diff options
Diffstat (limited to 'gc/solaris_threads.c')
| -rw-r--r-- | gc/solaris_threads.c | 940 |
1 files changed, 940 insertions, 0 deletions
diff --git a/gc/solaris_threads.c b/gc/solaris_threads.c new file mode 100644 index 0000000..65b2c65 --- /dev/null +++ b/gc/solaris_threads.c @@ -0,0 +1,940 @@ +/* + * Copyright (c) 1994 by Xerox Corporation. All rights reserved. + * + * THIS MATERIAL IS PROVIDED AS IS, WITH ABSOLUTELY NO WARRANTY EXPRESSED + * OR IMPLIED. ANY USE IS AT YOUR OWN RISK. + * + * Permission is hereby granted to use or copy this program + * for any purpose, provided the above notices are retained on all copies. + * Permission to modify the code and to distribute modified code is granted, + * provided the above notices are retained, and a notice that the code was + * modified is included with the above copyright notice. + */ +/* + * Support code for Solaris threads. Provides functionality we wish Sun + * had provided. Relies on some information we probably shouldn't rely on. + */ +/* Boehm, September 14, 1994 4:44 pm PDT */ + +# if defined(SOLARIS_THREADS) + +# include "gc_priv.h" +# include "solaris_threads.h" +# include <thread.h> +# include <synch.h> +# include <signal.h> +# include <fcntl.h> +# include <sys/types.h> +# include <sys/mman.h> +# include <sys/time.h> +# include <sys/resource.h> +# include <sys/stat.h> +# include <sys/syscall.h> +# include <sys/procfs.h> +# include <sys/lwp.h> +# include <sys/reg.h> +# define _CLASSIC_XOPEN_TYPES +# include <unistd.h> +# include <errno.h> + +/* + * This is the default size of the LWP arrays. If there are more LWPs + * than this when a stop-the-world GC happens, set_max_lwps will be + * called to cope. + * This must be higher than the number of LWPs at startup time. + * The threads library creates a thread early on, so the min. is 3 + */ +# define DEFAULT_MAX_LWPS 4 + +#undef thr_join +#undef thr_create +#undef thr_suspend +#undef thr_continue + +cond_t GC_prom_join_cv; /* Broadcast when any thread terminates */ +cond_t GC_create_cv; /* Signalled when a new undetached */ + /* thread starts. */ + + +#ifdef MMAP_STACKS +static int GC_zfd; +#endif /* MMAP_STACKS */ + +/* We use the allocation lock to protect thread-related data structures. */ + +/* We stop the world using /proc primitives. This makes some */ +/* minimal assumptions about the threads implementation. */ +/* We don't play by the rules, since the rules make this */ +/* impossible (as of Solaris 2.3). Also note that as of */ +/* Solaris 2.3 the various thread and lwp suspension */ +/* primitives failed to stop threads by the time the request */ +/* is completed. */ + + +static sigset_t old_mask; + +/* Sleep for n milliseconds, n < 1000 */ +void GC_msec_sleep(int n) +{ + struct timespec ts; + + ts.tv_sec = 0; + ts.tv_nsec = 1000000*n; + if (syscall(SYS_nanosleep, &ts, 0) < 0) { + ABORT("nanosleep failed"); + } +} +/* Turn off preemption; gross but effective. */ +/* Caller has allocation lock. */ +/* Actually this is not needed under Solaris 2.3 and */ +/* 2.4, but hopefully that'll change. */ +void preempt_off() +{ + sigset_t