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"
6 76193d7c 2003-09-30 devnull //static Thread *runthread(Proc*);
8 76193d7c 2003-09-30 devnull static char *_psstate[] = {
10 76193d7c 2003-09-30 devnull "Running",
12 76193d7c 2003-09-30 devnull "Rendezvous",
15 76193d7c 2003-09-30 devnull static char*
16 76193d7c 2003-09-30 devnull psstate(int s)
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];
24 76193d7c 2003-09-30 devnull _schedinit(void *arg)
27 76193d7c 2003-09-30 devnull Thread *t;
28 65de82a3 2004-06-09 devnull extern void ignusr1(int), _threaddie(int);
29 65de82a3 2004-06-09 devnull ignusr1(1);
30 76193d7c 2003-09-30 devnull signal(SIGTERM, _threaddie);
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))
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;
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;
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();
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--;
68 76193d7c 2003-09-30 devnull _sched();
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;
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");
82 76193d7c 2003-09-30 devnull p->newproc = nil;
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);
88 76193d7c 2003-09-30 devnull unlock(&p->lock);
89 76193d7c 2003-09-30 devnull _sched();
92 50e628cb 2003-11-23 devnull static Thread*
93 76193d7c 2003-09-30 devnull runthread(Proc *p)
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;
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;
105 76193d7c 2003-09-30 devnull lock(&p->readylock);
106 65de82a3 2004-06-09 devnull if(p->nsched%128 == 0){
107 65de82a3 2004-06-09 devnull /* clean up children */
108 5a8e63b2 2004-02-29 devnull e = errno;
109 5a8e63b2 2004-02-29 devnull if((c = _threadwaitchan) != nil){
110 5a8e63b2 2004-02-29 devnull if(c->n <= c->s){
111 5a8e63b2 2004-02-29 devnull sent = 0;
112 5a8e63b2 2004-02-29 devnull for(;;){
113 5a8e63b2 2004-02-29 devnull if((w = p->waitmsg) != nil)
114 5a8e63b2 2004-02-29 devnull p->waitmsg = nil;
116 5a8e63b2 2004-02-29 devnull w = waitnohang();
117 5a8e63b2 2004-02-29 devnull if(w == nil)
119 5a8e63b2 2004-02-29 devnull if(sent == 0){
120 5a8e63b2 2004-02-29 devnull unlock(&p->readylock);
121 5a8e63b2 2004-02-29 devnull sent = 1;
123 5a8e63b2 2004-02-29 devnull if(nbsendp(c, w) != 1)
126 5a8e63b2 2004-02-29 devnull p->waitmsg = w;
127 5a8e63b2 2004-02-29 devnull if(sent)
128 5a8e63b2 2004-02-29 devnull goto relock;
131 5a8e63b2 2004-02-29 devnull while((w = waitnohang()) != nil)
132 5a8e63b2 2004-02-29 devnull free(w);
134 5a8e63b2 2004-02-29 devnull errno = e;
136 65de82a3 2004-06-09 devnull if(q->head == nil){
137 e97ceade 2003-12-06 devnull if(p->idle){
138 e97ceade 2003-12-06 devnull if(p->idle->state != Ready){
139 e97ceade 2003-12-06 devnull fprint(2, "everyone is asleep\n");
140 e97ceade 2003-12-06 devnull exits("everyone is asleep");
142 e97ceade 2003-12-06 devnull unlock(&p->readylock);
143 32f69c36 2003-12-11 devnull _threaddebug(DBGSCHED, "running idle thread", p->nthreads);
