os_context_t *context);
boolean interrupt_maybe_gc_int(int signal, siginfo_t *info, void *v_context);
-void sigaddset_blockable(sigset_t *s)
+void sigaddset_deferrable(sigset_t *s)
{
sigaddset(s, SIGHUP);
sigaddset(s, SIGINT);
sigaddset(s, SIGUSR1);
sigaddset(s, SIGUSR2);
#ifdef LISP_FEATURE_SB_THREAD
- sigaddset(s, SIG_STOP_FOR_GC);
sigaddset(s, SIG_INTERRUPT_THREAD);
#endif
}
+void sigaddset_blockable(sigset_t *s)
+{
+ sigaddset_deferrable(s);
+#ifdef LISP_FEATURE_SB_THREAD
+ sigaddset(s, SIG_STOP_FOR_GC);
+#endif
+}
+
+/* initialized in interrupt_init */
+static sigset_t deferrable_sigset;
static sigset_t blockable_sigset;
inline static void check_blockables_blocked_or_lose()
struct interrupt_data *data;
check_blockables_blocked_or_lose();
- check_interrupts_enabled_or_lose(context);
thread=arch_os_get_current_thread();
data=thread->interrupt_data;
- /* Pseudo atomic may trigger several times for a single interrupt,
- * and while without-interrupts should not, a false trigger by
- * pseudo-atomic may eat a pending handler even from
- * without-interrupts. */
- if (data->pending_handler) {
-
- /* If we're here as the result of a pseudo-atomic as opposed
- * to WITHOUT-INTERRUPTS, then INTERRUPT_PENDING is already
- * NIL, because maybe_defer_handler sets
- * PSEUDO_ATOMIC_INTERRUPTED only if interrupts are enabled.*/
- SetSymbolValue(INTERRUPT_PENDING, NIL,thread);
-
- /* restore the saved signal mask from the original signal (the
- * one that interrupted us during the critical section) into the
- * os_context for the signal we're currently in the handler for.
- * This should ensure that when we return from the handler the
- * blocked signals are unblocked */
- sigcopyset(os_context_sigmask_addr(context), &data->pending_mask);
-
- sigemptyset(&data->pending_mask);
- /* This will break on sparc linux: the deferred handler really wants
- * to be called with a void_context */
- run_deferred_handler(data,(void *)context);
+ if (SymbolValue(GC_INHIBIT,thread)==NIL) {
+#ifdef LISP_FEATURE_SB_THREAD
+ if (SymbolValue(STOP_FOR_GC_PENDING,thread) != NIL) {
+ /* another thread has already initiated a gc, this attempt
+ * might as well be cancelled */
+ SetSymbolValue(GC_PENDING,NIL,thread);
+ SetSymbolValue(STOP_FOR_GC_PENDING,NIL,thread);
+ sig_stop_for_gc_handler(SIG_STOP_FOR_GC,NULL,context);
+ } else
+#endif
+ if (SymbolValue(GC_PENDING,thread) != NIL) {
+ /* GC_PENDING is cleared in SUB-GC, or if another thread
+ * is doing a gc already we will get a SIG_STOP_FOR_GC and
+ * that will clear it. */
+ interrupt_maybe_gc_int(0,NULL,context);
+ }
+ check_blockables_blocked_or_lose();
+ }
+
+ /* we may be here only to do the gc stuff, if interrupts are
+ * enabled run the pending handler */
+ if (!((SymbolValue(INTERRUPTS_ENABLED,thread) == NIL) ||
+ (
+#if !defined(LISP_FEATURE_X86) && !defined(LISP_FEATURE_X86_64)
+ (!foreign_function_call_active) &&
+#endif
+ arch_pseudo_atomic_atomic(context)))) {
+
+ /* There may be no pending handler, because it was only a gc
+ * that had to be executed or because pseudo atomic triggered
+ * twice for a single interrupt. For the interested reader,
+ * that may happen if an interrupt hits after the interrupted
+ * flag is cleared but before pseduo-atomic is set and a
+ * pseudo atomic is interrupted in that interrupt. */
+ if (data->pending_handler) {
+
+ /* If we're here as the result of a pseudo-atomic as opposed
+ * to WITHOUT-INTERRUPTS, then INTERRUPT_PENDING is already
+ * NIL, because maybe_defer_handler sets
+ * PSEUDO_ATOMIC_INTERRUPTED only if interrupts are enabled.*/
+ SetSymbolValue(INTERRUPT_PENDING, NIL,thread);
+
+ /* restore the saved signal mask from the original signal (the
+ * one that interrupted us during the critical section) into the
+ * os_context for the signal we're currently in the handler for.
