+/*
+ * This software is part of the SBCL system. See the README file for
+ * more information.
+ *
+ * This software is derived from the CMU CL system, which was
+ * written at Carnegie Mellon University and released into the
+ * public domain. The software is in the public domain and is
+ * provided with absolutely no warranty. See the COPYING and CREDITS
+ * files for more information.
+ */
+
+#include "sbcl.h"
+
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
+#ifndef LISP_FEATURE_WIN32
#include <sched.h>
+#endif
#include <signal.h>
#include <stddef.h>
#include <errno.h>
#include <sys/types.h>
+#ifndef LISP_FEATURE_WIN32
#include <sys/wait.h>
+#endif
+
+#ifdef LISP_FEATURE_MACH_EXCEPTION_HANDLER
+#include <mach/mach.h>
+#include <mach/mach_error.h>
+#include <mach/mach_types.h>
+#endif
-#include "sbcl.h"
#include "runtime.h"
-#include "validate.h" /* for CONTROL_STACK_SIZE etc */
+#include "validate.h" /* for BINDING_STACK_SIZE etc */
#include "alloc.h"
#include "thread.h"
#include "arch.h"
#include "interr.h" /* for lose() */
#include "gc-internal.h"
-#define ALIEN_STACK_SIZE (1*1024*1024) /* 1Mb size chosen at random */
+#ifdef LISP_FEATURE_WIN32
+/*
+ * Win32 doesn't have SIGSTKSZ, and we're not switching stacks anyway,
+ * so define it arbitrarily
+ */
+#define SIGSTKSZ 1024
+#endif
+
+#if defined(LISP_FEATURE_DARWIN) && defined(LISP_FEATURE_SB_THREAD)
+#define DELAY_THREAD_POST_MORTEM 5
+#define LOCK_CREATE_THREAD
+#endif
+
+#ifdef LISP_FEATURE_FREEBSD
+#define CREATE_CLEANUP_THREAD
+#define LOCK_CREATE_THREAD
+#endif
+
+#ifdef LISP_FEATURE_SB_THREAD
+struct thread_post_mortem {
+#ifdef DELAY_THREAD_POST_MORTEM
+ struct thread_post_mortem *next;
+#endif
+ os_thread_t os_thread;
+ pthread_attr_t *os_attr;
+ os_vm_address_t os_address;
+};
+
+#ifdef DELAY_THREAD_POST_MORTEM
+static int pending_thread_post_mortem_count = 0;
+pthread_mutex_t thread_post_mortem_lock = PTHREAD_MUTEX_INITIALIZER;
+#endif
+static struct thread_post_mortem * volatile pending_thread_post_mortem = 0;
+#endif
-int dynamic_values_bytes=4096*sizeof(lispobj); /* same for all threads */
+int dynamic_values_bytes=TLS_SIZE*sizeof(lispobj); /* same for all threads */
struct thread *all_threads;
-volatile lispobj all_threads_lock;
extern struct interrupt_data * global_interrupt_data;
-extern int linux_no_threads_p;
#ifdef LISP_FEATURE_SB_THREAD
-/* When trying to get all_threads_lock one should make sure that
- * sig_stop_for_gc is not blocked. Else there would be a possible
- * deadlock: gc locks it, other thread blocks signals, gc sends stop
- * request to other thread and waits, other thread blocks on lock. */
-void check_sig_stop_for_gc_can_arrive_or_lose()
-{
- /* Get the current sigmask, by blocking the empty set. */
- sigset_t empty,current;
- sigemptyset(&empty);
- thread_sigmask(SIG_BLOCK, &empty, ¤t);
- if (sigismember(¤t,SIG_STOP_FOR_GC))
- lose("SIG_STOP_FOR_GC is blocked\n");
- if (SymbolValue(INTERRUPTS_ENABLED,arch_os_get_current_thread()) == NIL)
- lose("interrupts disabled\n");
- if (arch_pseudo_atomic_atomic(NULL))
- lose("n pseudo atomic\n");
-}
-
-#ifdef QSHOW_SIGNALS
-#define FSHOW_SIGNAL FSHOW
-#else
-#define FSHOW_SIGNAL(args)
-#endif
-
-#define GET_ALL_THREADS_LOCK(name) \
- { \
- sigset_t _newset,_oldset; \
- sigemptyset(&_newset); \
- sigaddset_blockable(&_newset); \
- sigdelset(&_newset,SIG_STOP_FOR_GC); \
- thread_sigmask(SIG_BLOCK, &_newset, &_oldset); \
- check_sig_stop_for_gc_can_arrive_or_lose(); \
- FSHOW_SIGNAL((stderr,"/%s:waiting on lock=%ld, thread=%ld\n",name, \
- all_threads_lock,arch_os_get_current_thread()->os_thread)); \
- get_spinlock(&all_threads_lock,(long)arch_os_get_current_thread()); \
- FSHOW_SIGNAL((stderr,"/%s:got lock, thread=%ld\n", \
- name,arch_os_get_current_thread()->os_thread));
-
-#define RELEASE_ALL_THREADS_LOCK(name) \
- FSHOW_SIGNAL((stderr,"/%s:released lock\n",name)); \
- release_spinlock(&all_threads_lock); \
