source: trunk/gcc/boehm-gc/solaris_threads.c@ 2788

Last change on this file since 2788 was 2, checked in by bird, 23 years ago

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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(GC_SOLARIS_THREADS) || defined(GC_SOLARIS_PTHREADS)
20
21# include "private/gc_priv.h"
22# include "private/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
54cond_t GC_prom_join_cv; /* Broadcast when any thread terminates */
55cond_t GC_create_cv; /* Signalled when a new undetached */
56 /* thread starts. */
57
58
59#ifdef MMAP_STACKS
60static 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
74static sigset_t old_mask;
75
76/* Sleep for n milliseconds, n < 1000 */
77void 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. */
91void 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
100void preempt_on()
101{
102 syscall(SYS_sigprocmask, SIG_SETMASK, &old_mask, NULL);
103}
104
105int GC_main_proc_fd = -1;
106
107
108struct lwp_cache_entry {
109 lwpid_t lc_id;
110 int lc_descr; /* /proc file descriptor. */
111} GC_lwp_cache_default[DEFAULT_MAX_LWPS];
112
113static int max_lwps = DEFAULT_MAX_LWPS;
114static struct lwp_cache_entry *GC_lwp_cache = GC_lwp_cache_default;
115
116static prgregset_t GC_lwp_registers_default[DEFAULT_MAX_LWPS];
117static 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. */
122static 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
160static 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 */
173static lwpid_t GC_current_ids_default[DEFAULT_MAX_LWPS + 1];
174static lwpid_t *GC_current_ids = GC_current_ids_default;
175
176 /* Temporary used below (can be big if large number of LWPs) */
177static lwpid_t last_ids_default[DEFAULT_MAX_LWPS + 1];
178static lwpid_t *last_ids = last_ids_default;
179
180
181#define ROUNDUP(n) WORDS_TO_BYTES(ROUNDED_UP_WORDS(n))
182
183static 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). */
224static 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. */
341static 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
395GC_bool GC_multithreaded = 0;
396
397void GC_stop_world()
398{
399 preempt_off();
400 if (GC_multithreaded)
401 stop_all_lwps();
402}
403
404void GC_start_world()
405{
406 if (GC_multithreaded)
407 restart_all_lwps();
408 preempt_on();
409}
410
411void GC_thr_init(void);
412
413GC_bool GC_thr_initialized = FALSE;
414
415size_t GC_min_stack_sz;
416
417
418/*
419 * stack_head is stored at the top of free stacks
420 */
421struct stack_head {
422 struct stack_head *next;
423 ptr_t base;
424 thread_t owner;
425};
426
427# define N_FREE_LISTS 25
428struct stack_head *GC_stack_free_lists[N_FREE_LISTS] = { 0 };
429 /* GC_stack_free_lists[i] is free list for stacks of */
430 /* size GC_min_stack_sz*2**i. */
431 /* Free lists are linked through stack_head stored */ /* at top of stack. */
432
433/* Return a stack of size at least *stack_size. *stack_size is */
434/* replaced by the actual stack size. */
435/* Caller holds allocation lock. */
436ptr_t GC_stack_alloc(size_t * stack_size)
437{
438 register size_t requested_sz = *stack_size;
439 register size_t search_sz = GC_min_stack_sz;
440 register int index = 0; /* = log2(search_sz/GC_min_stack_sz) */
441 register ptr_t base;
442 register struct stack_head *result;
443
444 while (search_sz < requested_sz) {
445 search_sz *= 2;
446 index++;
447 }
448 if ((result = GC_stack_free_lists[index]) == 0
449 && (result = GC_stack_free_lists[index+1]) != 0) {
