Changeset 163414 in webkit for trunk/Source/JavaScriptCore/heap/MarkStack.cpp

Timestamp:

Feb 4, 2014, 4:08:40 PM (11 years ago)

Author:

[email protected]

Message:

Refactor MarkStackArray to allow more than JSCells to be stored
​https://bugs.webkit.org/show_bug.cgi?id=128203

Reviewed by Geoffrey Garen.

This patch refactors MarkStackArray into a separate template class named GCSegmentedArray.
This class allows subclassing to add functionality that only MarkStackArray wants.
Since it uses the JSC BlockAllocator instead of FastMalloc, this class can be used during
conservative stack scanning, which disallows using FastMalloc.

• GNUmakefile.list.am:
• JavaScriptCore.vcxproj/JavaScriptCore.vcxproj:
• JavaScriptCore.vcxproj/JavaScriptCore.vcxproj.filters:
• JavaScriptCore.xcodeproj/project.pbxproj:
• heap/BlockAllocator.h:
• heap/GCSegmentedArray.h: Added.

(JSC::GCArraySegment::GCArraySegment):
(JSC::GCArraySegment::data):

• heap/GCSegmentedArrayInlines.h: Added.

(JSC::GCSegmentedArray<T>::GCSegmentedArray):
(JSC::GCSegmentedArray<T>::~GCSegmentedArray):
(JSC::GCSegmentedArray<T>::clear):
(JSC::GCSegmentedArray<T>::expand):
(JSC::GCSegmentedArray<T>::refill):
(JSC::GCSegmentedArray<T>::fillVector):
(JSC::GCArraySegment<T>::create):
(JSC::GCSegmentedArray<T>::postIncTop):
(JSC::GCSegmentedArray<T>::preDecTop):
(JSC::GCSegmentedArray<T>::setTopForFullSegment):
(JSC::GCSegmentedArray<T>::setTopForEmptySegment):
(JSC::GCSegmentedArray<T>::top):
(JSC::GCSegmentedArray<T>::validatePrevious):
(JSC::GCSegmentedArray<T>::append):
(JSC::GCSegmentedArray<T>::canRemoveLast):
(JSC::GCSegmentedArray<T>::removeLast):
(JSC::GCSegmentedArray<T>::isEmpty):
(JSC::GCSegmentedArray<T>::size):

• heap/MarkStack.cpp:

(JSC::MarkStackArray::MarkStackArray):
(JSC::MarkStackArray::~MarkStackArray):
(JSC::MarkStackArray::donateSomeCellsTo):
(JSC::MarkStackArray::stealSomeCellsFrom):

• heap/MarkStack.h:
• heap/MarkStackInlines.h:

File:

• trunk/Source/JavaScriptCore/heap/MarkStack.cpp (modified) (4 diffs)

trunk/Source/JavaScriptCore/heap/MarkStack.cpp

@@ -26 +26 @@
 #include "config.h"
 #include "MarkStack.h"
-#include "MarkStackInlines.h"
-
-#include "ConservativeRoots.h"
-#include "CopiedSpace.h"
-#include "CopiedSpaceInlines.h"
-#include "Heap.h"
-#include "JSArray.h"
-#include "JSCell.h"
-#include "JSObject.h"
-
-#include "SlotVisitorInlines.h"
-#include "Structure.h"
-#include "WriteBarrier.h"
-#include <wtf/Atomics.h>
-#include <wtf/DataLog.h>
-#include <wtf/MainThread.h>
 
