Annotation of OpenXM_contrib/gc/solaris_threads.c, Revision 1.1
1.1 ! maekawa 1: /*
! 2: * Copyright (c) 1994 by Xerox Corporation. All rights reserved.
! 3: *
! 4: * THIS MATERIAL IS PROVIDED AS IS, WITH ABSOLUTELY NO WARRANTY EXPRESSED
! 5: * OR IMPLIED. ANY USE IS AT YOUR OWN RISK.
! 6: *
! 7: * Permission is hereby granted to use or copy this program
! 8: * for any purpose, provided the above notices are retained on all copies.
! 9: * Permission to modify the code and to distribute modified code is granted,
! 10: * provided the above notices are retained, and a notice that the code was
! 11: * modified is included with the above copyright notice.
! 12: */
! 13: /*
! 14: * Support code for Solaris threads. Provides functionality we wish Sun
! 15: * had provided. Relies on some information we probably shouldn't rely on.
! 16: */
! 17: /* Boehm, September 14, 1994 4:44 pm PDT */
! 18:
! 19: # if defined(SOLARIS_THREADS)
! 20:
! 21: # include "gc_priv.h"
! 22: # include "solaris_threads.h"
! 23: # include <thread.h>
! 24: # include <synch.h>
! 25: # include <signal.h>
! 26: # include <fcntl.h>
! 27: # include <sys/types.h>
! 28: # include <sys/mman.h>
! 29: # include <sys/time.h>
! 30: # include <sys/resource.h>
! 31: # include <sys/stat.h>
! 32: # include <sys/syscall.h>
! 33: # include <sys/procfs.h>
! 34: # include <sys/lwp.h>
! 35: # include <sys/reg.h>
! 36: # define _CLASSIC_XOPEN_TYPES
! 37: # include <unistd.h>
! 38: # include <errno.h>
! 39:
! 40: /*
! 41: * This is the default size of the LWP arrays. If there are more LWPs
! 42: * than this when a stop-the-world GC happens, set_max_lwps will be
! 43: * called to cope.
! 44: * This must be higher than the number of LWPs at startup time.
! 45: * The threads library creates a thread early on, so the min. is 3
! 46: */
! 47: # define DEFAULT_MAX_LWPS 4
! 48:
! 49: #undef thr_join
! 50: #undef thr_create
! 51: #undef thr_suspend
! 52: #undef thr_continue
! 53:
! 54: cond_t GC_prom_join_cv; /* Broadcast when any thread terminates */
! 55: cond_t GC_create_cv; /* Signalled when a new undetached */
! 56: /* thread starts. */
! 57:
! 58:
! 59: #ifdef MMAP_STACKS
! 60: static int GC_zfd;
! 61: #endif /* MMAP_STACKS */
! 62:
! 63: /* We use the allocation lock to protect thread-related data structures. */
! 64:
! 65: /* We stop the world using /proc primitives. This makes some */
! 66: /* minimal assumptions about the threads implementation. */
! 67: /* We don't play by the rules, since the rules make this */
! 68: /* impossible (as of Solaris 2.3). Also note that as of */
! 69: /* Solaris 2.3 the various thread and lwp suspension */
! 70: /* primitives failed to stop threads by the time the request */
! 71: /* is completed. */
! 72:
! 73:
! 74: static sigset_t old_mask;
! 75:
! 76: /* Sleep for n milliseconds, n < 1000 */
! 77: void GC_msec_sleep(int n)
! 78: {
! 79: struct timespec ts;
! 80:
! 81: ts.tv_sec = 0;
! 82: ts.tv_nsec = 1000000*n;
! 83: if (syscall(SYS_nanosleep, &ts, 0) < 0) {
! 84: ABORT("nanosleep failed");
! 85: }
! 86: }
! 87: /* Turn off preemption; gross but effective. */
! 88: /* Caller has allocation lock. */
! 89: /* Actually this is not needed under Solaris 2.3 and */
! 90: /* 2.4, but hopefully that'll change. */
! 91: void preempt_off()
! 92: {
! 93: sigset_t set;
! 94:
! 95: (void)sigfillset(&set);
! 96: sigdelset(&set, SIGABRT);
! 97: syscall(SYS_sigprocmask, SIG_SETMASK, &set, &old_mask);
! 98: }
! 99:
! 100: void preempt_on()
! 101: {
! 102: syscall(SYS_sigprocmask, SIG_SETMASK, &old_mask, NULL);
! 103: }
! 104:
! 105: int GC_main_proc_fd = -1;
! 106:
! 107:
! 108: struct lwp_cache_entry {
! 109: lwpid_t lc_id;
! 110: int lc_descr; /* /proc file descriptor. */
! 111: } GC_lwp_cache_default[DEFAULT_MAX_LWPS];
! 112:
! 113: static int max_lwps = DEFAULT_MAX_LWPS;
! 114: static struct lwp_cache_entry *GC_lwp_cache = GC_lwp_cache_default;
! 115:
! 116: static prgregset_t GC_lwp_registers_default[DEFAULT_MAX_LWPS];
! 117: static prgregset_t *GC_lwp_registers = GC_lwp_registers_default;
! 118:
! 119: /* Return a file descriptor for the /proc entry corresponding */
! 120: /* to the given lwp. The file descriptor may be stale if the */
! 121: /* lwp exited and a new one was forked. */
! 122: static int open_lwp(lwpid_t id)
! 123: {
! 124: int result;
! 125: static int next_victim = 0;
! 126: register int i;
! 127:
! 128: for (i = 0; i < max_lwps; i++) {
! 129: if (GC_lwp_cache[i].lc_id == id) return(GC_lwp_cache[i].lc_descr);
! 130: }
! 131: result = syscall(SYS_ioctl, GC_main_proc_fd, PIOCOPENLWP, &id);
! 132: /*
! 133: * If PIOCOPENLWP fails, try closing fds in the cache until it succeeds.
