is disabled.
* minor incompatible change: SB-KERNEL:INSTANCE-LAMBDA is
deprecated, and will go away in a future revision of SBCL.
+ * minor incompatible change: GC-ON and GC-OFF are no longer
+ implemented with a counter, it does not matter how many times gc
+ is switched on or off
* bug fix: discriminating functions for generic function classes
with non-standard methods for COMPUTE-APPLICABLE-METHODS no longer
make invalid assumptions about method precedence order. (reported
lists in some cases. This partially fixes bug 384.
* flush all standard streams before prompting in the REPL and the
debugger.
+ * bug fix: signal handling and triggering gc do not conflict
+ directly anymore, in particular a high frequency sb-sprof does
+ not prevent gc from running
* threads
** bug fix: RELEASE-FOREGROUND doesn't choke on session lock if
there is only one thread in the session
** bug fix: memory leak for streams created in one thread and
written to in another
** bug fix: lockup when compiled with gcc4
+ ** bug fix: race that allows the gc to be triggered when gc is
+ inhibited
changes in sbcl-0.9.3 relative to sbcl-0.9.2:
* New feature: Experimental support for bivalent streams: streams
;; lots of stuff which currently uses the SB!KERNEL package which
;; doesn't actually use the type system stuff.) And maybe other
;; possible splits too:
- ;; * Pull GC stuff (*GC-INHIBIT*, *NEED-TO-COLLECT-GARBAGE*, etc.)
+ ;; * Pull GC stuff (*GC-INHIBIT*, *GC-PENDING*, etc.)
;; out into SB-GC.
;; * Pull special case implementations of sequence functions (e.g.
;; %MAP-TO-LIST-ARITY-1 and %FIND-POSITION-IF-NOT) and
"%SXHASH-SIMPLE-SUBSTRING" "%TAN" "%TAN-QUICK" "%TANH"
"%UNARY-ROUND" "%UNARY-TRUNCATE" "%UNARY-FTRUNCATE"
"%WITH-ARRAY-DATA" "%WITH-ARRAY-DATA-MACRO"
- "*ALREADY-MAYBE-GCING*" "*CURRENT-LEVEL-IN-PRINT*"
- "*EMPTY-TYPE*" "*GC-INHIBIT*" "*NEED-TO-COLLECT-GARBAGE*"
+ "*CURRENT-LEVEL-IN-PRINT*"
+ "*EMPTY-TYPE*" "*GC-INHIBIT*" "*GC-PENDING*"
+ #!+sb-thread"*STOP-FOR-GC-PENDING*"
"*CONTROL-STACK-EXHAUSTION-SAP*" "*UNIVERSAL-TYPE*"
"*UNIVERSAL-FUN-TYPE*" "*UNPARSE-FUN-TYPE-SIMPLIFY*"
"*WILD-TYPE*" "WORD-LOGICAL-AND" "WORD-LOGICAL-ANDC1"
;; *TYPE-SYSTEM-INITIALIZED-WHEN-BOUND* so that it doesn't need to
;; be explicitly set in order to be meaningful.
(setf *after-gc-hooks* nil
- *gc-inhibit* 1
- *need-to-collect-garbage* nil
+ *gc-inhibit* t
+ *gc-pending* nil
+ #!+sb-thread *stop-for-gc-pending* #!+sb-thread nil
sb!unix::*interrupts-enabled* t
sb!unix::*interrupt-pending* nil
*break-on-signals* nil
(format t
"Control and binding stack usage is for the current thread only.~%")
(format t "Garbage collection is currently ~:[enabled~;DISABLED~].~%"
- (> *gc-inhibit* 0)))
+ *gc-inhibit*))
(defun room-intermediate-info ()
(room-minimal-info)
"Called after each garbage collection. In a multithreaded
environment these hooks may run in any thread.")
-;;;; The following specials are used to control when garbage
-;;;; collection occurs.
-
-;;; When the dynamic usage increases beyond this amount, the system
-;;; notes that a garbage collection needs to occur by setting
-;;; *NEED-TO-COLLECT-GARBAGE* to T. It starts out as NIL meaning
-;;; nobody has figured out what it should be yet.
-;;;
-;;; FIXME: *GC-TRIGGER* seems to be denominated in bytes, not words.