set; + + (void)sigfillset(&set); + sigdelset(&set, SIGABRT); + syscall(SYS_sigprocmask, SIG_SETMASK, &set, &old_mask); +} + +void preempt_on() +{ + syscall(SYS_sigprocmask, SIG_SETMASK, &old_mask, NULL); +} + +int GC_main_proc_fd = -1; + + +struct lwp_cache_entry { + lwpid_t lc_id; + int lc_descr; /* /proc file descriptor. */ +} GC_lwp_cache_default[DEFAULT_MAX_LWPS]; + +static int max_lwps = DEFAULT_MAX_LWPS; +static struct lwp_cache_entry *GC_lwp_cache = GC_lwp_cache_default; + +static prgregset_t GC_lwp_registers_default[DEFAULT_MAX_LWPS]; +static prgregset_t *GC_lwp_registers = GC_lwp_registers_default; + +/* Return a file descriptor for the /proc entry corresponding */ +/* to the given lwp. The file descriptor may be stale if the */ +/* lwp exited and a new one was forked. */ +static int open_lwp(lwpid_t id) +{ + int result; + static int next_victim = 0; + register int i; + + for (i = 0; i < max_lwps; i++) { + if (GC_lwp_cache[i].lc_id == id) return(GC_lwp_cache[i].lc_descr); + } + result = syscall(SYS_ioctl, GC_main_proc_fd, PIOCOPENLWP, &id); + /* + * If PIOCOPENLWP fails, try closing fds in the cache until it succeeds. + */ + if (result < 0 && errno == EMFILE) { + for (i = 0; i < max_lwps; i++) { + if (GC_lwp_cache[i].lc_id != 0) { + (void)syscall(SYS_close, GC_lwp_cache[i].lc_descr); + result = syscall(SYS_ioctl, GC_main_proc_fd, PIOCOPENLWP, &id); + if (result >= 0 || (result < 0 && errno != EMFILE)) + break; + } + } + } + if (result < 0) { + if (errno == EMFILE) { + ABORT("Too many open files"); + } + return(-1) /* exited? */; + } + if (GC_lwp_cache[next_victim].lc_id != 0) + (void)syscall(SYS_close, GC_lwp_cache[next_victim].lc_descr); + GC_lwp_cache[next_victim].lc_id = id; + GC_lwp_cache[next_victim].lc_descr = result; + if (++next_victim >= max_lwps) + next_victim = 0; + return(result); +} + +static void uncache_lwp(lwpid_t id) +{ + register int i; + + for (i = 0; i < max_lwps; i++) { + if (GC_lwp_cache[i].lc_id == id) { + (void)syscall(SYS_close, GC_lwp_cache[id].lc_descr); + GC_lwp_cache[i].lc_id = 0; + break; + } + } +} + /* Sequence of current lwp ids */ +static lwpid_t GC_current_ids_default[DEFAULT_MAX_LWPS + 1]; +static lwpid_t *GC_current_ids = GC_current_ids_default; + + /* Temporary used below (can be big if large number of LWPs) */ +static lwpid_t last_ids_default[DEFAULT_MAX_LWPS + 1]; +static lwpid_t *last_ids = last_ids_default; + + +#define ROUNDUP(n) WORDS_TO_BYTES(ROUNDED_UP_WORDS(n)) + +static void set_max_lwps(GC_word n) +{ + char *mem; + char *oldmem; + int required_bytes = ROUNDUP(n * sizeof(struct lwp_cache_entry)) + + ROUNDUP(n * sizeof(prgregset_t)) + + ROUNDUP((n + 1) * sizeof(lwpid_t)) + + ROUNDUP((n + 1) * sizeof(lwpid_t)); + + GC_expand_hp_inner(divHBLKSZ((word)required_bytes)); + oldmem = mem = GC_scratch_alloc(required_bytes); + if (0 == mem) ABORT("No space for lwp data structures"); + + /* + * We can either flush the old lwp cache or copy it over. Do the latter. + */ + memcpy(mem, GC_lwp_cache, max_lwps * sizeof(struct lwp_cache_entry)); + GC_lwp_cache = (struct lwp_cache_entry*)mem; + mem += ROUNDUP(n * sizeof(struct