1 /* kern_synch.c 3.8 10/14/12 */ 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; 34 register s, h; 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_stat = SSLEEP; 41 rp->p_wchan = chan; 42 rp->p_slptime = 0; 43 rp->p_pri = pri; 44 h = HASH(chan); 45 rp->p_link = slpque[h]; 46 slpque[h] = rp; 47 if(pri > PZERO) { 48 if(ISSIG(rp)) { 49 rp->p_wchan = 0; 50 rp->p_stat = SRUN; 51 slpque[h] = rp->p_link; 52 (void) spl0(); 53 goto psig; 54 } 55 (void) spl0(); 56 if(runin != 0) { 57 runin = 0; 58 wakeup((caddr_t)&runin); 59 } 60 swtch(); 61 if(ISSIG(rp)) 62 goto psig; 63 } else { 64 (void) spl0(); 65 swtch(); 66 } 67 splx(s); 68 return; 69 70 /* 71 * If priority was low (>PZERO) and 72 * there has been a signal, 73 * execute non-local goto to 74 * the qsav location. 75 * (see trap1/trap.c) 76 */ 77 psig: 78 longjmp(u.u_qsav); 79 /*NOTREACHED*/ 80 } 81 82 /* 83 * Sleep on chan at pri. 84 * Return in no more than the indicated number of seconds. 85 * (If seconds==0, no timeout implied) 86 * Return TS_OK if chan was awakened normally 87 * TS_TIME if timeout occurred 88 * TS_SIG if asynchronous signal occurred 89 */ 90 tsleep(chan, pri, seconds) 91 caddr_t chan; 92 { 93 label_t lqsav; 94 register struct proc *pp; 95 register sec, n, rval; 96 97 pp = u.u_procp; 98 n = spl7(); 99 sec = 0; 100 rval = 0; 101 if (pp->p_clktim && pp->p_clktim<seconds) 102 seconds = 0; 103 if (seconds) { 104 pp->p_flag |= STIMO; 105 sec = pp->p_clktim-seconds; 106 pp->p_clktim = seconds; 107 } 108 bcopy((caddr_t)u.u_qsav, (caddr_t)lqsav, sizeof (label_t)); 109 if (setjmp(u.u_qsav)) 110 rval = TS_SIG; 111 else { 112 sleep(chan, pri); 113 if ((pp->p_flag&STIMO)==0 && seconds) 114 rval = TS_TIME; 115 else 116 rval = TS_OK; 117 } 118 pp->p_flag &= ~STIMO; 119 bcopy((caddr_t)lqsav, (caddr_t)u.u_qsav, sizeof (label_t)); 120 if (sec > 0) 121 pp->p_clktim += sec; 122 else 123 pp->p_clktim = 0; 124 splx(n); 125 return(rval); 126 } 127 128 /* 129 * Remove a process from its wait queue 130 */ 131 unsleep(p) 132 register struct proc *p; 133 { 134 register struct proc **hp; 135 register s; 136 137 s = spl6(); 138 if (p->p_wchan) { 139 hp = &slpque[HASH(p->p_wchan)]; 140 while (*hp != p) 141 hp = &(*hp)->p_link; 142 *hp = p->p_link; 143 p->p_wchan = 0; 144 } 145 splx(s); 146 } 147 148 /* 149 * Wake up all processes sleeping on chan. 150 */ 151 wakeup(chan) 152 register caddr_t chan; 153 { 154 register struct proc *p, *q; 155 register i; 156 int s; 157 158 s = spl6(); 159 i = HASH(chan); 160 restart: 161 p = slpque[i]; 162 q = NULL; 163 while(p != NULL) { 164 if (p->p_rlink || p->p_stat != SSLEEP && p->p_stat != SSTOP) 165 panic("wakeup"); 166 if (p->p_wchan==chan && p->p_stat!