-;;; And limiting it to INDEX is fairly reasonable in order to avoid
-;;; bignum arithmetic on every allocation, and to minimize the need
-;;; for thought about weird gotchas of the GC-control mechanism itself
-;;; consing as it operates. But as of sbcl-0.7.5, 512Mbytes of memory
-;;; costs $54.95 at Fry's in Dallas but cheap consumer 64-bit machines
-;;; are still over the horizon, so gratuitously limiting our heap size
-;;; to FIXNUM bytes seems fairly stupid. It'd be reasonable to
-;;; (1) allow arbitrary UNSIGNED-BYTE values of *GC-TRIGGER*, or
-;;; (2) redenominate this variable in words instead of bytes, postponing
-;;; the problem to heaps which exceed 50% of the machine's address
-;;; space, or even
-;;; (3) redemoninate this variable in CONS-sized two-word units,
-;;; allowing it to cover the entire memory space at the price of
-;;; possible loss of clarity.
-;;; (And whatever is done, it'd also be good to rename the variable so
-;;; that it's clear what unit it's denominated in.)
-(declaim (type (or index null) *gc-trigger*))
-(defvar *gc-trigger* nil)
-
-;;; When T, indicates that a GC should have happened but did not due to
-;;; *GC-INHIBIT*.
-(defvar *need-to-collect-garbage* nil) ; initialized in cold init
\f
;;;; internal GC
(defun sub-gc (&key (gen 0))
(unless (eq sb!thread:*current-thread*
(sb!thread::mutex-value *already-in-gc*))
- ;; With gencgc, unless *NEED-TO-COLLECT-GARBAGE* every allocation
- ;; in this function triggers another gc, potentially exceeding
- ;; maximum interrupt nesting.
- (setf *need-to-collect-garbage* t)
- (when (zerop *gc-inhibit*)
+ ;; With gencgc, unless *GC-PENDING* every allocation in this
+ ;; function triggers another gc, potentially exceeding maximum
+ ;; interrupt nesting.
+ (setq *gc-pending* t)
+ (unless *gc-inhibit*
(sb!thread:with-mutex (*already-in-gc*)
(let ((old-usage (dynamic-usage))
(new-usage 0))
(without-interrupts
(gc-stop-the-world)
(collect-garbage gen)
- (setf *need-to-collect-garbage* nil
+ (setf *gc-pending* nil
new-usage (dynamic-usage))
(gc-start-the-world))
;; Interrupts re-enabled, but still inside the mutex.
(sb!alien:unsigned 32))
val))
-;;; FIXME: Aren't these utterly wrong if called inside WITHOUT-GCING?
-;;; Unless something that works there too can be deviced this fact
-;;; should be documented.
+;;; These work both regardless of whether we're inside WITHOUT-GCING
+;;; or not.
(defun gc-on ()
#!+sb-doc
"Enable the garbage collector."
- (setq *gc-inhibit* 0)
- (when *need-to-collect-garbage*
- (sub-gc))
+ (setq *gc-inhibit* nil)
+ (when (and (not *gc-inhibit*)
+ (or #!+sb-thread *stop-for-gc-pending*
+ *gc-pending*))
+ (sb!unix::receive-pending-interrupt))
nil)
(defun gc-off ()
#!+sb-doc
"Disable the garbage collector."
- (setq *gc-inhibit* 1)
+ (setq *gc-inhibit* t)
nil)
sb!debug:*stack-top-hint*
*handler-clusters*
*restart-clusters*
- *gc-inhibit* *need-to-collect-garbage*
+ *gc-inhibit* *gc-pending*
+ #!+sb-thread *stop-for-gc-pending*
*software-interrupt-vector* *load-verbose*
*load-print-stuff* *in-compilation-unit*
*aborted-compilation-unit-count* *char-name-alist*
(declare (optimize (safety 0) (speed 3)))
(sb!vm::locked-symbol-global-value-add ',symbol-name ,delta)))
-;;; When >0, inhibits garbage collection.
-(declaim (type index *gc-inhibit*))
(defvar *gc-inhibit*) ; initialized in cold init
+;;; When the dynamic usage increases beyond this amount, the system
+;;; notes that a garbage collection needs to occur by setting
+;;; *GC-PENDING* to T. It starts out as NIL meaning nobody has figured
+;;; out what it should be yet.
+(defvar *gc-pending* nil)
+
+#!+sb-thread
+(defvar *stop-for-gc-pending* nil)
+
(defmacro without-gcing (&body body)
#!+sb-doc
- "Executes the forms in the body without doing a garbage collection."
+ "Executes the forms in the body without doing a garbage
+collection. It inhibits both automatically and explicitly triggered
+gcs. Finally, upon leaving the BODY if gc is not inhibited it runs the
+pending gc. Similarly, if gc is triggered in another thread then it
+waits until gc is enabled in this thread."
