#include "alloc.h"
#include "dynbind.h"
#include "interr.h"
+#include "pseudo-atomic.h"
#include "genesis/fdefn.h"
#include "genesis/simple-fun.h"
#include "genesis/cons.h"
siginfo_t *info,
os_context_t *context);
+static void
+fill_current_sigmask(sigset_t *sigset)
+{
+ /* Get the current sigmask, by blocking the empty set. */
+ sigset_t empty;
+ sigemptyset(&empty);
+ thread_sigmask(SIG_BLOCK, &empty, sigset);
+}
+
void
sigaddset_deferrable(sigset_t *s)
{
sigaddset(s, SIGHUP);
sigaddset(s, SIGINT);
+ sigaddset(s, SIGTERM);
sigaddset(s, SIGQUIT);
sigaddset(s, SIGPIPE);
sigaddset(s, SIGALRM);
sigaddset(s, SIGVTALRM);
sigaddset(s, SIGPROF);
sigaddset(s, SIGWINCH);
+}
-#if !((defined(LISP_FEATURE_DARWIN) || defined(LISP_FEATURE_FREEBSD)) && defined(LISP_FEATURE_SB_THREAD))
- sigaddset(s, SIGUSR1);
- sigaddset(s, SIGUSR2);
+void
+sigdelset_deferrable(sigset_t *s)
+{
+ sigdelset(s, SIGHUP);
+ sigdelset(s, SIGINT);
+ sigdelset(s, SIGQUIT);
+ sigdelset(s, SIGPIPE);
+ sigdelset(s, SIGALRM);
+ sigdelset(s, SIGURG);
+ sigdelset(s, SIGTSTP);
+ sigdelset(s, SIGCHLD);
+ sigdelset(s, SIGIO);
+#ifndef LISP_FEATURE_HPUX
+ sigdelset(s, SIGXCPU);
+ sigdelset(s, SIGXFSZ);
#endif
+ sigdelset(s, SIGVTALRM);
+ sigdelset(s, SIGPROF);
+ sigdelset(s, SIGWINCH);
+}
+
+void
+sigaddset_blockable(sigset_t *sigset)
+{
+ sigaddset_deferrable(sigset);
+ sigaddset_gc(sigset);
+}
+void
+sigaddset_gc(sigset_t *sigset)
+{
#ifdef LISP_FEATURE_SB_THREAD
- sigaddset(s, SIG_INTERRUPT_THREAD);
+ sigaddset(sigset,SIG_STOP_FOR_GC);
#endif
}
void
-sigaddset_blockable(sigset_t *s)
+sigdelset_gc(sigset_t *sigset)
{
- sigaddset_deferrable(s);
#ifdef LISP_FEATURE_SB_THREAD
-#ifdef SIG_RESUME_FROM_GC
- sigaddset(s, SIG_RESUME_FROM_GC);
-#endif
- sigaddset(s, SIG_STOP_FOR_GC);
+ sigdelset(sigset,SIG_STOP_FOR_GC);
#endif
}
/* initialized in interrupt_init */
sigset_t deferrable_sigset;
sigset_t blockable_sigset;
+sigset_t gc_sigset;
#endif
+boolean
+deferrables_blocked_in_sigset_p(sigset_t *sigset)
+{
+#if !defined(LISP_FEATURE_WIN32)
+ int i;
+ for(i = 1; i < NSIG; i++) {
+ if (sigismember(&deferrable_sigset, i) && sigismember(sigset, i))
+ return 1;
+ }
+#endif
+ return 0;
+}
+
+void
+check_deferrables_unblocked_in_sigset_or_lose(sigset_t *sigset)
+{
+#if !defined(LISP_FEATURE_WIN32)
+ int i;
+ for(i = 1; i < NSIG; i++) {
+ if (sigismember(&deferrable_sigset, i) && sigismember(sigset, i))
+ lose("deferrable signal %d blocked\n",i);
+ }
+#endif
+}
+
+void
+check_deferrables_blocked_in_sigset_or_lose(sigset_t *sigset)
+{
+#if !defined(LISP_FEATURE_WIN32)
+ int i;
+ for(i = 1; i < NSIG; i++) {
+ if (sigismember(&deferrable_sigset, i) && !sigismember(sigset, i))
+ lose("deferrable signal %d not blocked\n",i);
+ }
+#endif
+}
+
+void
+check_deferrables_unblocked_or_lose(void)
+{
+#if !defined(LISP_FEATURE_WIN32)
+ sigset_t current;
+ fill_current_sigmask(¤t);
+ check_deferrables_unblocked_in_sigset_or_lose(¤t);
+#endif
+}
+
+void
+check_deferrables_blocked_or_lose(void)
