OVMS3/OVMS.V3/components/duktape/src-input/duk_heap_refcount.c

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/*
* Reference counting implementation.
*
* INCREF/DECREF, finalization and freeing of objects whose refcount reaches
* zero (refzero). These operations are very performance sensitive, so
* various small tricks are used in an attempt to maximize speed.
*/
#include "duk_internal.h"
#if defined(DUK_USE_REFERENCE_COUNTING)
#if !defined(DUK_USE_DOUBLE_LINKED_HEAP)
#error internal error, reference counting requires a double linked heap
#endif
/*
* Heap object refcount finalization.
*
* When an object is about to be freed, all other objects it refers to must
* be decref'd. Refcount finalization does NOT free the object or its inner
* allocations (mark-and-sweep shares these helpers), it just manipulates
* the refcounts.
*
* Note that any of the DECREFs may cause a refcount to drop to zero. If so,
* the object won't be refzero processed inline, but will just be queued to
* refzero_list and processed by an earlier caller working on refzero_list,
* eliminating C recursion from even long refzero cascades. If refzero
* finalization is triggered by mark-and-sweep, refzero conditions are ignored
* (objects are not even queued to refzero_list) because mark-and-sweep deals
* with them; refcounts are still updated so that they remain in sync with
* actual references.
*/
DUK_LOCAL void duk__decref_tvals_norz(duk_hthread *thr, duk_tval *tv, duk_idx_t count) {
DUK_ASSERT(count == 0 || tv != NULL);
while (count-- > 0) {
DUK_TVAL_DECREF_NORZ(thr, tv);
tv++;
}
}
DUK_INTERNAL void duk_hobject_refcount_finalize_norz(duk_heap *heap, duk_hobject *h) {
duk_hthread *thr;
duk_uint_fast32_t i;
duk_uint_fast32_t n;
duk_propvalue *p_val;
duk_tval *p_tv;
duk_hstring **p_key;
duk_uint8_t *p_flag;
duk_hobject *h_proto;
DUK_ASSERT(heap != NULL);
DUK_ASSERT(heap->heap_thread != NULL);
DUK_ASSERT(h);
DUK_ASSERT(DUK_HEAPHDR_GET_TYPE((duk_heaphdr *) h) == DUK_HTYPE_OBJECT);
thr = heap->heap_thread;
DUK_ASSERT(thr != NULL);
p_key = DUK_HOBJECT_E_GET_KEY_BASE(heap, h);
p_val = DUK_HOBJECT_E_GET_VALUE_BASE(heap, h);
p_flag = DUK_HOBJECT_E_GET_FLAGS_BASE(heap, h);
n = DUK_HOBJECT_GET_ENEXT(h);
while (n-- > 0) {
duk_hstring *key;
key = p_key[n];
if (DUK_UNLIKELY(key == NULL)) {
continue;
}
DUK_HSTRING_DECREF_NORZ(thr, key);
if (DUK_UNLIKELY(p_flag[n] & DUK_PROPDESC_FLAG_ACCESSOR)) {
duk_hobject *h_getset;
h_getset = p_val[n].a.get;
DUK_ASSERT(h_getset == NULL || DUK_HEAPHDR_IS_OBJECT((duk_heaphdr *) h_getset));
DUK_HOBJECT_DECREF_NORZ_ALLOWNULL(thr, h_getset);
h_getset = p_val[n].a.set;
DUK_ASSERT(h_getset == NULL || DUK_HEAPHDR_IS_OBJECT((duk_heaphdr *) h_getset));
DUK_HOBJECT_DECREF_NORZ_ALLOWNULL(thr, h_getset);
} else {
duk_tval *tv_val;
tv_val = &p_val[n].v;
DUK_TVAL_DECREF_NORZ(thr, tv_val);
}
}
p_tv = DUK_HOBJECT_A_GET_BASE(heap, h);
n = DUK_HOBJECT_GET_ASIZE(h);
while (n-- > 0) {
duk_tval *tv_val;
tv_val = p_tv + n;
DUK_TVAL_DECREF_NORZ(thr, tv_val);
}
/* Hash part is a 'weak reference' and doesn't contribute to refcounts. */
h_proto = (duk_hobject *) DUK_HOBJECT_GET_PROTOTYPE(heap, h);
DUK_ASSERT(h_proto == NULL || DUK_HEAPHDR_IS_OBJECT((duk_heaphdr *) h_proto));
DUK_HOBJECT_DECREF_NORZ_ALLOWNULL(thr, h_proto);
/* XXX: Object subclass tests are quite awkward at present, ideally
* we should be able to switch-case here with a dense index (subtype
* number or something). For now, fast path plain objects and arrays
* and bit test the rest individually.