lwp_cache_entry)); + + BZERO(GC_lwp_registers, max_lwps * sizeof(GC_lwp_registers[0])); + GC_lwp_registers = (prgregset_t *)mem; + mem += ROUNDUP(n * sizeof(prgregset_t)); + + + GC_current_ids = (lwpid_t *)mem; + mem += ROUNDUP((n + 1) * sizeof(lwpid_t)); + + last_ids = (lwpid_t *)mem; + mem += ROUNDUP((n + 1)* sizeof(lwpid_t)); + + if (mem > oldmem + required_bytes) + ABORT("set_max_lwps buffer overflow"); + + max_lwps = n; +} + + +/* Stop all lwps in process. Assumes preemption is off. */ +/* Caller has allocation lock (and any other locks he may */ +/* need). */ +static void stop_all_lwps() +{ + int lwp_fd; + char buf[30]; + prstatus_t status; + register int i; + GC_bool changed; + lwpid_t me = _lwp_self(); + + if (GC_main_proc_fd == -1) { + sprintf(buf, "/proc/%d", getpid()); + GC_main_proc_fd = syscall(SYS_open, buf, O_RDONLY); + if (GC_main_proc_fd < 0) { + if (errno == EMFILE) + ABORT("/proc open failed: too many open files"); + GC_printf1("/proc open failed: errno %d", errno); + abort(); + } + } + BZERO(GC_lwp_registers, sizeof (prgregset_t) * max_lwps); + for (i = 0; i < max_lwps; i++) + last_ids[i] = 0; + for (;;) { + if (syscall(SYS_ioctl, GC_main_proc_fd, PIOCSTATUS, &status) < 0) + ABORT("Main PIOCSTATUS failed"); + if (status.pr_nlwp < 1) + ABORT("Invalid number of lwps returned by PIOCSTATUS"); + if (status.pr_nlwp >= max_lwps) { + set_max_lwps(status.pr_nlwp*2 + 10); + /* + * The data in the old GC_current_ids and + * GC_lwp_registers has been trashed. Cleaning out last_ids + * will make sure every LWP gets re-examined. + */ + for (i = 0; i < max_lwps; i++) + last_ids[i] = 0; + continue; + } + if (syscall(SYS_ioctl, GC_main_proc_fd, PIOCLWPIDS, GC_current_ids) < 0) + ABORT("PIOCLWPIDS failed"); + changed = FALSE; + for (i = 0; GC_current_ids[i] != 0 && i < max_lwps; i++) { + if (GC_current_ids[i] != last_ids[i]) { + changed = TRUE; + if (GC_current_ids[i] != me) { + /* PIOCSTOP doesn't work without a writable */ + /* descriptor. And that makes the process */ + /* undebuggable. */ + if (_lwp_suspend(GC_current_ids[i]) < 0) { + /* Could happen if the lwp exited */ + uncache_lwp(GC_current_ids[i]); + GC_current_ids[i] = me; /* ignore */ + } + } + } + } + /* + * In the unlikely event something does a fork between the + * PIOCSTATUS and the PIOCLWPIDS. + */ + if (i >= max_lwps) + continue; + /* All lwps in GC_current_ids != me have been suspended. Note */ + /* that _lwp_suspend is idempotent. */ + for (i = 0; GC_current_ids[i] != 0; i++) { + if (GC_current_ids[i] != last_ids[i]) { + if (GC_current_ids[i] != me) { + lwp_fd = open_lwp(GC_current_ids[i]); + if (lwp_fd == -1) + { + GC_current_ids[i] = me; + continue; + } + /* LWP should be stopped. Empirically it sometimes */ + /* isn't, and more frequently the PR_STOPPED flag */ + /* is not set. Wait for PR_STOPPED. */ + if (syscall(SYS_ioctl, lwp_fd, + PIOCSTATUS, &status) < 0) { + /* Possible if the descriptor was stale, or */ + /* we encountered the 2.3 _lwp_suspend bug. */ + uncache_lwp(GC_current_ids[i]); + GC_current_ids[i] = me; /* handle next time. */ + } else { + while (!