! 134: */
! 135: if (result < 0 && errno == EMFILE) {
! 136: for (i = 0; i < max_lwps; i++) {
! 137: if (GC_lwp_cache[i].lc_id != 0) {
! 138: (void)syscall(SYS_close, GC_lwp_cache[i].lc_descr);
! 139: result = syscall(SYS_ioctl, GC_main_proc_fd, PIOCOPENLWP, &id);
! 140: if (result >= 0 || (result < 0 && errno != EMFILE))
! 141: break;
! 142: }
! 143: }
! 144: }
! 145: if (result < 0) {
! 146: if (errno == EMFILE) {
! 147: ABORT("Too many open files");
! 148: }
! 149: return(-1) /* exited? */;
! 150: }
! 151: if (GC_lwp_cache[next_victim].lc_id != 0)
! 152: (void)syscall(SYS_close, GC_lwp_cache[next_victim].lc_descr);
! 153: GC_lwp_cache[next_victim].lc_id = id;
! 154: GC_lwp_cache[next_victim].lc_descr = result;
! 155: if (++next_victim >= max_lwps)
! 156: next_victim = 0;
! 157: return(result);
! 158: }
! 159:
! 160: static void uncache_lwp(lwpid_t id)
! 161: {
! 162: register int i;
! 163:
! 164: for (i = 0; i < max_lwps; i++) {
! 165: if (GC_lwp_cache[i].lc_id == id) {
! 166: (void)syscall(SYS_close, GC_lwp_cache[id].lc_descr);
! 167: GC_lwp_cache[i].lc_id = 0;
! 168: break;
! 169: }
! 170: }
! 171: }
! 172: /* Sequence of current lwp ids */
! 173: static lwpid_t GC_current_ids_default[DEFAULT_MAX_LWPS + 1];
! 174: static lwpid_t *GC_current_ids = GC_current_ids_default;
! 175:
! 176: /* Temporary used below (can be big if large number of LWPs) */
! 177: static lwpid_t last_ids_default[DEFAULT_MAX_LWPS + 1];
! 178: static lwpid_t *last_ids = last_ids_default;
! 179:
! 180:
! 181: #define ROUNDUP(n) WORDS_TO_BYTES(ROUNDED_UP_WORDS(n))
! 182:
! 183: static void set_max_lwps(GC_word n)
! 184: {
! 185: char *mem;
! 186: char *oldmem;
! 187: int required_bytes = ROUNDUP(n * sizeof(struct lwp_cache_entry))
! 188: + ROUNDUP(n * sizeof(prgregset_t))
! 189: + ROUNDUP((n + 1) * sizeof(lwpid_t))
! 190: + ROUNDUP((n + 1) * sizeof(lwpid_t));
! 191:
! 192: GC_expand_hp_inner(divHBLKSZ((word)required_bytes));
! 193: oldmem = mem = GC_scratch_alloc(required_bytes);
! 194: if (0 == mem) ABORT("No space for lwp data structures");
! 195:
! 196: /*
! 197: * We can either flush the old lwp cache or copy it over. Do the latter.