+ * This should ensure that when we return from the handler the
+ * blocked signals are unblocked */
+ sigcopyset(os_context_sigmask_addr(context), &data->pending_mask);
+
+ sigemptyset(&data->pending_mask);
+ /* This will break on sparc linux: the deferred handler really wants
+ * to be called with a void_context */
+ run_deferred_handler(data,(void *)context);
+ }
}
}
\f
fake_foreign_function_call(context);
}
-#ifdef QSHOW_SIGNALS
- FSHOW((stderr,
- "/entering interrupt_handle_now(%d, info, context)\n",
- signal));
-#endif
+ FSHOW_SIGNAL((stderr,
+ "/entering interrupt_handle_now(%d, info, context)\n",
+ signal));
if (ARE_SAME_HANDLER(handler.c, SIG_DFL)) {
/* Allow signals again. */
thread_sigmask(SIG_SETMASK, os_context_sigmask_addr(context), 0);
-#ifdef QSHOW_SIGNALS
- SHOW("calling Lisp-level handler");
-#endif
+ FSHOW_SIGNAL((stderr,"/calling Lisp-level handler\n"));
funcall3(handler.lisp,
make_fixnum(signal),
context_sap);
} else {
-#ifdef QSHOW_SIGNALS
- SHOW("calling C-level handler");
-#endif
+ FSHOW_SIGNAL((stderr,"/calling C-level handler\n"));
/* Allow signals again. */
thread_sigmask(SIG_SETMASK, os_context_sigmask_addr(context), 0);
undo_fake_foreign_function_call(context); /* block signals again */
}
-#ifdef QSHOW_SIGNALS
- FSHOW((stderr,
- "/returning from interrupt_handle_now(%d, info, context)\n",
- signal));
-#endif
+ FSHOW_SIGNAL((stderr,
+ "/returning from interrupt_handle_now(%d, info, context)\n",
+ signal));
}
/* This is called at the end of a critical section if the indications
void
run_deferred_handler(struct interrupt_data *data, void *v_context) {
- /* The pending_handler may enable interrupts (see
- * interrupt_maybe_gc_int) and then another interrupt may hit,
- * overwrite interrupt_data, so reset the pending handler before
- * calling it. Trust the handler to finish with the siginfo before
- * enabling interrupts. */
+ /* The pending_handler may enable interrupts and then another
+ * interrupt may hit, overwrite interrupt_data, so reset the
+ * pending handler before calling it. Trust the handler to finish
+ * with the siginfo before enabling interrupts. */
void (*pending_handler) (int, siginfo_t*, void*)=data->pending_handler;
data->pending_handler=0;
(*pending_handler)(data->pending_signal,&(data->pending_info), v_context);
lose("interrupt already pending");
/* If interrupts are disabled then INTERRUPT_PENDING is set and
* not PSEDUO_ATOMIC_INTERRUPTED. This is important for a pseudo
- * atomic section inside a without-interrupts.
+ * atomic section inside a WITHOUT-INTERRUPTS.