+{
+#if !defined(LISP_FEATURE_WIN32)
+ sigset_t current;
+ fill_current_sigmask(¤t);
+ check_deferrables_blocked_in_sigset_or_lose(¤t);
+#endif
+}
+
void
check_blockables_blocked_or_lose(void)
{
#if !defined(LISP_FEATURE_WIN32)
- /* Get the current sigmask, by blocking the empty set. */
- sigset_t empty,current;
+ sigset_t current;
int i;
- sigemptyset(&empty);
- thread_sigmask(SIG_BLOCK, &empty, ¤t);
+ fill_current_sigmask(¤t);
for(i = 1; i < NSIG; i++) {
if (sigismember(&blockable_sigset, i) && !sigismember(¤t, i))
lose("blockable signal %d not blocked\n",i);
}
void
-unblock_gc_signals(void)
+check_gc_signals_unblocked_in_sigset_or_lose(sigset_t *sigset)
{
-#ifdef LISP_FEATURE_SB_THREAD
- sigset_t new;
- sigemptyset(&new);
-#if defined(SIG_RESUME_FROM_GC)
- sigaddset(&new,SIG_RESUME_FROM_GC);
+#if !defined(LISP_FEATURE_WIN32)
+ int i;
+ for(i = 1; i < NSIG; i++) {
+ if (sigismember(&gc_sigset, i) && sigismember(sigset, i))
+ lose("gc signal %d blocked\n",i);
+ }
#endif
- sigaddset(&new,SIG_STOP_FOR_GC);
- thread_sigmask(SIG_UNBLOCK,&new,0);
+}
+
+void
+check_gc_signals_unblocked_or_lose(void)
+{
+#if !defined(LISP_FEATURE_WIN32)
+ sigset_t current;
+ fill_current_sigmask(¤t);
+ check_gc_signals_unblocked_in_sigset_or_lose(¤t);
#endif
}
lose ("in pseudo atomic section\n");
}
+/* Save sigset (or the current sigmask if 0) if there is no pending
+ * handler, because that means that deferabbles are already blocked.
+ * The purpose is to avoid losing the pending gc signal if a
+ * deferrable interrupt async unwinds between clearing the pseudo
+ * atomic and trapping to GC.*/
+void
+maybe_save_gc_mask_and_block_deferrables(sigset_t *sigset)
+{
+ struct thread *thread = arch_os_get_current_thread();
+ struct interrupt_data *data = thread->interrupt_data;
+ sigset_t oldset;
+ /* Obviously, this function is called when signals may not be
+ * blocked. Let's make sure we are not interrupted. */
+ thread_sigmask(SIG_BLOCK, &blockable_sigset, &oldset);
+#ifndef LISP_FEATURE_SB_THREAD
+ /* With threads a SIG_STOP_FOR_GC and a normal GC may also want to
+ * block. */
+ if (data->gc_blocked_deferrables)
+ lose("gc_blocked_deferrables already true\n");
+#endif
+ if ((!data->pending_handler) &&
+ (!data->gc_blocked_deferrables)) {
+ FSHOW_SIGNAL((stderr,"/setting gc_blocked_deferrables\n"));
+ data->gc_blocked_deferrables = 1;
+ if (sigset) {
+ /* This is the sigmask of some context. */
+ sigcopyset(&data->pending_mask, sigset);
+ sigaddset_deferrable(sigset);
+ thread_sigmask(SIG_SETMASK,&oldset,0);
+ return;
+ } else {
+ /* Operating on the current sigmask. Save oldset and
+ * unblock gc signals. In the end, this is equivalent to
+ * blocking the deferrables. */
+ sigcopyset(&data->pending_mask, &oldset);
+ unblock_gc_signals();
+ return;
+ }
+ }
+ thread_sigmask(SIG_SETMASK,&oldset,0);
+}
+
+/* Are we leaving WITH-GCING and already running with interrupts
+ * enabled, without the protection of *GC-INHIBIT* T and there is gc