- thread_sigmask(SIG_SETMASK,&_oldset,0); \
- }
+pthread_mutex_t all_threads_lock = PTHREAD_MUTEX_INITIALIZER;
+#ifdef LOCK_CREATE_THREAD
+static pthread_mutex_t create_thread_lock = PTHREAD_MUTEX_INITIALIZER;
+#endif
+#ifdef LISP_FEATURE_GCC_TLS
+__thread struct thread *current_thread;
+#endif
#endif
-
#if defined(LISP_FEATURE_X86) || defined(LISP_FEATURE_X86_64)
extern lispobj call_into_lisp_first_time(lispobj fun, lispobj *args, int nargs);
#endif
-int
+static void
+link_thread(struct thread *th)
+{
+ if (all_threads) all_threads->prev=th;
+ th->next=all_threads;
+ th->prev=0;
+ all_threads=th;
+}
+
+#ifdef LISP_FEATURE_SB_THREAD
+static void
+unlink_thread(struct thread *th)
+{
+ if (th->prev)
+ th->prev->next = th->next;
+ else
+ all_threads = th->next;
+ if (th->next)
+ th->next->prev = th->prev;
+}
+#endif
+
+static int
initial_thread_trampoline(struct thread *th)
{
lispobj function;
#if defined(LISP_FEATURE_X86) || defined(LISP_FEATURE_X86_64)
lispobj *args = NULL;
#endif
- function = th->unbound_marker;
- th->unbound_marker = UNBOUND_MARKER_WIDETAG;
+ function = th->no_tls_value_marker;
+ th->no_tls_value_marker = NO_TLS_VALUE_MARKER_WIDETAG;
if(arch_os_thread_init(th)==0) return 1;
+ link_thread(th);
+ th->os_thread=thread_self();
+#ifndef LISP_FEATURE_WIN32
+ protect_control_stack_guard_page(1, NULL);
+ protect_binding_stack_guard_page(1, NULL);
+ protect_alien_stack_guard_page(1, NULL);
+#endif
- if(th->os_thread < 1) lose("th->os_thread not set up right");
- th->state=STATE_RUNNING;
#if defined(LISP_FEATURE_X86) || defined(LISP_FEATURE_X86_64)
return call_into_lisp_first_time(function,args,0);
#else
}
#ifdef LISP_FEATURE_SB_THREAD
+#define THREAD_STATE_LOCK_SIZE \
+ (sizeof(pthread_mutex_t))+(sizeof(pthread_cond_t))
+#else
+#define THREAD_STATE_LOCK_SIZE 0
+#endif
+
+#define THREAD_STRUCT_SIZE (thread_control_stack_size + BINDING_STACK_SIZE + \
+ ALIEN_STACK_SIZE + \
+ THREAD_STATE_LOCK_SIZE + \
+ dynamic_values_bytes + \
+ 32 * SIGSTKSZ + \
+ THREAD_ALIGNMENT_BYTES)
+
+#ifdef LISP_FEATURE_SB_THREAD
+/* THREAD POST MORTEM CLEANUP
+ *
+ * Memory allocated for the thread stacks cannot be reclaimed while
+ * the thread is still alive, so we need a mechanism for post mortem
+ * cleanups. FIXME: We actually have three, for historical reasons as
+ * the saying goes. Do we really need three? Nikodemus guesses that
+ * not anymore, now that we properly call pthread_attr_destroy before
+ * freeing the stack. */
+
+static struct thread_post_mortem *
+plan_thread_post_mortem(struct thread *corpse)
+{
+ if (corpse) {
+ struct thread_post_mortem *post_mortem = malloc(sizeof(struct thread_post_mortem));
+ gc_assert(post_mortem);
+ post_mortem->os_thread = corpse->os_thread;
+ post_mortem->os_attr = corpse->os_attr;
+ post_mortem->os_address = corpse->os_address;
+#ifdef DELAY_THREAD_POST_MORTEM
+ post_mortem->next = NULL;
+#endif
+ return post_mortem;
+ } else {
+ /* FIXME: When does this happen? */
+ return NULL;
+ }
+}
+
+static void
+perform_thread_post_mortem(struct thread_post_mortem *post_mortem)
+{
+#ifdef CREATE_POST_MORTEM_THREAD
+ pthread_detach(pthread_self());
+#endif
+ if (post_mortem) {
+ gc_assert(!pthread_join(post_mortem->os_thread, NULL));
+ gc_assert(!pthread_attr_destroy(post_mortem->os_attr));
+ free(post_mortem->os_attr);
+ os_invalidate(post_mortem->os_address, THREAD_STRUCT_SIZE);
+ free(post_mortem);
+ }
+}
+
+static void
+schedule_thread_post_mortem(struct thread *corpse)
+{
+ struct thread_post_mortem *post_mortem = NULL;
+ if (corpse) {
+ post_mortem = plan_thread_post_mortem(corpse);
+
+#ifdef DELAY_THREAD_POST_MORTEM
+ pthread_mutex_lock(&thread_post_mortem_lock);
+ /* First stick the new post mortem to the end of the queue. */
+ if (pending_thread_post_mortem) {
+ struct thread_post_mortem *next = pending_thread_post_mortem;
+ while (next->next) {
+ next = next->next;
+ }
+ next->next = post_mortem;
+ } else {