=SZOMB) { 167 if (q == NULL) 168 slpque[i] = p->p_link; 169 else 170 q->p_link = p->p_link; 171 p->p_wchan = 0; 172 p->p_slptime = 0; 173 if (p->p_stat == SSLEEP) { 174 /* OPTIMIZED INLINE EXPANSION OF setrun(p) */ 175 p->p_stat = SRUN; 176 if (p->p_flag & SLOAD) { 177 #ifndef FASTVAX 178 p->p_link = runq; 179 runq = p->p_link; 180 #else 181 setrq(p); 182 #endif 183 } 184 if(p->p_pri < curpri) 185 runrun++; 186 if(runout != 0 && (p->p_flag&SLOAD) == 0) { 187 runout = 0; 188 wakeup((caddr_t)&runout); 189 } 190 /* END INLINE EXPANSION */ 191 } 192 goto restart; 193 } 194 q = p; 195 p = p->p_link; 196 } 197 splx(s); 198 } 199 200 #ifdef FASTVAX 201 /* 202 * Initialize the (doubly-linked) run queues 203 * to be empty. 204 */ 205 rqinit() 206 { 207 register int i; 208 209 for (i = 0; i < NQS; i++) 210 qs[i].ph_link = qs[i].ph_rlink = (struct proc *)&qs[i]; 211 } 212 #endif 213 214 /* 215 * Set the process running; 216 * arrange for it to be swapped in if necessary. 217 */ 218 setrun(p) 219 register struct proc *p; 220 { 221 register caddr_t w; 222 register s; 223 224 s = spl6(); 225 switch (p->p_stat) { 226 227 case 0: 228 case SWAIT: 229 case SRUN: 230 case SZOMB: 231 default: 232 panic("setrun"); 233 234 case SSLEEP: 235 unsleep(p); /* e.g. when sending signals */ 236 break; 237 238 case SIDL: 239 case SSTOP: 240 break; 241 } 242 p->p_stat = SRUN; 243 if (p->p_flag & SLOAD) 244 setrq(p); 245 splx(s); 246 if(p->p_pri < curpri) 247 runrun++; 248 if(runout != 0 && (p->p_flag&SLOAD) == 0) { 249 runout = 0; 250 wakeup((caddr_t)&runout); 251 } 252 } 253 254 /* 255 * Set user priority. 256 * The rescheduling flag (runrun) 257 * is set if the priority is better 258 * than the currently running process. 259 */ 260 setpri(pp) 261 register struct proc *pp; 262 { 263 register p; 264 265 p = (pp->p_cpu & 0377)/16; 266 p += PUSER + pp->p_nice - NZERO; 267 if(p > 127) 268 p = 127; 269 if(p < curpri) 270 runrun++; 271 pp->p_usrpri = p; 272 return(p); 273 } 274 275 /* 276 * Create a new process-- the internal version of 277 * sys fork. 278 * It returns 1 in the new process, 0 in the old. 279 */ 280 newproc(isvfork) 281 { 282 register struct proc *p; 283 register struct proc *rpp, *rip; 284 register int n; 285 286 p = NULL; 287 /* 288 * First, just locate a slot for a process 289 * and copy the useful info from this process into it. 290 * The panic "cannot happen" because fork has already 291 * checked for the existence of a slot. 292 */ 293 retry: 294 mpid++; 295 if(mpid >= 30000) { 296 mpid = 0; 297 goto retry; 298 } 299 for(rpp = &proc[0]; rpp < &proc[NPROC]; rpp++) { 300 if(rpp->p_stat == NULL && p==NULL) 301 p = rpp; 302 if (rpp->p_pid==mpid || rpp->p_pgrp==mpid) 303 goto retry; 304 } 305 if ((rpp = p)==NULL) 306 panic("no procs"); 307 308 /* 309 * make proc entry for new proc 310 */ 311 312 rip = u.u_procp; 313 rpp->p_stat = SIDL; 314 rpp->p_clktim = 0; 315 rpp->p_flag = SLOAD | (rip->p_flag & SPAGI); 316 if (isvfork) { 317 rpp->p_flag |= SVFORK; 318 rpp->p_ndx = rip->p_ndx; 319 } else 320 rpp->p_ndx = rpp - proc; 321 rpp->p_uid = rip->p_uid; 322 rpp->p_pgrp = rip->p_pgrp; 323 rpp->p_nice = rip->p_nice; 324 rpp->p_textp = isvfork ? 