+ * (or stop for gc) pending, but we haven't trapped yet? */
+int
+in_leaving_without_gcing_race_p(struct thread *thread)
+{
+ return ((SymbolValue(IN_WITHOUT_GCING,thread) != NIL) &&
+ (SymbolValue(INTERRUPTS_ENABLED,thread) != NIL) &&
+ (SymbolValue(GC_INHIBIT,thread) == NIL) &&
+ ((SymbolValue(GC_PENDING,thread) != NIL)
+#if defined(LISP_FEATURE_SB_THREAD)
+ || (SymbolValue(STOP_FOR_GC_PENDING,thread) != NIL)
+#endif
+ ));
+}
+
+/* Check our baroque invariants. */
+void
+check_interrupt_context_or_lose(os_context_t *context)
+{
+ struct thread *thread = arch_os_get_current_thread();
+ struct interrupt_data *data = thread->interrupt_data;
+ int interrupt_deferred_p = (data->pending_handler != 0);
+ int interrupt_pending = (SymbolValue(INTERRUPT_PENDING,thread) != NIL);
+ sigset_t *sigset = os_context_sigmask_addr(context);
+ /* On PPC pseudo_atomic_interrupted is cleared when coming out of
+ * handle_allocation_trap. */
+#if defined(LISP_FEATURE_GENCGC) && !defined(LISP_FEATURE_PPC)
+ int interrupts_enabled = (SymbolValue(INTERRUPTS_ENABLED,thread) != NIL);
+ int gc_inhibit = (SymbolValue(GC_INHIBIT,thread) != NIL);
+ int gc_pending = (SymbolValue(GC_PENDING,thread) == T);
+ int pseudo_atomic_interrupted = get_pseudo_atomic_interrupted(thread);
+ int in_race_p = in_leaving_without_gcing_race_p(thread);
+ /* In the time window between leaving the *INTERRUPTS-ENABLED* NIL
+ * section and trapping, a SIG_STOP_FOR_GC would see the next
+ * check fail, for this reason sig_stop_for_gc handler does not
+ * call this function. */
+ if (interrupt_deferred_p) {
+ if (!(!interrupts_enabled || pseudo_atomic_interrupted || in_race_p))
+ lose("Stray deferred interrupt.\n");
+ }
+ if (gc_pending)
+ if (!(pseudo_atomic_interrupted || gc_inhibit || in_race_p))
+ lose("GC_PENDING, but why?\n");
+#if defined(LISP_FEATURE_SB_THREAD)
+ {
+ int stop_for_gc_pending =
+ (SymbolValue(STOP_FOR_GC_PENDING,thread) != NIL);
+ if (stop_for_gc_pending)
+ if (!(pseudo_atomic_interrupted || gc_inhibit || in_race_p))
+ lose("STOP_FOR_GC_PENDING, but why?\n");
+ }
+#endif
+#endif
+ if (interrupt_pending && !interrupt_deferred_p)
+ lose("INTERRUPT_PENDING but not pending handler.\n");
+ if ((data->gc_blocked_deferrables) && interrupt_pending)
+ lose("gc_blocked_deferrables and interrupt pending\n.");
+ if (data->gc_blocked_deferrables)
+ check_deferrables_blocked_in_sigset_or_lose(sigset);
+ if (interrupt_pending || interrupt_deferred_p)
+ check_deferrables_blocked_in_sigset_or_lose(sigset);
+ else {
+ check_deferrables_unblocked_in_sigset_or_lose(sigset);
+ /* If deferrables are unblocked then we are open to signals
+ * that run lisp code. */
+ check_gc_signals_unblocked_in_sigset_or_lose(sigset);
+ }
+}
+
/* When we catch an internal error, should we pass it back to Lisp to
* be handled in a high-level way? (Early in cold init, the answer is
* 'no', because Lisp is still too brain-dead to handle anything.
