#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 "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"
#endif
#if defined(LISP_FEATURE_DARWIN) && defined(LISP_FEATURE_SB_THREAD)
-#define QUEUE_FREEABLE_THREAD_STACKS
+#define DELAY_THREAD_POST_MORTEM 5
+#define LOCK_CREATE_THREAD
#endif
#ifdef LISP_FEATURE_FREEBSD
#define LOCK_CREATE_THREAD
#endif
-#define ALIEN_STACK_SIZE (1*1024*1024) /* 1Mb size chosen at random */
-
-struct freeable_stack {
-#ifdef QUEUE_FREEABLE_THREAD_STACKS
- struct freeable_stack *next;
+#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;
- os_vm_address_t stack;
+ pthread_attr_t *os_attr;
+ os_vm_address_t os_address;
};
-
-#ifdef QUEUE_FREEABLE_THREAD_STACKS
-static struct freeable_stack * volatile freeable_stack_queue = 0;
-static int freeable_stack_count = 0;
-pthread_mutex_t freeable_stack_lock = PTHREAD_MUTEX_INITIALIZER;
-#else
-static struct freeable_stack * volatile freeable_stack = 0;
+#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 */
-struct thread * volatile all_threads;
+int dynamic_values_bytes=TLS_SIZE*sizeof(lispobj); /* same for all threads */
+struct thread *all_threads;
extern struct interrupt_data * global_interrupt_data;
#ifdef LISP_FEATURE_SB_THREAD
#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)
link_thread(th);
th->os_thread=thread_self();
#ifndef LISP_FEATURE_WIN32
- protect_control_stack_guard_page(1);
+ protect_control_stack_guard_page(1, NULL);
+ protect_binding_stack_guard_page(1, NULL);
+ protect_alien_stack_guard_page(1, NULL);
#endif
#if defined(LISP_FEATURE_X86) || defined(LISP_FEATURE_X86_64)
#endif
}
-#define THREAD_STRUCT_SIZE (THREAD_CONTROL_STACK_SIZE + BINDING_STACK_SIZE + \
- ALIEN_STACK_SIZE + dynamic_values_bytes + \
- 32 * SIGSTKSZ)
-
#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
-#ifdef QUEUE_FREEABLE_THREAD_STACKS
+#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)
-queue_freeable_thread_stack(struct thread *thread_to_be_cleaned_up)
+#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 (thread_to_be_cleaned_up) {
- pthread_mutex_lock(&freeable_stack_lock);
- if (freeable_stack_queue) {
- struct freeable_stack *new_freeable_stack = 0, *next;
- next = freeable_stack_queue;
- while (next->next) {
- next = next->next;
- }
- new_freeable_stack = (struct freeable_stack *)
- os_validate(0, sizeof(struct freeable_stack));
- new_freeable_stack->next = NULL;
- new_freeable_stack->os_thread = thread_to_be_cleaned_up->os_thread;
- new_freeable_stack->stack = (os_vm_address_t)
- thread_to_be_cleaned_up->control_stack_start;
- next->next = new_freeable_stack;
- freeable_stack_count++;
- } else {
- struct freeable_stack *new_freeable_stack = 0;
- new_freeable_stack = (struct freeable_stack *)
- os_validate(0, sizeof(struct freeable_stack));
- new_freeable_stack->next = NULL;
- new_freeable_stack->os_thread = thread_to_be_cleaned_up->os_thread;
- new_freeable_stack->stack = (os_vm_address_t)
- thread_to_be_cleaned_up->control_stack_start;
- freeable_stack_queue = new_freeable_stack;
- freeable_stack_count++;
- }
- pthread_mutex_unlock(&freeable_stack_lock);
+ 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;
}
}
-#define FREEABLE_STACK_QUEUE_SIZE 4
-
static void
-free_freeable_stacks() {
- if (freeable_stack_queue && (freeable_stack_count > FREEABLE_STACK_QUEUE_SIZE)) {
- struct freeable_stack* old;
- pthread_mutex_lock(&freeable_stack_lock);
- old = freeable_stack_queue;
- freeable_stack_queue = old->next;
- freeable_stack_count--;
- gc_assert(pthread_join(old->os_thread, NULL) == 0);
- FSHOW((stderr, "freeing thread %x stack\n", old->os_thread));
- os_invalidate(old->stack, THREAD_STRUCT_SIZE);
- os_invalidate((os_vm_address_t)old, sizeof(struct freeable_stack));
- pthread_mutex_unlock(&freeable_stack_lock);
- }
-}
-
-#elif defined(CREATE_CLEANUP_THREAD)
-static void *
-cleanup_thread(void *arg)
+perform_thread_post_mortem(struct thread_post_mortem *post_mortem)
{
- struct freeable_stack *freeable = arg;
- pthread_t self = pthread_self();
-
- FSHOW((stderr, "/cleaner thread(%p): joining %p\n",
- self, freeable->os_thread));
- gc_assert(pthread_join(freeable->os_thread, NULL) == 0);
- FSHOW((stderr, "/cleaner thread(%p): free stack %p\n",
- self, freeable->stack));
- os_invalidate(freeable->stack, THREAD_STRUCT_SIZE);
- free(freeable);
-
- pthread_detach(self);
-
- return NULL;
-}
-
-static void
-create_cleanup_thread(struct thread *thread_to_be_cleaned_up)
-{
- pthread_t thread;
- int result;
-
- if (thread_to_be_cleaned_up) {
- struct freeable_stack *freeable =
- malloc(sizeof(struct freeable_stack));
