/* maybe_gc collects garbage if this goes negative. */
-intmax_t consing_until_gc;
+EMACS_INT consing_until_gc;
#ifdef HAVE_PDUMPER
/* Number of finalizers run: used to loop over GC until we stop
/* System byte and object counts reported by GC. */
+/* Assume byte counts fit in uintptr_t and object counts fit into
+ intptr_t. */
typedef uintptr_t byte_ct;
typedef intptr_t object_ct;
+/* Large-magnitude value for a threshold count, which fits in EMACS_INT.
+ Using only half the EMACS_INT range avoids overflow hassles.
+ There is no need to fit these counts into fixnums. */
+#define HI_THRESHOLD (EMACS_INT_MAX / 2)
+
/* Number of live and free conses etc. counted by the most-recent GC. */
static struct gcstat
/* The GC threshold in bytes, the last time it was calculated
from gc-cons-threshold and gc-cons-percentage. */
-static intmax_t gc_threshold;
+static EMACS_INT gc_threshold;
/* If nonzero, this is a warning delivered by malloc and not yet
displayed. */
XFLOAT (f)->u.data = n;
}
+/* Account for allocation of NBYTES in the heap. This is a separate
+ function to avoid hassles with implementation-defined conversion
+ from unsigned to signed types. */
+static void
+tally_consing (ptrdiff_t nbytes)
+{
+ consing_until_gc -= nbytes;
+}
+
#ifdef DOUG_LEA_MALLOC
static bool
pointers_fit_in_lispobj_p (void)
MALLOC_UNBLOCK_INPUT;
- consing_until_gc -= sizeof (struct interval);
+ tally_consing (sizeof (struct interval));
intervals_consed++;
RESET_INTERVAL (val);
val->gcmarkbit = 0;
MALLOC_UNBLOCK_INPUT;
++strings_consed;
- consing_until_gc -= sizeof *s;
+ tally_consing (sizeof *s);
#ifdef GC_CHECK_STRING_BYTES
if (!noninteractive)
old_data->string = NULL;
}
- consing_until_gc -= needed;
+ tally_consing (needed);
}
XFLOAT_INIT (val, float_value);
eassert (!XFLOAT_MARKED_P (XFLOAT (val)));
- consing_until_gc -= sizeof (struct Lisp_Float);
+ tally_consing (sizeof (struct Lisp_Float));
floats_consed++;
return val;
}
ptr->u.s.u.chain = cons_free_list;
ptr->u.s.car = dead_object ();
cons_free_list = ptr;
- if (INT_ADD_WRAPV (consing_until_gc, sizeof *ptr, &consing_until_gc))
- consing_until_gc = INTMAX_MAX;
+ ptrdiff_t nbytes = sizeof *ptr;
+ tally_consing (-nbytes);
}
DEFUN ("cons", Fcons, Scons, 2, 2, 0,
if (find_suspicious_object_in_range (p, (char *) p + nbytes))
emacs_abort ();
- consing_until_gc -= nbytes;
+ tally_consing (nbytes);
vector_cells_consed += len;
MALLOC_UNBLOCK_INPUT;
MALLOC_UNBLOCK_INPUT;
init_symbol (val, name);
- consing_until_gc -= sizeof (struct Lisp_Symbol);
+ tally_consing (sizeof (struct Lisp_Symbol));
symbols_consed++;
return val;
}
static void
allow_garbage_collection (intmax_t consing)
{
- consing_until_gc = consing - (INTMAX_MAX - consing_until_gc);
+ consing_until_gc = consing - (HI_THRESHOLD - consing_until_gc);
garbage_collection_inhibited--;
}
ptrdiff_t count = SPECPDL_INDEX ();
record_unwind_protect_intmax (allow_garbage_collection, consing_until_gc);
garbage_collection_inhibited++;
- consing_until_gc = INTMAX_MAX;
+ consing_until_gc = HI_THRESHOLD;
return count;
}
}
}
-/* Return the number of bytes to cons between GCs, assuming
- gc-cons-threshold is THRESHOLD and gc-cons-percentage is
- PERCENTAGE. */
-static intmax_t
-consing_threshold (intmax_t threshold, Lisp_Object percentage)
+/* Return the number of bytes to cons between GCs, given THRESHOLD and
+ PERCENTAGE. When calculating a threshold based on PERCENTAGE,
+ assume SINCE_GC bytes have been allocated since the most recent GC.
