1969 lines
64 KiB
C
1969 lines
64 KiB
C
/* -*- Mode: C; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
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*
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* ***** BEGIN LICENSE BLOCK *****
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* Version: MPL 1.1/GPL 2.0/LGPL 2.1
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*
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* The contents of this file are subject to the Mozilla Public License Version
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* 1.1 (the "License"); you may not use this file except in compliance with
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* the License. You may obtain a copy of the License at
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* http://www.mozilla.org/MPL/
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*
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* Software distributed under the License is distributed on an "AS IS" basis,
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* WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
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* for the specific language governing rights and limitations under the
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* License.
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*
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* The Original Code is Mozilla Communicator client code, released
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* March 31, 1998.
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*
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* The Initial Developer of the Original Code is
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* Netscape Communications Corporation.
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* Portions created by the Initial Developer are Copyright (C) 1998
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* the Initial Developer. All Rights Reserved.
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*
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* Contributor(s):
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*
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* Alternatively, the contents of this file may be used under the terms of
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* either of the GNU General Public License Version 2 or later (the "GPL"),
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* or the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
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* in which case the provisions of the GPL or the LGPL are applicable instead
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* of those above. If you wish to allow use of your version of this file only
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* under the terms of either the GPL or the LGPL, and not to allow others to
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* use your version of this file under the terms of the MPL, indicate your
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* decision by deleting the provisions above and replace them with the notice
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* and other provisions required by the GPL or the LGPL. If you do not delete
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* the provisions above, a recipient may use your version of this file under
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* the terms of any one of the MPL, the GPL or the LGPL.
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*
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* ***** END LICENSE BLOCK ***** */
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/*
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* JS Mark-and-Sweep Garbage Collector.
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*
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* This GC allocates only fixed-sized things big enough to contain two words
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* (pointers) on any host architecture. It allocates from an arena pool (see
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* jsarena.h). It uses an ideally parallel array of flag bytes to hold the
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* mark bit, finalizer type index, etc.
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*
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* XXX swizzle page to freelist for better locality of reference
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*/
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#include "jsstddef.h"
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#include <stdlib.h> /* for free, called by JS_ARENA_DESTROY */
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#include <string.h> /* for memset, called by jsarena.h macros if DEBUG */
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#include "jstypes.h"
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#include "jsarena.h" /* Added by JSIFY */
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#include "jsutil.h" /* Added by JSIFY */
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#include "jshash.h" /* Added by JSIFY */
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#include "jsapi.h"
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#include "jsatom.h"
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#include "jscntxt.h"
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#include "jsconfig.h"
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#include "jsdbgapi.h"
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#include "jsfun.h"
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#include "jsgc.h"
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#include "jsinterp.h"
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#include "jslock.h"
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#include "jsnum.h"
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#include "jsobj.h"
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#include "jsscope.h"
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#include "jsscript.h"
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#include "jsstr.h"
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#if JS_HAS_XML_SUPPORT
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#include "jsxml.h"
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#endif
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/*
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* GC arena sizing depends on amortizing arena overhead using a large number
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* of things per arena, and on the thing/flags ratio of 8:1 on most platforms.
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*
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* On 64-bit platforms, we would have half as many things per arena because
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* pointers are twice as big, so we double the bytes for things per arena.
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* This preserves the 1024 byte flags sub-arena size, which relates to the
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* GC_PAGE_SIZE (see below for why).
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*/
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#if JS_BYTES_PER_WORD == 8
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# define GC_THINGS_SHIFT 14 /* 16KB for things on Alpha, etc. */
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#else
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# define GC_THINGS_SHIFT 13 /* 8KB for things on most platforms */
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#endif
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#define GC_THINGS_SIZE JS_BIT(GC_THINGS_SHIFT)
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#define GC_FLAGS_SIZE (GC_THINGS_SIZE / sizeof(JSGCThing))
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#define GC_ARENA_SIZE (GC_THINGS_SIZE + GC_FLAGS_SIZE)
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/*
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* A GC arena contains one flag byte for each thing in its heap, and supports
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* O(1) lookup of a flag given its thing's address.
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*
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* To implement this, we take advantage of the thing/flags numerology: given
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* the 8K bytes worth of GC-things, there are 1K flag bytes. We mask a thing's
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* address with ~1023 to find a JSGCPageInfo record at the front of a mythical
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* "GC page" within the larger 8K thing arena. That JSGCPageInfo contains a
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* pointer to the 128 flag bytes corresponding to the things in the page, so we
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* index into this flags array using the thing's index within its page.
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*
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* To align thing pages on 1024-byte boundaries, we must allocate the 9KB of
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* flags+things arena payload, then find the first 0 mod 1024 boundary after
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* the first payload address. That's where things start, with a JSGCPageInfo
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* taking up the first thing-slot, as usual for 0 mod 1024 byte boundaries.
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* The effect of this alignment trick is to split the flags into at most 2
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* discontiguous spans, one before the things and one after (if we're really
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* lucky, and the arena payload starts on a 0 mod 1024 byte boundary, no need
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* to split).
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*
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* The overhead of this scheme for most platforms is (16+8*(8+1))/(16+9K) or
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* .95% (assuming 16 byte JSArena header size, and 8 byte JSGCThing size).
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*
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* Here's some ASCII art showing an arena:
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*
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* split
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* |
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* V
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* +--+-------+-------+-------+-------+-------+-------+-------+-------+-----+
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* |fB| tp0 | tp1 | tp2 | tp3 | tp4 | tp5 | tp6 | tp7 | fA |
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* +--+-------+-------+-------+-------+-------+-------+-------+-------+-----+
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* ^ ^
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* tI ---------+ |
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* tJ -------------------------------------------+
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*
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* - fB are the "before split" flags, fA are the "after split" flags
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* - tp0-tp7 are the 8 thing pages
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* - thing tI points into tp1, whose flags are below the split, in fB
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* - thing tJ points into tp5, clearly above the split
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*
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* In general, one of the thing pages will have some of its things' flags on
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* the low side of the split, and the rest of its things' flags on the high
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* side. All the other pages have flags only below or only above. Therefore
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* we'll have to test something to decide whether the split divides flags in
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* a given thing's page. So we store the split pointer (the pointer to tp0)
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* in each JSGCPageInfo, along with the flags pointer for the 128 flag bytes
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* ideally starting, for tp0 things, at the beginning of the arena's payload
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* (at the start of fB).
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*
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* That is, each JSGCPageInfo's flags pointer is 128 bytes from the previous,
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* or at the start of the arena if there is no previous page in this arena.
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* Thus these ideal 128-byte flag pages run contiguously from the start of the
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* arena (right over the split!), and the JSGCPageInfo flags pointers contain
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* no discontinuities over the split created by the thing pages. So if, for a
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* given JSGCPageInfo *pi, we find that
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*
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* pi->flags + ((jsuword)thing % 1024) / sizeof(JSGCThing) >= pi->split
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*
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* then we must add GC_THINGS_SIZE to the nominal flags pointer to jump over
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* all the thing pages that split the flags into two discontiguous spans.
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*
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* (If we need to implement card-marking for an incremental GC write barrier,
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* we can use the low byte of the pi->split pointer as the card-mark, for an
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* extremely efficient write barrier: when mutating an object obj, just store
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* a 1 byte at (uint8 *) ((jsuword)obj & ~1023) for little-endian platforms.
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* When finding flags, we'll of course have to mask split with ~255, but it is
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* guaranteed to be 1024-byte aligned, so no information is lost by overlaying
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* the card-mark byte on split's low byte.)
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*/
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#define GC_PAGE_SHIFT 10
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#define GC_PAGE_MASK ((jsuword) JS_BITMASK(GC_PAGE_SHIFT))
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#define GC_PAGE_SIZE JS_BIT(GC_PAGE_SHIFT)
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typedef struct JSGCPageInfo {
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uint8 *split;
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uint8 *flags;
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} JSGCPageInfo;
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#define FIRST_THING_PAGE(a) (((a)->base + GC_FLAGS_SIZE) & ~GC_PAGE_MASK)
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/*
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* Given a jsuword page pointer p and a thing size n, return the address of
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* the first thing in p. We know that any n not a power of two packs from
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* the end of the page leaving at least enough room for one JSGCPageInfo, but
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* not for another thing, at the front of the page (JS_ASSERTs below insist
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* on this).
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*
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* This works because all allocations are a multiple of sizeof(JSGCThing) ==
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* sizeof(JSGCPageInfo) in size.