(status.pr_flags & PR_STOPPED)) { + GC_msec_sleep(1); + if (syscall(SYS_ioctl, lwp_fd, + PIOCSTATUS, &status) < 0) { + ABORT("Repeated PIOCSTATUS failed"); + } + if (status.pr_flags & PR_STOPPED) break; + + GC_msec_sleep(20); + if (syscall(SYS_ioctl, lwp_fd, + PIOCSTATUS, &status) < 0) { + ABORT("Repeated PIOCSTATUS failed"); + } + } + if (status.pr_who != GC_current_ids[i]) { + /* can happen if thread was on death row */ + uncache_lwp(GC_current_ids[i]); + GC_current_ids[i] = me; /* handle next time. */ + continue; + } + /* Save registers where collector can */ + /* find them. */ + BCOPY(status.pr_reg, GC_lwp_registers[i], + sizeof (prgregset_t)); + } + } + } + } + if (!changed) break; + for (i = 0; i < max_lwps; i++) last_ids[i] = GC_current_ids[i]; + } +} + +/* Restart all lwps in process. Assumes preemption is off. */ +static void restart_all_lwps() +{ + int lwp_fd; + register int i; + GC_bool changed; + lwpid_t me = _lwp_self(); +# define PARANOID + + for (i = 0; GC_current_ids[i] != 0; i++) { +# ifdef PARANOID + if (GC_current_ids[i] != me) { + int lwp_fd = open_lwp(GC_current_ids[i]); + prstatus_t status; + + if (lwp_fd < 0) ABORT("open_lwp failed"); + if (syscall(SYS_ioctl, lwp_fd, + PIOCSTATUS, &status) < 0) { + ABORT("PIOCSTATUS failed in restart_all_lwps"); + } + if (memcmp(status.pr_reg, GC_lwp_registers[i], + sizeof (prgregset_t)) != 0) { + int j; + + for(j = 0; j < NGREG; j++) + { + GC_printf3("%i: %x -> %x\n", j, + GC_lwp_registers[i][j], + status.pr_reg[j]); + } + ABORT("Register contents changed"); + } + if (!status.pr_flags & PR_STOPPED) { + ABORT("lwp no longer stopped"); + } +#ifdef SPARC + { + gwindows_t windows; + if (syscall(SYS_ioctl, lwp_fd, + PIOCGWIN, &windows) < 0) { + ABORT("PIOCSTATUS failed in restart_all_lwps"); + } + if (windows.wbcnt > 0) ABORT("unsaved register windows"); + } +#endif + } +# endif /* PARANOID */ + if (GC_current_ids[i] == me) continue; + if (_lwp_continue(GC_current_ids[i]) < 0) { + ABORT("Failed to restart lwp"); + } + } + if (i >= max_lwps) ABORT("Too many lwps"); +} + +GC_bool GC_multithreaded = 0; + +void GC_stop_world() +{ + preempt_off(); + if (GC_multithreaded) + stop_all_lwps(); +} + +void GC_start_world() +{ + if (GC_multithreaded) + restart_all_lwps(); + preempt_on(); +} + +void GC_thr_init(void); + +GC_bool GC_thr_initialized = FALSE; + +size_t GC_min_stack_sz; + +size_t GC_page_sz; + +/* + * stack_head is stored at the top of free stacks + */ +struct stack_head { + struct stack_head *next; + ptr_t base; + thread_t owner; +}; + +# define N_FREE_LISTS 25 +struct stack_head *GC_stack_free_lists[N_FREE_LISTS] = { 0 }; + /* GC_stack_free_lists[i] is free list for stacks of */ + /* size GC_min_stack_sz*2**i. */ + /* Free lists are linked through stack_head stored */ /* at top of stack. */ + +/* Return a stack of size at least *stack_size. *stack_size is */ +/* replaced by the actual stack size. */ +/* Caller holds allocation lock. */ +ptr_t GC_stack_alloc(size_t * stack_size) +{ + register size_t requested_sz = *stack_size; + register size_t search_sz = GC_min_stack_sz; + register int index = 0; /* = log2(search_sz/GC_min_stack_sz) */ + register ptr_t