+ pending_thread_post_mortem = post_mortem;
+ }
+ /* Then, if there are enough things in the queue, clean up one
+ * from the head -- or increment the count, and null out the
+ * post_mortem we have. */
+ if (pending_thread_post_mortem_count > DELAY_THREAD_POST_MORTEM) {
+ post_mortem = pending_thread_post_mortem;
+ pending_thread_post_mortem = post_mortem->next;
+ } else {
+ pending_thread_post_mortem_count++;
+ post_mortem = NULL;
+ }
+ pthread_mutex_unlock(&thread_post_mortem_lock);
+ /* Finally run, the cleanup, if any. */
+ perform_thread_post_mortem(post_mortem);
+#elif defined(CREATE_POST_MORTEM_THREAD)
+ gc_assert(!pthread_create(&thread, NULL, perform_thread_post_mortem, post_mortem));
+#else
+ post_mortem = (struct thread_post_mortem *)
+ swap_lispobjs((lispobj *)(void *)&pending_thread_post_mortem,
+ (lispobj)post_mortem);
+ perform_thread_post_mortem(post_mortem);
+#endif
+ }
+}
/* this is the first thing that runs in the child (which is why the
* silly calling convention). Basically it calls the user's requested
new_thread_trampoline(struct thread *th)
{
lispobj function;
- function = th->unbound_marker;
- th->unbound_marker = UNBOUND_MARKER_WIDETAG;
- if(arch_os_thread_init(th)==0) return 1;
+ int result, lock_ret;
+
+ FSHOW((stderr,"/creating thread %lu\n", thread_self()));
+ check_deferrables_blocked_or_lose(0);
+ check_gc_signals_unblocked_or_lose(0);
+ function = th->no_tls_value_marker;
+ th->no_tls_value_marker = NO_TLS_VALUE_MARKER_WIDETAG;
+ if(arch_os_thread_init(th)==0) {
+ /* FIXME: handle error */
+ lose("arch_os_thread_init failed\n");
+ }
- /* wait here until our thread is linked into all_threads: see below */
- while(th->os_thread<1) sched_yield();
+ th->os_thread=thread_self();
+ protect_control_stack_guard_page(1, NULL);
+ protect_binding_stack_guard_page(1, NULL);
+ protect_alien_stack_guard_page(1, NULL);
+ /* Since GC can only know about this thread from the all_threads
+ * list and we're just adding this thread to it, there is no
+ * danger of deadlocking even with SIG_STOP_FOR_GC blocked (which
+ * it is not). */
+ lock_ret = pthread_mutex_lock(&all_threads_lock);
+ gc_assert(lock_ret == 0);
+ link_thread(th);
+ lock_ret = pthread_mutex_unlock(&all_threads_lock);
+ gc_assert(lock_ret == 0);
+
+ result = funcall0(function);
+
+ /* Block GC */
+ block_blockable_signals(0, 0);
+ set_thread_state(th, STATE_DEAD);
+
+ /* SIG_STOP_FOR_GC is blocked and GC might be waiting for this
+ * thread, but since we are already dead it won't wait long. */
+ lock_ret = pthread_mutex_lock(&all_threads_lock);
+ gc_assert(lock_ret == 0);
+
+ gc_alloc_update_page_tables(BOXED_PAGE_FLAG, &th->alloc_region);
+ unlink_thread(th);
+ pthread_mutex_unlock(&all_threads_lock);
+ gc_assert(lock_ret == 0);
- th->state=STATE_RUNNING;
- return funcall0(function);
+ if(th->tls_cookie>=0) arch_os_thread_cleanup(th);
+ pthread_mutex_destroy(th->state_lock);
+ pthread_cond_destroy(th->state_cond);
+
+ os_invalidate((os_vm_address_t)th->interrupt_data,
+ (sizeof (struct interrupt_data)));
+
+#ifdef LISP_FEATURE_MACH_EXCEPTION_HANDLER
+ FSHOW((stderr, "Deallocating mach port %x\n", THREAD_STRUCT_TO_EXCEPTION_PORT(th)));
+ mach_port_move_member(mach_task_self(),
+ THREAD_STRUCT_TO_EXCEPTION_PORT(th),
+ MACH_PORT_NULL);
+ mach_port_deallocate(mach_task_self(),
+ THREAD_STRUCT_TO_EXCEPTION_PORT(th));
+ mach_port_destroy(mach_task_self(),
+ THREAD_STRUCT_TO_EXCEPTION_PORT(th));
+#endif
+
+ schedule_thread_post_mortem(th);
+ FSHOW((stderr,"/exiting thread %lu\n", thread_self()));
+ return result;
}
+
#endif /* LISP_FEATURE_SB_THREAD */
+static void
+free_thread_struct(struct thread *th)
+{
+ if (th->interrupt_data)
+ os_invalidate((os_vm_address_t) th->interrupt_data,
+ (sizeof (struct interrupt_data)));
+ os_invalidate((os_vm_address_t) th->os_address,
+ THREAD_STRUCT_SIZE);
+}
+
/* this is called from any other thread to create the new one, and