*/
if (DUK_HOBJECT_HAS_FASTREFS(h)) {
/* Plain object or array, nothing more to do. While a
* duk_harray has additional fields, none of them need
* DECREF updates.
*/
DUK_ASSERT(DUK_HOBJECT_ALLOWS_FASTREFS(h));
return;
}
DUK_ASSERT(DUK_HOBJECT_PROHIBITS_FASTREFS(h));
/* Slow path: special object, start bit checks from most likely. */
/* XXX: reorg, more common first */
if (DUK_HOBJECT_IS_COMPFUNC(h)) {
duk_hcompfunc *f = (duk_hcompfunc *) h;
duk_tval *tv, *tv_end;
duk_hobject **funcs, **funcs_end;
DUK_HCOMPFUNC_ASSERT_VALID(f);
if (DUK_LIKELY(DUK_HCOMPFUNC_GET_DATA(heap, f) != NULL)) {
tv = DUK_HCOMPFUNC_GET_CONSTS_BASE(heap, f);
tv_end = DUK_HCOMPFUNC_GET_CONSTS_END(heap, f);
while (tv < tv_end) {
DUK_TVAL_DECREF_NORZ(thr, tv);
tv++;
}
funcs = DUK_HCOMPFUNC_GET_FUNCS_BASE(heap, f);
funcs_end = DUK_HCOMPFUNC_GET_FUNCS_END(heap, f);
while (funcs < funcs_end) {
duk_hobject *h_func;
h_func = *funcs;
DUK_ASSERT(h_func != NULL);
DUK_ASSERT(DUK_HEAPHDR_IS_OBJECT((duk_heaphdr *) h_func));
DUK_HCOMPFUNC_DECREF_NORZ(thr, (duk_hcompfunc *) h_func);
funcs++;
}
} else {
/* May happen in some out-of-memory corner cases. */
DUK_D(DUK_DPRINT("duk_hcompfunc 'data' is NULL, skipping decref"));
}
DUK_HEAPHDR_DECREF_ALLOWNULL(thr, (duk_heaphdr *) DUK_HCOMPFUNC_GET_LEXENV(heap, f));
DUK_HEAPHDR_DECREF_ALLOWNULL(thr, (duk_heaphdr *) DUK_HCOMPFUNC_GET_VARENV(heap, f));
DUK_HEAPHDR_DECREF_ALLOWNULL(thr, (duk_hbuffer *) DUK_HCOMPFUNC_GET_DATA(heap, f));
} else if (DUK_HOBJECT_IS_DECENV(h)) {
duk_hdecenv *e = (duk_hdecenv *) h;
DUK_HDECENV_ASSERT_VALID(e);
DUK_HTHREAD_DECREF_NORZ_ALLOWNULL(thr, e->thread);
DUK_HOBJECT_DECREF_NORZ_ALLOWNULL(thr, e->varmap);
} else if (DUK_HOBJECT_IS_OBJENV(h)) {
duk_hobjenv *e = (duk_hobjenv *) h;
DUK_HOBJENV_ASSERT_VALID(e);
DUK_ASSERT(e->target != NULL); /* Required for object environments. */
DUK_HOBJECT_DECREF_NORZ(thr, e->target);
#if defined(DUK_USE_BUFFEROBJECT_SUPPORT)
} else if (DUK_HOBJECT_IS_BUFOBJ(h)) {
duk_hbufobj *b = (duk_hbufobj *) h;
DUK_HBUFOBJ_ASSERT_VALID(b);
DUK_HBUFFER_DECREF_NORZ_ALLOWNULL(thr, (duk_hbuffer *) b->buf);
DUK_HOBJECT_DECREF_NORZ_ALLOWNULL(thr, (duk_hobject *) b->buf_prop);
#endif /* DUK_USE_BUFFEROBJECT_SUPPORT */
} else if (DUK_HOBJECT_IS_BOUNDFUNC(h)) {
duk_hboundfunc *f = (duk_hboundfunc *) (void *) h;
DUK_HBOUNDFUNC_ASSERT_VALID(f);
DUK_TVAL_DECREF_NORZ(thr, &f->target);
DUK_TVAL_DECREF_NORZ(thr, &f->this_binding);
duk__decref_tvals_norz(thr, f->args, f->nargs);
#if defined(DUK_USE_ES6_PROXY)
} else if (DUK_HOBJECT_IS_PROXY(h)) {
duk_hproxy *p = (duk_hproxy *) h;
DUK_HPROXY_ASSERT_VALID(p);
DUK_HOBJECT_DECREF_NORZ(thr, p->target);
DUK_HOBJECT_DECREF_NORZ(thr, p->handler);
#endif /* DUK_USE_ES6_PROXY */
} else if (DUK_HOBJECT_IS_THREAD(h)) {
duk_hthread *t = (duk_hthread *) h;
duk_activation *act;
duk_tval *tv;
DUK_HTHREAD_ASSERT_VALID(t);
tv = t->valstack;
while (tv < t->valstack_top) {
DUK_TVAL_DECREF_NORZ(thr, tv);
tv++;
}
for (act = t->callstack_curr; act != NULL; act = act->parent) {
DUK_HOBJECT_DECREF_NORZ_ALLOWNULL(thr, (duk_hobject *) DUK_ACT_GET_FUNC(act));
DUK_HOBJECT_DECREF_NORZ_ALLOWNULL(thr, (duk_hobject *) act->var_env);
DUK_HOBJECT_DECREF_NORZ_ALLOWNULL(thr, (duk_hobject *) act->lex_env);
#if defined(DUK_USE_NONSTD_FUNC_CALLER_PROPERTY)