0 : rip->p_textp; 325 rpp->p_pid = mpid; 326 rpp->p_ppid = rip->p_pid; 327 rpp->p_pptr = rip; 328 rpp->p_time = 0; 329 rpp->p_cpu = 0; 330 rpp->p_siga0 = rip->p_siga0; 331 rpp->p_siga1 = rip->p_siga1; 332 /* take along any pending signals, like stops? */ 333 if (isvfork) { 334 rpp->p_tsize = rpp->p_dsize = rpp->p_ssize = 0; 335 rpp->p_szpt = clrnd(ctopt(UPAGES)); 336 forkstat.cntvfork++; 337 forkstat.sizvfork += rip->p_dsize + rip->p_ssize; 338 } else { 339 rpp->p_tsize = rip->p_tsize; 340 rpp->p_dsize = rip->p_dsize; 341 rpp->p_ssize = rip->p_ssize; 342 rpp->p_szpt = rip->p_szpt; 343 forkstat.cntfork++; 344 forkstat.sizfork += rip->p_dsize + rip->p_ssize; 345 } 346 rpp->p_rssize = 0; 347 rpp->p_wchan = 0; 348 rpp->p_slptime = 0; 349 rpp->p_aveflt = rip->p_aveflt; 350 rate.v_pgin += rip->p_aveflt; 351 rpp->p_faults = 0; 352 n = PIDHASH(rpp->p_pid); 353 p->p_idhash = pidhash[n]; 354 pidhash[n] = rpp - proc; 355 356 /* 357 * make duplicate entries 358 * where needed 359 */ 360 361 multprog++; 362 363 for(n=0; n<NOFILE; n++) 364 if(u.u_ofile[n] != NULL) { 365 u.u_ofile[n]->f_count++; 366 if(!isvfork && u.u_vrpages[n]) 367 u.u_ofile[n]->f_inode->i_vfdcnt++; 368 } 369 370 u.u_cdir->i_count++; 371 if (u.u_rdir) 372 u.u_rdir->i_count++; 373 /* 374 * Partially simulate the environment 375 * of the new process so that when it is actually 376 * created (by copying) it will look right. 377 */ 378 379 rip->p_flag |= SKEEP; /* prevent parent from being swapped */ 380 381 if (procdup(rpp, isvfork)) 382 return (1); 383 384 spl6(); 385 rpp->p_stat = SRUN; 386 setrq(rpp); 387 spl0(); 388 /* SSWAP NOT NEEDED IN THIS CASE AS u.u_pcb.pcb_sswap SUFFICES */ 389 /* rpp->p_flag |= SSWAP; */ 390 rip->p_flag &= ~SKEEP; 391 if (isvfork) { 392 u.u_procp->p_xlink = rpp; 393 u.u_procp->p_flag |= SNOVM; 394 while (rpp->p_flag & SVFORK) 395 sleep((caddr_t)rpp, PZERO - 1); 396 if ((rpp->p_flag & SLOAD) == 0) 397 panic("newproc vfork"); 398 uaccess(rpp, Vfmap, &vfutl); 399 u.u_procp->p_xlink = 0; 400 vpassvm(rpp, u.u_procp, &vfutl, &u, Vfmap); 401 for (n = 0; n < NOFILE; n++) 402 if (vfutl.u_vrpages[n]) { 403 if ((u.u_vrpages[n] = vfutl.u_vrpages[n] - 1) == 0) 404 if (--u.u_ofile[n]->f_inode->i_vfdcnt < 0) 405 panic("newproc i_vfdcnt"); 406 vfutl.u_vrpages[n] = 0; 407 } 408 u.u_procp->p_flag &= ~SNOVM; 409 rpp->p_ndx = rpp - proc; 410 rpp->p_flag |= SVFDONE; 411 wakeup((caddr_t)rpp); 412 } 413 return (0); 414 } 415