base; + register struct stack_head *result; + + while (search_sz < requested_sz) { + search_sz *= 2; + index++; + } + if ((result = GC_stack_free_lists[index]) == 0 + && (result = GC_stack_free_lists[index+1]) != 0) { + /* Try next size up. */ + search_sz *= 2; index++; + } + if (result != 0) { + base = GC_stack_free_lists[index]->base; + GC_stack_free_lists[index] = GC_stack_free_lists[index]->next; + } else { +#ifdef MMAP_STACKS + base = (ptr_t)mmap(0, search_sz + GC_page_sz, + PROT_READ|PROT_WRITE, MAP_PRIVATE |MAP_NORESERVE, + GC_zfd, 0); + if (base == (ptr_t)-1) + { + *stack_size = 0; + return NULL; + } + + mprotect(base, GC_page_sz, PROT_NONE); + /* Should this use divHBLKSZ(search_sz + GC_page_sz) ? -- cf */ + GC_is_fresh((struct hblk *)base, divHBLKSZ(search_sz)); + base += GC_page_sz; + +#else + base = (ptr_t) GC_scratch_alloc(search_sz + 2*GC_page_sz); + if (base == NULL) + { + *stack_size = 0; + return NULL; + } + + base = (ptr_t)(((word)base + GC_page_sz) & ~(GC_page_sz - 1)); + /* Protect hottest page to detect overflow. */ +# ifdef SOLARIS23_MPROTECT_BUG_FIXED + mprotect(base, GC_page_sz, PROT_NONE); +# endif + GC_is_fresh((struct hblk *)base, divHBLKSZ(search_sz)); + + base += GC_page_sz; +#endif + } + *stack_size = search_sz; + return(base); +} + +/* Caller holds allocationlock. */ +void GC_stack_free(ptr_t stack, size_t size) +{ + register int index = 0; + register size_t search_sz = GC_min_stack_sz; + register struct stack_head *head; + +#ifdef MMAP_STACKS + /* Zero pointers */ + mmap(stack, size, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_NORESERVE|MAP_FIXED, + GC_zfd, 0); +#endif + while (search_sz < size) { + search_sz *= 2; + index++; + } + if (search_sz != size) ABORT("Bad stack size"); + + head = (struct stack_head *)(stack + search_sz - sizeof(struct stack_head)); + head->next = GC_stack_free_lists[index]; + head->base = stack; + GC_stack_free_lists[index] = head; +} + +void GC_my_stack_limits(); + +/* Notify virtual dirty bit implementation that known empty parts of */ +/* stacks do not contain useful data. */ +/* Caller holds allocation lock. */ +void GC_old_stacks_are_fresh() +{ +/* No point in doing this for MMAP stacks - and pointers are zero'd out */ +/* by the mmap in GC_stack_free */ +#ifndef MMAP_STACKS + register int i; + register struct stack_head *s; + register ptr_t p; + register size_t sz; + register struct hblk * h; + int dummy; + + for (i = 0, sz= GC_min_stack_sz; i < N_FREE_LISTS; + i++, sz *= 2) { + for (s = GC_stack_free_lists[i]; s != 0; s = s->next) { + p = s->base; + h = (struct hblk *)(((word)p + HBLKSIZE-1) & ~(HBLKSIZE-1)); + if ((ptr_t)h == p) { + GC_is_fresh((struct hblk *)p, divHBLKSZ(sz)); + } else { + GC_is_fresh((struct hblk *)p, divHBLKSZ(sz) - 1); + BZERO(p, (ptr_t)h - p); + } + } + } +#endif /* MMAP_STACKS */ + GC_my_stack_limits(); +} + +/* The set of all known threads. We intercept thread creation and */ +/* joins. We never actually create detached threads. We allocate all */ +/* new thread stacks ourselves. These allow us to maintain this */ +/* data structure. */ + +# define THREAD_TABLE_SZ 