DUK_HOBJECT_DECREF_NORZ_ALLOWNULL(thr, (duk_hobject *) act->prev_caller);
#endif
#if 0 /* nothing now */
for (cat = act->cat; cat != NULL; cat = cat->parent) {
}
#endif
}
for (i = 0; i < DUK_NUM_BUILTINS; i++) {
DUK_HOBJECT_DECREF_NORZ_ALLOWNULL(thr, (duk_hobject *) t->builtins[i]);
}
DUK_HTHREAD_DECREF_NORZ_ALLOWNULL(thr, (duk_hthread *) t->resumer);
} else {
/* We may come here if the object should have a FASTREFS flag
* but it's missing for some reason. Assert for never getting
* here; however, other than performance, this is harmless.
*/
DUK_D(DUK_DPRINT("missing FASTREFS flag for: %!iO", h));
DUK_ASSERT(0);
}
}
DUK_INTERNAL void duk_heaphdr_refcount_finalize_norz(duk_heap *heap, duk_heaphdr *hdr) {
DUK_ASSERT(heap != NULL);
DUK_ASSERT(heap->heap_thread != NULL);
DUK_ASSERT(hdr != NULL);
if (DUK_HEAPHDR_IS_OBJECT(hdr)) {
duk_hobject_refcount_finalize_norz(heap, (duk_hobject *) hdr);
}
/* DUK_HTYPE_BUFFER: nothing to finalize */
/* DUK_HTYPE_STRING: nothing to finalize */
}
/*
* Refzero processing for duk_hobject: queue a refzero'ed object to either
* finalize_list or refzero_list and process the relevent list(s) if
* necessary.
*
* Refzero_list is single linked, with only 'prev' pointers set and valid.
* All 'next' pointers are intentionally left as garbage. This doesn't
* matter because refzero_list is processed to completion before any other
* code (like mark-and-sweep) might walk the list.
*
* In more detail:
*
* - On first insert refzero_list is NULL and the new object becomes the
* first and only element on the list; duk__refcount_free_pending() is
* called and it starts processing the list from the initial element,
* i.e. the list tail.
*
* - As each object is refcount finalized, new objects may be queued to
* refzero_list head. Their 'next' pointers are left as garbage, but
* 'prev' points are set correctly, with the element at refzero_list
* having a NULL 'prev' pointer. The fact that refzero_list is non-NULL
* is used to reject (1) recursive duk__refcount_free_pending() and
* (2) finalize_list processing calls.
*
* - When we're done with the current object, read its 'prev' pointer and
* free the object. If 'prev' is NULL, we've reached head of list and are
* done: set refzero_list to NULL and process pending finalizers. Otherwise
* continue processing the list.
*
* A refzero cascade is free of side effects because it only involves
* queueing more objects and freeing memory; finalizer execution is blocked
* in the code path queueing objects to finalize_list. As a result the
* initial refzero call (which triggers duk__refcount_free_pending()) must
* check finalize_list so that finalizers are executed snappily.
*
* If finalize_list processing starts first, refzero may occur while we're
* processing finalizers. That's fine: that particular refzero cascade is
* handled to completion without side effects. Once the cascade is complete,
* we'll run pending finalizers but notice that we're already doing that and
* return.
*
* This could be expanded to allow incremental freeing: just bail out
* early and resume at a future alloc/decref/refzero. However, if that
* were done, the list structure would need to be kept consistent at all
* times, mark-and-sweep would need to handle refzero_list, etc.