* initialize all parts of it that can be initialized from another
* thread
*/
-struct thread * create_thread_struct(lispobj initial_function) {
+static struct thread *
+create_thread_struct(lispobj initial_function) {
union per_thread_data *per_thread;
struct thread *th=0; /* subdue gcc */
void *spaces=0;
+ void *aligned_spaces=0;
+#ifdef LISP_FEATURE_SB_THREAD
+ unsigned int i;
+#endif
- /* may as well allocate all the spaces at once: it saves us from
+ /* May as well allocate all the spaces at once: it saves us from
* having to decide what to do if only some of the allocations
- * succeed */
- spaces=os_validate(0,
- THREAD_CONTROL_STACK_SIZE+
- BINDING_STACK_SIZE+
- ALIEN_STACK_SIZE+
- dynamic_values_bytes+
- 32*SIGSTKSZ);
+ * succeed. SPACES must be appropriately aligned, since the GC
+ * expects the control stack to start at a page boundary -- and
+ * the OS may have even more rigorous requirements. We can't rely
+ * on the alignment passed from os_validate, since that might
+ * assume the current (e.g. 4k) pagesize, while we calculate with
+ * the biggest (e.g. 64k) pagesize allowed by the ABI. */
+ spaces=os_validate(0, THREAD_STRUCT_SIZE);
if(!spaces)
- return NULL;
+ return NULL;
+ /* Aligning up is safe as THREAD_STRUCT_SIZE has
+ * THREAD_ALIGNMENT_BYTES padding. */
+ aligned_spaces = (void *)((((unsigned long)(char *)spaces)
+ + THREAD_ALIGNMENT_BYTES-1)
+ &~(unsigned long)(THREAD_ALIGNMENT_BYTES-1));
per_thread=(union per_thread_data *)
- (spaces+
- THREAD_CONTROL_STACK_SIZE+
+ (aligned_spaces+
+ thread_control_stack_size+
BINDING_STACK_SIZE+
- ALIEN_STACK_SIZE);
+ ALIEN_STACK_SIZE +
+ THREAD_STATE_LOCK_SIZE);
- if(all_threads) {
- memcpy(per_thread,arch_os_get_current_thread(),
- dynamic_values_bytes);
- } else {
#ifdef LISP_FEATURE_SB_THREAD
- int i;
- for(i=0;i<(dynamic_values_bytes/sizeof(lispobj));i++)
- per_thread->dynamic_values[i]=UNBOUND_MARKER_WIDETAG;
- if(SymbolValue(FREE_TLS_INDEX,0)==UNBOUND_MARKER_WIDETAG)
+ for(i = 0; i < (dynamic_values_bytes / sizeof(lispobj)); i++)
+ per_thread->dynamic_values[i] = NO_TLS_VALUE_MARKER_WIDETAG;
+ if (all_threads == 0) {
+ if(SymbolValue(FREE_TLS_INDEX,0)==UNBOUND_MARKER_WIDETAG) {
SetSymbolValue
(FREE_TLS_INDEX,
+ /* FIXME: should be MAX_INTERRUPTS -1 ? */
make_fixnum(MAX_INTERRUPTS+
sizeof(struct thread)/sizeof(lispobj)),
0);
+ SetSymbolValue(TLS_INDEX_LOCK,make_fixnum(0),0);
+ }
#define STATIC_TLS_INIT(sym,field) \
((struct symbol *)(sym-OTHER_POINTER_LOWTAG))->tls_index= \
make_fixnum(THREAD_SLOT_OFFSET_WORDS(field))
STATIC_TLS_INIT(CONTROL_STACK_END,control_stack_end);
STATIC_TLS_INIT(ALIEN_STACK,alien_stack_pointer);
#if defined(LISP_FEATURE_X86) || defined (LISP_FEATURE_X86_64)
- STATIC_TLS_INIT(PSEUDO_ATOMIC_ATOMIC,pseudo_atomic_atomic);
- STATIC_TLS_INIT(PSEUDO_ATOMIC_INTERRUPTED,pseudo_atomic_interrupted);
+ STATIC_TLS_INIT(PSEUDO_ATOMIC_BITS,pseudo_atomic_bits);
#endif
#undef STATIC_TLS_INIT
-#endif
}
+#endif
th=&per_thread->thread;
- th->control_stack_start = spaces;
+ th->os_address = spaces;
+ th->control_stack_start = aligned_spaces;
th->binding_stack_start=
- (lispobj*)((void*)th->control_stack_start+THREAD_CONTROL_STACK_SIZE);
+ (lispobj*)((void*)th->control_stack_start+thread_control_stack_size);
th->control_stack_end = th->binding_stack_start;
th->alien_stack_start=
(lispobj*)((void*)th->binding_stack_start+BINDING_STACK_SIZE);
th->binding_stack_pointer=th->binding_stack_start;
th->this=th;
th->os_thread=0;
- th->interrupt_fun=NIL;
- th->interrupt_fun_lock=0;
- th->state=STATE_STARTING;
+#ifdef LISP_FEATURE_SB_THREAD
+ th->os_attr=malloc(sizeof(pthread_attr_t));
+ th->state_lock=(pthread_mutex_t *)((void *)th->alien_stack_start +
+ ALIEN_STACK_SIZE);
+ pthread_mutex_init(th->state_lock, NULL);
+ th->state_cond=(pthread_cond_t *)((void *)th->state_lock +
+ (sizeof(pthread_mutex_t)));
+ pthread_cond_init(th->state_cond, NULL);
+#endif
+ th->state=STATE_RUNNING;