*/
if (SymbolValue(INTERRUPTS_ENABLED,thread) == NIL) {
store_signal_data_for_later(data,handler,signal,info,context);
SetSymbolValue(INTERRUPT_PENDING, T,thread);
-#ifdef QSHOW_SIGNALS
- FSHOW((stderr,
- "/maybe_defer_handler(%x,%d),thread=%ld: deferred\n",
- (unsigned int)handler,signal,thread->os_thread));
-#endif
+ FSHOW_SIGNAL((stderr,
+ "/maybe_defer_handler(%x,%d),thread=%lu: deferred\n",
+ (unsigned int)handler,signal,
+ (unsigned long)thread->os_thread));
return 1;
}
/* a slightly confusing test. arch_pseudo_atomic_atomic() doesn't
* may succeed even when context is null (gencgc alloc()) */
if (
#if !defined(LISP_FEATURE_X86) && !defined(LISP_FEATURE_X86_64)
+ /* FIXME: this foreign_function_call_active test is dubious at
+ * best. If a foreign call is made in a pseudo atomic section
+ * (?) or more likely a pseudo atomic section is in a foreign
+ * call then an interrupt is executed immediately. Maybe it
+ * has to do with C code not maintaining pseudo atomic
+ * properly. MG - 2005-08-10 */
(!foreign_function_call_active) &&
#endif
arch_pseudo_atomic_atomic(context)) {
store_signal_data_for_later(data,handler,signal,info,context);
arch_set_pseudo_atomic_interrupted(context);
-#ifdef QSHOW_SIGNALS
- FSHOW((stderr,
- "/maybe_defer_handler(%x,%d),thread=%ld: deferred(PA)\n",
- (unsigned int)handler,signal,thread->os_thread));
-#endif
+ FSHOW_SIGNAL((stderr,
+ "/maybe_defer_handler(%x,%d),thread=%lu: deferred(PA)\n",
+ (unsigned int)handler,signal,
+ (unsigned long)thread->os_thread));
return 1;
}
-#ifdef QSHOW_SIGNALS
- FSHOW((stderr,
- "/maybe_defer_handler(%x,%d),thread=%ld: not deferred\n",
- (unsigned int)handler,signal,thread->os_thread));
-#endif
+ FSHOW_SIGNAL((stderr,
+ "/maybe_defer_handler(%x,%d),thread=%lu: not deferred\n",
+ (unsigned int)handler,signal,
+ (unsigned long)thread->os_thread));
return 0;
}
* signals are added to the mask in the context so that we are
* running with blocked signals when the handler returns */
sigcopyset(&(data->pending_mask),os_context_sigmask_addr(context));
- sigaddset_blockable(os_context_sigmask_addr(context));
+ sigaddset_deferrable(os_context_sigmask_addr(context));
}
}
#ifdef LISP_FEATURE_LINUX
os_restore_fp_control(context);
#endif
- if(maybe_defer_handler(interrupt_handle_now,data,
- signal,info,context))
+ if(maybe_defer_handler(interrupt_handle_now,data,signal,info,context))
return;
interrupt_handle_now(signal, info, context);
#ifdef LISP_FEATURE_DARWIN
{
os_context_t *context = (os_context_t*)void_context;
struct thread *thread=arch_os_get_current_thread();
+ struct interrupt_data *data=thread->interrupt_data;
#ifdef LISP_FEATURE_LINUX
os_restore_fp_control(context);
#endif
check_blockables_blocked_or_lose();
check_interrupts_enabled_or_lose(context);
- (*thread->interrupt_data->interrupt_low_level_handlers[signal])
+ (*data->interrupt_low_level_handlers[signal])
(signal, info, void_context);
#ifdef LISP_FEATURE_DARWIN
/* Work around G5 bug */
}
#ifdef LISP_FEATURE_SB_THREAD
+
void
sig_stop_for_gc_handler(int signal, siginfo_t *info, void *void_context)
{
sigset_t ss;
int i;
- /* need the context stored so it can have registers scavenged */
- fake_foreign_function_call(context);
+ if ((arch_pseudo_atomic_atomic(context) ||
+ SymbolValue(GC_INHIBIT,thread) != NIL)) {
+ SetSymbolValue(STOP_FOR_GC_PENDING,T,thread);
+ if (SymbolValue(GC_INHIBIT,thread) == NIL)
+ arch_set_pseudo_atomic_interrupted(context);
+ FSHOW_SIGNAL((stderr,"thread=%lu sig_stop_for_gc deferred\n",
+ thread->os_thread));
+ } else {
+ /* need the context stored so it can have registers scavenged */
+ fake_foreign_function_call(context);
- sigemptyset(&ss);
- for(i=1;i<NSIG;i++) sigaddset(&ss,i); /* Block everything. */
- thread_sigmask(SIG_BLOCK,&ss,0);
-
- /* The GC can't tell if a thread is a zombie, so this would be a
- * good time to let the kernel reap any of our children in that
- * awful state, to stop them from being waited for indefinitely.