*/
DUK_LOCAL void duk__refcount_free_pending(duk_heap *heap) {
duk_heaphdr *curr;
#if defined(DUK_USE_DEBUG)
duk_int_t count = 0;
#endif
DUK_ASSERT(heap != NULL);
curr = heap->refzero_list;
DUK_ASSERT(curr != NULL);
DUK_ASSERT(DUK_HEAPHDR_GET_PREV(heap, curr) == NULL); /* We're called on initial insert only. */
/* curr->next is GARBAGE. */
do {
duk_heaphdr *prev;
DUK_DDD(DUK_DDDPRINT("refzero processing %p: %!O", (void *) curr, (duk_heaphdr *) curr));
#if defined(DUK_USE_DEBUG)
count++;
#endif
DUK_ASSERT(curr != NULL);
DUK_ASSERT(DUK_HEAPHDR_GET_TYPE(curr) == DUK_HTYPE_OBJECT); /* currently, always the case */
/* FINALIZED may be set; don't care about flags here. */
/* Refcount finalize 'curr'. Refzero_list must be non-NULL
* here to prevent recursive entry to duk__refcount_free_pending().
*/
DUK_ASSERT(heap->refzero_list != NULL);
duk_hobject_refcount_finalize_norz(heap, (duk_hobject *) curr);
prev = DUK_HEAPHDR_GET_PREV(heap, curr);
DUK_ASSERT((prev == NULL && heap->refzero_list == curr) || \
(prev != NULL && heap->refzero_list != curr));
/* prev->next is intentionally not updated and is garbage. */
duk_free_hobject(heap, (duk_hobject *) curr); /* Invalidates 'curr'. */
curr = prev;
} while (curr != NULL);
heap->refzero_list = NULL;
DUK_DD(DUK_DDPRINT("refzero processed %ld objects", (long) count));
}
DUK_LOCAL DUK_INLINE void duk__refcount_refzero_hobject(duk_heap *heap, duk_hobject *obj, duk_bool_t skip_free_pending) {
duk_heaphdr *hdr;
duk_heaphdr *root;
DUK_ASSERT(heap != NULL);
DUK_ASSERT(heap->heap_thread != NULL);
DUK_ASSERT(obj != NULL);
DUK_ASSERT(DUK_HEAPHDR_GET_TYPE((duk_heaphdr *) obj) == DUK_HTYPE_OBJECT);
hdr = (duk_heaphdr *) obj;
/* Refzero'd objects must be in heap_allocated. They can't be in
* finalize_list because all objects on finalize_list have an
* artificial +1 refcount bump.
*/
#if defined(DUK_USE_ASSERTIONS)
DUK_ASSERT(duk_heap_in_heap_allocated(heap, (duk_heaphdr *) obj));
#endif
DUK_HEAP_REMOVE_FROM_HEAP_ALLOCATED(heap, hdr);
#if defined(DUK_USE_FINALIZER_SUPPORT)
/* This finalizer check MUST BE side effect free. It should also be
* as fast as possible because it's applied to every object freed.
*/
if (DUK_UNLIKELY(DUK_HOBJECT_HAS_FINALIZER_FAST(heap, (duk_hobject *) hdr) != 0U)) {
/* Special case: FINALIZED may be set if mark-and-sweep queued
* object for finalization, the finalizer was executed (and
* FINALIZED set), mark-and-sweep hasn't yet processed the
* object again, but its refcount drops to zero. Free without
* running the finalizer again.
*/
if (DUK_HEAPHDR_HAS_FINALIZED(hdr)) {
DUK_D(DUK_DPRINT("refzero'd object has finalizer and FINALIZED is set -> free"));
} else {
/* Set FINALIZABLE flag so that all objects on finalize_list
* will have it set and are thus detectable based on the
* flag alone.
*/
DUK_HEAPHDR_SET_FINALIZABLE(hdr);
DUK_ASSERT(!DUK_HEAPHDR_HAS_FINALIZED(hdr));
#if defined(DUK_USE_REFERENCE_COUNTING)
/* Bump refcount on finalize_list insert so that a
* refzero can never occur when an object is waiting
* for its finalizer call. Refzero might otherwise
* now happen because we allow duk_push_heapptr() for
* objects pending finalization.
*/
DUK_HEAPHDR_PREINC_REFCOUNT(hdr);
#endif
DUK_HEAP_INSERT_INTO_FINALIZE_LIST(heap, hdr);
/* Process finalizers unless skipping is explicitly
* requested (NORZ) or refzero_list is being processed
* (avoids side effects during a refzero cascade).
* If refzero_list is processed, the initial refzero
* call will run pending finalizers when refzero_list
* is done.
*/
if (!skip_free_pending && heap->refzero_list == NULL) {
duk_heap_process_finalize_list(heap);
}
return;
}
}
#endif /* DUK_USE_FINALIZER_SUPPORT */
/* No need to finalize, free object via refzero_list. */
root = heap->refzero_list;
DUK_HEAPHDR_SET_PREV(heap, hdr, NULL);
/* 'next' is left as GARBAGE. */
heap->refzero_list = hdr;
if (root == NULL) {
/* Object is now queued. Refzero_list was NULL so
* no-one is currently processing it; do it here.