128 /* Must be power of 2 */ +volatile GC_thread GC_threads[THREAD_TABLE_SZ]; + +/* Add a thread to GC_threads. We assume it wasn't already there. */ +/* Caller holds allocation lock. */ +GC_thread GC_new_thread(thread_t id) +{ + int hv = ((word)id) % THREAD_TABLE_SZ; + GC_thread result; + static struct GC_Thread_Rep first_thread; + static GC_bool first_thread_used = FALSE; + + if (!first_thread_used) { + result = &first_thread; + first_thread_used = TRUE; + /* Dont acquire allocation lock, since we may already hold it. */ + } else { + result = (struct GC_Thread_Rep *) + GC_generic_malloc_inner(sizeof(struct GC_Thread_Rep), NORMAL); + } + if (result == 0) return(0); + result -> id = id; + result -> next = GC_threads[hv]; + GC_threads[hv] = result; + /* result -> finished = 0; */ + (void) cond_init(&(result->join_cv), USYNC_THREAD, 0); + return(result); +} + +/* Delete a thread from GC_threads. We assume it is there. */ +/* (The code intentionally traps if it wasn't.) */ +/* Caller holds allocation lock. */ +void GC_delete_thread(thread_t id) +{ + int hv = ((word)id) % THREAD_TABLE_SZ; + register GC_thread p = GC_threads[hv]; + register GC_thread prev = 0; + + while (p -> id != id) { + prev = p; + p = p -> next; + } + if (prev == 0) { + GC_threads[hv] = p -> next; + } else { + prev -> next = p -> next; + } +} + +/* Return the GC_thread correpsonding to a given thread_t. */ +/* Returns 0 if it's not there. */ +/* Caller holds allocation lock. */ +GC_thread GC_lookup_thread(thread_t id) +{ + int hv = ((word)id) % THREAD_TABLE_SZ; + register GC_thread p = GC_threads[hv]; + + while (p != 0 && p -> id != id) p = p -> next; + return(p); +} + +# define MAX_ORIG_STACK_SIZE (8 * 1024 * 1024) + +word GC_get_orig_stack_size() { + struct rlimit rl; + static int warned = 0; + int result; + + if (getrlimit(RLIMIT_STACK, &rl) != 0) ABORT("getrlimit failed"); + result = (word)rl.rlim_cur & ~(HBLKSIZE-1); + if (result > MAX_ORIG_STACK_SIZE) { + if (!warned) { + WARN("Large stack limit(%ld): only scanning 8 MB", result); + warned = 1; + } + result = MAX_ORIG_STACK_SIZE; + } + return result; +} + +/* Notify dirty bit implementation of unused parts of my stack. */ +/* Caller holds allocation lock. */ +void GC_my_stack_limits() +{ + int dummy; + register ptr_t hottest = (ptr_t)((word)(&dummy) & ~(HBLKSIZE-1)); + register GC_thread me = GC_lookup_thread(thr_self()); + register size_t stack_size = me -> stack_size; + register ptr_t stack; + + if (stack_size == 0) { + /* original thread */ + /* Empirically, what should be the stack page with lowest */ + /* address is actually inaccessible. */ + stack_size = GC_get_orig_stack_size() - GC_page_sz; + stack = GC_stackbottom - stack_size + GC_page_sz; + } else { + stack = me -> stack; + } + if (stack > hottest || stack + stack_size < hottest) { + ABORT("sp out of bounds"); + } + GC_is_fresh((struct hblk *)stack, divHBLKSZ(hottest - stack)); +} + + +/* We hold allocation lock. We assume the world is stopped. */ +void GC_push_all_stacks() +{ + register int i; + register GC_thread p; + register ptr_t sp = GC_approx_sp(); + register ptr_t