source: webkit/trunk/JavaScriptCore/API/JSBase.cpp@ 52040

Last change on this file since 52040 was 52040, checked in by [email protected], 15 years ago

JavaScriptCore: Changed GC from mark-sweep to mark-allocate.

Reviewed by Sam Weinig.

Added WeakGCMap to keep WebCore blissfully ignorant about objects that
have become garbage but haven't run their destructors yet.

1% SunSpider speedup.
7.6% v8 speedup (37% splay speedup).
17% speedup on bench-alloc-nonretained.js.
18% speedup on bench-alloc-retained.js.

  • API/JSBase.cpp:

(JSGarbageCollect):

files.

  • debugger/Debugger.cpp:

(JSC::Debugger::recompileAllJSFunctions): Updated to use the Collector
iterator abstraction.

  • jsc.cpp:

(functionGC): Updated for rename.

  • runtime/Collector.cpp: Slightly reduced the number of allocations per

collection, so that small workloads only allocate on collector block,
rather than two.

(JSC::Heap::Heap): Updated to use the new allocateBlock function.

(JSC::Heap::destroy): Updated to use the new freeBlocks function.

(JSC::Heap::allocateBlock): New function to initialize a block when
allocating it.

(JSC::Heap::freeBlock): Consolidated the responsibility for running
destructors into this function.

(JSC::Heap::freeBlocks): Updated to use freeBlock.

(JSC::Heap::recordExtraCost): Sweep the heap in this reporting function,
so that allocation, which is more common, doesn't have to check extraCost.

(JSC::Heap::heapAllocate): Run destructors right before recycling a
garbage cell. This has better cache utilization than a separate sweep phase.

(JSC::Heap::resizeBlocks):
(JSC::Heap::growBlocks):
(JSC::Heap::shrinkBlocks): New set of functions for managing the size of
the heap, now that the heap doesn't maintain any information about its
size.

(JSC::isPointerAligned):
(JSC::isHalfCellAligned):
(JSC::isPossibleCell):
(JSC::isCellAligned):
(JSC::Heap::markConservatively): Cleaned up this code a bit.

(JSC::Heap::clearMarkBits):
(JSC::Heap::markedCells): Some helper functions for examining the the mark
bitmap.

(JSC::Heap::sweep): Simplified this function by using a DeadObjectIterator.

(JSC::Heap::markRoots): Reordered some operations for clarity.

(JSC::Heap::objectCount):
(JSC::Heap::addToStatistics):
(JSC::Heap::statistics): Rewrote these functions to calculate an object
count on demand, since the heap doesn't maintain this information by
itself.

(JSC::Heap::reset): New function for resetting the heap once we've
exhausted heap space.

(JSC::Heap::collectAllGarbage): This function matches the old collect()
behavior, but it's now an uncommon function used only by API.

  • runtime/Collector.h:

(JSC::CollectorBitmap::count):
(JSC::CollectorBitmap::isEmpty): Added some helper functions for managing
the collector mark bitmap.

(JSC::Heap::reportExtraMemoryCost): Changed reporting from cell equivalents
to bytes, so it's easier to understand.

  • runtime/CollectorHeapIterator.h:

(JSC::CollectorHeapIterator::CollectorHeapIterator):
(JSC::CollectorHeapIterator::operator!=):
(JSC::CollectorHeapIterator::operator*):
(JSC::CollectorHeapIterator::advance):
(JSC::::LiveObjectIterator):
(JSC::::operator):
(JSC::::DeadObjectIterator):
(JSC::::ObjectIterator): New iterators for encapsulating details about
heap layout, and what's live and dead on the heap.

  • runtime/JSArray.cpp:

(JSC::JSArray::putSlowCase):
(JSC::JSArray::increaseVectorLength): Delay reporting extra cost until
we're fully constructed, so the heap mark phase won't visit us in an
invalid state.

  • runtime/JSCell.h:

(JSC::JSCell::):
(JSC::JSCell::createDummyStructure):
(JSC::JSCell::JSCell):

  • runtime/JSGlobalData.cpp:

(JSC::JSGlobalData::JSGlobalData):

  • runtime/JSGlobalData.h: Added a dummy cell to simplify allocation logic.
  • runtime/JSString.h:

(JSC::jsSubstring): Don't report extra cost for substrings, since they
share a buffer that's already reported extra cost.