#endif
union interrupt_handler interrupt_handlers[NSIG];
-/* At the toplevel repl we routinely call this function. The signal
- * mask ought to be clear anyway most of the time, but may be non-zero
- * if we were interrupted e.g. while waiting for a queue. */
+void
+block_blockable_signals(void)
+{
+#ifndef LISP_FEATURE_WIN32
+ thread_sigmask(SIG_BLOCK, &blockable_sigset, 0);
+#endif
+}
+
+void
+block_deferrable_signals(void)
+{
+#ifndef LISP_FEATURE_WIN32
+ thread_sigmask(SIG_BLOCK, &deferrable_sigset, 0);
+#endif
+}
void
-reset_signal_mask(void)
+unblock_deferrable_signals_in_sigset(sigset_t *sigset)
{
#ifndef LISP_FEATURE_WIN32
- sigset_t new;
- sigemptyset(&new);
- thread_sigmask(SIG_SETMASK,&new,0);
+ if (interrupt_handler_pending_p())
+ lose("unblock_deferrable_signals_in_sigset: losing proposition\n");
+ check_gc_signals_unblocked_in_sigset_or_lose(sigset);
+ sigdelset_deferrable(sigset);
#endif
}
void
-block_blockable_signals(void)
+unblock_deferrable_signals(void)
{
#ifndef LISP_FEATURE_WIN32
- thread_sigmask(SIG_BLOCK, &blockable_sigset, 0);
+ if (interrupt_handler_pending_p())
+ lose("unblock_deferrable_signals: losing proposition\n");
+ check_gc_signals_unblocked_or_lose();
+ thread_sigmask(SIG_UNBLOCK, &deferrable_sigset, 0);
#endif
}
void
-block_deferrable_signals(void)
+unblock_gc_signals(void)
+{
+#if defined(LISP_FEATURE_SB_THREAD) && !defined(LISP_FEATURE_WIN32)
+ thread_sigmask(SIG_UNBLOCK,&gc_sigset,0);
+#endif
+}
+
+void
+unblock_signals_in_context_and_maybe_warn(os_context_t *context)
{
#ifndef LISP_FEATURE_WIN32
- thread_sigmask(SIG_BLOCK, &deferrable_sigset, 0);
+ int i, oops=0;
+ sigset_t *sigset=os_context_sigmask_addr(context);
+ for(i = 1; i < NSIG; i++) {
+ if (sigismember(&gc_sigset, i) && sigismember(sigset, i)) {
+ if (!oops) {
+ fprintf(stderr,
+"Enabling blocked gc signals to allow returning to Lisp without risking\n\
+gc deadlocks. Since GC signals are only blocked in signal handlers when \n\
+they are not safe to interrupt at all, this is a pretty severe occurrence.\n");
+ }
+ oops=1;
+ }
+ }
+ sigdelset_gc(sigset);
+ if (!interrupt_handler_pending_p()) {
+ unblock_deferrable_signals_in_sigset(sigset);
+ }
#endif
}
/* Allocate the SAP object while the interrupts are still
* disabled. */
+ unblock_gc_signals();
context_sap = alloc_sap(context);
#ifndef LISP_FEATURE_WIN32
thread_sigmask(SIG_SETMASK, os_context_sigmask_addr(context), 0);
#endif
+#if defined(LISP_FEATURE_LINUX) && defined(LISP_FEATURE_MIPS)
+ /* Workaround for blocked SIGTRAP. */
+ {
+ sigset_t newset;
+ sigemptyset(&newset);
+ sigaddset(&newset, SIGTRAP);
+ thread_sigmask(SIG_UNBLOCK, &newset, 0);
+ }
+#endif
+
SHOW("in interrupt_internal_error");
#ifdef QSHOW
/* Display some rudimentary debugging information about the
arch_skip_instruction(context);
}
+boolean
+interrupt_handler_pending_p(void)
+{
+ struct thread *thread = arch_os_get_current_thread();
+ struct interrupt_data *data = thread->interrupt_data;
+ return (data->pending_handler != 0);
+}
+
void
interrupt_handle_pending(os_context_t *context)
{
/* Win32 only needs to handle the GC cases (for now?) */
- struct thread *thread;
+ struct thread *thread = arch_os_get_current_thread();
+ struct interrupt_data *data = thread->interrupt_data;
- /* Punt if in PA section, marking it as interrupted. This can
- * happenat least if we pick up a GC request while in a
- * WITHOUT-GCING with an outer PA -- it is not immediately clear
- * to me that this should/could ever happen, but better safe then
- * sorry. --NS 2007-05-15 */
if (arch_pseudo_atomic_atomic(context)) {
- arch_set_pseudo_atomic_interrupted(context);
- return;
+ lose("Handling pending interrupt in pseduo atomic.");
}
- thread = arch_os_get_current_thread();
-
FSHOW_SIGNAL((stderr, "/entering interrupt_handle_pending\n"));
check_blockables_blocked_or_lose();
- /* If pseudo_atomic_interrupted is set then the interrupt is going
- * to be handled now, ergo it's safe to clear it. */
- arch_clear_pseudo_atomic_interrupted(context);
+ /* If GC/SIG_STOP_FOR_GC struck during PA and there was no pending
+ * handler, then the pending mask was saved and
+ * gc_blocked_deferrables set. Hence, there can be no pending
+ * handler and it's safe to restore the pending mask.