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*/
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#define FIRST_THING(p,n) (((n) & ((n) - 1)) \
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? (p) + (uint32)(GC_PAGE_SIZE % (n)) \
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: (p) + (n))
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static JSGCThing *
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gc_new_arena(JSArenaPool *pool, size_t nbytes)
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{
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uint8 *flagp, *split, *pagep, *limit;
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JSArena *a;
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jsuword p;
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JSGCThing *thing;
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JSGCPageInfo *pi;
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/* Use JS_ArenaAllocate to grab another 9K-net-size hunk of space. */
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flagp = (uint8 *) JS_ArenaAllocate(pool, GC_ARENA_SIZE);
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if (!flagp)
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return NULL;
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a = pool->current;
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/* Reset a->avail to start at the flags split, aka the first thing page. */
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p = FIRST_THING_PAGE(a);
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split = pagep = (uint8 *) p;
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a->avail = FIRST_THING(p, nbytes);
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JS_ASSERT(a->avail >= p + sizeof(JSGCPageInfo));
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thing = (JSGCThing *) a->avail;
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JS_ArenaCountAllocation(pool, a->avail - p);
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a->avail += nbytes;
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/* Initialize the JSGCPageInfo records at the start of every thing page. */
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limit = pagep + GC_THINGS_SIZE;
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do {
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pi = (JSGCPageInfo *) pagep;
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pi->split = split;
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pi->flags = flagp;
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flagp += GC_PAGE_SIZE >> (GC_THINGS_SHIFT - GC_PAGE_SHIFT);
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pagep += GC_PAGE_SIZE;
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} while (pagep < limit);
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return thing;
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}
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uint8 *
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js_GetGCThingFlags(void *thing)
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{
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JSGCPageInfo *pi;
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uint8 *flagp;
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pi = (JSGCPageInfo *) ((jsuword)thing & ~GC_PAGE_MASK);
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flagp = pi->flags + ((jsuword)thing & GC_PAGE_MASK) / sizeof(JSGCThing);
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if (flagp >= pi->split)
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flagp += GC_THINGS_SIZE;
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return flagp;
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}
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JSBool
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js_IsAboutToBeFinalized(JSContext *cx, void *thing)
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{
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uint8 flags = *js_GetGCThingFlags(thing);
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return !(flags & (GCF_MARK | GCF_LOCK | GCF_FINAL));
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}
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typedef void (*GCFinalizeOp)(JSContext *cx, JSGCThing *thing);
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#ifndef DEBUG
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# define js_FinalizeDouble NULL
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#endif
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#if !JS_HAS_XML_SUPPORT
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# define js_FinalizeXMLNamespace NULL
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# define js_FinalizeXMLQName NULL
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# define js_FinalizeXML NULL
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#endif
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static GCFinalizeOp gc_finalizers[GCX_NTYPES] = {
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(GCFinalizeOp) js_FinalizeObject, /* GCX_OBJECT */
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(GCFinalizeOp) js_FinalizeString, /* GCX_STRING */
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(GCFinalizeOp) js_FinalizeDouble, /* GCX_DOUBLE */
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(GCFinalizeOp) js_FinalizeString, /* GCX_MUTABLE_STRING */
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NULL, /* GCX_PRIVATE */
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(GCFinalizeOp) js_FinalizeXMLNamespace, /* GCX_NAMESPACE */
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(GCFinalizeOp) js_FinalizeXMLQName, /* GCX_QNAME */
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(GCFinalizeOp) js_FinalizeXML, /* GCX_XML */
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NULL, /* GCX_EXTERNAL_STRING */
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NULL,
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NULL,
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NULL,
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NULL,
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NULL,
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NULL,
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NULL
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};
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#ifdef GC_MARK_DEBUG
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static const char newborn_external_string[] = "newborn external string";
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static const char *gc_typenames[GCX_NTYPES] = {
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"newborn object",
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"newborn string",
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"newborn double",
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"newborn mutable string",
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"newborn private",
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"newborn Namespace",
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"newborn QName",
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"newborn XML",
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newborn_external_string,
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newborn_external_string,
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newborn_external_string,
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newborn_external_string,
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newborn_external_string,
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newborn_external_string,
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newborn_external_string,
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newborn_external_string
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};
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#endif
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intN
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js_ChangeExternalStringFinalizer(JSStringFinalizeOp oldop,
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JSStringFinalizeOp newop)
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{
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uintN i;
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for (i = GCX_EXTERNAL_STRING; i < GCX_NTYPES; i++) {
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if (gc_finalizers[i] == (GCFinalizeOp) oldop) {
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gc_finalizers[i] = (GCFinalizeOp) newop;
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return (intN) i;
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}
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}
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return -1;
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}
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#ifdef JS_GCMETER
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#define METER(x) x
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#else
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#define METER(x) /* nothing */
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#endif
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/* Initial size of the gcRootsHash table (SWAG, small enough to amortize). */
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#define GC_ROOTS_SIZE 256
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#define GC_FINALIZE_LEN 1024
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JSBool
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js_InitGC(JSRuntime *rt, uint32 maxbytes)
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{
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uintN i;
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JS_ASSERT(sizeof(JSGCThing) == sizeof(JSGCPageInfo));
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JS_ASSERT(sizeof(JSGCThing) >= sizeof(JSObject));
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JS_ASSERT(sizeof(JSGCThing) >= sizeof(JSString));
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JS_ASSERT(sizeof(JSGCThing) >= sizeof(jsdouble));
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JS_ASSERT(GC_FLAGS_SIZE >= GC_PAGE_SIZE);
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JS_ASSERT(sizeof(JSStackHeader) >= 2 * sizeof(jsval));
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for (i = 0; i < GC_NUM_FREELISTS; i++)
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JS_InitArenaPool(&rt->gcArenaPool[i], "gc-arena", GC_ARENA_SIZE, 1);
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if (!JS_DHashTableInit(&rt->gcRootsHash, JS_DHashGetStubOps(), NULL,
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sizeof(JSGCRootHashEntry), GC_ROOTS_SIZE)) {
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rt->gcRootsHash.ops = NULL;
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return JS_FALSE;
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}
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rt->gcLocksHash = NULL; /* create lazily */
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rt->gcMaxBytes = maxbytes;
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return JS_TRUE;
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}
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#ifdef JS_GCMETER
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JS_FRIEND_API(void)
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js_DumpGCStats(JSRuntime *rt, FILE *fp)
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{
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uintN i;
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fprintf(fp, "\nGC allocation statistics:\n");
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#define UL(x) ((unsigned long)(x))
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#define ULSTAT(x) UL(rt->gcStats.x)
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fprintf(fp, " public bytes allocated: %lu\n", UL(rt->gcBytes));
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fprintf(fp, " private bytes allocated: %lu\n", UL(rt->gcPrivateBytes));
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fprintf(fp, " alloc attempts: %lu\n", ULSTAT(alloc));
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for (i = 0; i < GC_NUM_FREELISTS; i++) {
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fprintf(fp, " GC freelist %u length: %lu\n",
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i, ULSTAT(freelen[i]));
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fprintf(fp, " recycles via GC freelist %u: %lu\n",
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i, ULSTAT(recycle[i]));
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}
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fprintf(fp, "allocation retries after GC: %lu\n", ULSTAT(retry));
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fprintf(fp, " allocation failures: %lu\n", ULSTAT(fail));
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fprintf(fp, " things born locked: %lu\n", ULSTAT(lockborn));
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fprintf(fp, " valid lock calls: %lu\n", ULSTAT(lock));
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fprintf(fp, " valid unlock calls: %lu\n", ULSTAT(unlock));
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fprintf(fp, " mark recursion depth: %lu\n", ULSTAT(depth));
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fprintf(fp, " maximum mark recursion: %lu\n", ULSTAT(maxdepth));
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fprintf(fp, " mark C recursion depth: %lu\n", ULSTAT(cdepth));
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fprintf(fp, " maximum mark C recursion: %lu\n", ULSTAT(maxcdepth));
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fprintf(fp, " mark C stack overflows: %lu\n", ULSTAT(dswmark));
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fprintf(fp, " mark DSW recursion depth: %lu\n", ULSTAT(dswdepth));
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fprintf(fp, " maximum mark DSW recursion: %lu\n", ULSTAT(maxdswdepth));
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fprintf(fp, " mark DSW up-tree movement: %lu\n", ULSTAT(dswup));
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fprintf(fp, "DSW up-tree obj->slot steps: %lu\n", ULSTAT(dswupstep));
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fprintf(fp, " maximum GC nesting level: %lu\n", ULSTAT(maxlevel));
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fprintf(fp, "potentially useful GC calls: %lu\n", ULSTAT(poke));
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fprintf(fp, " useless GC calls: %lu\n", ULSTAT(nopoke));
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fprintf(fp, " thing arenas freed so far: %lu\n", ULSTAT(afree));
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fprintf(fp, " stack segments scanned: %lu\n", ULSTAT(stackseg));
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fprintf(fp, "stack segment slots scanned: %lu\n", ULSTAT(segslots));
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#undef UL
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#undef US
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#ifdef JS_ARENAMETER
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JS_DumpArenaStats(fp);
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#endif
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}
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#endif
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#ifdef DEBUG
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JS_STATIC_DLL_CALLBACK(JSDHashOperator)
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js_root_printer(JSDHashTable *table, JSDHashEntryHdr *hdr, uint32 i, void *arg)
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{
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uint32 *leakedroots = (uint32 *)arg;
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JSGCRootHashEntry *rhe = (JSGCRootHashEntry *)hdr;
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(*leakedroots)++;
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fprintf(stderr,
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"JS engine warning: leaking GC root \'%s\' at %p\n",
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rhe->name ? (char *)rhe->name : "", rhe->root);
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return JS_DHASH_NEXT;
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}
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#endif
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void
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js_FinishGC(JSRuntime *rt)
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{
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uintN i;
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#ifdef JS_ARENAMETER
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JS_DumpArenaStats(stdout);
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#endif
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#ifdef JS_GCMETER
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js_DumpGCStats(rt, stdout);
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#endif
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for (i = 0; i < GC_NUM_FREELISTS; i++) {
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JS_FinishArenaPool(&rt->gcArenaPool[i]);
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rt->gcFreeList[i] = NULL;
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}
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JS_ArenaFinish();
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if (rt->gcRootsHash.ops) {
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#ifdef DEBUG
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uint32 leakedroots = 0;
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/* Warn (but don't assert) debug builds of any remaining roots. */
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JS_DHashTableEnumerate(&rt->gcRootsHash, js_root_printer,
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&leakedroots);
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if (leakedroots > 0) {
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if (leakedroots == 1) {
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fprintf(stderr,
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"JS engine warning: 1 GC root remains after destroying the JSRuntime.\n"
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" This root may point to freed memory. Objects reachable\n"
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" through it have not been finalized.\n");
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} else {
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fprintf(stderr,
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"JS engine warning: %lu GC roots remain after destroying the JSRuntime.\n"
|
|
" These roots may point to freed memory. Objects reachable\n"
|
|
" through them have not been finalized.\n",
|
|
(unsigned long) leakedroots);
|
|
}
|
|
}
|
|
#endif
|
|
|
|
JS_DHashTableFinish(&rt->gcRootsHash);
|
|
rt->gcRootsHash.ops = NULL;
|
|
}
|
|
if (rt->gcLocksHash) {
|
|
JS_DHashTableDestroy(rt->gcLocksHash);
|
|
rt->gcLocksHash = NULL;
|
|
}
|
|
}
|
|
|
|
JSBool
|
|
js_AddRoot(JSContext *cx, void *rp, const char *name)
|
|
{
|
|
JSBool ok = js_AddRootRT(cx->runtime, rp, name);
|
|
if (!ok)
|
|
JS_ReportOutOfMemory(cx);
|
|
return ok;
|
|
}
|
|
|
|
JSBool
|
|
js_AddRootRT(JSRuntime *rt, void *rp, const char *name)
|
|
{
|
|
JSBool ok;
|
|
JSGCRootHashEntry *rhe;
|
|
|
|
/*
|
|
* Due to the long-standing, but now removed, use of rt->gcLock across the
|
|
* bulk of js_GC, API users have come to depend on JS_AddRoot etc. locking
|
|
* properly with a racing GC, without calling JS_AddRoot from a request.
|
|
* We have to preserve API compatibility here, now that we avoid holding
|
|
* rt->gcLock across the mark phase (including the root hashtable mark).
|
|
*
|
|
* If the GC is running and we're called on another thread, wait for this
|
|
* GC activation to finish. We can safely wait here (in the case where we
|
|
* are called within a request on another thread's context) without fear
|
|
* of deadlock because the GC doesn't set rt->gcRunning until after it has
|
|
* waited for all active requests to end.