  • runtime/Tracing.d:
  • runtime/Tracing.h: Changed these dtrace hooks not to report object

counts, since they're no longer cheap to compute.

  • runtime/UString.h: Updated for renames.
  • runtime/WeakGCMap.h: Added.

(JSC::WeakGCMap::isEmpty):
(JSC::WeakGCMap::uncheckedGet):
(JSC::WeakGCMap::uncheckedBegin):
(JSC::WeakGCMap::uncheckedEnd):
(JSC::::get):
(JSC::::take):
(JSC::::set):
(JSC::::uncheckedRemove): Mentioned above.

  • wtf/StdLibExtras.h:

(WTF::bitCount): Added a bit population count function, so the heap can
count live objects to fulfill statistics questions.

JavaScriptGlue: Changed GC from mark-sweep to mark-allocate.

Reviewed by Sam Weinig.

  • JavaScriptGlue.cpp:

(JSCollect): Updated for rename. Fixed a bug where JSGlue would not check
to avoid nested GC calls.

WebCore: Changed GC from mark-sweep to mark-allocate.

Reviewed by Sam Weinig.

  • ForwardingHeaders/runtime/WeakGCMap.h: Added.
  • bindings/js/GCController.cpp:

(WebCore::collect):
(WebCore::GCController::gcTimerFired):
(WebCore::GCController::garbageCollectNow): Updated for rename.

  • bindings/js/JSDOMBinding.cpp:

(WebCore::removeWrappers):
(WebCore::hasCachedDOMObjectWrapperUnchecked):
(WebCore::hasCachedDOMObjectWrapper):
(WebCore::hasCachedDOMNodeWrapperUnchecked):
(WebCore::forgetDOMObject):
(WebCore::forgetDOMNode):
(WebCore::isObservableThroughDOM):
(WebCore::markDOMNodesForDocument):
(WebCore::markDOMObjectWrapper):
(WebCore::markDOMNodeWrapper):

  • bindings/js/JSDOMBinding.h: Changed DOM wrapper maps to be WeakGCMaps.

Don't ASSERT that an item must be in the WeakGCMap when its destructor
runs, since it might have been overwritten in the map first.

  • bindings/js/JSDocumentCustom.cpp:

(WebCore::toJS): Changed Document from a DOM object wrapper to a DOM node
wrapper, to simplify some code.

  • bindings/js/JSInspectedObjectWrapper.cpp:

(WebCore::JSInspectedObjectWrapper::JSInspectedObjectWrapper):
(WebCore::JSInspectedObjectWrapper::~JSInspectedObjectWrapper):

  • bindings/js/JSInspectorCallbackWrapper.cpp: Use a WeakGCMap for these

wrappers.

  • bindings/js/JSNodeCustom.cpp:

(WebCore::JSNode::markChildren): Updated for WeakGCMap and Document using
a DOM node wrapper instead of a DOM object wrapper.

  • bindings/js/JSSVGPODTypeWrapper.h:

(WebCore::JSSVGDynamicPODTypeWrapperCache::wrapperMap):
(WebCore::JSSVGDynamicPODTypeWrapperCache::lookupOrCreateWrapper):
(WebCore::JSSVGDynamicPODTypeWrapperCache::forgetWrapper):
(WebCore::::~JSSVGDynamicPODTypeWrapper): Shined a small beam of sanity
on this code. Use hashtable-based lookup in JSSVGPODTypeWrapper.h instead
of linear lookup through iteration, since that's what hashtables were
invented for. Make JSSVGPODTypeWrapper.h responsible for reomving itself
from the table, instead of its JS wrapper, to decouple these objects from
GC, and because these objects are refCounted, not solely owned by their
JS wrappers.