* With refzero processing just doing a cascade of
* free calls, we can process it directly even when
* NORZ macros are used: there are no side effects.
*/
duk__refcount_free_pending(heap);
DUK_ASSERT(heap->refzero_list == NULL);
/* Process finalizers only after the entire cascade
* is finished. In most cases there's nothing to
* finalize, so fast path check to avoid a call.
*/
#if defined(DUK_USE_FINALIZER_SUPPORT)
if (!skip_free_pending && DUK_UNLIKELY(heap->finalize_list != NULL)) {
duk_heap_process_finalize_list(heap);
}
#endif
} else {
DUK_ASSERT(DUK_HEAPHDR_GET_PREV(heap, root) == NULL);
DUK_HEAPHDR_SET_PREV(heap, root, hdr);
/* Object is now queued. Because refzero_list was
* non-NULL, it's already being processed by someone
* in the C call stack, so we're done.
*/
}
}
#if defined(DUK_USE_FINALIZER_SUPPORT)
DUK_INTERNAL DUK_ALWAYS_INLINE void duk_refzero_check_fast(duk_hthread *thr) {
DUK_ASSERT(thr != NULL);
DUK_ASSERT(thr->heap != NULL);
DUK_ASSERT(thr->heap->refzero_list == NULL); /* Processed to completion inline. */
if (DUK_UNLIKELY(thr->heap->finalize_list != NULL)) {
duk_heap_process_finalize_list(thr->heap);
}
}
DUK_INTERNAL void duk_refzero_check_slow(duk_hthread *thr) {
DUK_ASSERT(thr != NULL);
DUK_ASSERT(thr->heap != NULL);
DUK_ASSERT(thr->heap->refzero_list == NULL); /* Processed to completion inline. */
if (DUK_UNLIKELY(thr->heap->finalize_list != NULL)) {
duk_heap_process_finalize_list(thr->heap);
}
}
#endif /* DUK_USE_FINALIZER_SUPPORT */
/*
* Refzero processing for duk_hstring.
*/
DUK_LOCAL DUK_INLINE void duk__refcount_refzero_hstring(duk_heap *heap, duk_hstring *str) {
DUK_ASSERT(heap != NULL);
DUK_ASSERT(heap->heap_thread != NULL);
DUK_ASSERT(str != NULL);
DUK_ASSERT(DUK_HEAPHDR_GET_TYPE((duk_heaphdr *) str) == DUK_HTYPE_STRING);
duk_heap_strcache_string_remove(heap, str);
duk_heap_strtable_unlink(heap, str);
duk_free_hstring(heap, str);
}
/*
* Refzero processing for duk_hbuffer.
*/
DUK_LOCAL DUK_INLINE void duk__refcount_refzero_hbuffer(duk_heap *heap, duk_hbuffer *buf) {
DUK_ASSERT(heap != NULL);
DUK_ASSERT(heap->heap_thread != NULL);
DUK_ASSERT(buf != NULL);
DUK_ASSERT(DUK_HEAPHDR_GET_TYPE((duk_heaphdr *) buf) == DUK_HTYPE_BUFFER);
DUK_HEAP_REMOVE_FROM_HEAP_ALLOCATED(heap, (duk_heaphdr *) buf);
duk_free_hbuffer(heap, buf);
}
/*
* Incref and decref functions.
*
* Decref may trigger immediate refzero handling, which may free and finalize
* an arbitrary number of objects (a "DECREF cascade").
*
* Refzero handling is skipped entirely if (1) mark-and-sweep is running or
* (2) execution is paused in the debugger. The objects are left in the heap,
* and will be freed by mark-and-sweep or eventual heap destruction.
*
* This is necessary during mark-and-sweep because refcounts are also updated
* during the sweep phase (otherwise objects referenced by a swept object
* would have incorrect refcounts) which then calls here. This could be
* avoided by using separate decref macros in mark-and-sweep; however,
* mark-and-sweep also calls finalizers which would use the ordinary decref
* macros anyway.
*
* We can't process refzeros (= free objects) when the debugger is running
* as the debugger might make an object unreachable but still continue
* inspecting it (or even cause it to be pushed back). So we must rely on
* mark-and-sweep to collect them.
*
* The DUK__RZ_SUPPRESS_CHECK() condition is also used in heap destruction
* when running finalizers for remaining objects: the flag prevents objects
* from being moved around in heap linked lists while that's being done.
*
* The suppress condition is important to performance.