+ *
+ * Note, that if gc_blocked_deferrables is false we may still have
+ * to GC. In this case, we are coming out of a WITHOUT-GCING or a
+ * pseudo atomic was interrupt be a deferrable first. */
+ if (data->gc_blocked_deferrables) {
+ if (data->pending_handler)
+ lose("GC blocked deferrables but still got a pending handler.");
+ if (SymbolValue(GC_INHIBIT,thread)!=NIL)
+ lose("GC blocked deferrables while GC is inhibited.");
+ /* 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);
+ data->gc_blocked_deferrables = 0;
+ }
if (SymbolValue(GC_INHIBIT,thread)==NIL) {
+ void *original_pending_handler = data->pending_handler;
+
#ifdef LISP_FEATURE_SB_THREAD
if (SymbolValue(STOP_FOR_GC_PENDING,thread) != NIL) {
/* STOP_FOR_GC_PENDING and GC_PENDING are cleared by
* the signal handler if it actually stops us. */
+ arch_clear_pseudo_atomic_interrupted(context);
sig_stop_for_gc_handler(SIG_STOP_FOR_GC,NULL,context);
} else
#endif
- if (SymbolValue(GC_PENDING,thread) != NIL) {
+ /* Test for T and not for != NIL since the value :IN-PROGRESS
+ * is used in SUB-GC as part of the mechanism to supress
+ * recursive gcs.*/
+ if (SymbolValue(GC_PENDING,thread) == T) {
+
+ /* Two reasons for doing this. First, if there is a
+ * pending handler we don't want to run. Second, we are
+ * going to clear pseudo atomic interrupted to avoid
+ * spurious trapping on every allocation in SUB_GC and
+ * having a pending handler with interrupts enabled and
+ * without pseudo atomic interrupted breaks an
+ * invariant. */
+ if (data->pending_handler) {
+ bind_variable(ALLOW_WITH_INTERRUPTS, NIL, thread);
+ bind_variable(INTERRUPTS_ENABLED, NIL, thread);
+ }
+
+ arch_clear_pseudo_atomic_interrupted(context);
+
/* 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. */
- maybe_gc(context);
+ * that will clear it.
+ *
+ * If there is a pending handler or gc was triggerred in a
+ * signal handler then maybe_gc won't run POST_GC and will
+ * return normally. */
+ if (!maybe_gc(context))
+ lose("GC not inhibited but maybe_gc did not GC.");
+
+ if (data->pending_handler) {
+ unbind(thread);
+ unbind(thread);
+ }
+ } else if (SymbolValue(GC_PENDING,thread) != NIL) {
+ /* It's not NIL or T so GC_PENDING is :IN-PROGRESS. If
+ * GC-PENDING is not NIL then we cannot trap on pseudo
+ * atomic due to GC (see if(GC_PENDING) logic in
+ * cheneygc.c an gengcgc.c), plus there is a outer
+ * WITHOUT-INTERRUPTS SUB_GC, so how did we end up
+ * here? */
+ lose("Trapping to run pending handler while GC in progress.");
}
+
check_blockables_blocked_or_lose();
+
+ /* No GC shall be lost. If SUB_GC triggers another GC then
+ * that should be handled on the spot. */
+ if (SymbolValue(GC_PENDING,thread) != NIL)
+ lose("GC_PENDING after doing gc.");
+#ifdef LISP_FEATURE_SB_THREAD
+ if (SymbolValue(STOP_FOR_GC_PENDING,thread) != NIL)
+ lose("STOP_FOR_GC_PENDING after doing gc.");
+#endif
+ /* Check two things. First, that gc does not clobber a handler
+ * that's already pending. Second, that there is no interrupt
+ * lossage: if original_pending_handler was NULL then even if
+ * an interrupt arrived during GC (POST-GC, really) it was