- gc_assert(freeable != NULL);
- freeable->os_thread = thread_to_be_cleaned_up->os_thread;
- freeable->stack =
- (os_vm_address_t) thread_to_be_cleaned_up->control_stack_start;
- result = pthread_create(&thread, NULL, cleanup_thread, freeable);
- gc_assert(result == 0);
- sched_yield();
+#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);
}
}
-#else
static void
-free_thread_stack_later(struct thread *thread_to_be_cleaned_up)
+schedule_thread_post_mortem(struct thread *corpse)
{
- struct freeable_stack *new_freeable_stack = 0;
- if (thread_to_be_cleaned_up) {
- new_freeable_stack = (struct freeable_stack *)
- os_validate(0, sizeof(struct freeable_stack));
- new_freeable_stack->os_thread = thread_to_be_cleaned_up->os_thread;
- new_freeable_stack->stack = (os_vm_address_t)
- thread_to_be_cleaned_up->control_stack_start;
- }
- new_freeable_stack = (struct freeable_stack *)
- swap_lispobjs((lispobj *)(void *)&freeable_stack,
- (lispobj)new_freeable_stack);
- if (new_freeable_stack) {
- FSHOW((stderr,"/reaping %p\n", (void*) new_freeable_stack->os_thread));
- /* Under NPTL pthread_join really waits until the thread
- * exists and the stack can be safely freed. This is sadly not
- * mandated by the pthread spec. */
- gc_assert(pthread_join(new_freeable_stack->os_thread, NULL) == 0);
- os_invalidate(new_freeable_stack->stack, THREAD_STRUCT_SIZE);
- os_invalidate((os_vm_address_t) new_freeable_stack,
- sizeof(struct freeable_stack));
+ 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
}
}
-#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
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) {
}
th->os_thread=thread_self();
- protect_control_stack_guard_page(1);
+ 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). */
+ * 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);
result = funcall0(function);
/* Block GC */
- block_blockable_signals();
- th->state=STATE_DEAD;
+ 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(0, &th->alloc_region);
+ 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);
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 QUEUE_FREEABLE_THREAD_STACKS
- queue_freeable_thread_stack(th);
-#elif defined(CREATE_CLEANUP_THREAD)
- create_cleanup_thread(th);
-#else
- free_thread_stack_later(th);
+#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
- FSHOW((stderr,"/exiting thread %p\n", thread_self()));
+ schedule_thread_post_mortem(th);
+ FSHOW((stderr,"/exiting thread %lu\n", thread_self()));
return result;
}
if (th->interrupt_data)
os_invalidate((os_vm_address_t) th->interrupt_data,
(sizeof (struct interrupt_data)));
- os_invalidate((os_vm_address_t) th->control_stack_start,
+ os_invalidate((os_vm_address_t) th->os_address,
THREAD_STRUCT_SIZE);
}
union per_thread_data *per_thread;
struct thread *th=0; /* subdue gcc */
void *spaces=0;
+ void *aligned_spaces=0;
#ifdef LISP_FEATURE_SB_THREAD
- int i;
+ 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 */
+ * 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);
#ifdef LISP_FEATURE_SB_THREAD
for(i = 0; i < (dynamic_values_bytes / sizeof(lispobj)); i++)
#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;
+#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
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
return 0;
}
th->interrupt_data->pending_handler = 0;
+ th->interrupt_data->gc_blocked_deferrables = 0;
+#ifdef LISP_FEATURE_PPC
+ th->interrupt_data->allocation_trap_context = 0;
+#endif
th->no_tls_value_marker=initial_function;
th->stepping = NIL;
return th;
}
+#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);
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");
}
{
/* 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;
- int retcode, initcode, sizecode, addrcode;
+ int retcode = 0, initcode;
FSHOW_SIGNAL((stderr,"/create_os_thread: creating new thread\n"));
-#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
- sigemptyset(&newset);
/* 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. */
- sigaddset_deferrable(&newset);
- thread_sigmask(SIG_BLOCK, &newset, &oldset);
+ block_deferrable_signals(0, &oldset);
-#if defined(LISP_FEATURE_DARWIN)
-#define CONTROL_STACK_ADJUST 8192 /* darwin wants page-aligned stacks */
-#else
-#define CONTROL_STACK_ADJUST 16
+#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
- if((initcode = pthread_attr_init(&attr)) ||
- /* FIXME: why do we even have this in the first place? */
- (pthread_attr_setstack(&attr,th->control_stack_start,
- THREAD_CONTROL_STACK_SIZE-CONTROL_STACK_ADJUST)) ||
-#undef CONTROL_STACK_ADJUST