#ifdef LISP_FEATURE_STACK_GROWS_DOWNWARD_NOT_UPWARD
th->alien_stack_pointer=((void *)th->alien_stack_start
+ ALIEN_STACK_SIZE-N_WORD_BYTES);
th->alien_stack_pointer=((void *)th->alien_stack_start);
#endif
#if defined(LISP_FEATURE_X86) || defined (LISP_FEATURE_X86_64)
- th->pseudo_atomic_interrupted=0;
- th->pseudo_atomic_atomic=0;
+ th->pseudo_atomic_bits=0;
#endif
#ifdef LISP_FEATURE_GENCGC
gc_set_region_empty(&th->alloc_region);
#if defined(LISP_FEATURE_X86) || defined (LISP_FEATURE_X86_64)
SetSymbolValue(BINDING_STACK_POINTER,(lispobj)th->binding_stack_pointer,th);
SetSymbolValue(ALIEN_STACK,(lispobj)th->alien_stack_pointer,th);
- SetSymbolValue(PSEUDO_ATOMIC_ATOMIC,(lispobj)th->pseudo_atomic_atomic,th);
- SetSymbolValue(PSEUDO_ATOMIC_INTERRUPTED,th->pseudo_atomic_interrupted,th);
+ SetSymbolValue(PSEUDO_ATOMIC_BITS,(lispobj)th->pseudo_atomic_bits,th);
#else
current_binding_stack_pointer=th->binding_stack_pointer;
current_control_stack_pointer=th->control_stack_start;
bind_variable(FREE_INTERRUPT_CONTEXT_INDEX,make_fixnum(0),th);
bind_variable(INTERRUPT_PENDING, NIL,th);
bind_variable(INTERRUPTS_ENABLED,T,th);
+ bind_variable(ALLOW_WITH_INTERRUPTS,T,th);
+ bind_variable(GC_PENDING,NIL,th);
+ bind_variable(ALLOC_SIGNAL,NIL,th);
+#ifdef LISP_FEATURE_SB_THREAD
+ bind_variable(STOP_FOR_GC_PENDING,NIL,th);
+#endif
th->interrupt_data = (struct interrupt_data *)
os_validate(0,(sizeof (struct interrupt_data)));
- if(all_threads)
- memcpy(th->interrupt_data,
- arch_os_get_current_thread()->interrupt_data,
- sizeof (struct interrupt_data));
- else
- memcpy(th->interrupt_data,global_interrupt_data,
- sizeof (struct interrupt_data));
+ if (!th->interrupt_data) {
+ free_thread_struct(th);
+ return 0;
+ }
+ th->interrupt_data->pending_handler = 0;
+ th->interrupt_data->gc_blocked_deferrables = 0;
+ th->no_tls_value_marker=initial_function;
- th->unbound_marker=initial_function;
+ th->stepping = NIL;
return th;
}
-void link_thread(struct thread *th,os_thread_t kid_tid)
-{
- if (all_threads) all_threads->prev=th;
- th->next=all_threads;
- th->prev=0;
- all_threads=th;
- /* note that th->os_thread is 0 at this time. We rely on
- * all_threads_lock to ensure that we don't have >1 thread with
- * os_thread=0 on the list at once
- */
- protect_control_stack_guard_page(th,1);
- /* child will not start until this is set */
- th->os_thread=kid_tid;
-}
+#ifdef LISP_FEATURE_MACH_EXCEPTION_HANDLER
+mach_port_t setup_mach_exception_handling_thread();
+kern_return_t mach_thread_init(mach_port_t thread_exception_port);
+
+#endif
void create_initial_thread(lispobj initial_function) {
struct thread *th=create_thread_struct(initial_function);
- os_thread_t kid_tid=thread_self();
- if(th && kid_tid>0) {
- link_thread(th,kid_tid);
- initial_thread_trampoline(all_threads); /* no return */
- } else lose("can't create initial thread");
+ if(th) {
+#ifdef LISP_FEATURE_MACH_EXCEPTION_HANDLER
+ setup_mach_exception_handling_thread();
+#endif
+ initial_thread_trampoline(th); /* no return */
+ } else lose("can't create initial thread\n");
}
#ifdef LISP_FEATURE_SB_THREAD
#ifndef __USE_XOPEN2K
extern int pthread_attr_setstack (pthread_attr_t *__attr, void *__stackaddr,
- size_t __stacksize);
+ size_t __stacksize);
#endif
boolean create_os_thread(struct thread *th,os_thread_t *kid_tid)
{
/* The new thread inherits the restrictive signal mask set here,
* and enables signals again when it is set up properly. */
- pthread_attr_t attr;
- sigset_t newset,oldset;
+ sigset_t oldset;
boolean r=1;
- sigemptyset(&newset);
- sigaddset_blockable(&newset);
- thread_sigmask(SIG_BLOCK, &newset, &oldset);
-
- if((pthread_attr_init(&attr)) ||
- (pthread_attr_setstack(&attr,th->control_stack_start,
- THREAD_CONTROL_STACK_SIZE-16)) ||
- (pthread_create
- (kid_tid,&attr,(void *(*)(void *))new_thread_trampoline,th)))
- r=0;
- thread_sigmask(SIG_SETMASK,&oldset,0);
- return r;
-}
-
-struct thread *create_thread(lispobj initial_function) {