! 198: */
! 199: memcpy(mem, GC_lwp_cache, max_lwps * sizeof(struct lwp_cache_entry));
! 200: GC_lwp_cache = (struct lwp_cache_entry*)mem;
! 201: mem += ROUNDUP(n * sizeof(struct lwp_cache_entry));
! 202:
! 203: BZERO(GC_lwp_registers, max_lwps * sizeof(GC_lwp_registers[0]));
! 204: GC_lwp_registers = (prgregset_t *)mem;
! 205: mem += ROUNDUP(n * sizeof(prgregset_t));
! 206:
! 207:
! 208: GC_current_ids = (lwpid_t *)mem;
! 209: mem += ROUNDUP((n + 1) * sizeof(lwpid_t));
! 210:
! 211: last_ids = (lwpid_t *)mem;
! 212: mem += ROUNDUP((n + 1)* sizeof(lwpid_t));
! 213:
! 214: if (mem > oldmem + required_bytes)
! 215: ABORT("set_max_lwps buffer overflow");
! 216:
! 217: max_lwps = n;
! 218: }
! 219:
! 220:
! 221: /* Stop all lwps in process. Assumes preemption is off. */
! 222: /* Caller has allocation lock (and any other locks he may */
! 223: /* need). */
! 224: static void stop_all_lwps()
! 225: {
! 226: int lwp_fd;
! 227: char buf[30];
! 228: prstatus_t status;
! 229: register int i;
! 230: GC_bool changed;
! 231: lwpid_t me = _lwp_self();
! 232:
! 233: if (GC_main_proc_fd == -1) {
! 234: sprintf(buf, "/proc/%d", getpid());
! 235: GC_main_proc_fd = syscall(SYS_open, buf, O_RDONLY);
! 236: if (GC_main_proc_fd < 0) {
! 237: if (errno == EMFILE)
! 238: ABORT("/proc open failed: too many open files");
! 239: GC_printf1("/proc open failed: errno %d", errno);
! 240: abort();
! 241: }
! 242: }
! 243: BZERO(GC_lwp_registers, sizeof (prgregset_t) * max_lwps);
! 244: for (i = 0; i < max_lwps; i++)
! 245: last_ids[i] = 0;
! 246: for (;;) {
! 247: if (syscall(SYS_ioctl, GC_main_proc_fd, PIOCSTATUS, &status) < 0)
! 248: ABORT("Main PIOCSTATUS failed");
! 249: if (status.pr_nlwp < 1)
! 250: ABORT("Invalid number of lwps returned by PIOCSTATUS");
! 251: if (status.pr_nlwp >= max_lwps) {
! 252: set_max_lwps(status.pr_nlwp*2 + 10);
! 253: /*
! 254: * The data in the old GC_current_ids and
! 255: * GC_lwp_registers has been trashed. Cleaning out last_ids
! 256: * will make sure every LWP gets re-examined.
! 257: */
! 258: for (i = 0; i < max_lwps; i++)
! 259: last_ids[i] = 0;
! 260: continue;
! 261: }
! 262: if (syscall(SYS_ioctl, GC_main_proc_fd, PIOCLWPIDS, GC_current_ids) < 0)
! 263: ABORT("PIOCLWPIDS failed");
! 264: changed = FALSE;
! 265: for (i = 0; GC_current_ids[i] != 0 && i < max_lwps; i++) {
! 266: if (GC_current_ids[i] != last_ids[i]) {
! 267: changed = TRUE;
! 268: if (GC_current_ids[i] != me) {
! 269: /* PIOCSTOP doesn't work without a writable */
! 270: /* descriptor. And that makes the process */
! 271: /* undebuggable. */
! 272: if (_lwp_suspend(GC_current_ids[i]) < 0) {
! 273: /* Could happen if the lwp exited */
! 274: uncache_lwp(GC_current_ids[i]);
! 275: GC_current_ids[i] = me; /* ignore */
! 276: }
! 277: }
! 278: }
! 279: }
! 280: /*
! 281: * In the unlikely event something does a fork between the
! 282: * PIOCSTATUS and the PIOCLWPIDS.
! 283: */
! 284: if (i >= max_lwps)
! 285: continue;
! 286: /* All lwps in GC_current_ids != me have been suspended. Note */
! 287: /* that _lwp_suspend is idempotent. */
! 288: for (i = 0; GC_current_ids[i] != 0; i++) {
! 289: if (GC_current_ids[i] != last_ids[i]) {
! 290: if (GC_current_ids[i] != me) {
! 291: lwp_fd = open_lwp(GC_current_ids[i]);
! 292: if (lwp_fd == -1)
! 293: {
! 294: GC_current_ids[i] = me;
! 295: continue;
! 296: }
! 297: /* LWP should be stopped. Empirically it sometimes */
! 298: /* isn't, and more frequently the PR_STOPPED flag */
! 299: /* is not set. Wait for PR_STOPPED. */
! 300: if (syscall(SYS_ioctl, lwp_fd,
! 301: PIOCSTATUS, &status) < 0) {
! 302: /* Possible if the descriptor was stale, or */
! 303: /* we encountered the 2.3 _lwp_suspend bug. */
! 304: uncache_lwp(GC_current_ids[i]);
