)
 55 76193d7c 2003-09-30 devnull 				t->nextt->prevt = t->prevt;
 56 76193d7c 2003-09-30 devnull 			else
 57 76193d7c 2003-09-30 devnull 				p->threads.tail = t->prevt;
 58 76193d7c 2003-09-30 devnull 			unlock(&p->lock);
 59 76193d7c 2003-09-30 devnull 			if(t->inrendez){
 60 76193d7c 2003-09-30 devnull 				_threadflagrendez(t);
 61 76193d7c 2003-09-30 devnull 				_threadbreakrendez();
 62 76193d7c 2003-09-30 devnull 			}
 63 76193d7c 2003-09-30 devnull 			_stackfree(t->stk);
 64 76193d7c 2003-09-30 devnull 			free(t->cmdname);
 65 76193d7c 2003-09-30 devnull 			free(t);	/* XXX how do we know there are no references? */
 66 cd7ddc9b 2003-11-23 devnull 			p->nthreads--;
 67 76193d7c 2003-09-30 devnull 			t = nil;
 68 76193d7c 2003-09-30 devnull 			_sched();
 69 76193d7c 2003-09-30 devnull 		}
 70 5a8e63b2 2004-02-29 devnull /*
 71 76193d7c 2003-09-30 devnull 		if(p->needexec){
 72 76193d7c 2003-09-30 devnull 			t->ret = _schedexec(&p->exec);
 73 76193d7c 2003-09-30 devnull 			p->needexec = 0;
 74 76193d7c 2003-09-30 devnull 		}
 75 5a8e63b2 2004-02-29 devnull */
 76 76193d7c 2003-09-30 devnull 		if(p->newproc){
 77 76193d7c 2003-09-30 devnull 			t->ret = _schedfork(p->newproc);
 78 76193d7c 2003-09-30 devnull 			if(t->ret < 0){
 79 76193d7c 2003-09-30 devnull //fprint(2, "_schedfork: %r\n");
 80 76193d7c 2003-09-30 devnull 				abort();
 81 76193d7c 2003-09-30 devnull }
 82 76193d7c 2003-09-30 devnull 			p->newproc = nil;
 83 76193d7c 2003-09-30 devnull 		}
 84 76193d7c 2003-09-30 devnull 		t->state = t->nextstate;
 85 76193d7c 2003-09-30 devnull 		if(t->state == Ready)
 86 76193d7c 2003-09-30 devnull 			_threadready(t);
 87 76193d7c 2003-09-30 devnull 	}
 88 76193d7c 2003-09-30 devnull 	unlock(&p->lock);
 89 76193d7c 2003-09-30 devnull 	_sched();
 90 76193d7c 2003-09-30 devnull }
 91 76193d7c 2003-09-30 devnull 
 92 50e628cb 2003-11-23 devnull static Thread*
 93 76193d7c 2003-09-30 devnull runthread(Proc *p)
 94 76193d7c 2003-09-30 devnull {
 95 5a8e63b2 2004-02-29 devnull 	Channel *c;
 96 76193d7c 2003-09-30 devnull 	Thread *t;
 97 76193d7c 2003-09-30 devnull 	Tqueue *q;
 98 5a8e63b2 2004-02-29 devnull 	Waitmsg *w;
 99 5a8e63b2 2004-02-29 devnull 	int e, sent;
100 76193d7c 2003-09-30 devnull 
101 e97ceade 2003-12-06 devnull 	if(p->nthreads==0 || (p->nthreads==1 && p->idle))
102 76193d7c 2003-09-30 devnull 		return nil;
103 76193d7c 2003-09-30 devnull 	q = &p->ready;
104 5a8e63b2 2004-02-29 devnull relock:
105 76193d7c 2003-09-30 devnull 	lock(&p->readylock);
106 76193d7c 2003-09-30 devnull 	if(q->head == nil){
107 5a8e63b2 2004-02-29 devnull 		e = errno;
108 5a8e63b2 2004-02-29 devnull 		if((c = _threadwaitchan) != nil){
109 5a8e63b2 2004-02-29 devnull 			if(c->n <= c->s){
110 5a8e63b2 2004-02-29 devnull 				sent = 0;
111 5a8e63b2 2004-02-29 devnull 				for(;;){
112 5a8e63b2 2004-02-29 devnull 					if((w = p->waitmsg) != nil)
113 5a8e63b2 2004-02-29 devnull 						p->waitmsg = nil;