  • bindings/scripts/CodeGeneratorJS.pm:
  • dom/Document.h: Adopted changes above.
  • Property svn:eol-style set to native
File size: 4.5 KB
Line 
1/*
2 * Copyright (C) 2006, 2007 Apple Inc. All rights reserved.
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
6 * are met:
7 * 1. Redistributions of source code must retain the above copyright
8 * notice, this list of conditions and the following disclaimer.
9 * 2. Redistributions in binary form must reproduce the above copyright
10 * notice, this list of conditions and the following disclaimer in the
11 * documentation and/or other materials provided with the distribution.
12 *
13 * THIS SOFTWARE IS PROVIDED BY APPLE COMPUTER, INC. ``AS IS'' AND ANY
14 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
15 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
16 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE COMPUTER, INC. OR
17 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
18 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
19 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
20 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
21 * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
22 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
23 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
24 */
25
26#include "config.h"
27#include "JSBase.h"
28#include "JSBasePrivate.h"
29
30#include "APICast.h"
31#include "Completion.h"
32#include "OpaqueJSString.h"
33#include "SourceCode.h"
34#include <interpreter/CallFrame.h>
35#include <runtime/InitializeThreading.h>
36#include <runtime/Completion.h>
37#include <runtime/JSGlobalObject.h>
38#include <runtime/JSLock.h>
39#include <runtime/JSObject.h>
40
41using namespace JSC;
42
43JSValueRef JSEvaluateScript(JSContextRef ctx, JSStringRef script, JSObjectRef thisObject, JSStringRef sourceURL, int startingLineNumber, JSValueRef* exception)
44{
45 ExecState* exec = toJS(ctx);
46 exec->globalData().heap.registerThread();
47 JSLock lock(exec);
48
49 JSObject* jsThisObject = toJS(thisObject);
50
51 // evaluate sets "this" to the global object if it is NULL
52 JSGlobalObject* globalObject = exec->dynamicGlobalObject();
53 SourceCode source = makeSource(script->ustring(), sourceURL->ustring(), startingLineNumber);
54 Completion completion = evaluate(globalObject->globalExec(), globalObject->globalScopeChain(), source, jsThisObject);
55
56 if (completion.complType() == Throw) {
57 if (exception)
58 *exception = toRef(exec, completion.value());
59 return 0;
60 }
61
62 if (completion.value())
63 return toRef(exec, completion.value());
64
65 // happens, for example, when the only statement is an empty (';') statement
66 return toRef(exec, jsUndefined());
67}
68
69bool JSCheckScriptSyntax(JSContextRef ctx, JSStringRef script, JSStringRef sourceURL, int startingLineNumber, JSValueRef* exception)
70{
71 ExecState* exec = toJS(ctx);
72 exec->globalData().heap.registerThread();
73 JSLock lock(exec);
74
75 SourceCode source = makeSource(script->ustring(), sourceURL->ustring(), startingLineNumber);
76 Completion completion = checkSyntax(exec->dynamicGlobalObject()->globalExec(), source);
77 if (completion.complType() == Throw) {
78 if (exception)
79 *exception = toRef(exec, completion.value());
80 return false;
81 }
82
83 return true;
84}
85
86void JSGarbageCollect(JSContextRef ctx)
87{
88 // We used to recommend passing NULL as an argument here, which caused the only heap to be collected.
89 // As there is no longer a shared heap, the previously recommended usage became a no-op (but the GC
90 // will happen when the context group is destroyed).
91 // Because the function argument was originally ignored, some clients may pass their released context here,
92 // in which case there is a risk of crashing if another thread performs GC on the same heap in between.
93 if (!ctx)
94 return;
95
96 ExecState* exec = toJS(ctx);
97 JSGlobalData& globalData = exec->globalData();
98
99 JSLock lock(globalData.isSharedInstance ? LockForReal : SilenceAssertionsOnly);
100
101 if (!globalData.heap.isBusy())
102 globalData.heap.collectAllGarbage();
103
104 // FIXME: Perhaps we should trigger a second mark and sweep
105 // once the garbage collector is done if this is called when
106 // the collector is busy.
107}
108
109void JSReportExtraMemoryCost(JSContextRef ctx, size_t size)
110{
111 ExecState* exec = toJS(ctx);
112 exec->globalData().heap.registerThread();
113 JSLock lock(exec);
114
115 exec->globalData().heap.reportExtraMemoryCost(size);
116}
Note: See TracBrowser for help on using the repository browser.