! 305: GC_current_ids[i] = me; /* handle next time. */
! 306: } else {
! 307: while (!(status.pr_flags & PR_STOPPED)) {
! 308: GC_msec_sleep(1);
! 309: if (syscall(SYS_ioctl, lwp_fd,
! 310: PIOCSTATUS, &status) < 0) {
! 311: ABORT("Repeated PIOCSTATUS failed");
! 312: }
! 313: if (status.pr_flags & PR_STOPPED) break;
! 314:
! 315: GC_msec_sleep(20);
! 316: if (syscall(SYS_ioctl, lwp_fd,
! 317: PIOCSTATUS, &status) < 0) {
! 318: ABORT("Repeated PIOCSTATUS failed");
! 319: }
! 320: }
! 321: if (status.pr_who != GC_current_ids[i]) {
! 322: /* can happen if thread was on death row */
! 323: uncache_lwp(GC_current_ids[i]);
! 324: GC_current_ids[i] = me; /* handle next time. */
! 325: continue;
! 326: }
! 327: /* Save registers where collector can */
! 328: /* find them. */
! 329: BCOPY(status.pr_reg, GC_lwp_registers[i],
! 330: sizeof (prgregset_t));
! 331: }
! 332: }
! 333: }
! 334: }
! 335: if (!changed) break;
! 336: for (i = 0; i < max_lwps; i++) last_ids[i] = GC_current_ids[i];
! 337: }
! 338: }
! 339:
! 340: /* Restart all lwps in process. Assumes preemption is off. */
! 341: static void restart_all_lwps()
! 342: {
! 343: int lwp_fd;
! 344: register int i;
! 345: GC_bool changed;
! 346: lwpid_t me = _lwp_self();
! 347: # define PARANOID
! 348:
! 349: for (i = 0; GC_current_ids[i] != 0; i++) {
! 350: # ifdef PARANOID
! 351: if (GC_current_ids[i] != me) {
! 352: int lwp_fd = open_lwp(GC_current_ids[i]);
! 353: prstatus_t status;
! 354:
! 355: if (lwp_fd < 0) ABORT("open_lwp failed");
! 356: if (syscall(SYS_ioctl, lwp_fd,
! 357: PIOCSTATUS, &status) < 0) {
! 358: ABORT("PIOCSTATUS failed in restart_all_lwps");
! 359: }
! 360: if (memcmp(status.pr_reg, GC_lwp_registers[i],
! 361: sizeof (prgregset_t)) != 0) {
! 362: int j;
! 363:
! 364: for(j = 0; j < NGREG; j++)
! 365: {
! 366: GC_printf3("%i: %x -> %x\n", j,
! 367: GC_lwp_registers[i][j],
! 368: status.pr_reg[j]);
! 369: }
! 370: ABORT("Register contents changed");
! 371: }
! 372: if (!status.pr_flags & PR_STOPPED) {
! 373: ABORT("lwp no longer stopped");
! 374: }
! 375: #ifdef SPARC
! 376: {
! 377: gwindows_t windows;
! 378: if (syscall(SYS_ioctl, lwp_fd,
! 379: PIOCGWIN, &windows) < 0) {
! 380: ABORT("PIOCSTATUS failed in restart_all_lwps");
! 381: }
! 382: if (windows.wbcnt > 0) ABORT("unsaved register windows");
! 383: }
! 384: #endif
! 385: }
! 386: # endif /* PARANOID */
! 387: if (GC_current_ids[i] == me) continue;
! 388: if (_lwp_continue(GC_current_ids[i]) < 0) {
! 389: ABORT("Failed to restart lwp");
! 390: }
! 391: }
! 392: if (i >= max_lwps) ABORT("Too many lwps");
! 393: }
! 394:
! 395: GC_bool GC_multithreaded = 0;
! 396:
! 397: void GC_stop_world()
! 398: {
! 399: preempt_off();
! 400: if (GC_multithreaded)
! 401: stop_all_lwps();
! 402: }
! 403:
! 404: void GC_start_world()
! 405: {
! 406: if (GC_multithreaded)
! 407: restart_all_lwps();
! 408: preempt_on();
! 409: }
! 410:
! 411: void GC_thr_init(void);
! 412:
! 413: GC_bool GC_thr_initialized = FALSE;
! 414:
! 415: size_t GC_min_stack_sz;
! 416:
! 417: size_t GC_page_sz;
! 418:
! 419: /*
! 420: * stack_head is stored at the top of free stacks
! 421: */
! 422: struct stack_head {
! 423: struct stack_head *next;
! 424: ptr_t base;
! 425: thread_t owner;
! 426: };
! 427:
! 428: # define N_FREE_LISTS 25
! 429: struct stack_head *GC_stack_free_lists[N_FREE_LISTS] = { 0 };
! 430: /* GC_stack_free_lists[i] is free list for stacks of */
! 431: /* size GC_min_stack_sz*2**i. */
! 432: /* Free lists are linked through stack_head stored */ /* at top of stack. */
! 433:
! 434: /* Return a stack of size at least *stack_size. *stack_size is */
! 435: /* replaced by the actual stack size. */
! 436: /* Caller holds allocation lock. */
! 437: ptr_t GC_stack_alloc(size_t * stack_size)