*/
#define DUK__RZ_SUPPRESS_ASSERT1() do { \
DUK_ASSERT(thr != NULL); \
DUK_ASSERT(thr->heap != NULL); \
/* When mark-and-sweep runs, heap_thread must exist. */ \
DUK_ASSERT(thr->heap->ms_running == 0 || thr->heap->heap_thread != NULL); \
/* In normal operation finalizers are executed with ms_running == 0 \
* so we should never see ms_running == 1 and thr != heap_thread. \
* In heap destruction finalizers are executed with ms_running != 0 \
* to e.g. prevent refzero; a special value ms_running == 2 is used \
* in that case so it can be distinguished from the normal runtime \
* case, and allows a stronger assertion here (GH-2030). \
*/ \
DUK_ASSERT(!(thr->heap->ms_running == 1 && thr != thr->heap->heap_thread)); \
/* We may be called when the heap is initializing and we process \
* refzeros normally, but mark-and-sweep and finalizers are prevented \
* if that's the case. \
*/ \
DUK_ASSERT(thr->heap->heap_initializing == 0 || thr->heap->ms_prevent_count > 0); \
DUK_ASSERT(thr->heap->heap_initializing == 0 || thr->heap->pf_prevent_count > 0); \
} while (0)
#if defined(DUK_USE_DEBUGGER_SUPPORT)
#define DUK__RZ_SUPPRESS_ASSERT2() do { \
/* When debugger is paused, ms_running is set. */ \
DUK_ASSERT(!DUK_HEAP_HAS_DEBUGGER_PAUSED(thr->heap) || thr->heap->ms_running != 0); \
} while (0)
#define DUK__RZ_SUPPRESS_COND() (heap->ms_running != 0)
#else
#define DUK__RZ_SUPPRESS_ASSERT2() do { } while (0)
#define DUK__RZ_SUPPRESS_COND() (heap->ms_running != 0)
#endif /* DUK_USE_DEBUGGER_SUPPORT */
#define DUK__RZ_SUPPRESS_CHECK() do { \
DUK__RZ_SUPPRESS_ASSERT1(); \
DUK__RZ_SUPPRESS_ASSERT2(); \
if (DUK_UNLIKELY(DUK__RZ_SUPPRESS_COND())) { \
DUK_DDD(DUK_DDDPRINT("refzero handling suppressed (not even queued) when mark-and-sweep running, object: %p", (void *) h)); \
return; \
} \
} while (0)
#define DUK__RZ_STRING() do { \
duk__refcount_refzero_hstring(heap, (duk_hstring *) h); \
} while (0)
#define DUK__RZ_BUFFER() do { \
duk__refcount_refzero_hbuffer(heap, (duk_hbuffer *) h); \
} while (0)
#define DUK__RZ_OBJECT() do { \
duk__refcount_refzero_hobject(heap, (duk_hobject *) h, skip_free_pending); \
} while (0)
/* XXX: test the effect of inlining here vs. NOINLINE in refzero helpers */
#if defined(DUK_USE_FAST_REFCOUNT_DEFAULT)
#define DUK__RZ_INLINE DUK_ALWAYS_INLINE
#else
#define DUK__RZ_INLINE /*nop*/
#endif
DUK_LOCAL DUK__RZ_INLINE void duk__hstring_refzero_helper(duk_hthread *thr, duk_hstring *h) {
duk_heap *heap;
DUK_ASSERT(thr != NULL);
DUK_ASSERT(h != NULL);
heap = thr->heap;
DUK__RZ_SUPPRESS_CHECK();
DUK__RZ_STRING();
}
DUK_LOCAL DUK__RZ_INLINE void duk__hbuffer_refzero_helper(duk_hthread *thr, duk_hbuffer *h) {
duk_heap *heap;
DUK_ASSERT(thr != NULL);
DUK_ASSERT(h != NULL);
heap = thr->heap;
DUK__RZ_SUPPRESS_CHECK();
DUK__RZ_BUFFER();
}
DUK_LOCAL DUK__RZ_INLINE void duk__hobject_refzero_helper(duk_hthread *thr, duk_hobject *h, duk_bool_t skip_free_pending) {
duk_heap *heap;
DUK_ASSERT(thr != NULL);
DUK_ASSERT(h != NULL);
heap = thr->heap;
DUK__RZ_SUPPRESS_CHECK();
DUK__RZ_OBJECT();
}
DUK_LOCAL DUK__RZ_INLINE void duk__heaphdr_refzero_helper(duk_hthread *thr, duk_heaphdr *h, duk_bool_t skip_free_pending) {
duk_heap *heap;
duk_small_uint_t htype;
DUK_ASSERT(thr != NULL);
DUK_ASSERT(h != NULL);
heap = thr->heap;
htype = (duk_small_uint_t) DUK_HEAPHDR_GET_TYPE(h);
DUK_DDD(DUK_DDDPRINT("ms_running=%ld, heap_thread=%p", (long) thr->heap->ms_running, thr->heap->heap_thread));
DUK__RZ_SUPPRESS_CHECK();
switch (htype) {
case DUK_HTYPE_STRING:
/* Strings have no internal references but do have "weak"
* references in the string cache. Also note that strings
* are not on the heap_allocated list like other heap
* elements.