+ * handled. */
+ if (original_pending_handler != data->pending_handler)
+ lose("pending handler changed in gc: %x -> %d.",
+ original_pending_handler, data->pending_handler);
}
#ifndef LISP_FEATURE_WIN32
- /* we may be here only to do the gc stuff, if interrupts are
- * enabled run the pending handler */
- if (SymbolValue(INTERRUPTS_ENABLED,thread) != NIL) {
- struct interrupt_data *data = thread->interrupt_data;
-
- /* 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 pseudo-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);
- }
+ /* There may be no pending handler, because it was only a gc that
+ * had to be executed or because Lisp is a bit too eager to call
+ * DO-PENDING-INTERRUPT. */
+ if ((SymbolValue(INTERRUPTS_ENABLED,thread) != NIL) &&
+ (data->pending_handler)) {
+ /* No matter how we ended up here, clear both
+ * INTERRUPT_PENDING and pseudo atomic interrupted. It's safe
+ * because we checked above that there is no GC pending. */
+ SetSymbolValue(INTERRUPT_PENDING, NIL, thread);
+ arch_clear_pseudo_atomic_interrupted(context);
+ /* Restore the sigmask in the context. */
+ sigcopyset(os_context_sigmask_addr(context), &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);
}
+ /* It is possible that the end of this function was reached
+ * without never actually doing anything, the tests in Lisp for
+ * when to call receive-pending-interrupt are not exact. */
+ FSHOW_SIGNAL((stderr, "/exiting interrupt_handle_pending\n"));
#endif
}
\f
* Yeah, but non-gencgc platforms don't really wrap allocation
* in PA. MG - 2005-08-29 */
- lispobj info_sap,context_sap = alloc_sap(context);
- info_sap = alloc_sap(info);
+ lispobj info_sap, context_sap;
/* Leave deferrable signals blocked, the handler itself will
* allow signals again when it sees fit. */
-#ifdef LISP_FEATURE_SB_THREAD
- {
- sigset_t unblock;
- sigemptyset(&unblock);
- sigaddset(&unblock, SIG_STOP_FOR_GC);
-#ifdef SIG_RESUME_FROM_GC
- sigaddset(&unblock, SIG_RESUME_FROM_GC);
-#endif
- thread_sigmask(SIG_UNBLOCK, &unblock, 0);
- }
-#endif
+ unblock_gc_signals();
+ context_sap = alloc_sap(context);
+ info_sap = alloc_sap(info);
FSHOW_SIGNAL((stderr,"/calling Lisp-level handler\n"));
info_sap,
context_sap);
} else {
+ /* This cannot happen in sane circumstances. */
FSHOW_SIGNAL((stderr,"/calling C-level handler\n"));
void (*pending_handler) (int, siginfo_t*, void*)=data->pending_handler;
data->pending_handler=0;
+ FSHOW_SIGNAL((stderr, "/running deferred handler %p\n", pending_handler));
(*pending_handler)(data->pending_signal,&(data->pending_info), v_context);
}
if (SymbolValue(INTERRUPT_PENDING,thread) != NIL)
lose("interrupt already pending\n");
+ if (thread->interrupt_data->pending_handler)
+ lose("there is a pending handler already (PA)\n");
+ if (data->gc_blocked_deferrables)
+ lose("maybe_defer_handler: gc_blocked_deferrables true\n");
+ check_interrupt_context_or_lose(context);
/* 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.
+ *
+ * Also, if in_leaving_without_gcing_race_p then
+ * interrupt_handle_pending is going to be called soon, so
+ * stashing the signal away is safe.