! 438: {
! 439: register size_t requested_sz = *stack_size;
! 440: register size_t search_sz = GC_min_stack_sz;
! 441: register int index = 0; /* = log2(search_sz/GC_min_stack_sz) */
! 442: register ptr_t base;
! 443: register struct stack_head *result;
! 444:
! 445: while (search_sz < requested_sz) {
! 446: search_sz *= 2;
! 447: index++;
! 448: }
! 449: if ((result = GC_stack_free_lists[index]) == 0
! 450: && (result = GC_stack_free_lists[index+1]) != 0) {
! 451: /* Try next size up. */
! 452: search_sz *= 2; index++;
! 453: }
! 454: if (result != 0) {
! 455: base = GC_stack_free_lists[index]->base;
! 456: GC_stack_free_lists[index] = GC_stack_free_lists[index]->next;
! 457: } else {
! 458: #ifdef MMAP_STACKS
! 459: base = (ptr_t)mmap(0, search_sz + GC_page_sz,
! 460: PROT_READ|PROT_WRITE, MAP_PRIVATE |MAP_NORESERVE,
! 461: GC_zfd, 0);
! 462: if (base == (ptr_t)-1)
! 463: {
! 464: *stack_size = 0;
! 465: return NULL;
! 466: }
! 467:
! 468: mprotect(base, GC_page_sz, PROT_NONE);
! 469: /* Should this use divHBLKSZ(search_sz + GC_page_sz) ? -- cf */
! 470: GC_is_fresh((struct hblk *)base, divHBLKSZ(search_sz));
! 471: base += GC_page_sz;
! 472:
! 473: #else
! 474: base = (ptr_t) GC_scratch_alloc(search_sz + 2*GC_page_sz);
! 475: if (base == NULL)
! 476: {
! 477: *stack_size = 0;
! 478: return NULL;
! 479: }
! 480:
! 481: base = (ptr_t)(((word)base + GC_page_sz) & ~(GC_page_sz - 1));
! 482: /* Protect hottest page to detect overflow. */
! 483: # ifdef SOLARIS23_MPROTECT_BUG_FIXED
! 484: mprotect(base, GC_page_sz, PROT_NONE);
! 485: # endif
! 486: GC_is_fresh((struct hblk *)base, divHBLKSZ(search_sz));
! 487:
! 488: base += GC_page_sz;
! 489: #endif
! 490: }
! 491: *stack_size = search_sz;
! 492: return(base);
! 493: }
! 494:
! 495: /* Caller holds allocationlock. */
! 496: void GC_stack_free(ptr_t stack, size_t size)
! 497: {
! 498: register int index = 0;
! 499: register size_t search_sz = GC_min_stack_sz;
! 500: register struct stack_head *head;
! 501:
! 502: #ifdef MMAP_STACKS
! 503: /* Zero pointers */
! 504: mmap(stack, size, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_NORESERVE|MAP_FIXED,
! 505: GC_zfd, 0);
! 506: #endif
! 507: while (search_sz < size) {
! 508: search_sz *= 2;
! 509: index++;
! 510: }
! 511: if (search_sz != size) ABORT("Bad stack size");
! 512:
! 513: head = (struct stack_head *)(stack + search_sz - sizeof(struct stack_head));
! 514: head->next = GC_stack_free_lists[index];
! 515: head->base = stack;
! 516: GC_stack_free_lists[index] = head;
! 517: }
! 518:
! 519: void GC_my_stack_limits();
! 520:
! 521: /* Notify virtual dirty bit implementation that known empty parts of */
! 522: /* stacks do not contain useful data. */
! 523: /* Caller holds allocation lock. */
! 524: void GC_old_stacks_are_fresh()
! 525: {
! 526: /* No point in doing this for MMAP stacks - and pointers are zero'd out */
! 527: /* by the mmap in GC_stack_free */
! 528: #ifndef MMAP_STACKS
! 529: register int i;
! 530: register struct stack_head *s;
! 531: register ptr_t p;
! 532: register size_t sz;
! 533: register struct hblk * h;
! 534: int dummy;
! 535:
! 536: for (i = 0, sz= GC_min_stack_sz; i < N_FREE_LISTS;
! 537: i++, sz *= 2) {
! 538: for (s = GC_stack_free_lists[i]; s != 0; s = s->next) {
! 539: p = s->base;
! 540: h = (struct hblk *)(((word)p + HBLKSIZE-1) & ~(HBLKSIZE-1));
! 541: if ((ptr_t)h == p) {
! 542: GC_is_fresh((struct hblk *)p, divHBLKSZ(sz));
! 543: } else {
! 544: GC_is_fresh((struct hblk *)p, divHBLKSZ(sz) - 1);
! 545: BZERO(p, (ptr_t)h - p);
! 546: }
! 547: }
! 548: }
! 549: #endif /* MMAP_STACKS */
! 550: GC_my_stack_limits();
! 551: }
! 552:
! 553: /* The set of all known threads. We intercept thread creation and */