450 /* Try next size up. */
451 search_sz *= 2; index++;
452 }
453 if (result != 0) {
454 base = GC_stack_free_lists[index]->base;
455 GC_stack_free_lists[index] = GC_stack_free_lists[index]->next;
456 } else {
457#ifdef MMAP_STACKS
458 base = (ptr_t)mmap(0, search_sz + GC_page_size,
459 PROT_READ|PROT_WRITE, MAP_PRIVATE |MAP_NORESERVE,
460 GC_zfd, 0);
461 if (base == (ptr_t)-1)
462 {
463 *stack_size = 0;
464 return NULL;
465 }
466
467 mprotect(base, GC_page_size, PROT_NONE);
468 /* Should this use divHBLKSZ(search_sz + GC_page_size) ? -- cf */
469 GC_is_fresh((struct hblk *)base, divHBLKSZ(search_sz));
470 base += GC_page_size;
471
472#else
473 base = (ptr_t) GC_scratch_alloc(search_sz + 2*GC_page_size);
474 if (base == NULL)
475 {
476 *stack_size = 0;
477 return NULL;
478 }
479
480 base = (ptr_t)(((word)base + GC_page_size) & ~(GC_page_size - 1));
481 /* Protect hottest page to detect overflow. */
482# ifdef SOLARIS23_MPROTECT_BUG_FIXED
483 mprotect(base, GC_page_size, PROT_NONE);
484# endif
485 GC_is_fresh((struct hblk *)base, divHBLKSZ(search_sz));
486
487 base += GC_page_size;
488#endif
489 }
490 *stack_size = search_sz;
491 return(base);
492}
493
494/* Caller holds allocationlock. */
495void GC_stack_free(ptr_t stack, size_t size)
496{
497 register int index = 0;
498 register size_t search_sz = GC_min_stack_sz;
499 register struct stack_head *head;
500
501#ifdef MMAP_STACKS
502 /* Zero pointers */
503 mmap(stack, size, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_NORESERVE|MAP_FIXED,
504 GC_zfd, 0);
505#endif
506 while (search_sz < size) {
507 search_sz *= 2;
508 index++;
509 }
510 if (search_sz != size) ABORT("Bad stack size");
511
512 head = (struct stack_head *)(stack + search_sz - sizeof(struct stack_head));
513 head->next = GC_stack_free_lists[index];
514 head->base = stack;
515 GC_stack_free_lists[index] = head;
516}
517
518void GC_my_stack_limits();
519
520/* Notify virtual dirty bit implementation that known empty parts of */
521/* stacks do not contain useful data. */
522/* Caller holds allocation lock. */
523void GC_old_stacks_are_fresh()
524{
525/* No point in doing this for MMAP stacks - and pointers are zero'd out */
526/* by the mmap in GC_stack_free */
527#ifndef MMAP_STACKS
528 register int i;
529 register struct stack_head *s;
530 register ptr_t p;
531 register size_t sz;
532 register struct hblk * h;
533 int dummy;
534
535 for (i = 0, sz= GC_min_stack_sz; i < N_FREE_LISTS;
536 i++, sz *= 2) {
537 for (s = GC_stack_free_lists[i]; s != 0; s = s->next) {
538 p = s->base;
539 h = (struct hblk *)(((word)p + HBLKSIZE-1) & ~(HBLKSIZE-1));
540 if ((ptr_t)h == p) {
541 GC_is_fresh((struct hblk *)p, divHBLKSZ(sz));
542 } else {
543 GC_is_fresh((struct hblk *)p, divHBLKSZ(sz) - 1);
544 BZERO(p, (ptr_t)h - p);
545 }
546 }
547 }
548#endif /* MMAP_STACKS */
549 GC_my_stack_limits();
550}
551
552/* The set of all known threads. We intercept thread creation and */
553/* joins. We never actually create detached threads. We allocate all */
554/* new thread stacks ourselves. These allow us to maintain this */
555/* data structure. */
556
557# define THREAD_TABLE_SZ 128 /* Must be power of 2 */
558volatile GC_thread GC_threads[THREAD_TABLE_SZ];
559
560void GC_push_thread_structures GC_PROTO((void))
561{
562 GC_push_all((ptr_t)(GC_threads), (ptr_t)(GC_threads)+sizeof(GC_threads));
563}
564
565/* Add a thread to GC_threads. We assume it wasn't already there. */
566/* Caller holds allocation lock. */
567GC_thread GC_new_thread(thread_t id)