*/
- if (SymbolValue(INTERRUPTS_ENABLED,thread) == NIL) {
+ if ((SymbolValue(INTERRUPTS_ENABLED,thread) == NIL) ||
+ in_leaving_without_gcing_race_p(thread)) {
store_signal_data_for_later(data,handler,signal,info,context);
SetSymbolValue(INTERRUPT_PENDING, T,thread);
FSHOW_SIGNAL((stderr,
- "/maybe_defer_handler(%x,%d): deferred\n",
- (unsigned int)handler,signal));
+ "/maybe_defer_handler(%x,%d): deferred (RACE=%d)\n",
+ (unsigned int)handler,signal,
+ in_leaving_without_gcing_race_p(thread)));
+ check_interrupt_context_or_lose(context);
return 1;
}
/* a slightly confusing test. arch_pseudo_atomic_atomic() doesn't
FSHOW_SIGNAL((stderr,
"/maybe_defer_handler(%x,%d): deferred(PA)\n",
(unsigned int)handler,signal));
+ check_interrupt_context_or_lose(context);
return 1;
}
FSHOW_SIGNAL((stderr,
FSHOW_SIGNAL((stderr, "/store_signal_data_for_later: signal: %d\n",
signal));
- if(context) {
- /* the signal mask in the context (from before we were
- * interrupted) is copied to be restored when
- * run_deferred_handler happens. Then the usually-blocked
- * 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_deferrable(os_context_sigmask_addr(context));
- }
+ if(!context)
+ lose("Null context");
+
+ /* the signal mask in the context (from before we were
+ * interrupted) is copied to be restored when run_deferred_handler
+ * happens. Then the usually-blocked 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_deferrable(os_context_sigmask_addr(context));
}
static void
#ifdef LISP_FEATURE_SB_THREAD
+/* This function must not cons, because that may trigger a GC. */
void
sig_stop_for_gc_handler(int signal, siginfo_t *info, void *void_context)
{
struct thread *thread=arch_os_get_current_thread();
sigset_t ss;
- if (arch_pseudo_atomic_atomic(context)) {
+ /* Test for GC_INHIBIT _first_, else we'd trap on every single
+ * pseudo atomic until gc is finally allowed. */
+ if (SymbolValue(GC_INHIBIT,thread) != NIL) {
SetSymbolValue(STOP_FOR_GC_PENDING,T,thread);
- arch_set_pseudo_atomic_interrupted(context);
- FSHOW_SIGNAL((stderr, "sig_stop_for_gc deferred (PA)\n"));
+ FSHOW_SIGNAL((stderr, "sig_stop_for_gc deferred (*GC-INHIBIT*)\n"));
return;
- }
- else if (SymbolValue(GC_INHIBIT,thread) != NIL) {
+ } else if (arch_pseudo_atomic_atomic(context)) {
SetSymbolValue(STOP_FOR_GC_PENDING,T,thread);
- FSHOW_SIGNAL((stderr, "sig_stop_for_gc deferred (*GC-INHIBIT*)\n"));
+ arch_set_pseudo_atomic_interrupted(context);
+ maybe_save_gc_mask_and_block_deferrables
+ (os_context_sigmask_addr(context));
+ FSHOW_SIGNAL((stderr,"sig_stop_for_gc deferred (PA)\n"));
return;
}
+ FSHOW_SIGNAL((stderr, "/sig_stop_for_gc_handler\n"));
+
/* Not PA and GC not inhibited -- we can stop now. */
/* need the context stored so it can have registers scavenged */
SetSymbolValue(GC_PENDING,NIL,thread);
SetSymbolValue(STOP_FOR_GC_PENDING,NIL,thread);
- if(thread->state!=STATE_RUNNING) {
+ if(thread_state(thread)!=STATE_RUNNING) {
lose("sig_stop_for_gc_handler: wrong thread state: %ld\n",
fixnum_value(thread->state));
}
- thread->state=STATE_SUSPENDED;
+ set_thread_state(thread,STATE_SUSPENDED);
FSHOW_SIGNAL((stderr,"suspended\n"));
- sigemptyset(&ss);
-#if defined(SIG_RESUME_FROM_GC)
- sigaddset(&ss,SIG_RESUME_FROM_GC);
-#else
- sigaddset(&ss,SIG_STOP_FOR_GC);
-#endif
-
- /* It is possible to get SIGCONT (and probably other non-blockable
- * signals) here. */
-#ifdef SIG_RESUME_FROM_GC
- {
- int sigret;
- do { sigwait(&ss, &sigret); }
- while (sigret != SIG_RESUME_FROM_GC);
- }
-#else
- while (sigwaitinfo(&ss,0) != SIG_STOP_FOR_GC);
-#endif
-
+ wait_for_thread_state_change(thread, STATE_SUSPENDED);
FSHOW_SIGNAL((stderr,"resumed\n"));
- if(thread->state!=STATE_RUNNING) {
+
