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 f7012583 2003-11-25 devnull #if 0
  7 76193d7c 2003-09-30 devnull static char *_psstate[] = {
  8 76193d7c 2003-09-30 devnull 	"Dead",
  9 76193d7c 2003-09-30 devnull 	"Running",
 10 76193d7c 2003-09-30 devnull 	"Ready",
 11 76193d7c 2003-09-30 devnull 	"Rendezvous",
 12 76193d7c 2003-09-30 devnull };
 13 76193d7c 2003-09-30 devnull 
 14 76193d7c 2003-09-30 devnull static char*
 15 76193d7c 2003-09-30 devnull psstate(int s)
 16 76193d7c 2003-09-30 devnull {
 17 76193d7c 2003-09-30 devnull 	if(s < 0 || s >= nelem(_psstate))
 18 76193d7c 2003-09-30 devnull 		return "unknown";
 19 76193d7c 2003-09-30 devnull 	return _psstate[s];
 20 76193d7c 2003-09-30 devnull }
 21 64bcfff3 2003-11-25 devnull #endif
 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 76193d7c 2003-09-30 devnull 		if(p->needexec){
 71 76193d7c 2003-09-30 devnull 			t->ret = _schedexec(&p->exec);
 72 76193d7c 2003-09-30 devnull 			p->needexec = 0;
 73 76193d7c 2003-09-30 devnull 		}
 74 76193d7c 2003-09-30 devnull 		if(p->newproc){
 75 76193d7c 2003-09-30 devnull 			t->ret = _schedfork(p->newproc);
 76 76193d7c 2003-09-30 devnull 			if(t->ret < 0){
 77 76193d7c 2003-09-30 devnull //fprint(2, "_schedfork: %r\n");
 78 76193d7c 2003-09-30 devnull 				abort();
 79 76193d7c 2003-09-30 devnull }
 80 76193d7c 2003-09-30 devnull 			p->newproc = nil;
 81 76193d7c 2003-09-30 devnull 		}
 82 76193d7c 2003-09-30 devnull 		t->state = t->nextstate;
 83 76193d7c 2003-09-30 devnull 		if(t->state == Ready)
 84 76193d7c 2003-09-30 devnull 			_threadready(t);
 85 76193d7c 2003-09-30 devnull 	}
 86 76193d7c 2003-09-30 devnull 	unlock(&p->lock);
 87 76193d7c 2003-09-30 devnull 	_sched();
 88 76193d7c 2003-09-30 devnull }
 89 76193d7c 2003-09-30 devnull 
 90 50e628cb 2003-11-23 devnull static Thread*
 91 76193d7c 2003-09-30 devnull runthread(Proc *p)
 92 76193d7c 2003-09-30 devnull {
 93 76193d7c 2003-09-30 devnull 	Thread *t;
 94 76193d7c 2003-09-30 devnull 	Tqueue *q;
 95 76193d7c 2003-09-30 devnull 
 96 e97ceade 2003-12-06 devnull 	if(p->nthreads==0 || (p->nthreads==1 && p->idle))
 97 76193d7c 2003-09-30 devnull 		return nil;
 98 76193d7c 2003-09-30 devnull 	q = &p->ready;
 99 76193d7c 2003-09-30 devnull 	lock(&p->readylock);
100 76193d7c 2003-09-30 devnull 	if(q->head == nil){
101 e97ceade 2003-12-06 devnull 		if(p->idle){
102 e97ceade 2003-12-06 devnull 			if(p->idle->state != Ready){
103 e97ceade 2003-12-06 devnull 				fprint(2, "everyone is asleep\n");
104 e97ceade 2003-12-06 devnull 				exits("everyone is asleep");
105 e97ceade 2003-12-06 devnull 			}
106 e97ceade 2003-12-06 devnull 			unlock(&p->readylock);
107 32f69c36 2003-12-11 devnull 			_threaddebug(DBGSCHED, "running idle thread", p->nthreads);
108 e97ceade 2003-12-06 devnull 			return p->idle;
109 e97ceade 2003-12-06 devnull 		}
110 e97ceade 2003-12-06 devnull 
111 cd7ddc9b 2003-11-23 devnull 		_threaddebug(DBGSCHED, "sleeping for more work (%d threads)", p->nthreads);
112 32f69c36 2003-12-11 devnull 		q->asleep = 1;
113 76193d7c 2003-09-30 devnull 		unlock(&p->readylock);
114 76193d7c 2003-09-30 devnull 		while(rendezvous((ulong)q, 0) == ~0){