114 5a8e63b2 2004-02-29 devnull 					else
115 5a8e63b2 2004-02-29 devnull 						w = waitnohang();
116 5a8e63b2 2004-02-29 devnull 					if(w == nil)
117 5a8e63b2 2004-02-29 devnull 						break;
118 5a8e63b2 2004-02-29 devnull 					if(sent == 0){
119 5a8e63b2 2004-02-29 devnull 						unlock(&p->readylock);
120 5a8e63b2 2004-02-29 devnull 						sent = 1;
121 5a8e63b2 2004-02-29 devnull 					}
122 5a8e63b2 2004-02-29 devnull 					if(nbsendp(c, w) != 1)
123 5a8e63b2 2004-02-29 devnull 						break;
124 5a8e63b2 2004-02-29 devnull 				}
125 5a8e63b2 2004-02-29 devnull 				p->waitmsg = w;
126 5a8e63b2 2004-02-29 devnull 				if(sent)
127 5a8e63b2 2004-02-29 devnull 					goto relock;
128 5a8e63b2 2004-02-29 devnull 			}
129 5a8e63b2 2004-02-29 devnull 		}else{
130 5a8e63b2 2004-02-29 devnull 			while((w = waitnohang()) != nil)
131 5a8e63b2 2004-02-29 devnull 				free(w);
132 5a8e63b2 2004-02-29 devnull 		}
133 5a8e63b2 2004-02-29 devnull 		errno = e;
134 e97ceade 2003-12-06 devnull 		if(p->idle){
135 e97ceade 2003-12-06 devnull 			if(p->idle->state != Ready){
136 e97ceade 2003-12-06 devnull 				fprint(2, "everyone is asleep\n");
137 e97ceade 2003-12-06 devnull 				exits("everyone is asleep");
138 e97ceade 2003-12-06 devnull 			}
139 e97ceade 2003-12-06 devnull 			unlock(&p->readylock);
140 32f69c36 2003-12-11 devnull 			_threaddebug(DBGSCHED, "running idle thread", p->nthreads);
141 e97ceade 2003-12-06 devnull 			return p->idle;
142 e97ceade 2003-12-06 devnull 		}
143 e97ceade 2003-12-06 devnull 
144 cd7ddc9b 2003-11-23 devnull 		_threaddebug(DBGSCHED, "sleeping for more work (%d threads)", p->nthreads);
145 32f69c36 2003-12-11 devnull 		q->asleep = 1;
146 76193d7c 2003-09-30 devnull 		unlock(&p->readylock);
147 76193d7c 2003-09-30 devnull 		while(rendezvous((ulong)q, 0) == ~0){
148 76193d7c 2003-09-30 devnull 			if(_threadexitsallstatus)
149 76193d7c 2003-09-30 devnull 				exits(_threadexitsallstatus);
150 76193d7c 2003-09-30 devnull 		}
151 76193d7c 2003-09-30 devnull 		/* lock picked up from _threadready */
152 76193d7c 2003-09-30 devnull 	}
153 76193d7c 2003-09-30 devnull 	t = q->head;
154 76193d7c 2003-09-30 devnull 	q->head = t->next;
155 76193d7c 2003-09-30 devnull 	unlock(&p->readylock);
156 76193d7c 2003-09-30 devnull 	return t;
157 76193d7c 2003-09-30 devnull }
158 76193d7c 2003-09-30 devnull 
159 76193d7c 2003-09-30 devnull void
160 76193d7c 2003-09-30 devnull _sched(void)
161 76193d7c 2003-09-30 devnull {
162 76193d7c 2003-09-30 devnull 	Proc *p;
163 76193d7c 2003-09-30 devnull 	Thread *t;
164 76193d7c 2003-09-30 devnull 
165 76193d7c 2003-09-30 devnull Resched:
166 76193d7c 2003-09-30 devnull 	p = _threadgetproc();
167 76193d7c 2003-09-30 devnull //fprint(2, "p %p\n", p);
168 76193d7c 2003-09-30 devnull 	if((t = p->thread) != nil){
169 a3785ca2 2004-04-21 devnull 		if((ulong)&p < (ulong)t->stk+512){	/* stack overflow waiting to happen */