568{
569 int hv = ((word)id) % THREAD_TABLE_SZ;
570 GC_thread result;
571 static struct GC_Thread_Rep first_thread;
572 static GC_bool first_thread_used = FALSE;
573
574 if (!first_thread_used) {
575 result = &first_thread;
576 first_thread_used = TRUE;
577 /* Dont acquire allocation lock, since we may already hold it. */
578 } else {
579 result = (struct GC_Thread_Rep *)
580 GC_INTERNAL_MALLOC(sizeof(struct GC_Thread_Rep), NORMAL);
581 }
582 if (result == 0) return(0);
583 result -> id = id;
584 result -> next = GC_threads[hv];
585 GC_threads[hv] = result;
586 /* result -> finished = 0; */
587 (void) cond_init(&(result->join_cv), USYNC_THREAD, 0);
588 return(result);
589}
590
591/* Delete a thread from GC_threads. We assume it is there. */
592/* (The code intentionally traps if it wasn't.) */
593/* Caller holds allocation lock. */
594void GC_delete_thread(thread_t id)
595{
596 int hv = ((word)id) % THREAD_TABLE_SZ;
597 register GC_thread p = GC_threads[hv];
598 register GC_thread prev = 0;
599
600 while (p -> id != id) {
601 prev = p;
602 p = p -> next;
603 }
604 if (prev == 0) {
605 GC_threads[hv] = p -> next;
606 } else {
607 prev -> next = p -> next;
608 }
609}
610
611/* Return the GC_thread correpsonding to a given thread_t. */
612/* Returns 0 if it's not there. */
613/* Caller holds allocation lock. */
614GC_thread GC_lookup_thread(thread_t id)
615{
616 int hv = ((word)id) % THREAD_TABLE_SZ;
617 register GC_thread p = GC_threads[hv];
618
619 while (p != 0 && p -> id != id) p = p -> next;
620 return(p);
621}
622
623/* Solaris 2/Intel uses an initial stack size limit slightly bigger than the
624 SPARC default of 8 MB. Account for this to warn only if the user has
625 raised the limit beyond the default.
626
627 This is identical to DFLSSIZ defined in <sys/vm_machparam.h>. This file
628 is installed in /usr/platform/`uname -m`/include, which is not in the
629 default include directory list, so copy the definition here. */
630#ifdef I386
631# define MAX_ORIG_STACK_SIZE (8 * 1024 * 1024 + ((USRSTACK) & 0x3FFFFF))
632#else
633# define MAX_ORIG_STACK_SIZE (8 * 1024 * 1024)
634#endif
635
636word GC_get_orig_stack_size() {
637 struct rlimit rl;
638 static int warned = 0;
639 int result;
640
641 if (getrlimit(RLIMIT_STACK, &rl) != 0) ABORT("getrlimit failed");
642 result = (word)rl.rlim_cur & ~(HBLKSIZE-1);
643 if (result > MAX_ORIG_STACK_SIZE) {
644 if (!warned) {
645 WARN("Large stack limit(%ld): only scanning 8 MB\n", result);
646 warned = 1;
647 }
648 result = MAX_ORIG_STACK_SIZE;
649 }
650 return result;
651}
652
653/* Notify dirty bit implementation of unused parts of my stack. */
654/* Caller holds allocation lock. */
655void GC_my_stack_limits()
656{
657 int dummy;
658 register ptr_t hottest = (ptr_t)((word)(&dummy) & ~(HBLKSIZE-1));
659 register GC_thread me = GC_lookup_thread(thr_self());
660 register size_t stack_size = me -> stack_size;
661 register ptr_t stack;
662
663 if (stack_size == 0) {
664 /* original thread */
665 /* Empirically, what should be the stack page with lowest */
666 /* address is actually inaccessible. */
667 stack_size = GC_get_orig_stack_size() - GC_page_size;
668 stack = GC_stackbottom - stack_size + GC_page_size;
669 } else {
670 stack = me -> stack;
671 }
672 if (stack > hottest || stack + stack_size < hottest) {
673 ABORT("sp out of bounds");
674 }
675 GC_is_fresh((struct hblk *)stack, divHBLKSZ(hottest - stack));
676}
677
678
679/* We hold allocation lock. Should do exactly the right thing if the */