- struct thread *th;
- os_thread_t kid_tid=0;
- boolean success;
-
- if(linux_no_threads_p) return 0;
-
- th=create_thread_struct(initial_function);
- if(th==0) return 0;
-
- /* we must not be interrupted here after a successful
- * create_os_thread, because the kid will be waiting for its
- * thread struct to be linked */
- GET_ALL_THREADS_LOCK("create_thread")
+ int retcode = 0, initcode;
- success=create_os_thread(th,&kid_tid);
- if (success)
- link_thread(th,kid_tid);
- else
- os_invalidate((os_vm_address_t) th->control_stack_start,
- ((sizeof (lispobj))
- * (th->control_stack_end-th->control_stack_start)) +
- BINDING_STACK_SIZE+ALIEN_STACK_SIZE+dynamic_values_bytes+
- 32*SIGSTKSZ);
+ FSHOW_SIGNAL((stderr,"/create_os_thread: creating new thread\n"));
- RELEASE_ALL_THREADS_LOCK("create_thread")
+ /* Blocking deferrable signals is enough, no need to block
+ * SIG_STOP_FOR_GC because the child process is not linked onto
+ * all_threads until it's ready. */
+ block_deferrable_signals(0, &oldset);
- if (success)
- return th;
- else
- return 0;
-}
+#ifdef LOCK_CREATE_THREAD
+ retcode = pthread_mutex_lock(&create_thread_lock);
+ gc_assert(retcode == 0);
+ FSHOW_SIGNAL((stderr,"/create_os_thread: got lock\n"));
+#endif
-/* called from lisp from the thread object finalizer */
-void reap_dead_thread(struct thread *th)
-{
- if(th->state!=STATE_DEAD)
- lose("thread %p is not joinable, state=%d\n",th,th->state);
-#ifdef LISP_FEATURE_GENCGC
- {
- sigset_t newset,oldset;
- sigemptyset(&newset);
- sigaddset_blockable(&newset);
- thread_sigmask(SIG_BLOCK, &newset, &oldset);
- gc_alloc_update_page_tables(0, &th->alloc_region);
- release_spinlock(&all_threads_lock);
- thread_sigmask(SIG_SETMASK,&oldset,0);
+ if((initcode = pthread_attr_init(th->os_attr)) ||
+ /* call_into_lisp_first_time switches the stack for the initial
+ * thread. For the others, we use this. */
+ (pthread_attr_setstack(th->os_attr,th->control_stack_start,
+ thread_control_stack_size)) ||
+ (retcode = pthread_create
+ (kid_tid,th->os_attr,(void *(*)(void *))new_thread_trampoline,th))) {
+ FSHOW_SIGNAL((stderr, "init = %d\n", initcode));
+ FSHOW_SIGNAL((stderr, "pthread_create returned %d, errno %d\n",
+ retcode, errno));
+ if(retcode < 0) {
+ perror("create_os_thread");
+ }
+ r=0;
}
+
+#ifdef LOCK_CREATE_THREAD
+ retcode = pthread_mutex_unlock(&create_thread_lock);
+ gc_assert(retcode == 0);
+ FSHOW_SIGNAL((stderr,"/create_os_thread: released lock\n"));
#endif
- GET_ALL_THREADS_LOCK("reap_dead_thread")
- FSHOW((stderr,"/reap_dead_thread: reaping %ld\n",th->os_thread));
- if(th->prev)
- th->prev->next=th->next;
- else all_threads=th->next;
- if(th->next)
- th->next->prev=th->prev;
- RELEASE_ALL_THREADS_LOCK("reap_dead_thread")
- if(th->tls_cookie>=0) arch_os_thread_cleanup(th);
- gc_assert(pthread_join(th->os_thread,NULL)==0);
- os_invalidate((os_vm_address_t) th->control_stack_start,
- ((sizeof (lispobj))
- * (th->control_stack_end-th->control_stack_start)) +
- BINDING_STACK_SIZE+ALIEN_STACK_SIZE+dynamic_values_bytes+
- 32*SIGSTKSZ);
+ thread_sigmask(SIG_SETMASK,&oldset,0);
+ return r;
}
-int interrupt_thread(struct thread *th, lispobj function)
-{
- /* A thread may also become dead after this test. */
- if ((th->state != STATE_DEAD)) {
- /* In clone_threads, if A and B both interrupt C at
- * approximately the same time, it does not matter: the
- * second signal will be masked until the handler has
- * returned from the first one. In pthreads though, we
- * can't put the knowledge of what function to call into
- * the siginfo, so we have to store it in the destination
- * thread, and do it in such a way that A won't clobber
- * B's interrupt. Hence this stupid linked list.
- *
- * This does depend on SIG_INTERRUPT_THREAD being queued
- * (as POSIX RT signals are): we need to keep
- * interrupt_fun data for exactly as many signals as are
- * going to be received by the destination thread.