*/
DUK__RZ_STRING();
break;
case DUK_HTYPE_OBJECT:
/* Objects have internal references. Must finalize through
* the "refzero" work list.
*/
DUK__RZ_OBJECT();
break;
default:
/* Buffers have no internal references. However, a dynamic
* buffer has a separate allocation for the buffer. This is
* freed by duk_heap_free_heaphdr_raw().
*/
DUK_ASSERT(DUK_HEAPHDR_GET_TYPE(h) == DUK_HTYPE_BUFFER);
DUK__RZ_BUFFER();
break;
}
}
DUK_INTERNAL DUK_NOINLINE void duk_heaphdr_refzero(duk_hthread *thr, duk_heaphdr *h) {
duk__heaphdr_refzero_helper(thr, h, 0 /*skip_free_pending*/);
}
DUK_INTERNAL DUK_NOINLINE void duk_heaphdr_refzero_norz(duk_hthread *thr, duk_heaphdr *h) {
duk__heaphdr_refzero_helper(thr, h, 1 /*skip_free_pending*/);
}
DUK_INTERNAL DUK_NOINLINE void duk_hstring_refzero(duk_hthread *thr, duk_hstring *h) {
duk__hstring_refzero_helper(thr, h);
}
DUK_INTERNAL DUK_NOINLINE void duk_hbuffer_refzero(duk_hthread *thr, duk_hbuffer *h) {
duk__hbuffer_refzero_helper(thr, h);
}
DUK_INTERNAL DUK_NOINLINE void duk_hobject_refzero(duk_hthread *thr, duk_hobject *h) {
duk__hobject_refzero_helper(thr, h, 0 /*skip_free_pending*/);
}
DUK_INTERNAL DUK_NOINLINE void duk_hobject_refzero_norz(duk_hthread *thr, duk_hobject *h) {
duk__hobject_refzero_helper(thr, h, 1 /*skip_free_pending*/);
}
#if !defined(DUK_USE_FAST_REFCOUNT_DEFAULT)
DUK_INTERNAL void duk_tval_incref(duk_tval *tv) {
DUK_ASSERT(tv != NULL);
if (DUK_TVAL_NEEDS_REFCOUNT_UPDATE(tv)) {
duk_heaphdr *h = DUK_TVAL_GET_HEAPHDR(tv);
DUK_ASSERT(h != NULL);
DUK_ASSERT(DUK_HEAPHDR_HTYPE_VALID(h));
DUK_ASSERT_DISABLE(h->h_refcount >= 0);
DUK_HEAPHDR_PREINC_REFCOUNT(h);
DUK_ASSERT(DUK_HEAPHDR_GET_REFCOUNT(h) != 0); /* No wrapping. */
}
}
DUK_INTERNAL void duk_tval_decref(duk_hthread *thr, duk_tval *tv) {
DUK_ASSERT(thr != NULL);
DUK_ASSERT(tv != NULL);
if (DUK_TVAL_NEEDS_REFCOUNT_UPDATE(tv)) {
duk_heaphdr *h = DUK_TVAL_GET_HEAPHDR(tv);
DUK_ASSERT(h != NULL);
DUK_ASSERT(DUK_HEAPHDR_HTYPE_VALID(h));
DUK_ASSERT(DUK_HEAPHDR_GET_REFCOUNT(h) >= 1);
#if 0
if (DUK_HEAPHDR_PREDEC_REFCOUNT(h) != 0) {
return;
}
duk_heaphdr_refzero(thr, h);
#else
duk_heaphdr_decref(thr, h);
#endif
}
}
DUK_INTERNAL void duk_tval_decref_norz(duk_hthread *thr, duk_tval *tv) {
DUK_ASSERT(thr != NULL);
DUK_ASSERT(tv != NULL);
if (DUK_TVAL_NEEDS_REFCOUNT_UPDATE(tv)) {
duk_heaphdr *h = DUK_TVAL_GET_HEAPHDR(tv);
DUK_ASSERT(h != NULL);
DUK_ASSERT(DUK_HEAPHDR_HTYPE_VALID(h));
DUK_ASSERT(DUK_HEAPHDR_GET_REFCOUNT(h) >= 1);
#if 0
if (DUK_HEAPHDR_PREDEC_REFCOUNT(h) != 0) {
return;
}
duk_heaphdr_refzero_norz(thr, h);
#else
duk_heaphdr_decref_norz(thr, h);
#endif
}
}
#endif /* !DUK_USE_FAST_REFCOUNT_DEFAULT */
#define DUK__DECREF_ASSERTS() do { \
DUK_ASSERT(thr != NULL); \
DUK_ASSERT(thr->heap != NULL); \
DUK_ASSERT(h != NULL); \
DUK_ASSERT(DUK_HEAPHDR_HTYPE_VALID((duk_heaphdr *) h)); \