`(unwind-protect
- (progn
- (atomic-incf/symbol *gc-inhibit*)
+ (let ((*gc-inhibit* t))
,@body)
- (atomic-incf/symbol *gc-inhibit* -1)
- (when (and *need-to-collect-garbage* (zerop *gc-inhibit*))
- (sub-gc))))
+ ;; the test is racy, but it can err only on the overeager side
+ (when (and (not *gc-inhibit*)
+ (or #!+sb-thread *stop-for-gc-pending*
+ *gc-pending*))
+ (sb!unix::receive-pending-interrupt))))
\f
;;; EOF-OR-LOSE is a useful macro that handles EOF.
;;; listing the signals that were masked
(sb!alien:define-alien-routine "reset_signal_mask" sb!alien:void)
-(sb!alien:define-alien-routine "block_blockable_signals" sb!alien:void)
\f
;;;; C routines that actually do all the work of establishing signal handlers
(sb!alien:define-alien-routine ("install_handler" install-handler)
system-area-pointer
(lisp-fun-address unsigned-long))
+ (define-alien-routine "block_deferrable_signals_and_inhibit_gc"
+ void)
+
(define-alien-routine reap-dead-thread void
(thread-sap system-area-pointer))
(funcall real-function)
;; we're going down, can't handle
;; interrupts sanely anymore
- (sb!unix::block-blockable-signals)))))
- ;; and remove what can be the last reference to
- ;; the thread object
+ (block-deferrable-signals-and-inhibit-gc)))))
+ ;; and remove what can be the last reference to the
+ ;; thread object
(handle-thread-exit thread)
0))
(values))))))
;;; specials initialized by !COLD-INIT
;;; FIXME: These could be converted to DEFVARs.
-(declaim (special *gc-inhibit* *need-to-collect-garbage*
- *after-gc-hooks*
- #!+(or x86 x86-64) *pseudo-atomic-atomic*
+(declaim (special #!+(or x86 x86-64) *pseudo-atomic-atomic*
#!+(or x86 x86-64) *pseudo-atomic-interrupted*
sb!unix::*interrupts-enabled*
sb!unix::*interrupt-pending*
;; interrupt handling
*free-interrupt-context-index*
sb!unix::*interrupts-enabled*
- sb!unix::*interrupt-pending*))
+ sb!unix::*interrupt-pending*
+ *gc-inhibit*
+ *gc-pending*))
(defparameter *static-funs*
'(length
*free-interrupt-context-index*
sb!unix::*interrupts-enabled*
sb!unix::*interrupt-pending*
- ))
+ *gc-inhibit*
+ *gc-pending*))
(defparameter *static-funs*
'(length
*free-interrupt-context-index*
sb!unix::*interrupts-enabled*
sb!unix::*interrupt-pending*
- ))
+ *gc-inhibit*
+ *gc-pending*))
(defparameter *static-funs*
'(sb!kernel:two-arg-+
*free-interrupt-context-index*
sb!unix::*interrupts-enabled*
sb!unix::*interrupt-pending*
-
-
- ))
+ *gc-inhibit*
+ *gc-pending*))
(defparameter *static-funs*
'(length
*free-interrupt-context-index*
sb!unix::*interrupts-enabled*
sb!unix::*interrupt-pending*
- ))
+ *gc-inhibit*
+ *gc-pending*))
(defparameter *static-funs*
'(length
sb!unix::*interrupts-enabled*
sb!unix::*interrupt-pending*
*free-interrupt-context-index*
+ *gc-inhibit*
+ #!+sb-thread *stop-for-gc-pending*
+ *gc-pending*
*free-tls-index*
*control-stack-start*
*control-stack-end*
- *need-to-collect-garbage*
-
;; the floating point constants
*fp-constant-0d0*
*fp-constant-1d0*
sb!unix::*interrupts-enabled*
sb!unix::*interrupt-pending*
*free-interrupt-context-index*
+ *gc-inhibit*
+ #!+sb-thread *stop-for-gc-pending*
+ *gc-pending*
*free-tls-index*
*control-stack-start*
*control-stack-end*
- *need-to-collect-garbage*
-
;; the floating point constants
*fp-constant-0d0*
*fp-constant-1d0*
#include "genesis/bignum.h"
#include "genesis/sap.h"
-#define GET_FREE_POINTER() dynamic_space_free_pointer
-#define SET_FREE_POINTER(new_value) \
- (dynamic_space_free_pointer = (new_value))
-#define GET_GC_TRIGGER() current_auto_gc_trigger
-#define SET_GC_TRIGGER(new_value) \
- clear_auto_gc_trigger(); set_auto_gc_trigger(new_value);