170 a3785ca2 2004-04-21 devnull 			fprint(2, "stack overflow: stack at %lux, limit at %lux\n", (ulong)&p, (ulong)t->stk);
171 76193d7c 2003-09-30 devnull 			abort();
172 76193d7c 2003-09-30 devnull 		}
173 76193d7c 2003-09-30 devnull 	//	_threaddebug(DBGSCHED, "pausing, state=%s set %p goto %p",
174 76193d7c 2003-09-30 devnull 	//		psstate(t->state), &t->sched, &p->sched);
175 76193d7c 2003-09-30 devnull 		if(_setlabel(&t->sched)==0)
176 76193d7c 2003-09-30 devnull 			_gotolabel(&p->sched);
177 a3785ca2 2004-04-21 devnull 		_threadstacklimit(t->stk);
178 76193d7c 2003-09-30 devnull 		return;
179 76193d7c 2003-09-30 devnull 	}else{
180 76193d7c 2003-09-30 devnull 		t = runthread(p);
181 76193d7c 2003-09-30 devnull 		if(t == nil){
182 76193d7c 2003-09-30 devnull 			_threaddebug(DBGSCHED, "all threads gone; exiting");
183 76193d7c 2003-09-30 devnull 			_threaddelproc();
184 76193d7c 2003-09-30 devnull 			_schedexit(p);
185 76193d7c 2003-09-30 devnull 		}
186 32f69c36 2003-12-11 devnull 		_threaddebug(DBGSCHED, "running %d.%d", t->proc->pid, t->id);
187 76193d7c 2003-09-30 devnull 		p->thread = t;
188 76193d7c 2003-09-30 devnull 		if(t->moribund){
189 76193d7c 2003-09-30 devnull 			_threaddebug(DBGSCHED, "%d.%d marked to die");
190 76193d7c 2003-09-30 devnull 			goto Resched;
191 76193d7c 2003-09-30 devnull 		}
192 76193d7c 2003-09-30 devnull 		t->state = Running;
193 76193d7c 2003-09-30 devnull 		t->nextstate = Ready;
194 76193d7c 2003-09-30 devnull 		_gotolabel(&t->sched);
195 76193d7c 2003-09-30 devnull 	}
196 76193d7c 2003-09-30 devnull }
197 76193d7c 2003-09-30 devnull 
198 76193d7c 2003-09-30 devnull long
199 76193d7c 2003-09-30 devnull threadstack(void)
200 76193d7c 2003-09-30 devnull {
201 76193d7c 2003-09-30 devnull 	Proc *p;
202 76193d7c 2003-09-30 devnull 	Thread *t;
203 76193d7c 2003-09-30 devnull 
204 76193d7c 2003-09-30 devnull 	p = _threadgetproc();
205 76193d7c 2003-09-30 devnull 	t = p->thread;
206 76193d7c 2003-09-30 devnull 	return (ulong)&p - (ulong)t->stk;
207 76193d7c 2003-09-30 devnull }
208 76193d7c 2003-09-30 devnull 
209 76193d7c 2003-09-30 devnull void
210 76193d7c 2003-09-30 devnull _threadready(Thread *t)
211 76193d7c 2003-09-30 devnull {
212 76193d7c 2003-09-30 devnull 	Tqueue *q;
213 76193d7c 2003-09-30 devnull 
214 32f69c36 2003-12-11 devnull 	if(t == t->proc->idle){
215 32f69c36 2003-12-11 devnull 		_threaddebug(DBGSCHED, "idle thread is ready");
216 e97ceade 2003-12-06 devnull 		return;
217 32f69c36 2003-12-11 devnull 	}
218 e97ceade 2003-12-06 devnull 
219 76193d7c 2003-09-30 devnull 	assert(t->state == Ready);
220 76193d7c 2003-09-30 devnull 	_threaddebug(DBGSCHED, "readying %d.%d", t->proc->pid, t->id);
221 76193d7c 2003-09-30 devnull 	q = &t->proc->ready;
222 76193d7c 2003-09-30 devnull 	lock(&t->proc->readylock);
223 76193d7c 2003-09-30 devnull 	t->next = nil;
224 76193d7c 2003-09-30 devnull 	if(q->head==nil)
225 76193d7c 2003-09-30 devnull 		q->head = t;
