MediumLine* Heap::allocateMediumLineSlowCase(std::lock_guard<StaticMutex>& lock)
{
m_isAllocatingPages = true;
MediumPage* page = [this]() {
if (m_mediumPages.size())
return m_mediumPages.pop();
MediumPage* page = m_vmHeap.allocateMediumPage();
vmAllocatePhysicalPages(page->begin()->begin(), vmPageSize);
return page;
}();
MediumLine* line = page->begin();
for (auto it = line + 1; it != page->end(); ++it)
m_mediumLines.push(it);
page->ref(lock);
return line;
}
void Heap::allocateMediumBumpRanges(std::lock_guard<StaticMutex>& lock, size_t sizeClass, BumpAllocator& allocator, BumpRangeCache& rangeCache)
{
MediumPage* page = allocateMediumPage(lock, sizeClass);
BASSERT(!rangeCache.size());
MediumLine* lines = page->begin();
// Due to overlap from the previous line, the last line in the page may not be able to fit any objects.
size_t end = MediumPage::lineCount;
if (!m_mediumLineMetadata[sizeClass][MediumPage::lineCount - 1].objectCount)
--end;
// Find a free line.
for (size_t lineNumber = 0; lineNumber < end; ++lineNumber) {
if (lines[lineNumber].refCount(lock))
continue;
// In a fragmented page, some free ranges might not fit in the cache.
if (rangeCache.size() == rangeCache.capacity()) {
m_mediumPagesWithFreeLines[sizeClass].push(page);
return;
}
LineMetadata& lineMetadata = m_mediumLineMetadata[sizeClass][lineNumber];
char* begin = lines[lineNumber].begin() + lineMetadata.startOffset;
unsigned short objectCount = lineMetadata.objectCount;
lines[lineNumber].ref(lock, lineMetadata.objectCount);
page->ref(lock);
// Merge with subsequent free lines.
while (++lineNumber < end) {
if (lines[lineNumber].refCount(lock))
break;
LineMetadata& lineMetadata = m_mediumLineMetadata[sizeClass][lineNumber];
objectCount += lineMetadata.objectCount;
lines[lineNumber].ref(lock, lineMetadata.objectCount);
page->ref(lock);
}
if (!allocator.canAllocate())
allocator.refill({ begin, objectCount });
else
rangeCache.push({ begin, objectCount });
}
}