+ The returned value is positive and no greater than HI_THRESHOLD. */
+static EMACS_INT
+consing_threshold (intmax_t threshold, Lisp_Object percentage,
+ intmax_t since_gc)
{
if (!NILP (Vmemory_full))
return memory_full_cons_threshold;
if (FLOATP (percentage))
{
double tot = (XFLOAT_DATA (percentage)
- * total_bytes_of_live_objects ());
+ * (total_bytes_of_live_objects () + since_gc));
if (threshold < tot)
{
- if (tot < INTMAX_MAX)
- threshold = tot;
+ if (tot < HI_THRESHOLD)
+ return tot;
else
- threshold = INTMAX_MAX;
+ return HI_THRESHOLD;
}
}
- return threshold;
+ return min (threshold, HI_THRESHOLD);
}
}
-/* Adjust consing_until_gc, assuming gc-cons-threshold is THRESHOLD and
- gc-cons-percentage is PERCENTAGE. */
-static Lisp_Object
+/* Adjust consing_until_gc and gc_threshold, given THRESHOLD and PERCENTAGE.
+ Return the updated consing_until_gc. */
+
+static EMACS_INT
bump_consing_until_gc (intmax_t threshold, Lisp_Object percentage)
{
- /* If consing_until_gc is negative leave it alone, since this prevents
- negative integer overflow and a GC would have been done soon anyway. */
- if (0 <= consing_until_gc)
- {
- threshold = consing_threshold (threshold, percentage);
- intmax_t sum;
- if (INT_ADD_WRAPV (consing_until_gc, threshold - gc_threshold, &sum))
- {
- /* Scale the threshold down so that consing_until_gc does
- not overflow. */
- sum = INTMAX_MAX;
- threshold = INTMAX_MAX - consing_until_gc + gc_threshold;
- }
- consing_until_gc = sum;
- gc_threshold = threshold;
- }
-
- return Qnil;
+ /* Guesstimate that half the bytes allocated since the most
+ recent GC are still in use. */
+ EMACS_INT since_gc = (gc_threshold - consing_until_gc) >> 1;
+ EMACS_INT new_gc_threshold = consing_threshold (threshold, percentage,
+ since_gc);
+ consing_until_gc += new_gc_threshold - gc_threshold;
+ gc_threshold = new_gc_threshold;
+ return consing_until_gc;
}
/* Watch changes to gc-cons-threshold. */
intmax_t threshold;
if (! (INTEGERP (newval) && integer_to_intmax (newval, &threshold)))
return Qnil;
- return bump_consing_until_gc (threshold, Vgc_cons_percentage);
+ bump_consing_until_gc (threshold, Vgc_cons_percentage);
+ return Qnil;
}
/* Watch changes to gc-cons-percentage. */
watch_gc_cons_percentage (Lisp_Object symbol, Lisp_Object newval,
Lisp_Object operation, Lisp_Object where)
{
- return bump_consing_until_gc (gc_cons_threshold, newval);
+ bump_consing_until_gc (gc_cons_threshold, newval);
+ return Qnil;
+}
+
+/* It may be time to collect garbage. Recalculate consing_until_gc,
+ since it might depend on current usage, and do the garbage
+ collection if the recalculation says so. */
+void
+maybe_garbage_collect (void)
+{
+ if (bump_consing_until_gc (gc_cons_threshold, Vgc_cons_percentage) < 0)
+ garbage_collect ();
}
/* Subroutine of Fgarbage_collect that does most of the work. */
bool message_p;
ptrdiff_t count = SPECPDL_INDEX ();
struct timespec start;
- byte_ct tot_before = 0;
eassert (weak_hash_tables == NULL);
FOR_EACH_BUFFER (nextb)
compact_buffer (nextb);
- if (profiler_memory_running)
- tot_before = total_bytes_of_live_objects ();
+ byte_ct tot_before = (profiler_memory_running
+ ? total_bytes_of_live_objects ()
+ : (byte_ct) -1);
start = current_timespec ();
/* In case user calls debug_print during GC,
don't let that cause a recursive GC. */
- consing_until_gc = INTMAX_MAX;
+ consing_until_gc = HI_THRESHOLD;
/* Save what's currently displayed in the echo area. Don't do that
if we are GC'ing because we've run out of memory, since
unblock_input ();
consing_until_gc = gc_threshold
- = consing_threshold (gc_cons_threshold, Vgc_cons_percentage);
+ = consing_threshold (gc_cons_threshold, Vgc_cons_percentage, 0);
if (garbage_collection_messages && NILP (Vmemory_full))
{
gcs_done++;
/* Collect profiling data. */
- if (profiler_memory_running)
+ if (tot_before != (byte_ct) -1)
{
byte_ct tot_after = total_bytes_of_live_objects ();
- byte_ct swept = tot_before <= tot_after ? 0 : tot_before - tot_after;
- malloc_probe (min (swept, SIZE_MAX));
+ if (tot_after < tot_before)
+ malloc_probe (min (tot_before - tot_after, SIZE_MAX));
}
}
projects / emacs.git / commitdiff