bottom, top; + struct rlimit rl; + +# define PUSH(bottom,top) \ + if (GC_dirty_maintained) { \ + GC_push_dirty((bottom), (top), GC_page_was_ever_dirty, \ + GC_push_all_stack); \ + } else { \ + GC_push_all_stack((bottom), (top)); \ + } + GC_push_all_stack((ptr_t)GC_lwp_registers, + (ptr_t)GC_lwp_registers + + max_lwps * sizeof(GC_lwp_registers[0])); + for (i = 0; i < THREAD_TABLE_SZ; i++) { + for (p = GC_threads[i]; p != 0; p = p -> next) { + if (p -> stack_size != 0) { + bottom = p -> stack; + top = p -> stack + p -> stack_size; + } else { + /* The original stack. */ + bottom = GC_stackbottom - GC_get_orig_stack_size() + GC_page_sz; + top = GC_stackbottom; + } + if ((word)sp > (word)bottom && (word)sp < (word)top) bottom = sp; + PUSH(bottom, top); + } + } +} + + +int GC_is_thread_stack(ptr_t addr) +{ + register int i; + register GC_thread p; + register ptr_t bottom, top; + struct rlimit rl; + + for (i = 0; i < THREAD_TABLE_SZ; i++) { + for (p = GC_threads[i]; p != 0; p = p -> next) { + if (p -> stack_size != 0) { + if (p -> stack <= addr && + addr < p -> stack + p -> stack_size) + return 1; + } + } + } +} + +/* The only thread that ever really performs a thr_join. */ +void * GC_thr_daemon(void * dummy) +{ + void *status; + thread_t departed; + register GC_thread t; + register int i; + register int result; + + for(;;) { + start: + result = thr_join((thread_t)0, &departed, &status); + LOCK(); + if (result != 0) { + /* No more threads; wait for create. */ + for (i = 0; i < THREAD_TABLE_SZ; i++) { + for (t = GC_threads[i]; t != 0; t = t -> next) { + if (!(t -> flags & (DETACHED | FINISHED))) { + UNLOCK(); + goto start; /* Thread started just before we */ + /* acquired the lock. */ + } + } + } + cond_wait(&GC_create_cv, &GC_allocate_ml); + UNLOCK(); + } else { + t = GC_lookup_thread(departed); + GC_multithreaded--; + if (!(t -> flags & CLIENT_OWNS_STACK)) { + GC_stack_free(t -> stack, t -> stack_size); + } + if (t -> flags & DETACHED) { + GC_delete_thread(departed); + } else { + t -> status = status; + t -> flags |= FINISHED; + cond_signal(&(t -> join_cv)); + cond_broadcast(&GC_prom_join_cv); + } + UNLOCK(); + } + } +} + +/* We hold the allocation lock, or caller ensures that 2 instances */ +/* cannot be invoked concurrently. */ +void GC_thr_init(void) +{ + GC_thread t; + thread_t tid; + + if (GC_thr_initialized) + return; + GC_thr_initialized = TRUE; + GC_min_stack_sz = ((thr_min_stack() + 32*1024 + HBLKSIZE-1) + & ~(HBLKSIZE - 1)); + GC_page_sz = sysconf(_SC_PAGESIZE); +#ifdef MMAP_STACKS + GC_zfd = open("/dev/zero", O_RDONLY); + if (GC_zfd == -1) + ABORT("Can't open /dev/zero"); +#endif /* MMAP_STACKS */ + cond_init(&GC_prom_join_cv, USYNC_THREAD, 0); + cond_init(&GC_create_cv, USYNC_THREAD, 0); + /* Add the initial thread, so we can stop it. */ + t = GC_new_thread(thr_self()); + t -> stack_size = 0; + t -> flags = DETACHED | CLIENT_OWNS_STACK; + if (thr_create(0 /* stack */, 0 /* stack_size */, GC_thr_daemon, + 0 /* arg */, THR_DETACHED | THR_DAEMON, + &tid /* thread_id */) != 0) { + ABORT("Cant fork daemon"); + } + thr_setprio(tid, 126); +} + +/* We acquire the allocation lock