|
|
*/
|
|
JS_LOCK_GC(rt);
|
|
#ifdef JS_THREADSAFE
|
|
JS_ASSERT(!rt->gcRunning || rt->gcLevel > 0);
|
|
if (rt->gcRunning && rt->gcThread != js_CurrentThreadId()) {
|
|
do {
|
|
JS_AWAIT_GC_DONE(rt);
|
|
} while (rt->gcLevel > 0);
|
|
}
|
|
#endif
|
|
rhe = (JSGCRootHashEntry *) JS_DHashTableOperate(&rt->gcRootsHash, rp,
|
|
JS_DHASH_ADD);
|
|
if (rhe) {
|
|
rhe->root = rp;
|
|
rhe->name = name;
|
|
ok = JS_TRUE;
|
|
} else {
|
|
ok = JS_FALSE;
|
|
}
|
|
JS_UNLOCK_GC(rt);
|
|
return ok;
|
|
}
|
|
|
|
JSBool
|
|
js_RemoveRoot(JSRuntime *rt, void *rp)
|
|
{
|
|
/*
|
|
* Due to the JS_RemoveRootRT API, we may be called outside of a request.
|
|
* Same synchronization drill as above in js_AddRoot.
|
|
*/
|
|
JS_LOCK_GC(rt);
|
|
#ifdef JS_THREADSAFE
|
|
JS_ASSERT(!rt->gcRunning || rt->gcLevel > 0);
|
|
if (rt->gcRunning && rt->gcThread != js_CurrentThreadId()) {
|
|
do {
|
|
JS_AWAIT_GC_DONE(rt);
|
|
} while (rt->gcLevel > 0);
|
|
}
|
|
#endif
|
|
(void) JS_DHashTableOperate(&rt->gcRootsHash, rp, JS_DHASH_REMOVE);
|
|
rt->gcPoke = JS_TRUE;
|
|
JS_UNLOCK_GC(rt);
|
|
return JS_TRUE;
|
|
}
|
|
|
|
#ifdef DEBUG_brendan
|
|
#define NGCHIST 64
|
|
|
|
static struct GCHist {
|
|
JSBool lastDitch;
|
|
JSGCThing *freeList;
|
|
} gchist[NGCHIST];
|
|
|
|
unsigned gchpos;
|
|
#endif
|
|
|
|
void *
|
|
js_NewGCThing(JSContext *cx, uintN flags, size_t nbytes)
|
|
{
|
|
JSBool tried_gc;
|
|
JSRuntime *rt;
|
|
size_t nflags;
|
|
uintN i;
|
|
JSGCThing *thing, **flp;
|
|
uint8 *flagp;
|
|
JSLocalRootStack *lrs;
|
|
uint32 *bytesptr;
|
|
|
|
rt = cx->runtime;
|
|
JS_LOCK_GC(rt);
|
|
JS_ASSERT(!rt->gcRunning);
|
|
if (rt->gcRunning) {
|
|
METER(rt->gcStats.finalfail++);
|
|
JS_UNLOCK_GC(rt);
|
|
return NULL;
|
|
}
|
|
|
|
#ifdef TOO_MUCH_GC
|
|
#ifdef WAY_TOO_MUCH_GC
|
|
rt->gcPoke = JS_TRUE;
|
|
#endif
|
|
js_GC(cx, GC_KEEP_ATOMS | GC_ALREADY_LOCKED);
|
|
tried_gc = JS_TRUE;
|
|
#else
|
|
tried_gc = JS_FALSE;
|
|
#endif
|
|
|
|
METER(rt->gcStats.alloc++);
|
|
nbytes = JS_ROUNDUP(nbytes, sizeof(JSGCThing));
|
|
nflags = nbytes / sizeof(JSGCThing);
|
|
i = GC_FREELIST_INDEX(nbytes);
|
|
flp = &rt->gcFreeList[i];
|
|
|
|
retry:
|
|
thing = *flp;
|
|
if (thing) {
|
|
*flp = thing->next;
|
|
flagp = thing->flagp;
|
|
METER(rt->gcStats.freelen[i]--);
|
|
METER(rt->gcStats.recycle[i]++);
|
|
} else {
|
|
if (rt->gcBytes < rt->gcMaxBytes &&
|
|
(tried_gc || rt->gcMallocBytes < rt->gcMaxBytes))
|
|
{
|
|
/*
|
|
* Inline form of JS_ARENA_ALLOCATE adapted to truncate the current
|
|
* arena's limit to a GC_PAGE_SIZE boundary, and to skip over every
|
|
* GC_PAGE_SIZE-byte-aligned thing (which is actually not a thing,
|
|
* it's a JSGCPageInfo record).
|
|
*/
|
|
JSArenaPool *pool = &rt->gcArenaPool[i];
|
|
JSArena *a = pool->current;
|
|
jsuword p = a->avail;
|
|
jsuword q = p + nbytes;
|
|
|
|
if (q > (a->limit & ~GC_PAGE_MASK)) {
|
|
thing = gc_new_arena(pool, nbytes);
|
|
} else {
|
|
if ((p & GC_PAGE_MASK) == 0) {
|
|
/* Beware, p points to a JSGCPageInfo record! */
|
|
p = FIRST_THING(p, nbytes);
|
|
q = p + nbytes;
|
|
JS_ArenaCountAllocation(pool, p & GC_PAGE_MASK);
|
|
}
|
|
a->avail = q;
|
|
thing = (JSGCThing *)p;
|
|
}
|
|
JS_ArenaCountAllocation(pool, nbytes);
|
|
}
|
|
|
|
/*
|
|
* Consider doing a "last ditch" GC if thing couldn't be allocated.
|
|
*
|
|
* Keep rt->gcLock across the call into js_GC so we don't starve and
|
|
* lose to racing threads who deplete the heap just after js_GC has
|
|
* replenished it (or has synchronized with a racing GC that collected
|
|
* a bunch of garbage). This unfair scheduling can happen on certain
|
|
* operating systems. For the gory details, see Mozilla bug 162779
|
|
* (http://bugzilla.mozilla.org/show_bug.cgi?id=162779).
|
|
*/
|
|
if (!thing) {
|
|
if (!tried_gc) {
|
|
rt->gcPoke = JS_TRUE;
|
|
js_GC(cx, GC_KEEP_ATOMS | GC_ALREADY_LOCKED);
|
|
if (JS_HAS_NATIVE_BRANCH_CALLBACK_OPTION(cx) &&
|
|
cx->branchCallback &&
|
|
!cx->branchCallback(cx, NULL)) {
|
|
METER(rt->gcStats.retryhalt++);
|
|
JS_UNLOCK_GC(rt);
|
|
return NULL;
|
|
}
|
|
tried_gc = JS_TRUE;
|
|
METER(rt->gcStats.retry++);
|
|
goto retry;
|
|
}
|
|
goto fail;
|
|
}
|
|
|
|
/* Find the flags pointer given thing's address. */
|
|
flagp = js_GetGCThingFlags(thing);
|
|
}
|
|
|
|
lrs = cx->localRootStack;
|
|
if (lrs) {
|
|
/*
|
|
* If we're in a local root scope, don't set cx->newborn[type] at all,
|
|
* to avoid entraining garbage from it for an unbounded amount of time
|
|
* on this context. A caller will leave the local root scope and pop
|
|
* this reference, allowing thing to be GC'd if it has no other refs.
|
|
* See JS_EnterLocalRootScope and related APIs.
|
|
*/
|
|
if (js_PushLocalRoot(cx, lrs, (jsval) thing) < 0)
|
|
goto fail;
|
|
} else {
|
|
/*
|
|
* No local root scope, so we're stuck with the old, fragile model of
|
|
* depending on a pigeon-hole newborn per type per context.
|
|
*/
|
|
cx->newborn[flags & GCF_TYPEMASK] = thing;
|
|
}
|
|
|
|
/* We can't fail now, so update flags and rt->gc{,Private}Bytes. */
|
|
*flagp = (uint8)flags;
|
|
bytesptr = ((flags & GCF_TYPEMASK) == GCX_PRIVATE)
|
|
? &rt->gcPrivateBytes
|
|
: &rt->gcBytes;
|
|
*bytesptr += nbytes + nflags;
|
|
|
|
/*
|
|
* Clear thing before unlocking in case a GC run is about to scan it,
|
|
* finding it via cx->newborn[].
|
|
*/
|
|
thing->next = NULL;
|
|
thing->flagp = NULL;
|
|
#ifdef DEBUG_brendan
|
|
gchist[gchpos].lastDitch = tried_gc;
|
|
gchist[gchpos].freeList = *flp;
|
|
if (++gchpos == NGCHIST)
|
|
gchpos = 0;
|
|
#endif
|
|
METER(if (flags & GCF_LOCK) rt->gcStats.lockborn++);
|
|
JS_UNLOCK_GC(rt);
|
|
return thing;
|
|
|
|
fail:
|
|
METER(rt->gcStats.fail++);
|
|
JS_UNLOCK_GC(rt);
|
|
JS_ReportOutOfMemory(cx);
|
|
return NULL;
|
|
}
|
|
|
|
JSBool
|
|
js_LockGCThing(JSContext *cx, void *thing)
|
|
{
|
|
JSBool ok = js_LockGCThingRT(cx->runtime, thing);
|
|
if (!ok)
|
|
JS_ReportOutOfMemory(cx);
|
|
return ok;
|
|
}
|
|
|
|
/*
|
|
* Deep GC-things can't be locked just by setting the GCF_LOCK bit, because
|
|
* their descendants must be marked by the GC. To find them during the mark
|
|
* phase, they are added to rt->gcLocksHash, which is created lazily.
|
|
*
|
|
* NB: we depend on the order of GC-thing type indexes here!
|
|
*/
|
|
#define GC_TYPE_IS_STRING(t) ((t) == GCX_STRING || \
|
|
(t) >= GCX_EXTERNAL_STRING)
|
|
#define GC_TYPE_IS_XML(t) ((unsigned)((t) - GCX_NAMESPACE) <= \
|
|
(unsigned)(GCX_XML - GCX_NAMESPACE))
|
|
#define GC_TYPE_IS_DEEP(t) ((t) == GCX_OBJECT || GC_TYPE_IS_XML(t))
|
|
|
|
#define IS_DEEP_STRING(t,o) (GC_TYPE_IS_STRING(t) && \
|
|
JSSTRING_IS_DEPENDENT((JSString *)(o)))
|
|
|
|
#define GC_THING_IS_DEEP(t,o) (GC_TYPE_IS_DEEP(t) || IS_DEEP_STRING(t, o))
|
|
|
|
JSBool
|
|
js_LockGCThingRT(JSRuntime *rt, void *thing)
|
|
{
|
|
JSBool ok, deep;
|
|
uint8 *flagp, flags, lock, type;
|
|
JSGCLockHashEntry *lhe;
|
|
|
|
ok = JS_TRUE;
|
|
if (!thing)
|
|
return ok;
|
|
|
|
flagp = js_GetGCThingFlags(thing);
|
|
|
|
JS_LOCK_GC(rt);
|
|
flags = *flagp;
|
|
lock = (flags & GCF_LOCK);
|
|
type = (flags & GCF_TYPEMASK);
|
|
deep = GC_THING_IS_DEEP(type, thing);
|
|
|
|
/*
|
|
* Avoid adding a rt->gcLocksHash entry for shallow things until someone
|
|
* nests a lock -- then start such an entry with a count of 2, not 1.