115 76193d7c 2003-09-30 devnull 			if(_threadexitsallstatus)
116 76193d7c 2003-09-30 devnull 				exits(_threadexitsallstatus);
117 76193d7c 2003-09-30 devnull 		}
118 76193d7c 2003-09-30 devnull 		/* lock picked up from _threadready */
119 76193d7c 2003-09-30 devnull 	}
120 76193d7c 2003-09-30 devnull 	t = q->head;
121 76193d7c 2003-09-30 devnull 	q->head = t->next;
122 76193d7c 2003-09-30 devnull 	unlock(&p->readylock);
123 76193d7c 2003-09-30 devnull 	return t;
124 76193d7c 2003-09-30 devnull }
125 76193d7c 2003-09-30 devnull 
126 76193d7c 2003-09-30 devnull void
127 76193d7c 2003-09-30 devnull _sched(void)
128 76193d7c 2003-09-30 devnull {
129 76193d7c 2003-09-30 devnull 	Proc *p;
130 76193d7c 2003-09-30 devnull 	Thread *t;
131 76193d7c 2003-09-30 devnull 
132 76193d7c 2003-09-30 devnull Resched:
133 76193d7c 2003-09-30 devnull 	p = _threadgetproc();
134 76193d7c 2003-09-30 devnull //fprint(2, "p %p\n", p);
135 76193d7c 2003-09-30 devnull 	if((t = p->thread) != nil){
136 76193d7c 2003-09-30 devnull 		if((ulong)&p < (ulong)t->stk){	/* stack overflow */
137 76193d7c 2003-09-30 devnull 			fprint(2, "stack overflow %lux %lux\n", (ulong)&p, (ulong)t->stk);
138 76193d7c 2003-09-30 devnull 			abort();
139 76193d7c 2003-09-30 devnull 		}
140 76193d7c 2003-09-30 devnull 	//	_threaddebug(DBGSCHED, "pausing, state=%s set %p goto %p",
141 76193d7c 2003-09-30 devnull 	//		psstate(t->state), &t->sched, &p->sched);
142 76193d7c 2003-09-30 devnull 		if(_setlabel(&t->sched)==0)
143 76193d7c 2003-09-30 devnull 			_gotolabel(&p->sched);
144 76193d7c 2003-09-30 devnull 		return;
145 76193d7c 2003-09-30 devnull 	}else{
146 76193d7c 2003-09-30 devnull 		t = runthread(p);
147 76193d7c 2003-09-30 devnull 		if(t == nil){
148 76193d7c 2003-09-30 devnull 			_threaddebug(DBGSCHED, "all threads gone; exiting");
149 76193d7c 2003-09-30 devnull 			_threaddelproc();
150 76193d7c 2003-09-30 devnull 			_schedexit(p);
151 76193d7c 2003-09-30 devnull 		}
152 32f69c36 2003-12-11 devnull 		_threaddebug(DBGSCHED, "running %d.%d", t->proc->pid, t->id);
153 76193d7c 2003-09-30 devnull 		p->thread = t;
154 76193d7c 2003-09-30 devnull 		if(t->moribund){
155 76193d7c 2003-09-30 devnull 			_threaddebug(DBGSCHED, "%d.%d marked to die");
156 76193d7c 2003-09-30 devnull 			goto Resched;
157 76193d7c 2003-09-30 devnull 		}
158 76193d7c 2003-09-30 devnull 		t->state = Running;
159 76193d7c 2003-09-30 devnull 		t->nextstate = Ready;
160 76193d7c 2003-09-30 devnull 		_gotolabel(&t->sched);
161 76193d7c 2003-09-30 devnull 	}
162 76193d7c 2003-09-30 devnull }
163 76193d7c 2003-09-30 devnull 
164 76193d7c 2003-09-30 devnull long
165 76193d7c 2003-09-30 devnull threadstack(void)
166 76193d7c 2003-09-30 devnull {
167 76193d7c 2003-09-30 devnull 	Proc *p;
168 76193d7c 2003-09-30 devnull 	Thread *t;
169 76193d7c 2003-09-30 devnull 
170 76193d7c 2003-09-30 devnull 	p = _threadgetproc();
171 76193d7c 2003-09-30 devnull 	t = p->thread;
172 76193d7c 2003-09-30 devnull 	return (ulong)&p - (ulong)t->stk;
173 76193d7c 2003-09-30 devnull }
174 76193d7c 2003-09-30 devnull 
175 76193d7c 2003-09-30 devnull void