680/* world is stopped. Should not fail if it isn't. */
681void GC_push_all_stacks()
682{
683 register int i;
684 register GC_thread p;
685 register ptr_t sp = GC_approx_sp();
686 register ptr_t bottom, top;
687 struct rlimit rl;
688
689# define PUSH(bottom,top) \
690 if (GC_dirty_maintained) { \
691 GC_push_selected((bottom), (top), GC_page_was_ever_dirty, \
692 GC_push_all_stack); \
693 } else { \
694 GC_push_all_stack((bottom), (top)); \
695 }
696 GC_push_all_stack((ptr_t)GC_lwp_registers,
697 (ptr_t)GC_lwp_registers
698 + max_lwps * sizeof(GC_lwp_registers[0]));
699 for (i = 0; i < THREAD_TABLE_SZ; i++) {
700 for (p = GC_threads[i]; p != 0; p = p -> next) {
701 if (p -> stack_size != 0) {
702 bottom = p -> stack;
703 top = p -> stack + p -> stack_size;
704 } else {
705 /* The original stack. */
706 bottom = GC_stackbottom - GC_get_orig_stack_size() + GC_page_size;
707 top = GC_stackbottom;
708 }
709 if ((word)sp > (word)bottom && (word)sp < (word)top) bottom = sp;
710 PUSH(bottom, top);
711 }
712 }
713}
714
715
716int GC_is_thread_stack(ptr_t addr)
717{
718 register int i;
719 register GC_thread p;
720 register ptr_t bottom, top;
721
722 for (i = 0; i < THREAD_TABLE_SZ; i++) {
723 for (p = GC_threads[i]; p != 0; p = p -> next) {
724 if (p -> stack_size != 0) {
725 if (p -> stack <= addr &&
726 addr < p -> stack + p -> stack_size)
727 return 1;
728 }
729 }
730 }
731 return 0;
732}
733
734/* The only thread that ever really performs a thr_join. */
735void * GC_thr_daemon(void * dummy)
736{
737 void *status;
738 thread_t departed;
739 register GC_thread t;
740 register int i;
741 register int result;
742
743 for(;;) {
744 start:
745 result = thr_join((thread_t)0, &departed, &status);
746 LOCK();
747 if (result != 0) {
748 /* No more threads; wait for create. */
749 for (i = 0; i < THREAD_TABLE_SZ; i++) {
750 for (t = GC_threads[i]; t != 0; t = t -> next) {
751 if (!(t -> flags & (DETACHED | FINISHED))) {
752 UNLOCK();
753 goto start; /* Thread started just before we */
754 /* acquired the lock. */
755 }
756 }
757 }
758 cond_wait(&GC_create_cv, &GC_allocate_ml);
759 UNLOCK();
760 } else {
761 t = GC_lookup_thread(departed);
762 GC_multithreaded--;
763 if (!(t -> flags & CLIENT_OWNS_STACK)) {
764 GC_stack_free(t -> stack, t -> stack_size);
765 }
766 if (t -> flags & DETACHED) {
767 GC_delete_thread(departed);
768 } else {
769 t -> status = status;
770 t -> flags |= FINISHED;
771 cond_signal(&(t -> join_cv));
772 cond_broadcast(&GC_prom_join_cv);
773 }
774 UNLOCK();
775 }
776 }
777}
778
779/* We hold the allocation lock, or caller ensures that 2 instances */
780/* cannot be invoked concurrently. */
781void GC_thr_init(void)
782{
783 GC_thread t;
784 thread_t tid;
785
786 if (GC_thr_initialized)
787 return;
788 GC_thr_initialized = TRUE;
789 GC_min_stack_sz = ((thr_min_stack() + 32*1024 + HBLKSIZE-1)
790 & ~(HBLKSIZE - 1));
791#ifdef MMAP_STACKS
792 GC_zfd = open("/dev/zero", O_RDONLY);
793 if (GC_zfd == -1)
794 ABORT("Can't open /dev/zero");
795#endif /* MMAP_STACKS */
796 cond_init(&GC_prom_join_cv, USYNC_THREAD, 0);
797 cond_init(&GC_create_cv, USYNC_THREAD, 0);
798 /* Add the initial thread, so we can stop it. */
799 t = GC_new_thread(thr_self());
800 t -> stack_size = 0;
801 t -> flags = DETACHED | CLIENT_OWNS_STACK;
802 if (thr_create(0 /* stack */, 0 /* stack_size */, GC_thr_daemon,
803 0 /* arg */, THR_DETACHED | THR_DAEMON,
804 &tid /* thread_id */) != 0) {
805 ABORT("Cant fork daemon");
806 }
807 thr_setprio(tid, 126);