226 76193d7c 2003-09-30 devnull 	else
227 76193d7c 2003-09-30 devnull 		q->tail->next = t;
228 76193d7c 2003-09-30 devnull 	q->tail = t;
229 76193d7c 2003-09-30 devnull 	if(q->asleep){
230 cd7ddc9b 2003-11-23 devnull 		assert(q->asleep == 1);
231 76193d7c 2003-09-30 devnull 		q->asleep = 0;
232 76193d7c 2003-09-30 devnull 		/* lock passes to runthread */
233 76193d7c 2003-09-30 devnull 		_threaddebug(DBGSCHED, "waking process %d", t->proc->pid);
234 76193d7c 2003-09-30 devnull 		while(rendezvous((ulong)q, 0) == ~0){
235 76193d7c 2003-09-30 devnull 			if(_threadexitsallstatus)
236 76193d7c 2003-09-30 devnull 				exits(_threadexitsallstatus);
237 76193d7c 2003-09-30 devnull 		}
238 76193d7c 2003-09-30 devnull 	}else
239 76193d7c 2003-09-30 devnull 		unlock(&t->proc->readylock);
240 76193d7c 2003-09-30 devnull }
241 76193d7c 2003-09-30 devnull 
242 76193d7c 2003-09-30 devnull void
243 e97ceade 2003-12-06 devnull _threadidle(void)
244 e97ceade 2003-12-06 devnull {
245 e97ceade 2003-12-06 devnull 	Tqueue *q;
246 32f69c36 2003-12-11 devnull 	Thread *t, *idle;
247 e97ceade 2003-12-06 devnull 	Proc *p;
248 e97ceade 2003-12-06 devnull 
249 e97ceade 2003-12-06 devnull 	p = _threadgetproc();
250 e97ceade 2003-12-06 devnull 	q = &p->ready;
251 e97ceade 2003-12-06 devnull 	lock(&p->readylock);
252 32f69c36 2003-12-11 devnull 	assert(q->tail);
253 32f69c36 2003-12-11 devnull 	idle = q->tail;
254 32f69c36 2003-12-11 devnull 	if(q->head == idle){
255 32f69c36 2003-12-11 devnull 		q->head = nil;
256 e97ceade 2003-12-06 devnull 		q->tail = nil;
257 32f69c36 2003-12-11 devnull 	}else{
258 32f69c36 2003-12-11 devnull 		for(t=q->head; t->next!=q->tail; t=t->next)
259 32f69c36 2003-12-11 devnull 			;
260 32f69c36 2003-12-11 devnull 		t->next = nil;
261 32f69c36 2003-12-11 devnull 		q->tail = t;
262 32f69c36 2003-12-11 devnull 	}
263 32f69c36 2003-12-11 devnull 	p->idle = idle;
264 32f69c36 2003-12-11 devnull 	_threaddebug(DBGSCHED, "p->idle is %d\n", idle->id);
265 e97ceade 2003-12-06 devnull 	unlock(&p->readylock);
266 e97ceade 2003-12-06 devnull }
267 e97ceade 2003-12-06 devnull 
268 e97ceade 2003-12-06 devnull void
269 76193d7c 2003-09-30 devnull yield(void)
270 76193d7c 2003-09-30 devnull {
271 76193d7c 2003-09-30 devnull 	_sched();
272 76193d7c 2003-09-30 devnull }
273 02a1a5c1 2004-03-05 devnull 
274 02a1a5c1 2004-03-05 devnull void
275 02a1a5c1 2004-03-05 devnull threadstatus(void)
276 02a1a5c1 2004-03-05 devnull {
277 02a1a5c1 2004-03-05 devnull 	Proc *p;
278 02a1a5c1 2004-03-05 devnull 	Thread *t;
279 76193d7c 2003-09-30 devnull 
280 02a1a5c1 2004-03-05 devnull 	p = _threadgetproc();
281 02a1a5c1 2004-03-05 devnull 	for(t=p->threads.head; t; t=t->nextt)
282 02a1a5c1 2004-03-05 devnull 		fprint(2, "[%3d] %s userpc=%lux\n",
283 02a1a5c1 2004-03-05 devnull 			t->id, psstate(t->state), t->userpc);
284 02a1a5c1 2004-03-05 devnull }
285 02a1a5c1 2004-03-05 devnull