|
|
*/
|
|
if (lock || deep) {
|
|
if (!rt->gcLocksHash) {
|
|
rt->gcLocksHash =
|
|
JS_NewDHashTable(JS_DHashGetStubOps(), NULL,
|
|
sizeof(JSGCLockHashEntry),
|
|
GC_ROOTS_SIZE);
|
|
if (!rt->gcLocksHash) {
|
|
ok = JS_FALSE;
|
|
goto done;
|
|
}
|
|
} else if (lock == 0) {
|
|
#ifdef DEBUG
|
|
JSDHashEntryHdr *hdr =
|
|
JS_DHashTableOperate(rt->gcLocksHash, thing,
|
|
JS_DHASH_LOOKUP);
|
|
JS_ASSERT(JS_DHASH_ENTRY_IS_FREE(hdr));
|
|
#endif
|
|
}
|
|
|
|
lhe = (JSGCLockHashEntry *)
|
|
JS_DHashTableOperate(rt->gcLocksHash, thing, JS_DHASH_ADD);
|
|
if (!lhe) {
|
|
ok = JS_FALSE;
|
|
goto done;
|
|
}
|
|
if (!lhe->thing) {
|
|
lhe->thing = thing;
|
|
lhe->count = deep ? 1 : 2;
|
|
} else {
|
|
JS_ASSERT(lhe->count >= 1);
|
|
lhe->count++;
|
|
}
|
|
}
|
|
|
|
*flagp = (uint8)(flags | GCF_LOCK);
|
|
METER(rt->gcStats.lock++);
|
|
ok = JS_TRUE;
|
|
done:
|
|
JS_UNLOCK_GC(rt);
|
|
return ok;
|
|
}
|
|
|
|
JSBool
|
|
js_UnlockGCThingRT(JSRuntime *rt, void *thing)
|
|
{
|
|
uint8 *flagp, flags;
|
|
JSGCLockHashEntry *lhe;
|
|
|
|
if (!thing)
|
|
return JS_TRUE;
|
|
|
|
flagp = js_GetGCThingFlags(thing);
|
|
JS_LOCK_GC(rt);
|
|
flags = *flagp;
|
|
|
|
if (flags & GCF_LOCK) {
|
|
if (!rt->gcLocksHash ||
|
|
(lhe = (JSGCLockHashEntry *)
|
|
JS_DHashTableOperate(rt->gcLocksHash, thing,
|
|
JS_DHASH_LOOKUP),
|
|
JS_DHASH_ENTRY_IS_FREE(&lhe->hdr))) {
|
|
/* Shallow GC-thing with an implicit lock count of 1. */
|
|
JS_ASSERT(!GC_THING_IS_DEEP(flags & GCF_TYPEMASK, thing));
|
|
} else {
|
|
/* Basis or nested unlock of a deep thing, or nested of shallow. */
|
|
if (--lhe->count != 0)
|
|
goto out;
|
|
JS_DHashTableOperate(rt->gcLocksHash, thing, JS_DHASH_REMOVE);
|
|
}
|
|
*flagp = (uint8)(flags & ~GCF_LOCK);
|
|
}
|
|
|
|
rt->gcPoke = JS_TRUE;
|
|
out:
|
|
METER(rt->gcStats.unlock++);
|
|
JS_UNLOCK_GC(rt);
|
|
return JS_TRUE;
|
|
}
|
|
|
|
#ifdef GC_MARK_DEBUG
|
|
|
|
#include <stdio.h>
|
|
#include "jsprf.h"
|
|
|
|
JS_FRIEND_DATA(FILE *) js_DumpGCHeap;
|
|
JS_EXPORT_DATA(void *) js_LiveThingToFind;
|
|
|
|
#ifdef HAVE_XPCONNECT
|
|
#include "dump_xpc.h"
|
|
#endif
|
|
|
|
static const char *
|
|
gc_object_class_name(void* thing)
|
|
{
|
|
uint8 *flagp = js_GetGCThingFlags(thing);
|
|
const char *className = "";
|
|
static char depbuf[32];
|
|
|
|
switch (*flagp & GCF_TYPEMASK) {
|
|
case GCX_OBJECT: {
|
|
JSObject *obj = (JSObject *)thing;
|
|
JSClass *clasp = JSVAL_TO_PRIVATE(obj->slots[JSSLOT_CLASS]);
|
|
className = clasp->name;
|
|
#ifdef HAVE_XPCONNECT
|
|
if (clasp->flags & JSCLASS_PRIVATE_IS_NSISUPPORTS) {
|
|
jsval privateValue = obj->slots[JSSLOT_PRIVATE];
|
|
|
|
JS_ASSERT(clasp->flags & JSCLASS_HAS_PRIVATE);
|
|
if (!JSVAL_IS_VOID(privateValue)) {
|
|
void *privateThing = JSVAL_TO_PRIVATE(privateValue);
|
|
const char *xpcClassName = GetXPCObjectClassName(privateThing);
|
|
|
|
if (xpcClassName)
|
|
className = xpcClassName;
|
|
}
|
|
}
|
|
#endif
|
|
break;
|
|
}
|
|
|
|
case GCX_STRING:
|
|
case GCX_MUTABLE_STRING: {
|
|
JSString *str = (JSString *)thing;
|
|
if (JSSTRING_IS_DEPENDENT(str)) {
|
|
JS_snprintf(depbuf, sizeof depbuf, "start:%u, length:%u",
|
|
JSSTRDEP_START(str), JSSTRDEP_LENGTH(str));
|
|
className = depbuf;
|
|
} else {
|
|
className = "string";
|
|
}
|
|
break;
|
|
}
|
|
|
|
case GCX_DOUBLE:
|
|
className = "double";
|
|
break;
|
|
}
|
|
|
|
return className;
|
|
}
|
|
|
|
static void
|
|
gc_dump_thing(JSGCThing *thing, uint8 flags, GCMarkNode *prev, FILE *fp)
|
|
{
|
|
GCMarkNode *next = NULL;
|
|
char *path = NULL;
|
|
|
|
while (prev) {
|
|
next = prev;
|
|
prev = prev->prev;
|
|
}
|
|
while (next) {
|
|
uint8 nextFlags = *js_GetGCThingFlags(next->thing);
|
|
if ((nextFlags & GCF_TYPEMASK) == GCX_OBJECT) {
|
|
path = JS_sprintf_append(path, "%s(%s @ 0x%08p).",
|
|
next->name,
|
|
gc_object_class_name(next->thing),
|
|
(JSObject*)next->thing);
|
|
} else {
|
|
path = JS_sprintf_append(path, "%s(%s).",
|
|
next->name,
|
|
gc_object_class_name(next->thing));
|
|
}
|
|
next = next->next;
|
|
}
|
|
if (!path)
|
|
return;
|
|
|
|
fprintf(fp, "%08lx ", (long)thing);
|
|
switch (flags & GCF_TYPEMASK) {
|
|
case GCX_OBJECT:
|
|
{
|
|
JSObject *obj = (JSObject *)thing;
|
|
jsval privateValue = obj->slots[JSSLOT_PRIVATE];
|
|
void *privateThing = JSVAL_IS_VOID(privateValue)
|
|
? NULL
|
|
: JSVAL_TO_PRIVATE(privateValue);
|
|
const char *className = gc_object_class_name(thing);
|
|
fprintf(fp, "object %8p %s", privateThing, className);
|
|
break;
|
|
}
|
|
#if JS_HAS_XML_SUPPORT
|
|
case GCX_NAMESPACE:
|
|
{
|
|
JSXMLNamespace *ns = (JSXMLNamespace *)thing;
|
|
fprintf(fp, "namespace %s:%s",
|
|
JS_GetStringBytes(ns->prefix), JS_GetStringBytes(ns->uri));
|
|
break;
|
|
}
|
|
case GCX_QNAME:
|
|
{
|
|
JSXMLQName *qn = (JSXMLQName *)thing;
|
|
fprintf(fp, "qname %s(%s):%s",
|
|
JS_GetStringBytes(qn->prefix), JS_GetStringBytes(qn->uri),
|
|
JS_GetStringBytes(qn->localName));
|
|
break;
|
|
}
|
|
case GCX_XML:
|
|
{
|
|
extern const char *js_xml_class_str[];
|
|
JSXML *xml = (JSXML *)thing;
|
|
fprintf(fp, "xml %8p %s", xml, js_xml_class_str[xml->xml_class]);
|
|
break;
|
|
}
|
|
#endif
|
|
case GCX_DOUBLE:
|
|
fprintf(fp, "double %g", *(jsdouble *)thing);
|
|
break;
|
|
case GCX_PRIVATE:
|
|
fprintf(fp, "private %8p", (void *)thing);
|
|
break;
|
|
default:
|
|
fprintf(fp, "string %s", JS_GetStringBytes((JSString *)thing));
|
|
break;
|
|
}
|
|
fprintf(fp, " via %s\n", path);
|
|
free(path);
|
|
}
|
|
|
|
#endif /* !GC_MARK_DEBUG */
|
|
|
|
static void
|
|
gc_mark_atom_key_thing(void *thing, void *arg)
|
|
{
|
|
JSContext *cx = (JSContext *) arg;
|
|
|
|
GC_MARK(cx, thing, "atom", NULL);
|
|
}
|
|
|
|
void
|
|
js_MarkAtom(JSContext *cx, JSAtom *atom, void *arg)
|
|
{
|
|
jsval key;
|
|
|
|
if (atom->flags & ATOM_MARK)
|
|
return;
|
|
atom->flags |= ATOM_MARK;
|
|
key = ATOM_KEY(atom);
|
|
if (JSVAL_IS_GCTHING(key)) {
|
|
#ifdef GC_MARK_DEBUG
|
|
char name[32];
|
|
|
|
if (JSVAL_IS_STRING(key)) {
|
|
JS_snprintf(name, sizeof name, "'%s'",
|
|
JS_GetStringBytes(JSVAL_TO_STRING(key)));
|
|
} else {
|
|
JS_snprintf(name, sizeof name, "<%x>", key);
|
|
}
|
|
#endif
|
|
GC_MARK(cx, JSVAL_TO_GCTHING(key), name, arg);
|
|
}
|
|
if (atom->flags & ATOM_HIDDEN)
|
|
js_MarkAtom(cx, atom->entry.value, arg);
|
|
}
|
|
|
|
/*
|
|
* These macros help avoid passing the GC_MARK_DEBUG-only |arg| parameter
|
|
* during recursive calls when GC_MARK_DEBUG is not defined.