- */
- lispobj c=alloc_cons(function,NIL);
- int kill_status;
- /* interrupt_thread_handler locks this spinlock with
- * interrupts blocked and it does so for the sake of
- * arrange_return_to_lisp_function, so we must also block
- * them. */
- sigset_t newset,oldset;
- sigemptyset(&newset);
- sigaddset_blockable(&newset);
- thread_sigmask(SIG_BLOCK, &newset, &oldset);
- get_spinlock(&th->interrupt_fun_lock,
- (long)arch_os_get_current_thread());
- kill_status=thread_kill(th->os_thread,SIG_INTERRUPT_THREAD);
- if(kill_status==0) {
- ((struct cons *)native_pointer(c))->cdr=th->interrupt_fun;
- th->interrupt_fun=c;
- }
- release_spinlock(&th->interrupt_fun_lock);
- thread_sigmask(SIG_SETMASK,&oldset,0);
- return (kill_status ? -1 : 0);
+os_thread_t create_thread(lispobj initial_function) {
+ struct thread *th, *thread = arch_os_get_current_thread();
+ os_thread_t kid_tid = 0;
+
+ /* Must defend against async unwinds. */
+ if (SymbolValue(INTERRUPTS_ENABLED, thread) != NIL)
+ lose("create_thread is not safe when interrupts are enabled.\n");
+
+ /* Assuming that a fresh thread struct has no lisp objects in it,
+ * linking it to all_threads can be left to the thread itself
+ * without fear of gc lossage. initial_function violates this
+ * assumption and must stay pinned until the child starts up. */
+ th = create_thread_struct(initial_function);
+ if (th && !create_os_thread(th,&kid_tid)) {
+ free_thread_struct(th);
+ kid_tid = 0;
}
- errno=EPERM; return -1;
+ return kid_tid;
}
/* stopping the world is a two-stage process. From this thread we signal
void gc_stop_the_world()
{
struct thread *p,*th=arch_os_get_current_thread();
- FSHOW_SIGNAL((stderr,"/gc_stop_the_world:waiting on lock, thread=%ld\n",
- th->os_thread));
+ int status, lock_ret;
+#ifdef LOCK_CREATE_THREAD
+ /* KLUDGE: Stopping the thread during pthread_create() causes deadlock
+ * on FreeBSD. */
+ FSHOW_SIGNAL((stderr,"/gc_stop_the_world:waiting on create_thread_lock\n"));
+ lock_ret = pthread_mutex_lock(&create_thread_lock);
+ gc_assert(lock_ret == 0);
+ FSHOW_SIGNAL((stderr,"/gc_stop_the_world:got create_thread_lock\n"));
+#endif
+ FSHOW_SIGNAL((stderr,"/gc_stop_the_world:waiting on lock\n"));
/* keep threads from starting while the world is stopped. */
- get_spinlock(&all_threads_lock,(long)th);
- FSHOW_SIGNAL((stderr,"/gc_stop_the_world:got lock, thread=%ld\n",
- th->os_thread));
+ lock_ret = pthread_mutex_lock(&all_threads_lock); \
+ gc_assert(lock_ret == 0);
+
+ FSHOW_SIGNAL((stderr,"/gc_stop_the_world:got lock\n"));
/* stop all other threads by sending them SIG_STOP_FOR_GC */
for(p=all_threads; p; p=p->next) {
- while(p->state==STATE_STARTING) sched_yield();
- if((p!=th) && (p->state==STATE_RUNNING)) {
- FSHOW_SIGNAL((stderr,"/gc_stop_the_world:sending sig_stop to %ld\n",
+ gc_assert(p->os_thread != 0);
+ FSHOW_SIGNAL((stderr,"/gc_stop_the_world: thread=%lu, state=%x\n",
+ p->os_thread, thread_state(p)));
+ if((p!=th) && ((thread_state(p)==STATE_RUNNING))) {
+ FSHOW_SIGNAL((stderr,"/gc_stop_the_world: suspending thread %lu\n",
p->os_thread));
- if(thread_kill(p->os_thread,SIG_STOP_FOR_GC)==-1) {
- /* we can't kill the thread; assume because it died
- * since we last checked */
- p->state=STATE_DEAD;
- FSHOW_SIGNAL((stderr,"/gc_stop_the_world:assuming %ld dead\n",
- p->os_thread));
+ /* We already hold all_thread_lock, P can become DEAD but
+ * cannot exit, ergo it's safe to use pthread_kill. */
+ status=pthread_kill(p->os_thread,SIG_STOP_FOR_GC);
+ if (status==ESRCH) {
+ /* This thread has exited. */
+ gc_assert(thread_state(p)==STATE_DEAD);
+ } else if (status) {
+ lose("cannot send suspend thread=%lu: %d, %s\n",
+ p->os_thread,status,strerror(status));
}
}
}
FSHOW_SIGNAL((stderr,"/gc_stop_the_world:signals sent\n"));
- /* wait for the running threads to stop or finish */
- for(p=all_threads;p;) {
- gc_assert(p->os_thread!=0);
- gc_assert(p->state!=STATE_STARTING);
- if((p==th) || (p->state==STATE_SUSPENDED) ||
- (p->state==STATE_DEAD)) {
- p=p->next;
+ for(p=all_threads;p;p=p->next) {