 namespace JSC {
 
-COMPILE_ASSERT(MarkStackSegment::blockSize == WeakBlock::blockSize, blockSizeMatch);
-
 MarkStackArray::MarkStackArray(BlockAllocator& blockAllocator)
-    : m_blockAllocator(blockAllocator)
-    , m_top(0)
-    , m_numberOfSegments(0)
+    : GCSegmentedArray<const JSCell*>(blockAllocator)
 {
-    m_segments.push(MarkStackSegment::create(m_blockAllocator.allocate<MarkStackSegment>()));
-    m_numberOfSegments++;
-}
-
-MarkStackArray::~MarkStackArray()
-{
-    ASSERT(m_numberOfSegments == 1);
-    ASSERT(m_segments.size() == 1);
-    m_blockAllocator.deallocate(MarkStackSegment::destroy(m_segments.removeHead()));
-    m_numberOfSegments--;
-    ASSERT(!m_numberOfSegments);
-    ASSERT(!m_segments.size());
-}
-
-void MarkStackArray::clear()
-{
-    if (!m_segments.head())
-        return;
-    MarkStackSegment* next;
-    for (MarkStackSegment* current = m_segments.head(); current->next(); current = next) {
-        next = current->next();
-        m_segments.remove(current);
-        m_blockAllocator.deallocate(MarkStackSegment::destroy(current));
-    }
-    m_top = 0;
-    m_numberOfSegments = 1;
-#if !ASSERT_DISABLED
-    m_segments.head()->m_top = 0;
-#endif
-}
-
-void MarkStackArray::expand()
-{
-    ASSERT(m_segments.head()->m_top == s_segmentCapacity);
-    
-    MarkStackSegment* nextSegment = MarkStackSegment::create(m_blockAllocator.allocate<MarkStackSegment>());
-    m_numberOfSegments++;
-    
-#if !ASSERT_DISABLED
-    nextSegment->m_top = 0;
-#endif
-
-    m_segments.push(nextSegment);
-    setTopForEmptySegment();
-    validatePrevious();
-}
-
-bool MarkStackArray::refill()
-{
-    validatePrevious();
-    if (top())
-        return true;
-    m_blockAllocator.deallocate(MarkStackSegment::destroy(m_segments.removeHead()));
-    ASSERT(m_numberOfSegments > 1);
-    m_numberOfSegments--;
-    setTopForFullSegment();
-    validatePrevious();
-    return true;
 }
 
@@ -134 +56 @@
     // Remove our head and the head of the other list before we start moving segments around.
     // We'll add them back on once we're done donating.
-    MarkStackSegment* myHead = m_segments.removeHead();
-    MarkStackSegment* otherHead = other.m_segments.removeHead();
+    GCArraySegment<const JSCell*>* myHead = m_segments.removeHead();
+    GCArraySegment<const JSCell*>* otherHead = other.m_segments.removeHead();
 
     while (segmentsToDonate--) {
-        MarkStackSegment* current = m_segments.removeHead();
+        GCArraySegment<const JSCell*>* current = m_segments.removeHead();
         ASSERT(current);
         ASSERT(m_numberOfSegments > 1);
@@ -166 +88 @@
     if (other.m_numberOfSegments > 1) {
         // Move the heads of the lists aside. We'll push them back on after.
-        MarkStackSegment* otherHead = other.m_segments.removeHead();
-        MarkStackSegment* myHead = m_segments.removeHead();
+        GCArraySegment<const JSCell*>* otherHead = other.m_segments.removeHead();
+        GCArraySegment<const JSCell*>* myHead = m_segments.removeHead();
 
         ASSERT(other.m_segments.head()->m_top == s_segmentCapacity);
@@ -189 +111 @@
 }
 
-void MarkStackArray::fillVector(Vector<const JSCell*>& vector)
-{
-    ASSERT(vector.size() == size());
-
-    MarkStackSegment* currentSegment = m_segments.head();
-    if (!currentSegment)
-        return;
-
-    unsigned count = 0;
-    for (unsigned i = 0; i < m_top; ++i) {
-        ASSERT(currentSegment->data()[i]);
-        vector[count++] = currentSegment->data()[i];
-    }
-
-    currentSegment = currentSegment->next();
-    while (currentSegment) {
-        for (unsigned i = 0; i < s_segmentCapacity; ++i) {
-            ASSERT(currentSegment->data()[i]);
-            vector[count++] = currentSegment->data()[i];
-        }
-        currentSegment = currentSegment->next();
-    }
-}
-
 } // namespace JSC