|
|
*/
|
|
#ifdef GC_MARK_DEBUG
|
|
# define UNMARKED_GC_THING_FLAGS(thing, arg) \
|
|
UnmarkedGCThingFlags(thing, arg)
|
|
# define NEXT_UNMARKED_GC_THING(vp, end, thingp, flagpp, arg) \
|
|
NextUnmarkedGCThing(vp, end, thingp, flagpp, arg)
|
|
# define MARK_GC_THING(cx, thing, flagp, arg) \
|
|
MarkGCThing(cx, thing, flagp, arg)
|
|
# define CALL_GC_THING_MARKER(marker, cx, thing, arg) \
|
|
marker(cx, thing, arg)
|
|
#else
|
|
# define UNMARKED_GC_THING_FLAGS(thing, arg) \
|
|
UnmarkedGCThingFlags(thing)
|
|
# define NEXT_UNMARKED_GC_THING(vp, end, thingp, flagpp, arg) \
|
|
NextUnmarkedGCThing(vp, end, thingp, flagpp)
|
|
# define MARK_GC_THING(cx, thing, flagp, arg) \
|
|
MarkGCThing(cx, thing, flagp)
|
|
# define CALL_GC_THING_MARKER(marker, cx, thing, arg) \
|
|
marker(cx, thing, NULL)
|
|
#endif
|
|
|
|
static uint8 *
|
|
UNMARKED_GC_THING_FLAGS(void *thing, void *arg)
|
|
{
|
|
uint8 flags, *flagp;
|
|
|
|
if (!thing)
|
|
return NULL;
|
|
|
|
flagp = js_GetGCThingFlags(thing);
|
|
flags = *flagp;
|
|
JS_ASSERT(flags != GCF_FINAL);
|
|
#ifdef GC_MARK_DEBUG
|
|
if (js_LiveThingToFind == thing)
|
|
gc_dump_thing(thing, flags, arg, stderr);
|
|
#endif
|
|
|
|
if (flags & GCF_MARK)
|
|
return NULL;
|
|
|
|
return flagp;
|
|
}
|
|
|
|
static jsval *
|
|
NEXT_UNMARKED_GC_THING(jsval *vp, jsval *end, void **thingp, uint8 **flagpp,
|
|
void *arg)
|
|
{
|
|
jsval v;
|
|
void *thing;
|
|
uint8 *flagp;
|
|
|
|
while (vp < end) {
|
|
v = *vp;
|
|
if (JSVAL_IS_GCTHING(v)) {
|
|
thing = JSVAL_TO_GCTHING(v);
|
|
flagp = UNMARKED_GC_THING_FLAGS(thing, arg);
|
|
if (flagp) {
|
|
*thingp = thing;
|
|
*flagpp = flagp;
|
|
return vp;
|
|
}
|
|
}
|
|
vp++;
|
|
}
|
|
return NULL;
|
|
}
|
|
|
|
static void
|
|
DeutschSchorrWaite(JSContext *cx, void *thing, uint8 *flagp);
|
|
|
|
static JSBool
|
|
MARK_GC_THING(JSContext *cx, void *thing, uint8 *flagp, void *arg)
|
|
{
|
|
JSRuntime *rt;
|
|
JSObject *obj;
|
|
jsval v, *vp, *end;
|
|
JSString *str;
|
|
void *next_thing;
|
|
uint8 *next_flagp;
|
|
#ifdef JS_GCMETER
|
|
uint32 tailCallNesting;
|
|
#endif
|
|
#ifdef GC_MARK_DEBUG
|
|
JSScope *scope;
|
|
JSScopeProperty *sprop;
|
|
char name[32];
|
|
#endif
|
|
int stackDummy;
|
|
|
|
rt = cx->runtime;
|
|
METER(tailCallNesting = 0);
|
|
METER(if (++rt->gcStats.cdepth > rt->gcStats.maxcdepth)
|
|
rt->gcStats.maxcdepth = rt->gcStats.cdepth);
|
|
|
|
#ifndef GC_MARK_DEBUG
|
|
start:
|
|
#endif
|
|
JS_ASSERT(flagp);
|
|
METER(if (++rt->gcStats.depth > rt->gcStats.maxdepth)
|
|
rt->gcStats.maxdepth = rt->gcStats.depth);
|
|
if (*flagp & GCF_MARK) {
|
|
/*
|
|
* This should happen only if recursive MARK_GC_THING marks flags
|
|
* already stored in the caller's *next_flagp.
|
|
*/
|
|
goto out;
|
|
}
|
|
|
|
*flagp |= GCF_MARK;
|
|
|
|
#ifdef GC_MARK_DEBUG
|
|
if (js_DumpGCHeap)
|
|
gc_dump_thing(thing, *flagp, arg, js_DumpGCHeap);
|
|
#endif
|
|
|
|
switch (*flagp & GCF_TYPEMASK) {
|
|
case GCX_OBJECT:
|
|
/* If obj->slots is null, obj must be a newborn. */
|
|
obj = (JSObject *) thing;
|
|
vp = obj->slots;
|
|
if (!vp)
|
|
goto out;
|
|
|
|
/* Switch to Deutsch-Schorr-Waite if we exhaust our stack quota. */
|
|
if (!JS_CHECK_STACK_SIZE(cx, stackDummy)) {
|
|
METER(rt->gcStats.dswmark++);
|
|
DeutschSchorrWaite(cx, thing, flagp);
|
|
goto out;
|
|
}
|
|
|
|
/* Mark slots if they are small enough to be GC-allocated. */
|
|
if ((vp[-1] + 1) * sizeof(jsval) <= GC_NBYTES_MAX)
|
|
GC_MARK(cx, vp - 1, "slots", arg);
|
|
|
|
/* Set up local variables to loop over unmarked things. */
|
|
end = vp + ((obj->map->ops->mark)
|
|
? CALL_GC_THING_MARKER(obj->map->ops->mark, cx, obj, arg)
|
|
: JS_MIN(obj->map->freeslot, obj->map->nslots));
|
|
|
|
vp = NEXT_UNMARKED_GC_THING(vp, end, &thing, &flagp, arg);
|
|
if (!vp)
|
|
goto out;
|
|
v = *vp;
|
|
|
|
/*
|
|
* Here, thing is the first value in obj->slots referring to an
|
|
* unmarked GC-thing.
|
|
*/
|
|
#ifdef GC_MARK_DEBUG
|
|
scope = OBJ_IS_NATIVE(obj) ? OBJ_SCOPE(obj) : NULL;
|
|
#endif
|
|
for (;;) {
|
|
/* Check loop invariants. */
|
|
JS_ASSERT(v == *vp && JSVAL_IS_GCTHING(v));
|
|
JS_ASSERT(thing == JSVAL_TO_GCTHING(v));
|
|
JS_ASSERT(flagp == js_GetGCThingFlags(thing));
|
|
|
|
#ifdef GC_MARK_DEBUG
|
|
if (scope) {
|
|
uint32 slot;
|
|
jsval nval;
|
|
|
|
slot = vp - obj->slots;
|
|
for (sprop = SCOPE_LAST_PROP(scope); ; sprop = sprop->parent) {
|
|
if (!sprop) {
|
|
switch (slot) {
|
|
case JSSLOT_PROTO:
|
|
strcpy(name, js_proto_str);
|
|
break;
|
|
case JSSLOT_PARENT:
|
|
strcpy(name, js_parent_str);
|
|
break;
|
|
default:
|
|
JS_snprintf(name, sizeof name,
|
|
"**UNKNOWN SLOT %ld**",
|
|
(long)slot);
|
|
break;
|
|
}
|
|
break;
|
|
}
|
|
if (sprop->slot == slot) {
|
|
nval = ID_TO_VALUE(sprop->id);
|
|
if (JSVAL_IS_INT(nval)) {
|
|
JS_snprintf(name, sizeof name, "%ld",
|
|
(long)JSVAL_TO_INT(nval));
|
|
} else if (JSVAL_IS_STRING(nval)) {
|
|
JS_snprintf(name, sizeof name, "%s",
|
|
JS_GetStringBytes(JSVAL_TO_STRING(nval)));
|
|
} else {
|
|
strcpy(name, "**FINALIZED ATOM KEY**");
|
|
}
|
|
break;
|
|
}
|
|
}
|
|
} else {
|
|
strcpy(name, "**UNKNOWN OBJECT MAP ENTRY**");
|
|
}
|
|
#endif
|
|
|
|
do {
|
|
vp = NEXT_UNMARKED_GC_THING(vp+1, end, &next_thing, &next_flagp,
|
|
arg);
|
|
if (!vp) {
|
|
/*
|
|
* Here thing came from the last unmarked GC-thing slot.
|
|
* We can eliminate tail recursion unless GC_MARK_DEBUG
|
|
* is defined.
|
|
*/
|
|
#ifdef GC_MARK_DEBUG
|
|
GC_MARK(cx, thing, name, arg);
|
|
goto out;
|
|
#else
|
|
METER(++tailCallNesting);
|
|
goto start;
|
|
#endif
|
|
}
|
|
} while (next_thing == thing);
|
|
v = *vp;
|
|
|
|
#ifdef GC_MARK_DEBUG
|
|
GC_MARK(cx, thing, name, arg);
|
|
#else
|
|
MARK_GC_THING(cx, thing, flagp, arg);
|
|
#endif
|
|
thing = next_thing;
|
|
flagp = next_flagp;
|
|
}
|
|
break;
|
|
|
|
#ifdef DEBUG
|
|
case GCX_STRING:
|
|
str = (JSString *)thing;
|
|
JS_ASSERT(!JSSTRING_IS_DEPENDENT(str));
|
|
break;
|
|
#endif
|
|
|
|
case GCX_MUTABLE_STRING:
|
|
str = (JSString *)thing;
|
|
if (JSSTRING_IS_DEPENDENT(str)) {
|
|
thing = JSSTRDEP_BASE(str);
|
|
flagp = UNMARKED_GC_THING_FLAGS(thing, arg);
|
|
if (flagp) {
|
|
#ifdef GC_MARK_DEBUG
|
|
GC_MARK(cx, thing, "base", arg);
|
|
goto out;
|
|
#else
|
|
METER(++tailCallNesting);
|
|
goto start;
|
|
#endif
|
|
}
|
|
}
|
|
break;
|
|
|
|
#if JS_HAS_XML_SUPPORT
|
|
case GCX_NAMESPACE:
|
|
CALL_GC_THING_MARKER(js_MarkXMLNamespace, cx, (JSXMLNamespace *)thing,
|
|
arg);
|
|
break;
|
|
|
|
case GCX_QNAME:
|
|
CALL_GC_THING_MARKER(js_MarkXMLQName, cx, (JSXMLQName *)thing, arg);
|
|
break;
|
|
|
|
case GCX_XML:
|
|
CALL_GC_THING_MARKER(js_MarkXML, cx, (JSXML *)thing, arg);
|
|
break;
|
|
#endif
|
|
}
|
|
|
|
out:
|
|
METER(rt->gcStats.depth -= 1 + tailCallNesting);
|
|
METER(rt->gcStats.cdepth--);
|
|
return JS_TRUE;
|
|
}
|
|
|
|
/*
|
|
* An invalid object reference that's distinct from JSVAL_TRUE and JSVAL_FALSE
|
|
* when tagged as a boolean. Used to indicate empty DSW mark stack.
