1 /* kern_synch.c 3.15 10/11/80 */ 2 3 #include "../h/param.h" 4 #include "../h/systm.h" 5 #include "../h/dir.h" 6 #include "../h/user.h" 7 #include "../h/proc.h" 8 #include "../h/file.h" 9 #include "../h/inode.h" 10 #include "../h/vm.h" 11 #include "../h/pte.h" 12 #include "../h/inline.h" 13 14 15 #define SQSIZE 0100 /* Must be power of 2 */ 16 #define HASH(x) (( (int) x >> 5) & (SQSIZE-1)) 17 struct proc *slpque[SQSIZE]; 18 19 /* 20 * Give up the processor till a wakeup occurs 21 * on chan, at which time the process 22 * enters the scheduling queue at priority pri. 23 * The most important effect of pri is that when 24 * pri<=PZERO a signal cannot disturb the sleep; 25 * if pri>PZERO signals will be processed. 26 * Callers of this routine must be prepared for 27 * premature return, and check that the reason for 28 * sleeping has gone away. 29 */ 30 sleep(chan, pri) 31 caddr_t chan; 32 { 33 register struct proc *rp, **hp; 34 register s; 35 36 rp = u.u_procp; 37 s = spl6(); 38 if (chan==0 || rp->p_stat != SRUN || rp->p_rlink) 39 panic("sleep"); 40 rp->p_wchan = chan; 41 rp->p_slptime = 0; 42 rp->p_pri = pri; 43 hp = &slpque[HASH(chan)]; 44 rp->p_link = *hp; 45 *hp = rp; 46 if(pri > PZERO) { 47 if(ISSIG(rp)) { 48 if (rp->p_wchan) 49 unsleep(rp); 50 rp->p_stat = SRUN; 51 (void) spl0(); 52 goto psig; 53 } 54 if (rp->p_wchan == 0) 55 goto out; 56 rp->p_stat = SSLEEP; 57 (void) spl0(); 58 if(runin != 0) { 59 runin = 0; 60 wakeup((caddr_t)&runin); 61 } 62 swtch(); 63 if(ISSIG(rp)) 64 goto psig; 65 } else { 66 rp->p_stat = SSLEEP; 67 (void) spl0(); 68 swtch(); 69 } 70 out: 71 splx(s); 72 return; 73 74 /* 75 * If priority was low (>PZERO) and 76 * there has been a signal, 77 * execute non-local goto to 78 * the qsav location. 79 * (see trap1/trap.c) 80 */ 81 psig: 82 longjmp(u.u_qsav); 83 /*NOTREACHED*/ 84 } 85 86 /* 87 * Sleep on chan at pri. 88 * Return in no more than the indicated number of seconds. 89 * (If seconds==0, no timeout implied) 90 * Return TS_OK if chan was awakened normally 91 * TS_TIME if timeout occurred 92 * TS_SIG if asynchronous signal occurred 93 */ 94 tsleep(chan, pri, seconds) 95 caddr_t chan; 96 { 97 label_t lqsav; 98 register struct proc *pp; 99 register sec, n, rval; 100 101 pp = u.u_procp; 102 n = spl7(); 103 sec = 0; 104 rval = 0; 105 if (pp->p_clktim && pp->p_clktim<seconds) 106 seconds = 0; 107 if (seconds) { 108 pp->p_flag |= STIMO; 109 sec = pp->p_clktim-seconds; 110 pp->p_clktim = seconds; 111 } 112 bcopy((caddr_t)u.u_qsav, (caddr_t)lqsav, sizeof (label_t)); 113 if (setjmp(u.u_qsav)) 114 rval = TS_SIG; 115 else { 116 sleep(chan, pri); 117 if ((pp->p_flag&STIMO)==0 && seconds) 118 rval = TS_TIME; 119 else 120 rval = TS_OK; 121 } 122 pp->p_flag &= ~STIMO; 123 bcopy((caddr_t)lqsav, (caddr_t)u.u_qsav, sizeof (label_t)); 124 if (sec > 0) 125 pp->p_clktim += sec; 126 else 127 pp->p_clktim = 0; 128 splx(n); 129 return(rval); 130 } 131 132 /* 133 * Remove a process from its wait queue 134 */ 135 unsleep(p) 136 register struct proc *p; 137 { 138 register