+ if (p!=th) {
+ FSHOW_SIGNAL
+ ((stderr,
+ "/gc_stop_the_world: waiting for thread=%lu: state=%x\n",
+ p->os_thread, thread_state(p)));
+ wait_for_thread_state_change(p, STATE_RUNNING);
+ if (p->state == STATE_RUNNING)
+ lose("/gc_stop_the_world: unexpected state");
}
}
FSHOW_SIGNAL((stderr,"/gc_stop_the_world:end\n"));
void gc_start_the_world()
{
struct thread *p,*th=arch_os_get_current_thread();
+ int lock_ret;
/* if a resumed thread creates a new thread before we're done with
* this loop, the new thread will get consed on the front of
* all_threads, but it won't have been stopped so won't need
FSHOW_SIGNAL((stderr,"/gc_start_the_world:begin\n"));
for(p=all_threads;p;p=p->next) {
gc_assert(p->os_thread!=0);
- if((p!=th) && (p->state!=STATE_DEAD)) {
- if(p->state!=STATE_SUSPENDED) {
- lose("gc_start_the_world: wrong thread state is %ld\n",
- fixnum_value(p->state));
+ if (p!=th) {
+ lispobj state = thread_state(p);
+ if (state != STATE_DEAD) {
+ if(state != STATE_SUSPENDED) {
+ lose("gc_start_the_world: wrong thread state is %d\n",
+ fixnum_value(state));
+ }
+ FSHOW_SIGNAL((stderr, "/gc_start_the_world: resuming %lu\n",
+ p->os_thread));
+ set_thread_state(p, STATE_RUNNING);
}
- thread_kill(p->os_thread,SIG_STOP_FOR_GC);
}
}
- /* we must wait for all threads to leave stopped state else we
- * risk signal accumulation and lose any meaning of
- * thread->state */
- for(p=all_threads;p;) {
- if((p==th) || (p->state!=STATE_SUSPENDED)) {
- p=p->next;
- }
- }
- release_spinlock(&all_threads_lock);
+
+ lock_ret = pthread_mutex_unlock(&all_threads_lock);
+ gc_assert(lock_ret == 0);
+#ifdef LOCK_CREATE_THREAD
+ lock_ret = pthread_mutex_unlock(&create_thread_lock);
+ gc_assert(lock_ret == 0);
+#endif
+
FSHOW_SIGNAL((stderr,"/gc_start_the_world:end\n"));
}
#endif
+
+int
+thread_yield()
+{
+#ifdef LISP_FEATURE_SB_THREAD
+ return sched_yield();
+#else
+ return 0;
+#endif
+}
+
+/* If the thread id given does not belong to a running thread (it has
+ * exited or never even existed) pthread_kill _may_ fail with ESRCH,
+ * but it is also allowed to just segfault, see
+ * <http://udrepper.livejournal.com/16844.html>.
+ *
+ * Relying on thread ids can easily backfire since ids are recycled
+ * (NPTL recycles them extremely fast) so a signal can be sent to
+ * another process if the one it was sent to exited.
+ *
+ * We send signals in two places: signal_interrupt_thread sends a
+ * signal that's harmless if delivered to another thread, but
+ * SIG_STOP_FOR_GC is fatal.
+ *
+ * For these reasons, we must make sure that the thread is still alive
+ * when the pthread_kill is called and return if the thread is
+ * exiting. */
+int
+kill_safely(os_thread_t os_thread, int signal)
+{
+ FSHOW_SIGNAL((stderr,"/kill_safely: %lu, %d\n", os_thread, signal));
+ {
+#ifdef LISP_FEATURE_SB_THREAD
+ sigset_t oldset;
+ struct thread *thread;
+ /* pthread_kill is not async signal safe and we don't want to be
+ * interrupted while holding the lock. */
+ block_deferrable_signals(0, &oldset);
+ pthread_mutex_lock(&all_threads_lock);
+ for (thread = all_threads; thread; thread = thread->next) {
+ if (thread->os_thread == os_thread) {
+ int status = pthread_kill(os_thread, signal);
+ if (status)
+ lose("kill_safely: pthread_kill failed with %d\n", status);
+ break;
+ }
+ }
+ pthread_mutex_unlock(&all_threads_lock);
+ thread_sigmask(SIG_SETMASK,&oldset,0);
+ if (thread)
+ return 0;
+ else
+ return -1;
+#else
+ int status;
+ if (os_thread != 0)
+ lose("kill_safely: who do you want to kill? %d?\n", os_thread);
+ /* Dubious (as in don't know why it works) workaround for the
+ * signal sometimes not being generated on darwin. */
+#ifdef LISP_FEATURE_DARWIN
+ {
+ sigset_t oldset;
+ sigprocmask(SIG_BLOCK, &deferrable_sigset, &oldset);
+ status = raise(signal);
+ sigprocmask(SIG_SETMASK,&oldset,0);
+ }
+#else
+ status = raise(signal);
+#endif
+ if (status == 0) {
+ return 0;
+ } else {
+ lose("cannot raise signal %d, %d %s\n",
+ signal, status, strerror(errno));
+ }
+#endif
+ }
+}