144 e97ceade 2003-12-06 devnull return p->idle;
147 cd7ddc9b 2003-11-23 devnull _threaddebug(DBGSCHED, "sleeping for more work (%d threads)", p->nthreads);
148 32f69c36 2003-12-11 devnull q->asleep = 1;
149 76193d7c 2003-09-30 devnull unlock(&p->readylock);
150 76193d7c 2003-09-30 devnull while(rendezvous((ulong)q, 0) == ~0){
151 76193d7c 2003-09-30 devnull if(_threadexitsallstatus)
152 76193d7c 2003-09-30 devnull exits(_threadexitsallstatus);
154 76193d7c 2003-09-30 devnull /* lock picked up from _threadready */
156 76193d7c 2003-09-30 devnull t = q->head;
157 76193d7c 2003-09-30 devnull q->head = t->next;
158 76193d7c 2003-09-30 devnull unlock(&p->readylock);
159 76193d7c 2003-09-30 devnull return t;
163 fb36ed82 2004-04-21 devnull needstack(int howmuch)
165 fb36ed82 2004-04-21 devnull Proc *p;
166 fb36ed82 2004-04-21 devnull Thread *t;
168 fb36ed82 2004-04-21 devnull p = _threadgetproc();
169 fb36ed82 2004-04-21 devnull if(p == nil || (t=p->thread) == nil)
171 fb36ed82 2004-04-21 devnull if((ulong)&howmuch < (ulong)t->stk+howmuch){ /* stack overflow waiting to happen */
172 fb36ed82 2004-04-21 devnull fprint(2, "stack overflow: stack at 0x%lux, limit at 0x%lux, need 0x%lux\n", (ulong)&p, (ulong)t->stk, howmuch);
173 fb36ed82 2004-04-21 devnull abort();
178 76193d7c 2003-09-30 devnull _sched(void)
180 76193d7c 2003-09-30 devnull Proc *p;
181 76193d7c 2003-09-30 devnull Thread *t;
183 76193d7c 2003-09-30 devnull Resched:
184 76193d7c 2003-09-30 devnull p = _threadgetproc();
185 76193d7c 2003-09-30 devnull //fprint(2, "p %p\n", p);
186 76193d7c 2003-09-30 devnull if((t = p->thread) != nil){
187 fb36ed82 2004-04-21 devnull needstack(512);
188 76193d7c 2003-09-30 devnull // _threaddebug(DBGSCHED, "pausing, state=%s set %p goto %p",
189 76193d7c 2003-09-30 devnull // psstate(t->state), &t->sched, &p->sched);
190 76193d7c 2003-09-30 devnull if(_setlabel(&t->sched)==0)
191 76193d7c 2003-09-30 devnull _gotolabel(&p->sched);
192 c4097c29 2004-05-11 devnull _threadstacklimit(t->stk, t->stk+t->stksize);
193 c4097c29 2004-05-11 devnull return p->nsched++;
195 76193d7c 2003-09-30 devnull t = runthread(p);
196 76193d7c 2003-09-30 devnull if(t == nil){
197 76193d7c 2003-09-30 devnull _threaddebug(DBGSCHED, "all threads gone; exiting");
198 76193d7c 2003-09-30 devnull _threaddelproc();
199 76193d7c 2003-09-30 devnull _schedexit(p);
201 32f69c36 2003-12-11 devnull _threaddebug(DBGSCHED, "running %d.%d", t->proc->pid, t->id);
202 76193d7c 2003-09-30 devnull p->thread = t;
203 76193d7c 2003-09-30 devnull if(t->moribund){
204 76193d7c 2003-09-30 devnull _threaddebug(DBGSCHED, "%d.%d marked to die");
205 76193d7c 2003-09-30 devnull goto Resched;
207 76193d7c 2003-09-30 devnull t->state = Running;
208 76193d7c 2003-09-30 devnull t->nextstate = Ready;
209 76193d7c 2003-09-30 devnull _gotolabel(&t->sched);
210 65de82a3 2004-06-09 devnull for(;;);
215 76193d7c 2003-09-30 devnull threadstack(void)
217 76193d7c 2003-09-30 devnull Proc *p;
218 76193d7c 2003-09-30 devnull Thread *t;
220 76193d7c 2003-09-30 devnull p = _threadgetproc();