DUK_ASSERT(DUK_HEAPHDR_GET_REFCOUNT((duk_heaphdr *) h) >= 1); \
} while (0)
#if defined(DUK_USE_ROM_OBJECTS)
#define DUK__INCREF_SHARED() do { \
if (DUK_HEAPHDR_HAS_READONLY((duk_heaphdr *) h)) { \
return; \
} \
DUK_HEAPHDR_PREINC_REFCOUNT((duk_heaphdr *) h); \
DUK_ASSERT(DUK_HEAPHDR_GET_REFCOUNT((duk_heaphdr *) h) != 0); /* No wrapping. */ \
} while (0)
#define DUK__DECREF_SHARED() do { \
if (DUK_HEAPHDR_HAS_READONLY((duk_heaphdr *) h)) { \
return; \
} \
if (DUK_HEAPHDR_PREDEC_REFCOUNT((duk_heaphdr *) h) != 0) { \
return; \
} \
} while (0)
#else
#define DUK__INCREF_SHARED() do { \
DUK_HEAPHDR_PREINC_REFCOUNT((duk_heaphdr *) h); \
DUK_ASSERT(DUK_HEAPHDR_GET_REFCOUNT((duk_heaphdr *) h) != 0); /* No wrapping. */ \
} while (0)
#define DUK__DECREF_SHARED() do { \
if (DUK_HEAPHDR_PREDEC_REFCOUNT((duk_heaphdr *) h) != 0) { \
return; \
} \
} while (0)
#endif
#if !defined(DUK_USE_FAST_REFCOUNT_DEFAULT)
/* This will in practice be inlined because it's just an INC instructions
* and a bit test + INC when ROM objects are enabled.
*/
DUK_INTERNAL void duk_heaphdr_incref(duk_heaphdr *h) {
DUK_ASSERT(h != NULL);
DUK_ASSERT(DUK_HEAPHDR_HTYPE_VALID(h));
DUK_ASSERT_DISABLE(DUK_HEAPHDR_GET_REFCOUNT(h) >= 0);
DUK__INCREF_SHARED();
}
DUK_INTERNAL void duk_heaphdr_decref(duk_hthread *thr, duk_heaphdr *h) {
DUK__DECREF_ASSERTS();
DUK__DECREF_SHARED();
duk_heaphdr_refzero(thr, h);
/* Forced mark-and-sweep when GC torture enabled; this could happen
* on any DECREF (but not DECREF_NORZ).
*/
DUK_GC_TORTURE(thr->heap);
}
DUK_INTERNAL void duk_heaphdr_decref_norz(duk_hthread *thr, duk_heaphdr *h) {
DUK__DECREF_ASSERTS();
DUK__DECREF_SHARED();
duk_heaphdr_refzero_norz(thr, h);
}
#endif /* !DUK_USE_FAST_REFCOUNT_DEFAULT */
#if 0 /* Not needed. */
DUK_INTERNAL void duk_hstring_decref(duk_hthread *thr, duk_hstring *h) {
DUK__DECREF_ASSERTS();
DUK__DECREF_SHARED();
duk_hstring_refzero(thr, h);
}
DUK_INTERNAL void duk_hstring_decref_norz(duk_hthread *thr, duk_hstring *h) {
DUK__DECREF_ASSERTS();
DUK__DECREF_SHARED();
duk_hstring_refzero_norz(thr, h);
}
DUK_INTERNAL void duk_hbuffer_decref(duk_hthread *thr, duk_hbuffer *h) {
DUK__DECREF_ASSERTS();
DUK__DECREF_SHARED();
duk_hbuffer_refzero(thr, h);
}
DUK_INTERNAL void duk_hbuffer_decref_norz(duk_hthread *thr, duk_hbuffer *h) {
DUK__DECREF_ASSERTS();
DUK__DECREF_SHARED();
duk_hbuffer_refzero_norz(thr, h);
}
DUK_INTERNAL void duk_hobject_decref(duk_hthread *thr, duk_hobject *h) {
DUK__DECREF_ASSERTS();
DUK__DECREF_SHARED();
duk_hobject_refzero(thr, h);
}
DUK_INTERNAL void duk_hobject_decref_norz(duk_hthread *thr, duk_hobject *h) {
DUK__DECREF_ASSERTS();
DUK__DECREF_SHARED();
duk_hobject_refzero_norz(thr, h);
}
#endif
#else /* DUK_USE_REFERENCE_COUNTING */
/* no refcounting */
#endif /* DUK_USE_REFERENCE_COUNTING */