! 554: /* joins. We never actually create detached threads. We allocate all */
! 555: /* new thread stacks ourselves. These allow us to maintain this */
! 556: /* data structure. */
! 557:
! 558: # define THREAD_TABLE_SZ 128 /* Must be power of 2 */
! 559: volatile GC_thread GC_threads[THREAD_TABLE_SZ];
! 560:
! 561: /* Add a thread to GC_threads. We assume it wasn't already there. */
! 562: /* Caller holds allocation lock. */
! 563: GC_thread GC_new_thread(thread_t id)
! 564: {
! 565: int hv = ((word)id) % THREAD_TABLE_SZ;
! 566: GC_thread result;
! 567: static struct GC_Thread_Rep first_thread;
! 568: static GC_bool first_thread_used = FALSE;
! 569:
! 570: if (!first_thread_used) {
! 571: result = &first_thread;
! 572: first_thread_used = TRUE;
! 573: /* Dont acquire allocation lock, since we may already hold it. */
! 574: } else {
! 575: result = (struct GC_Thread_Rep *)
! 576: GC_generic_malloc_inner(sizeof(struct GC_Thread_Rep), NORMAL);
! 577: }
! 578: if (result == 0) return(0);
! 579: result -> id = id;
! 580: result -> next = GC_threads[hv];
! 581: GC_threads[hv] = result;
! 582: /* result -> finished = 0; */
! 583: (void) cond_init(&(result->join_cv), USYNC_THREAD, 0);
! 584: return(result);
! 585: }
! 586:
! 587: /* Delete a thread from GC_threads. We assume it is there. */
! 588: /* (The code intentionally traps if it wasn't.) */
! 589: /* Caller holds allocation lock. */
! 590: void GC_delete_thread(thread_t id)
! 591: {
! 592: int hv = ((word)id) % THREAD_TABLE_SZ;
! 593: register GC_thread p = GC_threads[hv];
! 594: register GC_thread prev = 0;
! 595:
! 596: while (p -> id != id) {
! 597: prev = p;
! 598: p = p -> next;
! 599: }
! 600: if (prev == 0) {
! 601: GC_threads[hv] = p -> next;
! 602: } else {
! 603: prev -> next = p -> next;
! 604: }
! 605: }
! 606:
! 607: /* Return the GC_thread correpsonding to a given thread_t. */
! 608: /* Returns 0 if it's not there. */
! 609: /* Caller holds allocation lock. */
! 610: GC_thread GC_lookup_thread(thread_t id)
! 611: {
! 612: int hv = ((word)id) % THREAD_TABLE_SZ;
! 613: register GC_thread p = GC_threads[hv];
! 614:
! 615: while (p != 0 && p -> id != id) p = p -> next;
! 616: return(p);
! 617: }
! 618:
! 619: /* Notify dirty bit implementation of unused parts of my stack. */
! 620: /* Caller holds allocation lock. */
! 621: void GC_my_stack_limits()
! 622: {
! 623: int dummy;
! 624: register ptr_t hottest = (ptr_t)((word)(&dummy) & ~(HBLKSIZE-1));
! 625: register GC_thread me = GC_lookup_thread(thr_self());
! 626: register size_t stack_size = me -> stack_size;
! 627: register ptr_t stack;
! 628:
! 629: if (stack_size == 0) {
! 630: /* original thread */
! 631: struct rlimit rl;
! 632:
! 633: if (getrlimit(RLIMIT_STACK, &rl) != 0) ABORT("getrlimit failed");
! 634: /* Empirically, what should be the stack page with lowest */
! 635: /* address is actually inaccessible. */
! 636: stack_size = ((word)rl.rlim_cur & ~(HBLKSIZE-1)) - GC_page_sz;
! 637: stack = GC_stackbottom - stack_size + GC_page_sz;
! 638: } else {
! 639: stack = me -> stack;
! 640: }
! 641: if (stack > hottest || stack + stack_size < hottest) {
! 642: ABORT("sp out of bounds");
! 643: }
! 644: GC_is_fresh((struct hblk *)stack, divHBLKSZ(hottest - stack));
! 645: }
! 646:
! 647:
! 648: /* We hold allocation lock. We assume the world is stopped. */
! 649: void GC_push_all_stacks()
! 650: {
! 651: register int i;
! 652: register GC_thread p;
! 653: register ptr_t sp = GC_approx_sp();
! 654: register ptr_t bottom, top;
! 655: struct rlimit rl;
! 656:
! 657: # define PUSH(bottom,top) \
! 658: if (GC_dirty_maintained) { \
! 659: GC_push_dirty((bottom), (top), GC_page_was_ever_dirty, \
! 660: GC_push_all_stack); \
! 661: } else { \
! 662: GC_push_all_stack((bottom), (top)); \
! 663: }