struct proc **hp; 139 register s; 140 141 s = spl6(); 142 if (p->p_wchan) { 143 hp = &slpque[HASH(p->p_wchan)]; 144 while (*hp != p) 145 hp = &(*hp)->p_link; 146 *hp = p->p_link; 147 p->p_wchan = 0; 148 } 149 splx(s); 150 } 151 152 /* 153 * Wake up all processes sleeping on chan. 154 */ 155 wakeup(chan) 156 register caddr_t chan; 157 { 158 register struct proc *p, **q, **h; 159 int s; 160 161 s = spl6(); 162 h = &slpque[HASH(chan)]; 163 restart: 164 for (q = h; p = *q; ) { 165 if (p->p_rlink || p->p_stat != SSLEEP && p->p_stat != SSTOP) 166 panic("wakeup"); 167 if (p->p_wchan==chan) { 168 p->p_wchan = 0; 169 *q = p->p_link; 170 p->p_slptime = 0; 171 if (p->p_stat == SSLEEP) { 172 /* OPTIMIZED INLINE EXPANSION OF setrun(p) */ 173 p->p_stat = SRUN; 174 if (p->p_flag & SLOAD) { 175 #ifndef FASTVAX 176 p->p_link = runq; 177 runq = p->p_link; 178 #else 179 setrq(p); 180 #endif 181 } 182 if(p->p_pri < curpri) 183 runrun++; 184 if(runout != 0 && (p->p_flag&SLOAD) == 0) { 185 runout = 0; 186 wakeup((caddr_t)&runout); 187 } 188 /* END INLINE EXPANSION */ 189 goto restart; 190 } 191 } else 192 q = &p->p_link; 193 } 194 splx(s); 195 } 196 197 #ifdef FASTVAX 198 /* 199 * Initialize the (doubly-linked) run queues 200 * to be empty. 201 */ 202 rqinit() 203 { 204 register int i; 205 206 for (i = 0; i < NQS; i++) 207 qs[i].ph_link = qs[i].ph_rlink = (struct proc *)&qs[i]; 208 } 209 #endif 210 211 /* 212 * Set the process running; 213 * arrange for it to be swapped in if necessary. 214 */ 215 setrun(p) 216 register struct proc *p; 217 { 218 register s; 219 220 s = spl6(); 221 switch (p->p_stat) { 222 223 case 0: 224 case SWAIT: 225 case SRUN: 226 case SZOMB: 227 default: 228 panic("setrun"); 229 230 case SSTOP: 231 case SSLEEP: 232 unsleep(p); /* e.g. when sending signals */ 233 break; 234 235 case SIDL: 236 break; 237 } 238 p->p_stat = SRUN; 239 if (p->p_flag & SLOAD) 240 setrq(p); 241 splx(s); 242 if(p->p_pri < curpri) 243 runrun++; 244 if(runout != 0 && (p->p_flag&SLOAD) == 0) { 245 runout = 0; 246 wakeup((caddr_t)&runout); 247 } 248 } 249 250 /* 251 * Set user priority. 252 * The rescheduling flag (runrun) 253 * is set if the priority is better 254 * than the currently running process. 255 */ 256 setpri(pp) 257 register struct proc *pp; 258 { 259 register p; 260 261 p = (pp->p_cpu & 0377)/16; 262 p += PUSER + pp->p_nice - NZERO; 263 if(p > 127) 264 p = 127; 265 if(p < curpri) 266 runrun++; 267 pp->p_usrpri = p; 268 return(p); 269 } 270 271 /* 272 * Create a new process-- the internal version of 273 * sys fork. 274 * It returns 1 in the new process, 0 in the old. 275 */ 276 newproc(isvfork) 277 { 278 register struct proc *p; 279 register struct proc *rpp, *rip; 280 register int n; 281 282 p = NULL; 283 /* 284 * First, just locate a slot for a process 285 * and copy the useful info from this process into it. 286 * The panic "cannot happen" because fork has already 287 * checked for the existence of a slot. 288 */ 289 retry: 290 mpid++; 291 if(mpid >= 30000) { 292 mpid = 0; 293 goto retry; 294 } 295 for(rpp = &proc[0]; rpp < &proc[NPROC]; rpp++) { 296 if(rpp->p_stat == NULL && p==NULL) 297 p = rpp; 298 if (rpp->p_pid==mpid || rpp->p_pgrp==mpid) 299 goto retry; 300 } 301 if ((rpp = p)==NULL) 302 panic("no procs"); 303 304 /* 305 * make proc entry for new proc 306 */ 307 308 rip = u.u_procp; 309 rpp->p_stat = SIDL; 310 rpp->p_clktim = 0; 311 rpp->p_flag = SLOAD | (rip->p_flag & (SPAGI|SDETACH|SNUSIG)); 312 if (isvfork) { 313 rpp->p_flag |= SVFORK; 314 rpp->p_ndx = rip->p_ndx; 315 } else 316 rpp->p_ndx = rpp - proc; 317 rpp->p_uid = rip->p_uid; 318 rpp->p_pgrp = rip->p_pgrp; 319 rpp->p_nice = rip->p_nice; 320 rpp->p_textp = isvfork ? 0 : rip->p_textp; 321 rpp->p_pid = mpid; 322 rpp->p_ppid = rip->p_pid; 323 rpp->p_pptr = rip; 324 rpp->p_time = 0; 325 rpp->p_cpu = 0; 326 rpp->p_siga0 = rip->p_siga0; 327 rpp->p_siga1 = rip->p_siga1; 328 /* take along any pending signals, like stops? */ 329 if (isvfork) { 330 rpp->p_tsize = rpp->p_dsize = rpp->p_ssize = 0; 331 rpp->p_szpt = clrnd(ctopt(UPAGES)); 332 forkstat.cntvfork++; 333 forkstat.sizvfork += rip->p_dsize + rip->p_ssize; 334 } else { 335 rpp->p_tsize = rip->p_tsize; 336 rpp->p_dsize = rip->p_dsize; 337 rpp->p_ssize = rip->p_ssize; 338 rpp->p_szpt = rip->p_szpt; 339 forkstat.cntfork++; 340 forkstat.sizfork += rip->p_dsize + rip->p_ssize; 341 } 342 rpp->p_rssize = 0; 343 rpp->p_wchan = 0; 344 rpp->p_slptime = 0; 345 rpp->p_pctcpu = 0; 346 rpp->p_cpticks = 0; 347 n = PIDHASH(rpp->p_pid); 348 p->p_idhash = pidhash[n]; 349 pidhash[n] = rpp - proc; 350 351 /* 352 * make duplicate entries 353 * where needed 354 */ 355 356 multprog++; 357 358 for(n=0; n<NOFILE; n++) 359 if(u.u_ofile[n] != NULL) { 360 u.u_ofile[n]->f_count++; 361 if(!isvfork && u.u_vrpages[n]) 362 u.u_ofile[n]->f_inode->i_vfdcnt++; 363 } 364 365 u.u_cdir->i_count++; 366 if (u.u_rdir) 367 u.u_rdir->i_count++; 368 /* 369 * Partially simulate the environment 370 * of the new process so that when it is actually 371 * created (by copying) it will look right. 372 */ 373 374 rip->p_flag |= SKEEP; /* prevent parent from being swapped */ 375 376 if (procdup(rpp, isvfork)) 377 return (1); 378 379 spl6(); 380 rpp->p_stat = SRUN; 381 setrq(rpp); 382 spl0(); 383 /* SSWAP NOT NEEDED IN THIS CASE AS u.u_pcb.pcb_sswap SUFFICES */ 384 /* rpp->p_flag |= SSWAP; */ 385 rip->p_flag &= ~SKEEP; 386 if (isvfork) { 387 u.u_procp->p_xlink = rpp; 388 u.u_procp->p_flag |= SNOVM; 389 while (rpp->p_flag & SVFORK) 390 sleep((caddr_t)rpp, PZERO - 1); 391 if ((rpp->p_flag & SLOAD) == 0) 392 panic("newproc vfork"); 393 uaccess(rpp, Vfmap, &vfutl); 394 u.u_procp->p_xlink = 0; 395 vpassvm(rpp, u.u_procp, &vfutl, &u, Vfmap); 396 for (n = 0; n < NOFILE; n++) 397 if (vfutl.u_vrpages[n]) { 398 if ((u.u_vrpages[n] = vfutl.u_vrpages[n] - 1) == 0) 399 if (--u.u_ofile[n]->f_inode->i_vfdcnt < 0) 400 panic("newproc i_vfdcnt"); 401 vfutl.u_vrpages[n] = 0; 402 } 403 u.u_procp->p_flag &= ~SNOVM; 404 rpp->p_ndx = rpp - proc; 405 rpp->p_flag |= SVFDONE; 406 wakeup((caddr_t)rpp); 407 } 408 return (0); 409 } 410