221 76193d7c 2003-09-30 devnull t = p->thread;
222 76193d7c 2003-09-30 devnull return (ulong)&p - (ulong)t->stk;
226 76193d7c 2003-09-30 devnull _threadready(Thread *t)
228 76193d7c 2003-09-30 devnull Tqueue *q;
230 32f69c36 2003-12-11 devnull if(t == t->proc->idle){
231 32f69c36 2003-12-11 devnull _threaddebug(DBGSCHED, "idle thread is ready");
235 76193d7c 2003-09-30 devnull assert(t->state == Ready);
236 76193d7c 2003-09-30 devnull _threaddebug(DBGSCHED, "readying %d.%d", t->proc->pid, t->id);
237 76193d7c 2003-09-30 devnull q = &t->proc->ready;
238 76193d7c 2003-09-30 devnull lock(&t->proc->readylock);
239 76193d7c 2003-09-30 devnull t->next = nil;
240 76193d7c 2003-09-30 devnull if(q->head==nil)
241 76193d7c 2003-09-30 devnull q->head = t;
243 76193d7c 2003-09-30 devnull q->tail->next = t;
244 76193d7c 2003-09-30 devnull q->tail = t;
245 76193d7c 2003-09-30 devnull if(q->asleep){
246 cd7ddc9b 2003-11-23 devnull assert(q->asleep == 1);
247 76193d7c 2003-09-30 devnull q->asleep = 0;
248 76193d7c 2003-09-30 devnull /* lock passes to runthread */
249 76193d7c 2003-09-30 devnull _threaddebug(DBGSCHED, "waking process %d", t->proc->pid);
250 76193d7c 2003-09-30 devnull while(rendezvous((ulong)q, 0) == ~0){
251 76193d7c 2003-09-30 devnull if(_threadexitsallstatus)
252 76193d7c 2003-09-30 devnull exits(_threadexitsallstatus);
255 76193d7c 2003-09-30 devnull unlock(&t->proc->readylock);
259 e97ceade 2003-12-06 devnull _threadidle(void)
261 e97ceade 2003-12-06 devnull Tqueue *q;
262 32f69c36 2003-12-11 devnull Thread *t, *idle;
263 e97ceade 2003-12-06 devnull Proc *p;
265 e97ceade 2003-12-06 devnull p = _threadgetproc();
266 e97ceade 2003-12-06 devnull q = &p->ready;
267 e97ceade 2003-12-06 devnull lock(&p->readylock);
268 32f69c36 2003-12-11 devnull assert(q->tail);
269 32f69c36 2003-12-11 devnull idle = q->tail;
270 32f69c36 2003-12-11 devnull if(q->head == idle){
271 32f69c36 2003-12-11 devnull q->head = nil;
272 e97ceade 2003-12-06 devnull q->tail = nil;
274 32f69c36 2003-12-11 devnull for(t=q->head; t->next!=q->tail; t=t->next)
276 32f69c36 2003-12-11 devnull t->next = nil;
277 32f69c36 2003-12-11 devnull q->tail = t;
279 32f69c36 2003-12-11 devnull p->idle = idle;
280 32f69c36 2003-12-11 devnull _threaddebug(DBGSCHED, "p->idle is %d\n", idle->id);
281 e97ceade 2003-12-06 devnull unlock(&p->readylock);
285 76193d7c 2003-09-30 devnull yield(void)
287 c4097c29 2004-05-11 devnull Proc *p;
288 c4097c29 2004-05-11 devnull int nsched;
290 c4097c29 2004-05-11 devnull p = _threadgetproc();
291 c4097c29 2004-05-11 devnull nsched = p->nsched;
292 c4097c29 2004-05-11 devnull return _sched() - nsched;
296 02a1a5c1 2004-03-05 devnull threadstatus(void)
298 02a1a5c1 2004-03-05 devnull Proc *p;
299 02a1a5c1 2004-03-05 devnull Thread *t;
301 02a1a5c1 2004-03-05 devnull p = _threadgetproc();
302 02a1a5c1 2004-03-05 devnull for(t=p->threads.head; t; t=t->nextt)
303 02a1a5c1 2004-03-05 devnull fprint(2, "[%3d] %s userpc=%lux\n",
304 02a1a5c1 2004-03-05 devnull t->id, psstate(t->state), t->userpc);