! 664: GC_push_all_stack((ptr_t)GC_lwp_registers,
! 665: (ptr_t)GC_lwp_registers
! 666: + max_lwps * sizeof(GC_lwp_registers[0]));
! 667: for (i = 0; i < THREAD_TABLE_SZ; i++) {
! 668: for (p = GC_threads[i]; p != 0; p = p -> next) {
! 669: if (p -> stack_size != 0) {
! 670: bottom = p -> stack;
! 671: top = p -> stack + p -> stack_size;
! 672: } else {
! 673: /* The original stack. */
! 674: if (getrlimit(RLIMIT_STACK, &rl) != 0) ABORT("getrlimit failed");
! 675: bottom = GC_stackbottom - rl.rlim_cur + GC_page_sz;
! 676: top = GC_stackbottom;
! 677: }
! 678: if ((word)sp > (word)bottom && (word)sp < (word)top) bottom = sp;
! 679: PUSH(bottom, top);
! 680: }
! 681: }
! 682: }
! 683:
! 684:
! 685: int GC_is_thread_stack(ptr_t addr)
! 686: {
! 687: register int i;
! 688: register GC_thread p;
! 689: register ptr_t bottom, top;
! 690: struct rlimit rl;
! 691:
! 692: for (i = 0; i < THREAD_TABLE_SZ; i++) {
! 693: for (p = GC_threads[i]; p != 0; p = p -> next) {
! 694: if (p -> stack_size != 0) {
! 695: if (p -> stack <= addr &&
! 696: addr < p -> stack + p -> stack_size)
! 697: return 1;
! 698: }
! 699: }
! 700: }
! 701: }
! 702:
! 703: /* The only thread that ever really performs a thr_join. */
! 704: void * GC_thr_daemon(void * dummy)
! 705: {
! 706: void *status;
! 707: thread_t departed;
! 708: register GC_thread t;
! 709: register int i;
! 710: register int result;
! 711:
! 712: for(;;) {
! 713: start:
! 714: result = thr_join((thread_t)0, &departed, &status);
! 715: LOCK();
! 716: if (result != 0) {
! 717: /* No more threads; wait for create. */
! 718: for (i = 0; i < THREAD_TABLE_SZ; i++) {
! 719: for (t = GC_threads[i]; t != 0; t = t -> next) {
! 720: if (!(t -> flags & (DETACHED | FINISHED))) {
! 721: UNLOCK();
! 722: goto start; /* Thread started just before we */
! 723: /* acquired the lock. */
! 724: }
! 725: }
! 726: }
! 727: cond_wait(&GC_create_cv, &GC_allocate_ml);
! 728: UNLOCK();
! 729: } else {
! 730: t = GC_lookup_thread(departed);
! 731: GC_multithreaded--;
! 732: if (!(t -> flags & CLIENT_OWNS_STACK)) {
! 733: GC_stack_free(t -> stack, t -> stack_size);
! 734: }
! 735: if (t -> flags & DETACHED) {
! 736: GC_delete_thread(departed);
! 737: } else {
! 738: t -> status = status;
! 739: t -> flags |= FINISHED;
! 740: cond_signal(&(t -> join_cv));
! 741: cond_broadcast(&GC_prom_join_cv);
! 742: }
! 743: UNLOCK();
! 744: }
! 745: }
! 746: }
! 747:
! 748: /* We hold the allocation lock, or caller ensures that 2 instances */
! 749: /* cannot be invoked concurrently. */
! 750: void GC_thr_init(void)
! 751: {
! 752: GC_thread t;
! 753: thread_t tid;
! 754:
! 755: if (GC_thr_initialized)
! 756: return;
! 757: GC_thr_initialized = TRUE;
! 758: GC_min_stack_sz = ((thr_min_stack() + 32*1024 + HBLKSIZE-1)
! 759: & ~(HBLKSIZE - 1));
! 760: GC_page_sz = sysconf(_SC_PAGESIZE);
! 761: #ifdef MMAP_STACKS
! 762: GC_zfd = open("/dev/zero", O_RDONLY);
! 763: if (GC_zfd == -1)
! 764: ABORT("Can't open /dev/zero");
! 765: #endif /* MMAP_STACKS */
! 766: cond_init(&GC_prom_join_cv, USYNC_THREAD, 0);
! 767: cond_init(&GC_create_cv, USYNC_THREAD, 0);
! 768: /* Add the initial thread, so we can stop it. */
! 769: t = GC_new_thread(thr_self());
! 770: t -> stack_size = 0;
! 771: t -> flags = DETACHED | CLIENT_OWNS_STACK;
! 772: if (thr_create(0 /* stack */, 0 /* stack_size */, GC_thr_daemon,
! 773: 0 /* arg */, THR_DETACHED | THR_DAEMON,
! 774: &tid /* thread_id */) != 0) {
! 775: ABORT("Cant fork daemon");
! 776: }
! 777: thr_setprio(tid, 126);
! 778: }
! 779:
! 780: /* We acquire the allocation lock to prevent races with */
! 781: /* stopping/starting world. */
! 782: /* This is no more correct than the underlying Solaris 2.X */
! 783: /* implementation. Under 2.3 THIS IS BROKEN. */