176 76193d7c 2003-09-30 devnull _threadready(Thread *t)
177 76193d7c 2003-09-30 devnull {
178 76193d7c 2003-09-30 devnull 	Tqueue *q;
179 76193d7c 2003-09-30 devnull 
180 32f69c36 2003-12-11 devnull 	if(t == t->proc->idle){
181 32f69c36 2003-12-11 devnull 		_threaddebug(DBGSCHED, "idle thread is ready");
182 e97ceade 2003-12-06 devnull 		return;
183 32f69c36 2003-12-11 devnull 	}
184 e97ceade 2003-12-06 devnull 
185 76193d7c 2003-09-30 devnull 	assert(t->state == Ready);
186 76193d7c 2003-09-30 devnull 	_threaddebug(DBGSCHED, "readying %d.%d", t->proc->pid, t->id);
187 76193d7c 2003-09-30 devnull 	q = &t->proc->ready;
188 76193d7c 2003-09-30 devnull 	lock(&t->proc->readylock);
189 76193d7c 2003-09-30 devnull 	t->next = nil;
190 76193d7c 2003-09-30 devnull 	if(q->head==nil)
191 76193d7c 2003-09-30 devnull 		q->head = t;
192 76193d7c 2003-09-30 devnull 	else
193 76193d7c 2003-09-30 devnull 		q->tail->next = t;
194 76193d7c 2003-09-30 devnull 	q->tail = t;
195 76193d7c 2003-09-30 devnull 	if(q->asleep){
196 cd7ddc9b 2003-11-23 devnull 		assert(q->asleep == 1);
197 76193d7c 2003-09-30 devnull 		q->asleep = 0;
198 76193d7c 2003-09-30 devnull 		/* lock passes to runthread */
199 76193d7c 2003-09-30 devnull 		_threaddebug(DBGSCHED, "waking process %d", t->proc->pid);
200 76193d7c 2003-09-30 devnull 		while(rendezvous((ulong)q, 0) == ~0){
201 76193d7c 2003-09-30 devnull 			if(_threadexitsallstatus)
202 76193d7c 2003-09-30 devnull 				exits(_threadexitsallstatus);
203 76193d7c 2003-09-30 devnull 		}
204 76193d7c 2003-09-30 devnull 	}else
205 76193d7c 2003-09-30 devnull 		unlock(&t->proc->readylock);
206 76193d7c 2003-09-30 devnull }
207 76193d7c 2003-09-30 devnull 
208 76193d7c 2003-09-30 devnull void
209 e97ceade 2003-12-06 devnull _threadidle(void)
210 e97ceade 2003-12-06 devnull {
211 e97ceade 2003-12-06 devnull 	Tqueue *q;
212 32f69c36 2003-12-11 devnull 	Thread *t, *idle;
213 e97ceade 2003-12-06 devnull 	Proc *p;
214 e97ceade 2003-12-06 devnull 
215 e97ceade 2003-12-06 devnull 	p = _threadgetproc();
216 e97ceade 2003-12-06 devnull 	q = &p->ready;
217 e97ceade 2003-12-06 devnull 	lock(&p->readylock);
218 32f69c36 2003-12-11 devnull 	assert(q->tail);
219 32f69c36 2003-12-11 devnull 	idle = q->tail;
220 32f69c36 2003-12-11 devnull 	if(q->head == idle){
221 32f69c36 2003-12-11 devnull 		q->head = nil;
222 e97ceade 2003-12-06 devnull 		q->tail = nil;
223 32f69c36 2003-12-11 devnull 	}else{
224 32f69c36 2003-12-11 devnull 		for(t=q->head; t->next!=q->tail; t=t->next)
225 32f69c36 2003-12-11 devnull 			;
226 32f69c36 2003-12-11 devnull 		t->next = nil;
227 32f69c36 2003-12-11 devnull 		q->tail = t;
228 32f69c36 2003-12-11 devnull 	}
229 32f69c36 2003-12-11 devnull 	p->idle = idle;
230 32f69c36 2003-12-11 devnull 	_threaddebug(DBGSCHED, "p->idle is %d\n", idle->id);
231 e97ceade 2003-12-06 devnull 	unlock(&p->readylock);
232 e97ceade 2003-12-06 devnull }
233 e97ceade 2003-12-06 devnull 
234 e97ceade 2003-12-06 devnull void
235 76193d7c 2003-09-30 devnull yield(void)
236 76193d7c 2003-09-30 devnull {
237 76193d7c 2003-09-30 devnull 	_sched();
238 76193d7c 2003-09-30 devnull }
239 76193d7c 2003-09-30 devnull