+ if(thread_state(thread)!=STATE_RUNNING) {
lose("sig_stop_for_gc_handler: wrong thread state on wakeup: %ld\n",
- fixnum_value(thread->state));
+ fixnum_value(thread_state(thread)));
}
undo_fake_foreign_function_call(context);
}
+
#endif
void
void
arrange_return_to_lisp_function(os_context_t *context, lispobj function)
{
+ check_gc_signals_unblocked_in_sigset_or_lose
+ (os_context_sigmask_addr(context));
#if !(defined(LISP_FEATURE_X86) || defined(LISP_FEATURE_X86_64))
void * fun=native_pointer(function);
void *code = &(((struct simple_fun *) fun)->code);
(long)function));
}
-#ifdef LISP_FEATURE_SB_THREAD
-
-/* FIXME: this function can go away when all lisp handlers are invoked
- * via arrange_return_to_lisp_function. */
-void
-interrupt_thread_handler(int num, siginfo_t *info, void *v_context)
-{
- os_context_t *context = (os_context_t*)arch_os_get_context(&v_context);
-
- FSHOW_SIGNAL((stderr,"/interrupt_thread_handler\n"));
- check_blockables_blocked_or_lose();
-
- /* let the handler enable interrupts again when it sees fit */
- sigaddset_deferrable(os_context_sigmask_addr(context));
- arrange_return_to_lisp_function(context,
- StaticSymbolFunction(RUN_INTERRUPTION));
-}
-
-#endif
-
/* KLUDGE: Theoretically the approach we use for undefined alien
* variables should work for functions as well, but on PPC/Darwin
* we get bus error at bogus addresses instead, hence this workaround,
protect_control_stack_guard_page(0);
protect_control_stack_return_guard_page(1);
+#ifdef LISP_FEATURE_C_STACK_IS_CONTROL_STACK
+ /* For the unfortunate case, when the control stack is
+ * exhausted in a signal handler. */
+ unblock_signals_in_context_and_maybe_warn(context);
+#endif
arrange_return_to_lisp_function
(context, StaticSymbolFunction(CONTROL_STACK_EXHAUSTED_ERROR));
return 1;
* unprotect this one. This works even if we somehow missed
* the return-guard-page, and hit it on our way to new
* exhaustion instead. */
+ fprintf(stderr, "INFO: Control stack guard page reprotected\n");
protect_control_stack_guard_page(1);
protect_control_stack_return_guard_page(0);
return 1;
sa.sa_flags = SA_SIGINFO | SA_RESTART
| (sigaction_nodefer_works ? SA_NODEFER : 0);
#ifdef LISP_FEATURE_C_STACK_IS_CONTROL_STACK
- if((signal==SIG_MEMORY_FAULT)
-#ifdef SIG_INTERRUPT_THREAD
- || (signal==SIG_INTERRUPT_THREAD)
-#endif
- )
+ if((signal==SIG_MEMORY_FAULT))
sa.sa_flags |= SA_ONSTACK;
#endif
#endif
}
+/* This must not go through lisp as it's allowed anytime, even when on
+ * the altstack. */
+void
+sigabrt_handler(int signal, siginfo_t *info, void *void_context)
+{
+ lose("SIGABRT received.\n");
+}
+
void
interrupt_init(void)
{
see_if_sigaction_nodefer_works();
sigemptyset(&deferrable_sigset);
sigemptyset(&blockable_sigset);
+ sigemptyset(&gc_sigset);
sigaddset_deferrable(&deferrable_sigset);
sigaddset_blockable(&blockable_sigset);
+ sigaddset_gc(&gc_sigset);
/* Set up high level handler information. */
for (i = 0; i < NSIG; i++) {
* 3-argument form is expected.) */
(void (*)(int, siginfo_t*, void*))SIG_DFL;
}
-
+ undoably_install_low_level_interrupt_handler(SIGABRT, sigabrt_handler);
SHOW("returning from interrupt_init()");
#endif
}
current_memory_fault_address = addr;
/* To allow debugging memory faults in signal handlers and such. */
corruption_warning_and_maybe_lose("Memory fault");
+ unblock_signals_in_context_and_maybe_warn(context);
arrange_return_to_lisp_function(context,
StaticSymbolFunction(MEMORY_FAULT_ERROR));
}
{
lispobj context_sap;
fake_foreign_function_call(context);
+ unblock_gc_signals();
context_sap = alloc_sap(context);
#ifndef LISP_FEATURE_WIN32
thread_sigmask(SIG_SETMASK, os_context_sigmask_addr(context), 0);
unhandled_trap_error(context);
}
}
-
projects / sbcl.git / blobdiff