! 784: int GC_thr_suspend(thread_t target_thread)
! 785: {
! 786: GC_thread t;
! 787: int result;
! 788:
! 789: LOCK();
! 790: result = thr_suspend(target_thread);
! 791: if (result == 0) {
! 792: t = GC_lookup_thread(target_thread);
! 793: if (t == 0) ABORT("thread unknown to GC");
! 794: t -> flags |= SUSPENDED;
! 795: }
! 796: UNLOCK();
! 797: return(result);
! 798: }
! 799:
! 800: int GC_thr_continue(thread_t target_thread)
! 801: {
! 802: GC_thread t;
! 803: int result;
! 804:
! 805: LOCK();
! 806: result = thr_continue(target_thread);
! 807: if (result == 0) {
! 808: t = GC_lookup_thread(target_thread);
! 809: if (t == 0) ABORT("thread unknown to GC");
! 810: t -> flags &= ~SUSPENDED;
! 811: }
! 812: UNLOCK();
! 813: return(result);
! 814: }
! 815:
! 816: int GC_thr_join(thread_t wait_for, thread_t *departed, void **status)
! 817: {
! 818: register GC_thread t;
! 819: int result = 0;
! 820:
! 821: LOCK();
! 822: if (wait_for == 0) {
! 823: register int i;
! 824: register GC_bool thread_exists;
! 825:
! 826: for (;;) {
! 827: thread_exists = FALSE;
! 828: for (i = 0; i < THREAD_TABLE_SZ; i++) {
! 829: for (t = GC_threads[i]; t != 0; t = t -> next) {
! 830: if (!(t -> flags & DETACHED)) {
! 831: if (t -> flags & FINISHED) {
! 832: goto found;
! 833: }
! 834: thread_exists = TRUE;
! 835: }
! 836: }
! 837: }
! 838: if (!thread_exists) {
! 839: result = ESRCH;
! 840: goto out;
! 841: }
! 842: cond_wait(&GC_prom_join_cv, &GC_allocate_ml);
! 843: }
! 844: } else {
! 845: t = GC_lookup_thread(wait_for);
! 846: if (t == 0 || t -> flags & DETACHED) {
! 847: result = ESRCH;
! 848: goto out;
! 849: }
! 850: if (wait_for == thr_self()) {
! 851: result = EDEADLK;
! 852: goto out;
! 853: }
! 854: while (!(t -> flags & FINISHED)) {
! 855: cond_wait(&(t -> join_cv), &GC_allocate_ml);
! 856: }
! 857:
! 858: }
! 859: found:
! 860: if (status) *status = t -> status;
! 861: if (departed) *departed = t -> id;
! 862: cond_destroy(&(t -> join_cv));
! 863: GC_delete_thread(t -> id);
! 864: out:
! 865: UNLOCK();
! 866: return(result);
! 867: }
! 868:
! 869:
! 870: int
! 871: GC_thr_create(void *stack_base, size_t stack_size,
! 872: void *(*start_routine)(void *), void *arg, long flags,
! 873: thread_t *new_thread)
! 874: {
! 875: int result;
! 876: GC_thread t;
! 877: thread_t my_new_thread;
! 878: word my_flags = 0;
! 879: void * stack = stack_base;
! 880:
! 881: LOCK();
! 882: if (!GC_thr_initialized)
! 883: {
! 884: GC_thr_init();
! 885: }
! 886: GC_multithreaded++;
! 887: if (stack == 0) {
! 888: if (stack_size == 0) stack_size = GC_min_stack_sz;
! 889: stack = (void *)GC_stack_alloc(&stack_size);
! 890: if (stack == 0) {
! 891: GC_multithreaded--;
! 892: UNLOCK();
! 893: return(ENOMEM);
! 894: }
! 895: } else {
! 896: my_flags |= CLIENT_OWNS_STACK;
! 897: }
! 898: if (flags & THR_DETACHED) my_flags |= DETACHED;
! 899: if (flags & THR_SUSPENDED) my_flags |= SUSPENDED;
! 900: result = thr_create(stack, stack_size, start_routine,
! 901: arg, flags & ~THR_DETACHED, &my_new_thread);
! 902: if (result == 0) {
! 903: t = GC_new_thread(my_new_thread);
! 904: t -> flags = my_flags;
! 905: if (!(my_flags & DETACHED)) cond_init(&(t -> join_cv), USYNC_THREAD, 0);
! 906: t -> stack = stack;
! 907: t -> stack_size = stack_size;
! 908: if (new_thread != 0) *new_thread = my_new_thread;
! 909: cond_signal(&GC_create_cv);
! 910: } else {
! 911: GC_multithreaded--;
! 912: if (!(my_flags & CLIENT_OWNS_STACK)) {
! 913: GC_stack_free(stack, stack_size);
! 914: }
! 915: }
! 916: UNLOCK();
! 917: return(result);
! 918: }
! 919:
! 920: # else /* SOLARIS_THREADS */
! 921:
! 922: #ifndef LINT
! 923: int GC_no_sunOS_threads;
! 924: #endif
! 925: #endif
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