|
|
*
|
|
* Reversed pointers that link the DSW mark stack through obj->slots entries
|
|
* are also tagged as booleans so we can find each pointer and unreverse it.
|
|
* Because no object pointer is <= 16, these values can be distinguished from
|
|
* JSVAL_EMPTY, JSVAL_TRUE, and JSVAL_FALSE.
|
|
*/
|
|
#define JSVAL_EMPTY (2 << JSVAL_TAGBITS)
|
|
|
|
/*
|
|
* To optimize native objects to avoid O(n^2) explosion in pathological cases,
|
|
* we use a dswIndex member of JSScope to tell where in obj->slots to find the
|
|
* reversed pointer. Scrounging space in JSScope by packing existing members
|
|
* tighter yielded 16 bits of index, which we use directly if obj->slots has
|
|
* 64K or fewer slots. Otherwise we make scope->dswIndex a fixed-point 16-bit
|
|
* fraction of the number of slots.
|
|
*/
|
|
static JS_INLINE uint16
|
|
EncodeDSWIndex(jsval *vp, jsval *slots)
|
|
{
|
|
uint32 nslots, limit, index;
|
|
jsdouble d;
|
|
|
|
nslots = slots[-1];
|
|
limit = JS_BIT(16);
|
|
index = PTRDIFF(vp, slots, jsval);
|
|
JS_ASSERT(index < nslots);
|
|
if (nslots > limit) {
|
|
d = ((jsdouble)index / nslots) * limit;
|
|
JS_ASSERT(0 <= d && d < limit);
|
|
return (uint16) d;
|
|
}
|
|
return (uint16) index;
|
|
}
|
|
|
|
static JS_INLINE uint32
|
|
DecodeDSWIndex(uint16 dswIndex, jsval *slots)
|
|
{
|
|
uint32 nslots, limit;
|
|
jsdouble d;
|
|
|
|
nslots = slots[-1];
|
|
limit = JS_BIT(16);
|
|
JS_ASSERT(dswIndex < nslots);
|
|
if (nslots > limit) {
|
|
d = ((jsdouble)dswIndex * nslots) / limit;
|
|
JS_ASSERT(0 <= d && d < nslots);
|
|
return (uint32) d;
|
|
}
|
|
return dswIndex;
|
|
}
|
|
|
|
static void
|
|
DeutschSchorrWaite(JSContext *cx, void *thing, uint8 *flagp)
|
|
{
|
|
jsval top, parent, v, *vp, *end;
|
|
JSObject *obj;
|
|
JSScope *scope;
|
|
#ifdef JS_GCMETER
|
|
JSRuntime *rt = cx->runtime;
|
|
#endif
|
|
|
|
top = JSVAL_EMPTY;
|
|
|
|
down:
|
|
METER(if (++rt->gcStats.dswdepth > rt->gcStats.maxdswdepth)
|
|
rt->gcStats.maxdswdepth = rt->gcStats.dswdepth);
|
|
obj = (JSObject *) thing;
|
|
parent = OBJECT_TO_JSVAL(obj);
|
|
|
|
/* Precompute for quick testing to set and get scope->dswIndex. */
|
|
scope = (OBJ_IS_NATIVE(obj) && OBJ_SCOPE(obj)->object == obj)
|
|
? OBJ_SCOPE(obj)
|
|
: NULL;
|
|
|
|
/* Mark slots if they are small enough to be GC-allocated. */
|
|
vp = obj->slots;
|
|
if ((vp[-1] + 1) * sizeof(jsval) <= GC_NBYTES_MAX)
|
|
GC_MARK(cx, vp - 1, "slots", NULL);
|
|
|
|
end = vp + ((obj->map->ops->mark)
|
|
? obj->map->ops->mark(cx, obj, NULL)
|
|
: JS_MIN(obj->map->freeslot, obj->map->nslots));
|
|
|
|
*flagp |= GCF_MARK;
|
|
|
|
for (;;) {
|
|
while ((vp = NEXT_UNMARKED_GC_THING(vp, end, &thing, &flagp, NULL))
|
|
!= NULL) {
|
|
v = *vp;
|
|
JS_ASSERT(JSVAL_TO_GCTHING(v) == thing);
|
|
|
|
if (JSVAL_IS_OBJECT(v)) {
|
|
*vp = JSVAL_SETTAG(top, JSVAL_BOOLEAN);
|
|
top = parent;
|
|
if (scope)
|
|
scope->dswIndex = EncodeDSWIndex(vp, obj->slots);
|
|
goto down;
|
|
}
|
|
|
|
/* Handle string and double GC-things. */
|
|
MARK_GC_THING(cx, thing, flagp, NULL);
|
|
}
|
|
|
|
/* If we are back at the root (or we never left it), we're done. */
|
|
METER(rt->gcStats.dswdepth--);
|
|
if (scope)
|
|
scope->dswIndex = 0;
|
|
if (top == JSVAL_EMPTY)
|
|
return;
|
|
|
|
/* Time to go back up the spanning tree. */
|
|
METER(rt->gcStats.dswup++);
|
|
obj = JSVAL_TO_OBJECT(top);
|
|
vp = obj->slots;
|
|
end = vp + vp[-1];
|
|
|
|
/*
|
|
* If obj is native and owns its own scope, we can minimize the cost
|
|
* of searching for the reversed pointer.
|
|
*/
|
|
scope = (OBJ_IS_NATIVE(obj) && OBJ_SCOPE(obj)->object == obj)
|
|
? OBJ_SCOPE(obj)
|
|
: NULL;
|
|
if (scope)
|
|
vp += DecodeDSWIndex(scope->dswIndex, vp);
|
|
|
|
/*
|
|
* Alas, we must search for the reversed pointer. If we used the
|
|
* scope->dswIndex hint, we'll step over a few slots for objects with
|
|
* a few times 64K slots, etc. For more typical (that is, far fewer
|
|
* than 64K slots) native objects that own their own scopes, this loop
|
|
* won't iterate at all. The order of complexity for host objects and
|
|
* unmutated native objects is O(n^2), but n (4 or 5 in most cases) is
|
|
* low enough that we don't care.
|
|
*
|
|
* We cannot use a reversed pointer into obj->slots, because there
|
|
* is no way to find an object from an address within its slots.
|
|
*/
|
|
v = *vp;
|
|
while (v <= JSVAL_TRUE || !JSVAL_IS_BOOLEAN(v)) {
|
|
METER(rt->gcStats.dswupstep++);
|
|
JS_ASSERT(vp + 1 < end);
|
|
v = *++vp;
|
|
}
|
|
|
|
*vp++ = parent;
|
|
parent = top;
|
|
top = JSVAL_CLRTAG(v);
|
|
}
|
|
}
|
|
|
|
void
|
|
js_MarkGCThing(JSContext *cx, void *thing, void *arg)
|
|
{
|
|
uint8 *flagp;
|
|
|
|
flagp = UNMARKED_GC_THING_FLAGS(thing, arg);
|
|
if (!flagp)
|
|
return;
|
|
MARK_GC_THING(cx, thing, flagp, arg);
|
|
}
|
|
|
|
JS_STATIC_DLL_CALLBACK(JSDHashOperator)
|
|
gc_root_marker(JSDHashTable *table, JSDHashEntryHdr *hdr, uint32 num, void *arg)
|
|
{
|
|
JSGCRootHashEntry *rhe = (JSGCRootHashEntry *)hdr;
|
|
jsval *rp = (jsval *)rhe->root;
|
|
jsval v = *rp;
|
|
|
|
/* Ignore null object and scalar values. */
|
|
if (!JSVAL_IS_NULL(v) && JSVAL_IS_GCTHING(v)) {
|
|
JSContext *cx = (JSContext *)arg;
|
|
#ifdef DEBUG
|
|
uintN i;
|
|
JSArena *a;
|
|
jsuword firstpage;
|
|
JSBool root_points_to_gcArenaPool = JS_FALSE;
|
|
void *thing = JSVAL_TO_GCTHING(v);
|
|
|
|
for (i = 0; i < GC_NUM_FREELISTS; i++) {
|
|
for (a = cx->runtime->gcArenaPool[i].first.next; a; a = a->next) {
|
|
firstpage = FIRST_THING_PAGE(a);
|
|
if (JS_UPTRDIFF(thing, firstpage) < a->avail - firstpage) {
|
|
root_points_to_gcArenaPool = JS_TRUE;
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
if (!root_points_to_gcArenaPool && rhe->name) {
|
|
fprintf(stderr,
|
|
"JS API usage error: the address passed to JS_AddNamedRoot currently holds an\n"
|
|
"invalid jsval. This is usually caused by a missing call to JS_RemoveRoot.\n"
|
|
"The root's name is \"%s\".\n",
|
|
rhe->name);
|
|
}
|
|
JS_ASSERT(root_points_to_gcArenaPool);
|
|
#endif
|
|
|
|
GC_MARK(cx, JSVAL_TO_GCTHING(v), rhe->name ? rhe->name : "root", NULL);
|
|
}
|
|
return JS_DHASH_NEXT;
|
|
}
|
|
|
|
JS_STATIC_DLL_CALLBACK(JSDHashOperator)
|
|
gc_lock_marker(JSDHashTable *table, JSDHashEntryHdr *hdr, uint32 num, void *arg)
|
|
{
|
|
JSGCLockHashEntry *lhe = (JSGCLockHashEntry *)hdr;
|
|
void *thing = (void *)lhe->thing;
|
|
JSContext *cx = (JSContext *)arg;
|
|
|
|
GC_MARK(cx, thing, "locked object", NULL);
|
|
return JS_DHASH_NEXT;
|
|
}
|
|
|
|
void
|
|
js_ForceGC(JSContext *cx, uintN gcflags)
|
|
{
|
|
uintN i;
|
|
|
|
for (i = 0; i < GCX_NTYPES; i++)
|
|
cx->newborn[i] = NULL;
|
|
cx->lastAtom = NULL;
|
|
cx->runtime->gcPoke = JS_TRUE;
|
|
js_GC(cx, gcflags);
|
|
JS_ArenaFinish();
|
|
}
|
|
|
|
#define GC_MARK_JSVALS(cx, len, vec, name) \
|
|
JS_BEGIN_MACRO \
|
|
jsval _v, *_vp, *_end; \
|
|
\
|
|
for (_vp = vec, _end = _vp + len; _vp < _end; _vp++) { \
|
|
_v = *_vp; \
|
|
if (JSVAL_IS_GCTHING(_v)) \
|
|
GC_MARK(cx, JSVAL_TO_GCTHING(_v), name, NULL); \
|
|
} \
|
|
JS_END_MACRO
|
|
|
|
void
|
|
js_GC(JSContext *cx, uintN gcflags)
|
|
{
|
|
JSRuntime *rt;
|
|
JSContext *iter, *acx;
|
|
JSStackFrame *fp, *chain;
|
|
uintN i, depth, nslots, type;
|
|
JSStackHeader *sh;
|
|
JSTempValueRooter *tvr;
|
|
size_t nbytes, nflags;
|
|
JSArena *a, **ap;
|
|
uint8 flags, *flagp, *split;
|
|
JSGCThing *thing, *limit, **flp, **oflp;
|
|
GCFinalizeOp finalizer;
|
|
uint32 *bytesptr;
|
|
JSBool all_clear;
|
|
#ifdef JS_THREADSAFE
|
|
jsword currentThread;
|
|
uint32 requestDebit;
|
|
#endif
|
|
|
|
rt = cx->runtime;
|
|
#ifdef JS_THREADSAFE
|
|
/* Avoid deadlock. */
|
|
JS_ASSERT(!JS_IS_RUNTIME_LOCKED(rt));
|
|
#endif
|
|
|
|
/*
|
|
* Don't collect garbage if the runtime isn't up, and cx is not the last
|
|
* context in the runtime. The last context must force a GC, and nothing
|
|
* should suppress that final collection or there may be shutdown leaks,
|
|
* or runtime bloat until the next context is created.