+ 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,&attr,(void *(*)(void *))new_thread_trampoline,th))) {
- FSHOW_SIGNAL((stderr, "init, size, addr = %d, %d, %d\n", initcode, sizecode, addrcode));
- FSHOW_SIGNAL((stderr, printf("pthread_create returned %d, errno %d\n", retcode, errno)));
- FSHOW_SIGNAL((stderr, "wanted stack size %d, min stack size %d\n",
- THREAD_CONTROL_STACK_SIZE-16, PTHREAD_STACK_MIN));
+ (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 QUEUE_FREEABLE_THREAD_STACKS
- free_freeable_stacks();
-#endif
- thread_sigmask(SIG_SETMASK,&oldset,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
+ thread_sigmask(SIG_SETMASK,&oldset,0);
return r;
}
os_thread_t create_thread(lispobj initial_function) {
- struct thread *th;
- os_thread_t kid_tid;
+ 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==0) return 0;
-
- if (create_os_thread(th,&kid_tid)) {
- return kid_tid;
- } else {
+ if (th && !create_os_thread(th,&kid_tid)) {
free_thread_struct(th);
- return 0;
- }
-}
-
-/* Send the signo to os_thread, retry if the rt signal queue is
- * full. */
-int
-kill_thread_safely(os_thread_t os_thread, int signo)
-{
- int r;
- /* The man page does not mention EAGAIN as a valid return value
- * for either pthread_kill or kill. But that's theory, this is
- * practice. By waiting here we assume that the delivery of this
- * signal is not necessary for the delivery of the signals in the
- * queue. In other words, we _assume_ there are no deadlocks. */
- while ((r=pthread_kill(os_thread,signo))==EAGAIN) {
- /* wait a bit then try again in the hope of the rt signal
- * queue not being full */
- FSHOW_SIGNAL((stderr,"/rt signal queue full\n"));
- /* FIXME: some kind of backoff (random, exponential) would be
- * nice. */
- sleep(1);
- }
- return r;
-}
-
-int signal_interrupt_thread(os_thread_t os_thread)
-{
- int status = kill_thread_safely(os_thread, SIG_INTERRUPT_THREAD);
- if (status == 0) {
- return 0;
- } else if (status == ESRCH) {
- return -1;
- } else {
- lose("cannot send SIG_INTERRUPT_THREAD to thread=%lu: %d, %s\n",
- os_thread, status, strerror(status));
+ kid_tid = 0;
}
+ return kid_tid;
}
/* stopping the world is a two-stage process. From this thread we signal
#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, thread=%lu\n",
- th->os_thread));
+ 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, thread=%lu\n",
- th->os_thread));
+ FSHOW_SIGNAL((stderr,"/gc_stop_the_world:got create_thread_lock\n"));
#endif
- FSHOW_SIGNAL((stderr,"/gc_stop_the_world:waiting on lock, thread=%lu\n",
- th->os_thread));
+ FSHOW_SIGNAL((stderr,"/gc_stop_the_world:waiting on lock\n"));
/* keep threads from starting while the world is stopped. */
lock_ret = pthread_mutex_lock(&all_threads_lock); \
gc_assert(lock_ret == 0);
- FSHOW_SIGNAL((stderr,"/gc_stop_the_world:got lock, thread=%lu\n",
- th->os_thread));
+ 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) {
gc_assert(p->os_thread != 0);
- FSHOW_SIGNAL((stderr,"/gc_stop_the_world: p->state: %x\n", p->state));
- if((p!=th) && ((p->state==STATE_RUNNING))) {
- FSHOW_SIGNAL((stderr,"/gc_stop_the_world: suspending %x, os_thread %x\n",
- p, p->os_thread));
- status=kill_thread_safely(p->os_thread,SIG_STOP_FOR_GC);
+ 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));
+ /* 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(p->state==STATE_DEAD);
+ 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;) {
- FSHOW_SIGNAL((stderr,"/gc_stop_the_world: th: %p, p: %p\n", th, p));
- if((p!=th) && (p->state==STATE_RUNNING)) {
- sched_yield();
- } else {
- 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 status, lock_ret;
+ 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 %d\n",
- fixnum_value(p->state));
- }
- FSHOW_SIGNAL((stderr, "/gc_start_the_world: resuming %lu\n",
- p->os_thread));
- p->state=STATE_RUNNING;
-
-#if defined(SIG_RESUME_FROM_GC)
- status=kill_thread_safely(p->os_thread,SIG_RESUME_FROM_GC);
-#else
- status=kill_thread_safely(p->os_thread,SIG_STOP_FOR_GC);
-#endif
- if (status) {
- lose("cannot resume thread=%lu: %d, %s\n",
- p->os_thread,status,strerror(status));
+ 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);
}
}
}
- /* If we waited here until all threads leave STATE_SUSPENDED, then
- * SIG_STOP_FOR_GC wouldn't need to be a rt signal. That has some
- * performance implications, but does away with the 'rt signal
- * queue full' problem. */
lock_ret = pthread_mutex_unlock(&all_threads_lock);
gc_assert(lock_ret == 0);
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
+ }
+}
projects / sbcl.git / blobdiff