- * Userland reaping is done later when GC is finished */
- if(thread->state!=STATE_RUNNING) {
- lose("sig_stop_for_gc_handler: wrong thread state: %ld\n",
- fixnum_value(thread->state));
- }
- thread->state=STATE_SUSPENDED;
+ sigemptyset(&ss);
+ for(i=1;i<NSIG;i++) sigaddset(&ss,i); /* Block everything. */
+ thread_sigmask(SIG_BLOCK,&ss,0);
+
+ /* The GC can't tell if a thread is a zombie, so this would be a
+ * good time to let the kernel reap any of our children in that
+ * awful state, to stop them from being waited for indefinitely.
+ * Userland reaping is done later when GC is finished */
+ if(thread->state!=STATE_RUNNING) {
+ lose("sig_stop_for_gc_handler: wrong thread state: %ld\n",
+ fixnum_value(thread->state));
+ }
+ thread->state=STATE_SUSPENDED;
+ FSHOW_SIGNAL((stderr,"thread=%lu suspended\n",thread->os_thread));
+
+ sigemptyset(&ss); sigaddset(&ss,SIG_STOP_FOR_GC);
+ sigwaitinfo(&ss,0);
+ FSHOW_SIGNAL((stderr,"thread=%lu resumed\n",thread->os_thread));
+ if(thread->state!=STATE_RUNNING) {
+ lose("sig_stop_for_gc_handler: wrong thread state on wakeup: %ld\n",
+ fixnum_value(thread->state));
+ }
- sigemptyset(&ss); sigaddset(&ss,SIG_STOP_FOR_GC);
- sigwaitinfo(&ss,0);
- if(thread->state!=STATE_SUSPENDED) {
- lose("sig_stop_for_gc_handler: wrong thread state on wakeup: %ld\n",
- fixnum_value(thread->state));
+ undo_fake_foreign_function_call(context);
}
- thread->state=STATE_RUNNING;
-
- undo_fake_foreign_function_call(context);
}
#endif
{
os_context_t *context = (os_context_t*)arch_os_get_context(&v_context);
/* The order of interrupt execution is peculiar. If thread A
- * interrupts thread B with I1, I2 and B for some reason recieves
+ * interrupts thread B with I1, I2 and B for some reason receives
* I1 when FUN2 is already on the list, then it is FUN2 that gets
* to run first. But when FUN2 is run SIG_INTERRUPT_THREAD is
* enabled again and I2 hits pretty soon in FUN2 and run
* thread interrupt execution is undefined. */
struct thread *th=arch_os_get_current_thread();
struct cons *c;
+ lispobj function;
if (th->state != STATE_RUNNING)
- lose("interrupt_thread_handler: thread %ld in wrong state: %d\n",
+ lose("interrupt_thread_handler: thread %lu in wrong state: %d\n",
th->os_thread,fixnum_value(th->state));
get_spinlock(&th->interrupt_fun_lock,(long)th);
c=((struct cons *)native_pointer(th->interrupt_fun));
- arrange_return_to_lisp_function(context,c->car);
+ function=c->car;
th->interrupt_fun=c->cdr;
release_spinlock(&th->interrupt_fun_lock);
+ if (function==NIL)
+ lose("interrupt_thread_handler: NIL function\n");
+ arrange_return_to_lisp_function(context,function);
}
#endif
{
os_context_t *context=(os_context_t *) void_context;
struct thread *th=arch_os_get_current_thread();
- struct interrupt_data *data=
- th ? th->interrupt_data : global_interrupt_data;
+ struct interrupt_data *data=th->interrupt_data;
- if(!data->pending_handler && !foreign_function_call_active &&
- gc_trigger_hit(signal, info, context)){
+ if(!foreign_function_call_active && gc_trigger_hit(signal, info, context)){
+ struct thread *thread=arch_os_get_current_thread();
clear_auto_gc_trigger();
- if(!maybe_defer_handler(interrupt_maybe_gc_int,
- data,signal,info,void_context))
- interrupt_maybe_gc_int(signal,info,void_context);
+ /* Don't flood the system with interrupts if the need to gc is
+ * already noted. This can happen for example when SUB-GC
+ * allocates or after a gc triggered in a WITHOUT-GCING. */
+ if (SymbolValue(GC_PENDING,thread) == NIL) {
+ if (SymbolValue(GC_INHIBIT,thread) == NIL) {
+ if (arch_pseudo_atomic_atomic(context)) {
+ /* set things up so that GC happens when we finish
+ * the PA section */
+ SetSymbolValue(GC_PENDING,T,thread);
+ arch_set_pseudo_atomic_interrupted(context);
+ } else {
+ interrupt_maybe_gc_int(signal,info,void_context);
+ }
+ } else {
+ SetSymbolValue(GC_PENDING,T,thread);
+ }
+ }
return 1;
}
return 0;
interrupt_maybe_gc_int(int signal, siginfo_t *info, void *void_context)
{
os_context_t *context=(os_context_t *) void_context;
+ struct thread *thread=arch_os_get_current_thread();
check_blockables_blocked_or_lose();
fake_foreign_function_call(context);
* and signal a storage condition from there.
