#define LOCK_CREATE_THREAD
#endif
-#define ALIEN_STACK_SIZE (1*1024*1024) /* 1Mb size chosen at random */
-
#ifdef LISP_FEATURE_SB_THREAD
struct thread_post_mortem {
#ifdef DELAY_THREAD_POST_MORTEM
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)
int result, lock_ret;
FSHOW((stderr,"/creating thread %lu\n", thread_self()));
- check_deferrables_blocked_or_lose();
- check_gc_signals_unblocked_or_lose();
+ 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
result = funcall0(function);
/* Block GC */
- block_blockable_signals();
+ block_blockable_signals(0, 0);
set_thread_state(th, STATE_DEAD);
/* SIG_STOP_FOR_GC is blocked and GC might be waiting for this
/* 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. */
- thread_sigmask(SIG_BLOCK, &deferrable_sigset, &oldset);
+ block_deferrable_signals(0, &oldset);
#ifdef LOCK_CREATE_THREAD
retcode = pthread_mutex_lock(&create_thread_lock);
#endif
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)) ||
+ /* 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, printf("pthread_create returned %d, errno %d\n", retcode, errno)));
+ FSHOW_SIGNAL((stderr, "pthread_create returned %d, errno %d\n",
+ retcode, errno));
if(retcode < 0) {
perror("create_os_thread");
}
/* 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
return kid_tid;
}
-int signal_interrupt_thread(os_thread_t os_thread)
-{
- int status = pthread_kill(os_thread, SIG_INTERRUPT_THREAD);
- FSHOW_SIGNAL((stderr,"/signal_interrupt_thread: %lu\n", os_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));
- }
-}
-
/* stopping the world is a two-stage process. From this thread we signal
* all the others with SIG_STOP_FOR_GC. The handler for this signal does
* the usual pseudo-atomic checks (we don't want to stop a thread while
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. */
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
+ }
+}