to prevent races with */ +/* stopping/starting world. */ +/* This is no more correct than the underlying Solaris 2.X */ +/* implementation. Under 2.3 THIS IS BROKEN. */ +int GC_thr_suspend(thread_t target_thread) +{ + GC_thread t; + int result; + + LOCK(); + result = thr_suspend(target_thread); + if (result == 0) { + t = GC_lookup_thread(target_thread); + if (t == 0) ABORT("thread unknown to GC"); + t -> flags |= SUSPENDED; + } + UNLOCK(); + return(result); +} + +int GC_thr_continue(thread_t target_thread) +{ + GC_thread t; + int result; + + LOCK(); + result = thr_continue(target_thread); + if (result == 0) { + t = GC_lookup_thread(target_thread); + if (t == 0) ABORT("thread unknown to GC"); + t -> flags &= ~SUSPENDED; + } + UNLOCK(); + return(result); +} + +int GC_thr_join(thread_t wait_for, thread_t *departed, void **status) +{ + register GC_thread t; + int result = 0; + + LOCK(); + if (wait_for == 0) { + register int i; + register GC_bool thread_exists; + + for (;;) { + thread_exists = FALSE; + for (i = 0; i < THREAD_TABLE_SZ; i++) { + for (t = GC_threads[i]; t != 0; t = t -> next) { + if (!(t -> flags & DETACHED)) { + if (t -> flags & FINISHED) { + goto found; + } + thread_exists = TRUE; + } + } + } + if (!thread_exists) { + result = ESRCH; + goto out; + } + cond_wait(&GC_prom_join_cv, &GC_allocate_ml); + } + } else { + t = GC_lookup_thread(wait_for); + if (t == 0 || t -> flags & DETACHED) { + result = ESRCH; + goto out; + } + if (wait_for == thr_self()) { + result = EDEADLK; + goto out; + } + while (!(t -> flags & FINISHED)) { + cond_wait(&(t -> join_cv), &GC_allocate_ml); + } + + } + found: + if (status) *status = t -> status; + if (departed) *departed = t -> id; + cond_destroy(&(t -> join_cv)); + GC_delete_thread(t -> id); + out: + UNLOCK(); + return(result); +} + + +int +GC_thr_create(void *stack_base, size_t stack_size, + void *(*start_routine)(void *), void *arg, long flags, + thread_t *new_thread) +{ + int result; + GC_thread t; + thread_t my_new_thread; + word my_flags = 0; + void * stack = stack_base; + + LOCK(); + if (!GC_thr_initialized) + { + GC_thr_init(); + } + GC_multithreaded++; + if (stack == 0) { + if (stack_size == 0) stack_size = GC_min_stack_sz; + stack = (void *)GC_stack_alloc(&stack_size); + if (stack == 0) { + GC_multithreaded--; + UNLOCK(); + return(ENOMEM); + } + } else { + my_flags |= CLIENT_OWNS_STACK; + } + if (flags & THR_DETACHED) my_flags |= DETACHED; + if (flags & THR_SUSPENDED) my_flags |= SUSPENDED; + result = thr_create(stack, stack_size, start_routine, + arg, flags & ~THR_DETACHED, &my_new_thread); + if (result == 0) { + t = GC_new_thread(my_new_thread); + t -> flags = my_flags; + if (!(my_flags & DETACHED)) cond_init(&(t -> join_cv), USYNC_THREAD, 0); + t -> stack = stack; + t -> stack_size = stack_size; + if (new_thread != 0) *new_thread = my_new_thread; + cond_signal(&GC_create_cv); + } else { + GC_multithreaded--; + if (!(my_flags & CLIENT_OWNS_STACK)) { + GC_stack_free(stack, stack_size); + } + } + UNLOCK(); + return(result); +} + +# else /* SOLARIS_THREADS */ + +#ifndef LINT + int GC_no_sunOS_threads; +#endif +#endif |