-
#define ALIGNED_SIZE(n) (n+LOWTAG_MASK) & ~LOWTAG_MASK
#if defined LISP_FEATURE_GENCGC
}
#else
+
+#define GET_FREE_POINTER() dynamic_space_free_pointer
+#define SET_FREE_POINTER(new_value) \
+ (dynamic_space_free_pointer = (new_value))
+#define GET_GC_TRIGGER() current_auto_gc_trigger
+#define SET_GC_TRIGGER(new_value) \
+ clear_auto_gc_trigger(); set_auto_gc_trigger(new_value);
+
+/* FIXME: this is not pseudo atomic at all, but is called only from
+ * interrupt safe places like interrupt handlers. MG - 2005-08-09 */
static lispobj *
pa_alloc(int bytes)
{
char *
alloc(long nbytes)
{
- struct thread *th=arch_os_get_current_thread();
+ struct thread *thread=arch_os_get_current_thread();
struct alloc_region *region=
#ifdef LISP_FEATURE_SB_THREAD
- th ? &(th->alloc_region) : &boxed_region;
+ thread ? &(thread->alloc_region) : &boxed_region;
#else
&boxed_region;
#endif
* we should GC in the near future
*/
if (auto_gc_trigger && bytes_allocated > auto_gc_trigger) {
- struct thread *thread=arch_os_get_current_thread();
+ gc_assert(fixnum_value(SymbolValue(PSEUDO_ATOMIC_ATOMIC,thread)));
/* 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(NEED_TO_COLLECT_GARBAGE,thread) == NIL) {
+ if (SymbolValue(GC_PENDING,thread) == NIL) {
/* set things up so that GC happens when we finish the PA
- * section. We only do this if there wasn't a pending
- * handler already, in case it was a gc. If it wasn't a
- * GC, the next allocation will get us back to this point
- * anyway, so no harm done
- */
- struct interrupt_data *data=th->interrupt_data;
- sigset_t new_mask,old_mask;
- sigemptyset(&new_mask);
- sigaddset_blockable(&new_mask);
- thread_sigmask(SIG_BLOCK,&new_mask,&old_mask);
-
- if(!data->pending_handler) {
- if(!maybe_defer_handler(interrupt_maybe_gc_int,data,0,0,0))
- lose("Not in atomic: %d.\n",
- SymbolValue(PSEUDO_ATOMIC_ATOMIC,thread));
- /* Leave the signals blocked just as if it was
- * deferred the normal way and set the
- * pending_mask. */
- sigcopyset(&(data->pending_mask),&old_mask);
- SetSymbolValue(NEED_TO_COLLECT_GARBAGE,T,thread);
- } else {
- thread_sigmask(SIG_SETMASK,&old_mask,0);
- }
+ * section */
+ SetSymbolValue(GC_PENDING,T,thread);
+ if (SymbolValue(GC_INHIBIT,thread) == NIL)
+ arch_set_pseudo_atomic_interrupted(0);
}
}
new_obj = gc_alloc_with_region(nbytes,0,region,0);
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()
thread_sigmask(SIG_SETMASK,&new,0);
}
-void block_blockable_signals ()
+void block_deferrable_signals_and_inhibit_gc ()
+{
+ struct thread *thread=arch_os_get_current_thread();
+ sigset_t block;
+ sigemptyset(&block);
+ sigaddset_deferrable(&block);
+ thread_sigmask(SIG_BLOCK, &block, 0);
+ bind_variable(GC_INHIBIT,T,thread);
+}
+
+static void block_blockable_signals ()
{
sigset_t block;
sigemptyset(&block);
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
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);
* 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)) {
* 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));
}
}
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_RUNNING) {
- lose("sig_stop_for_gc_handler: wrong thread state on wakeup: %ld\n",
- fixnum_value(thread->state));
+ undo_fake_foreign_function_call(context);
}
-
- undo_fake_foreign_function_call(context);
}
#endif
struct interrupt_data *data=
th ? th->interrupt_data : global_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);
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;
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);
extern union interrupt_handler interrupt_handlers[NSIG];