|
|
*/
|
|
if (rt->state != JSRTS_UP && !(gcflags & GC_LAST_CONTEXT))
|
|
return;
|
|
|
|
/*
|
|
* Let the API user decide to defer a GC if it wants to (unless this
|
|
* is the last context). Invoke the callback regardless.
|
|
*/
|
|
if (rt->gcCallback) {
|
|
if (!rt->gcCallback(cx, JSGC_BEGIN) && !(gcflags & GC_LAST_CONTEXT))
|
|
return;
|
|
}
|
|
|
|
/* Lock out other GC allocator and collector invocations. */
|
|
if (!(gcflags & GC_ALREADY_LOCKED))
|
|
JS_LOCK_GC(rt);
|
|
|
|
/* Do nothing if no mutator has executed since the last GC. */
|
|
if (!rt->gcPoke) {
|
|
METER(rt->gcStats.nopoke++);
|
|
if (!(gcflags & GC_ALREADY_LOCKED))
|
|
JS_UNLOCK_GC(rt);
|
|
return;
|
|
}
|
|
METER(rt->gcStats.poke++);
|
|
rt->gcPoke = JS_FALSE;
|
|
|
|
#ifdef JS_THREADSAFE
|
|
/* Bump gcLevel and return rather than nest on this thread. */
|
|
currentThread = js_CurrentThreadId();
|
|
if (rt->gcThread == currentThread) {
|
|
JS_ASSERT(rt->gcLevel > 0);
|
|
rt->gcLevel++;
|
|
METER(if (rt->gcLevel > rt->gcStats.maxlevel)
|
|
rt->gcStats.maxlevel = rt->gcLevel);
|
|
if (!(gcflags & GC_ALREADY_LOCKED))
|
|
JS_UNLOCK_GC(rt);
|
|
return;
|
|
}
|
|
|
|
/*
|
|
* If we're in one or more requests (possibly on more than one context)
|
|
* running on the current thread, indicate, temporarily, that all these
|
|
* requests are inactive. NB: if cx->thread is 0, then cx is not using
|
|
* the request model, and does not contribute to rt->requestCount.
|
|
*/
|
|
requestDebit = 0;
|
|
if (cx->thread) {
|
|
/*
|
|
* Check all contexts for any with the same thread-id. XXX should we
|
|
* keep a sub-list of contexts having the same id?
|
|
*/
|
|
iter = NULL;
|
|
while ((acx = js_ContextIterator(rt, JS_FALSE, &iter)) != NULL) {
|
|
if (acx->thread == cx->thread && acx->requestDepth)
|
|
requestDebit++;
|
|
}
|
|
} else {
|
|
/*
|
|
* We assert, but check anyway, in case someone is misusing the API.
|
|
* Avoiding the loop over all of rt's contexts is a win in the event
|
|
* that the GC runs only on request-less contexts with 0 thread-ids,
|
|
* in a special thread such as might be used by the UI/DOM/Layout
|
|
* "mozilla" or "main" thread in Mozilla-the-browser.
|
|
*/
|
|
JS_ASSERT(cx->requestDepth == 0);
|
|
if (cx->requestDepth)
|
|
requestDebit = 1;
|
|
}
|
|
if (requestDebit) {
|
|
JS_ASSERT(requestDebit <= rt->requestCount);
|
|
rt->requestCount -= requestDebit;
|
|
if (rt->requestCount == 0)
|
|
JS_NOTIFY_REQUEST_DONE(rt);
|
|
}
|
|
|
|
/* If another thread is already in GC, don't attempt GC; wait instead. */
|
|
if (rt->gcLevel > 0) {
|
|
/* Bump gcLevel to restart the current GC, so it finds new garbage. */
|
|
rt->gcLevel++;
|
|
METER(if (rt->gcLevel > rt->gcStats.maxlevel)
|
|
rt->gcStats.maxlevel = rt->gcLevel);
|
|
|
|
/* Wait for the other thread to finish, then resume our request. */
|
|
while (rt->gcLevel > 0)
|
|
JS_AWAIT_GC_DONE(rt);
|
|
if (requestDebit)
|
|
rt->requestCount += requestDebit;
|
|
if (!(gcflags & GC_ALREADY_LOCKED))
|
|
JS_UNLOCK_GC(rt);
|
|
return;
|
|
}
|
|
|
|
/* No other thread is in GC, so indicate that we're now in GC. */
|
|
rt->gcLevel = 1;
|
|
rt->gcThread = currentThread;
|
|
|
|
/* Wait for all other requests to finish. */
|
|
while (rt->requestCount > 0)
|
|
JS_AWAIT_REQUEST_DONE(rt);
|
|
|
|
#else /* !JS_THREADSAFE */
|
|
|
|
/* Bump gcLevel and return rather than nest; the outer gc will restart. */
|
|
rt->gcLevel++;
|
|
METER(if (rt->gcLevel > rt->gcStats.maxlevel)
|
|
rt->gcStats.maxlevel = rt->gcLevel);
|
|
if (rt->gcLevel > 1)
|
|
return;
|
|
|
|
#endif /* !JS_THREADSAFE */
|
|
|
|
/*
|
|
* Set rt->gcRunning here within the GC lock, and after waiting for any
|
|
* active requests to end, so that new requests that try to JS_AddRoot,
|
|
* JS_RemoveRoot, or JS_RemoveRootRT block in JS_BeginRequest waiting for
|
|
* rt->gcLevel to drop to zero, while request-less calls to the *Root*
|
|
* APIs block in js_AddRoot or js_RemoveRoot (see above in this file),
|
|
* waiting for GC to finish.
|
|
*/
|
|
rt->gcRunning = JS_TRUE;
|
|
JS_UNLOCK_GC(rt);
|
|
|
|
/* If a suspended compile is running on another context, keep atoms. */
|
|
if (rt->gcKeepAtoms)
|
|
gcflags |= GC_KEEP_ATOMS;
|
|
|
|
/* Reset malloc counter. */
|
|
rt->gcMallocBytes = 0;
|
|
|
|
/* Drop atoms held by the property cache, and clear property weak links. */
|
|
js_DisablePropertyCache(cx);
|
|
js_FlushPropertyCache(cx);
|
|
#ifdef DEBUG_notme
|
|
{ extern void js_DumpScopeMeters(JSRuntime *rt);
|
|
js_DumpScopeMeters(rt);
|
|
}
|
|
#endif
|
|
|
|
restart:
|
|
rt->gcNumber++;
|
|
|
|
/*
|
|
* Mark phase.
|
|
*/
|
|
JS_DHashTableEnumerate(&rt->gcRootsHash, gc_root_marker, cx);
|
|
if (rt->gcLocksHash)
|
|
JS_DHashTableEnumerate(rt->gcLocksHash, gc_lock_marker, cx);
|
|
js_MarkAtomState(&rt->atomState, gcflags, gc_mark_atom_key_thing, cx);
|
|
js_MarkWatchPoints(rt);
|
|
js_MarkScriptFilenames(rt, gcflags);
|
|
|
|
iter = NULL;
|
|
while ((acx = js_ContextIterator(rt, JS_TRUE, &iter)) != NULL) {
|
|
/*
|
|
* Iterate frame chain and dormant chains. Temporarily tack current
|
|
* frame onto the head of the dormant list to ease iteration.
|
|
*
|
|
* (NB: see comment on this whole "dormant" thing in js_Execute.)
|
|
*/
|
|
chain = acx->fp;
|
|
if (chain) {
|
|
JS_ASSERT(!chain->dormantNext);
|
|
chain->dormantNext = acx->dormantFrameChain;
|
|
} else {
|
|
chain = acx->dormantFrameChain;
|
|
}
|
|
|
|
for (fp = chain; fp; fp = chain = chain->dormantNext) {
|
|
do {
|
|
if (fp->callobj)
|
|
GC_MARK(cx, fp->callobj, "call object", NULL);
|
|
if (fp->argsobj)
|
|
GC_MARK(cx, fp->argsobj, "arguments object", NULL);
|
|
if (fp->varobj)
|
|
GC_MARK(cx, fp->varobj, "variables object", NULL);
|
|
if (fp->script) {
|
|
js_MarkScript(cx, fp->script, NULL);
|
|
if (fp->spbase) {
|
|
/*
|
|
* Don't mark what has not been pushed yet, or what
|
|
* has been popped already.