808}
809
810/* We acquire the allocation lock to prevent races with */
811/* stopping/starting world. */
812/* This is no more correct than the underlying Solaris 2.X */
813/* implementation. Under 2.3 THIS IS BROKEN. */
814int GC_thr_suspend(thread_t target_thread)
815{
816 GC_thread t;
817 int result;
818
819 LOCK();
820 result = thr_suspend(target_thread);
821 if (result == 0) {
822 t = GC_lookup_thread(target_thread);
823 if (t == 0) ABORT("thread unknown to GC");
824 t -> flags |= SUSPENDED;
825 }
826 UNLOCK();
827 return(result);
828}
829
830int GC_thr_continue(thread_t target_thread)
831{
832 GC_thread t;
833 int result;
834
835 LOCK();
836 result = thr_continue(target_thread);
837 if (result == 0) {
838 t = GC_lookup_thread(target_thread);
839 if (t == 0) ABORT("thread unknown to GC");
840 t -> flags &= ~SUSPENDED;
841 }
842 UNLOCK();
843 return(result);
844}
845
846int GC_thr_join(thread_t wait_for, thread_t *departed, void **status)
847{
848 register GC_thread t;
849 int result = 0;
850
851 LOCK();
852 if (wait_for == 0) {
853 register int i;
854 register GC_bool thread_exists;
855
856 for (;;) {
857 thread_exists = FALSE;
858 for (i = 0; i < THREAD_TABLE_SZ; i++) {
859 for (t = GC_threads[i]; t != 0; t = t -> next) {
860 if (!(t -> flags & DETACHED)) {
861 if (t -> flags & FINISHED) {
862 goto found;
863 }
864 thread_exists = TRUE;
865 }
866 }
867 }
868 if (!thread_exists) {
869 result = ESRCH;
870 goto out;
871 }
872 cond_wait(&GC_prom_join_cv, &GC_allocate_ml);
873 }
874 } else {
875 t = GC_lookup_thread(wait_for);
876 if (t == 0 || t -> flags & DETACHED) {
877 result = ESRCH;
878 goto out;
879 }
880 if (wait_for == thr_self()) {
881 result = EDEADLK;
882 goto out;
883 }
884 while (!(t -> flags & FINISHED)) {
885 cond_wait(&(t -> join_cv), &GC_allocate_ml);
886 }
887
888 }
889 found:
890 if (status) *status = t -> status;
891 if (departed) *departed = t -> id;
892 cond_destroy(&(t -> join_cv));
893 GC_delete_thread(t -> id);
894 out:
895 UNLOCK();
896 return(result);
897}
898
899
900int
901GC_thr_create(void *stack_base, size_t stack_size,
902 void *(*start_routine)(void *), void *arg, long flags,
903 thread_t *new_thread)
904{
905 int result;
906 GC_thread t;
907 thread_t my_new_thread;
908 word my_flags = 0;
909 void * stack = stack_base;
910
911 LOCK();
912 if (!GC_is_initialized) GC_init_inner();
913 GC_multithreaded++;
914 if (stack == 0) {
915 if (stack_size == 0) stack_size = 1024*1024;
916 stack = (void *)GC_stack_alloc(&stack_size);
917 if (stack == 0) {
918 GC_multithreaded--;
919 UNLOCK();
920 return(ENOMEM);
921 }
922 } else {
923 my_flags |= CLIENT_OWNS_STACK;
924 }
925 if (flags & THR_DETACHED) my_flags |= DETACHED;
926 if (flags & THR_SUSPENDED) my_flags |= SUSPENDED;
927 result = thr_create(stack, stack_size, start_routine,
928 arg, flags & ~THR_DETACHED, &my_new_thread);
929 if (result == 0) {
930 t = GC_new_thread(my_new_thread);
931 t -> flags = my_flags;
932 if (!(my_flags & DETACHED)) cond_init(&(t -> join_cv), USYNC_THREAD, 0);
933 t -> stack = stack;
934 t -> stack_size = stack_size;
935 if (new_thread != 0) *new_thread = my_new_thread;
936 cond_signal(&GC_create_cv);
937 } else {
938 GC_multithreaded--;
939 if (!(my_flags & CLIENT_OWNS_STACK)) {
940 GC_stack_free(stack, stack_size);
941 }
942 }
943 UNLOCK();
944 return(result);
945}
946
947# else /* !GC_SOLARIS_THREADS */
948
949#ifndef LINT
950 int GC_no_sunOS_threads;
951#endif
952#endif
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