+/* Set all deferrable signals into *s. */
+void sigaddset_deferrable(sigset_t *s);
/* Set all blockable signals into *s. */
void sigaddset_blockable(sigset_t *s);
thread_sigmask(SIG_BLOCK, &empty, ¤t);
if (sigismember(¤t,SIG_STOP_FOR_GC))
lose("SIG_STOP_FOR_GC cannot arrive: it is blocked\n");
- if (SymbolValue(INTERRUPTS_ENABLED,arch_os_get_current_thread()) == NIL)
- lose("SIG_STOP_FOR_GC cannot arrive: interrupts disabled\n");
+ if (SymbolValue(GC_INHIBIT,arch_os_get_current_thread()) != NIL)
+ lose("SIG_STOP_FOR_GC cannot arrive: gc is inhibited\n");
if (arch_pseudo_atomic_atomic(NULL))
lose("SIG_STOP_FOR_GC cannot arrive: in pseudo atomic\n");
}
{ \
sigset_t _newset,_oldset; \
sigemptyset(&_newset); \
- sigaddset_blockable(&_newset); \
- sigdelset(&_newset,SIG_STOP_FOR_GC); \
+ sigaddset_deferrable(&_newset); \
thread_sigmask(SIG_BLOCK, &_newset, &_oldset); \
check_sig_stop_for_gc_can_arrive_or_lose(); \
FSHOW_SIGNAL((stderr,"/%s:waiting on lock=%ld, thread=%lu\n",name, \
bind_variable(FREE_INTERRUPT_CONTEXT_INDEX,make_fixnum(0),th);
bind_variable(INTERRUPT_PENDING, NIL,th);
bind_variable(INTERRUPTS_ENABLED,T,th);
+ bind_variable(GC_PENDING,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)));
sigset_t newset,oldset;
boolean r=1;
sigemptyset(&newset);
- sigaddset_blockable(&newset);
+ sigaddset_deferrable(&newset);
thread_sigmask(SIG_BLOCK, &newset, &oldset);
if((pthread_attr_init(&attr)) ||
--- /dev/null
+;;;; gc tests
+
+;;;; This software is part of the SBCL system. See the README file for
+;;;; more information.
+;;;;
+;;;; While most of SBCL is derived from the CMU CL system, the test
+;;;; files (like this one) were written from scratch after the fork
+;;;; from CMU CL.
+;;;
+;;;; This software is in the public domain and is provided with
+;;;; absoluely no warranty. See the COPYING and CREDITS files for
+;;;; more information.
+
+(in-package :cl-user)
+
+(defparameter *x* ())
+
+(defun cons-madly ()
+ (loop repeat 10000 do
+ (setq *x* (make-string 100000))))
+
+;; check that WITHOUT-INTERRUPTS doesn't block the gc trigger
+(sb-sys:without-interrupts (cons-madly))
+
+;; check that WITHOUT-INTERRUPTS doesn't block SIG_STOP_FOR_GC
+#+sb-thread
+(sb-sys:without-interrupts
+ (let ((thread (sb-thread:make-thread (lambda () (sb-ext:gc)))))
+ (loop while (sb-thread:thread-alive-p thread))))
+
+(let ((gc-happend nil))
+ (push (lambda () (setq gc-happend t)) sb-ext:*after-gc-hooks*)
+
+ ;; check GC-{ON,OFF} works and gc is deferred
+ (gc-off)
+ (gc)
+ (assert (not gc-happend))
+ (gc-on)
+ (assert gc-happend)
+
+ ;; check that WITHOUT-GCING defers explicit gc
+ (setq gc-happend nil)
+ (sb-sys:without-gcing
+ (gc)
+ (assert (not gc-happend)))
+ (assert gc-happend)
+
+ ;; check that WITHOUT-GCING defers SIG_STOP_FOR_GC
+ #+sb-thread
+ (let ((in-without-gcing nil))
+ (setq gc-happend nil)
+ (sb-thread:make-thread (lambda ()
+ (loop while (not in-without-gcing))
+ (sb-ext:gc)))
+ (sb-sys:without-gcing
+ (setq in-without-gcing t)
+ (sleep 3)
+ (assert (not gc-happend)))
+ ;; give the hook time to run
+ (sleep 1)
+ (assert gc-happend))
+
+ ;; check GC-ON works even in a WITHOUT-GCING
+ (setq gc-happend nil)
+ (sb-sys:without-gcing
+ (gc)
+ (assert (not gc-happend))
+ (gc-on)
+ (assert gc-happend)
+ (setq gc-happend nil))
+ (assert (not gc-happend)))
+
+(sb-ext:quit :unix-status 104)
;;; checkins which aren't released. (And occasionally for internal
;;; versions, especially for internal versions off the main CVS
;;; branch, it gets hairier, e.g. "0.pre7.14.flaky4.13".)
-"0.9.3.40"
+"0.9.3.41"
projects / sbcl.git / commitdiff