|
|
*/
|
|
depth = fp->script->depth;
|
|
nslots = (JS_UPTRDIFF(fp->sp, fp->spbase)
|
|
< depth * sizeof(jsval))
|
|
? (uintN)(fp->sp - fp->spbase)
|
|
: depth;
|
|
GC_MARK_JSVALS(cx, nslots, fp->spbase, "operand");
|
|
}
|
|
}
|
|
GC_MARK(cx, fp->thisp, "this", NULL);
|
|
if (fp->argv) {
|
|
nslots = fp->argc;
|
|
if (fp->fun) {
|
|
if (fp->fun->nargs > nslots)
|
|
nslots = fp->fun->nargs;
|
|
nslots += fp->fun->extra;
|
|
}
|
|
GC_MARK_JSVALS(cx, nslots, fp->argv, "arg");
|
|
}
|
|
if (JSVAL_IS_GCTHING(fp->rval))
|
|
GC_MARK(cx, JSVAL_TO_GCTHING(fp->rval), "rval", NULL);
|
|
if (fp->vars)
|
|
GC_MARK_JSVALS(cx, fp->nvars, fp->vars, "var");
|
|
GC_MARK(cx, fp->scopeChain, "scope chain", NULL);
|
|
if (fp->sharpArray)
|
|
GC_MARK(cx, fp->sharpArray, "sharp array", NULL);
|
|
|
|
if (fp->xmlNamespace)
|
|
GC_MARK(cx, fp->xmlNamespace, "xmlNamespace", NULL);
|
|
} while ((fp = fp->down) != NULL);
|
|
}
|
|
|
|
/* Cleanup temporary "dormant" linkage. */
|
|
if (acx->fp)
|
|
acx->fp->dormantNext = NULL;
|
|
|
|
/* Mark other roots-by-definition in acx. */
|
|
GC_MARK(cx, acx->globalObject, "global object", NULL);
|
|
for (i = 0; i < GCX_NTYPES; i++)
|
|
GC_MARK(cx, acx->newborn[i], gc_typenames[i], NULL);
|
|
if (acx->lastAtom)
|
|
GC_MARK_ATOM(cx, acx->lastAtom, NULL);
|
|
if (JSVAL_IS_GCTHING(acx->lastInternalResult)) {
|
|
thing = JSVAL_TO_GCTHING(acx->lastInternalResult);
|
|
if (thing)
|
|
GC_MARK(cx, thing, "lastInternalResult", NULL);
|
|
}
|
|
#if JS_HAS_EXCEPTIONS
|
|
if (acx->throwing && JSVAL_IS_GCTHING(acx->exception))
|
|
GC_MARK(cx, JSVAL_TO_GCTHING(acx->exception), "exception", NULL);
|
|
#endif
|
|
#if JS_HAS_LVALUE_RETURN
|
|
if (acx->rval2set && JSVAL_IS_GCTHING(acx->rval2))
|
|
GC_MARK(cx, JSVAL_TO_GCTHING(acx->rval2), "rval2", NULL);
|
|
#endif
|
|
|
|
for (sh = acx->stackHeaders; sh; sh = sh->down) {
|
|
METER(rt->gcStats.stackseg++);
|
|
METER(rt->gcStats.segslots += sh->nslots);
|
|
GC_MARK_JSVALS(cx, sh->nslots, JS_STACK_SEGMENT(sh), "stack");
|
|
}
|
|
|
|
if (acx->localRootStack)
|
|
js_MarkLocalRoots(cx, acx->localRootStack);
|
|
for (tvr = acx->tempValueRooters; tvr; tvr = tvr->down) {
|
|
if (tvr->count < 0) {
|
|
if (JSVAL_IS_GCTHING(tvr->u.value)) {
|
|
GC_MARK(cx, JSVAL_TO_GCTHING(tvr->u.value), "tvr->u.value",
|
|
NULL);
|
|
}
|
|
} else {
|
|
GC_MARK_JSVALS(cx, tvr->count, tvr->u.array, "tvr->u.array");
|
|
}
|
|
}
|
|
}
|
|
#ifdef DUMP_CALL_TABLE
|
|
js_DumpCallTable(cx);
|
|
#endif
|
|
|
|
if (rt->gcCallback)
|
|
(void) rt->gcCallback(cx, JSGC_MARK_END);
|
|
|
|
/*
|
|
* Sweep phase.
|
|
*
|
|
* Finalize as we sweep, outside of rt->gcLock, but with rt->gcRunning set
|
|
* so that any attempt to allocate a GC-thing from a finalizer will fail,
|
|
* rather than nest badly and leave the unmarked newborn to be swept.
|
|
*
|
|
* Finalize smaller objects before larger, to guarantee finalization of
|
|
* GC-allocated obj->slots after obj. See FreeSlots in jsobj.c.
|
|
*/
|
|
js_SweepAtomState(&rt->atomState);
|
|
js_SweepScopeProperties(rt);
|
|
js_SweepScriptFilenames(rt);
|
|
for (i = 0; i < GC_NUM_FREELISTS; i++) {
|
|
nbytes = GC_FREELIST_NBYTES(i);
|
|
nflags = nbytes / sizeof(JSGCThing);
|
|
|
|
for (a = rt->gcArenaPool[i].first.next; a; a = a->next) {
|
|
flagp = (uint8 *) a->base;
|
|
split = (uint8 *) FIRST_THING_PAGE(a);
|
|
limit = (JSGCThing *) a->avail;
|
|
for (thing = (JSGCThing *) split; thing < limit; thing += nflags) {
|
|
if (((jsuword)thing & GC_PAGE_MASK) == 0) {
|
|
thing = (JSGCThing *) FIRST_THING((jsuword)thing, nbytes);
|
|
flagp = js_GetGCThingFlags(thing);
|
|
}
|
|
flags = *flagp;
|
|
if (flags & GCF_MARK) {
|
|
*flagp &= ~GCF_MARK;
|
|
} else if (!(flags & (GCF_LOCK | GCF_FINAL))) {
|
|
/* Call the finalizer with GCF_FINAL ORed into flags. */
|
|
type = flags & GCF_TYPEMASK;
|
|
finalizer = gc_finalizers[type];
|
|
if (finalizer) {
|
|
*flagp = (uint8)(flags | GCF_FINAL);
|
|
if (type >= GCX_EXTERNAL_STRING)
|
|
js_PurgeDeflatedStringCache((JSString *)thing);
|
|
finalizer(cx, thing);
|
|
}
|
|
|
|
/* Set flags to GCF_FINAL, signifying that thing is free. */
|
|
*flagp = GCF_FINAL;
|
|
|
|
bytesptr = (type == GCX_PRIVATE)
|
|
? &rt->gcPrivateBytes
|
|
: &rt->gcBytes;
|
|
JS_ASSERT(*bytesptr >= nbytes + nflags);
|
|
*bytesptr -= nbytes + nflags;
|
|
}
|
|
flagp += nflags;
|
|
if (JS_UPTRDIFF(flagp, split) < nflags)
|
|
flagp += GC_THINGS_SIZE;
|
|
}
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Free phase.
|
|
* Free any unused arenas and rebuild the JSGCThing freelist.
|
|
*/
|
|
for (i = 0; i < GC_NUM_FREELISTS; i++) {
|
|
ap = &rt->gcArenaPool[i].first.next;
|
|
a = *ap;
|
|
if (!a)
|
|
continue;
|
|
|
|
all_clear = JS_TRUE;
|
|
flp = oflp = &rt->gcFreeList[i];
|
|
*flp = NULL;
|
|
METER(rt->gcStats.freelen[i] = 0);
|
|
|
|
nbytes = GC_FREELIST_NBYTES(i);
|
|
nflags = nbytes / sizeof(JSGCThing);
|
|
do {
|
|
flagp = (uint8 *) a->base;
|
|
split = (uint8 *) FIRST_THING_PAGE(a);
|
|
limit = (JSGCThing *) a->avail;
|
|
for (thing = (JSGCThing *) split; thing < limit; thing += nflags) {
|
|
if (((jsuword)thing & GC_PAGE_MASK) == 0) {
|
|
thing = (JSGCThing *) FIRST_THING((jsuword)thing, nbytes);
|
|
flagp = js_GetGCThingFlags(thing);
|
|
}
|
|
if (*flagp != GCF_FINAL) {
|
|
all_clear = JS_FALSE;
|
|
} else {
|
|
thing->flagp = flagp;
|
|
*flp = thing;
|
|
flp = &thing->next;
|
|
METER(rt->gcStats.freelen[i]++);
|
|
}
|
|
flagp += nflags;
|
|
if (JS_UPTRDIFF(flagp, split) < nflags)
|
|
flagp += GC_THINGS_SIZE;
|
|
}
|
|
|
|
if (all_clear) {
|
|
JS_ARENA_DESTROY(&rt->gcArenaPool[i], a, ap);
|
|
flp = oflp;
|
|
METER(rt->gcStats.afree++);
|
|
} else {
|
|
ap = &a->next;
|
|
all_clear = JS_TRUE;
|
|
oflp = flp;
|
|
}
|
|
} while ((a = *ap) != NULL);
|
|
|
|
/* Terminate the new freelist. */
|
|
*flp = NULL;
|
|
}
|
|
|
|
if (rt->gcCallback)
|
|
(void) rt->gcCallback(cx, JSGC_FINALIZE_END);
|
|
#ifdef DEBUG_notme
|
|
{ extern void DumpSrcNoteSizeHist();
|
|
DumpSrcNoteSizeHist();
|
|
printf("GC HEAP SIZE %lu (%lu)\n",
|
|
(unsigned long)rt->gcBytes, (unsigned long)rt->gcPrivateBytes);
|
|
}
|
|
#endif
|
|
|
|
JS_LOCK_GC(rt);
|
|
if (rt->gcLevel > 1 || rt->gcPoke) {
|
|
rt->gcLevel = 1;
|
|
rt->gcPoke = JS_FALSE;
|
|
JS_UNLOCK_GC(rt);
|
|
goto restart;
|
|
}
|
|
js_EnablePropertyCache(cx);
|
|
rt->gcLevel = 0;
|
|
rt->gcLastBytes = rt->gcBytes;
|
|
rt->gcRunning = JS_FALSE;
|
|
|
|
#ifdef JS_THREADSAFE
|
|
/* If we were invoked during a request, pay back the temporary debit. */
|
|
if (requestDebit)
|
|
rt->requestCount += requestDebit;
|
|
rt->gcThread = 0;
|
|
JS_NOTIFY_GC_DONE(rt);
|
|
if (!(gcflags & GC_ALREADY_LOCKED))
|
|
JS_UNLOCK_GC(rt);
|
|
#endif
|
|
|
|
if (rt->gcCallback) {
|
|
if (gcflags & GC_ALREADY_LOCKED)
|
|
JS_UNLOCK_GC(rt);
|
|
(void) rt->gcCallback(cx, JSGC_END);
|
|
if (gcflags & GC_ALREADY_LOCKED)
|
|
JS_LOCK_GC(rt);
|
|
}
|
|
}
|