*/
- /* restore the signal mask from the interrupted context before
- * calling into Lisp */
- if (context)
+ /* Restore the signal mask from the interrupted context before
+ * calling into Lisp if interrupts are enabled. Why not always?
+ *
+ * Suppose there is a WITHOUT-INTERRUPTS block far, far out. If an
+ * interrupt hits while in SUB-GC, it is deferred and the
+ * os_context_sigmask of that interrupt is set to block further
+ * deferrable interrupts (until the first one is
+ * handled). Unfortunately, that context refers to this place and
+ * when we return from here the signals will not be blocked.
+ *
+ * A kludgy alternative is to propagate the sigmask change to the
+ * outer context.
+ */
+ if(SymbolValue(INTERRUPTS_ENABLED,thread)!=NIL)
thread_sigmask(SIG_SETMASK, os_context_sigmask_addr(context), 0);
-
+#ifdef LISP_FEATURE_SB_THREAD
+ else {
+ sigset_t new;
+ sigaddset(&new,SIG_STOP_FOR_GC);
+ thread_sigmask(SIG_UNBLOCK,&new,0);
+ }
+#endif
funcall0(SymbolFunction(SUB_GC));
undo_fake_foreign_function_call(context);
{
struct sigaction sa;
struct thread *th=arch_os_get_current_thread();
+ /* It may be before the initial thread is started. */
struct interrupt_data *data=
th ? th->interrupt_data : global_interrupt_data;
lose("bad signal number %d", signal);
}
- if (sigismember(&blockable_sigset,signal))
+ if (sigismember(&deferrable_sigset,signal))
sa.sa_sigaction = low_level_maybe_now_maybe_later;
else
sa.sa_sigaction = handler;
sigset_t old, new;
union interrupt_handler oldhandler;
struct thread *th=arch_os_get_current_thread();
+ /* It may be before the initial thread is started. */
struct interrupt_data *data=
th ? th->interrupt_data : global_interrupt_data;
sigaddset(&new, signal);
thread_sigmask(SIG_BLOCK, &new, &old);
- sigemptyset(&new);
- sigaddset_blockable(&new);
-
FSHOW((stderr, "/data->interrupt_low_level_handlers[signal]=%x\n",
(unsigned int)data->interrupt_low_level_handlers[signal]));
if (data->interrupt_low_level_handlers[signal]==0) {
if (ARE_SAME_HANDLER(handler, SIG_DFL) ||
ARE_SAME_HANDLER(handler, SIG_IGN)) {
sa.sa_sigaction = handler;
- } else if (sigismember(&new, signal)) {
+ } else if (sigismember(&deferrable_sigset, signal)) {
sa.sa_sigaction = maybe_now_maybe_later;
} else {
sa.sa_sigaction = interrupt_handle_now_handler;
{
int i;
SHOW("entering interrupt_init()");
+ sigemptyset(&deferrable_sigset);
sigemptyset(&blockable_sigset);
+ sigaddset_deferrable(&deferrable_sigset);
sigaddset_blockable(&blockable_sigset);
global_interrupt_data=calloc(sizeof(struct interrupt_data), 1);
projects / sbcl.git / blobdiff