Method getSpace

src/jrd/MetaName.cpp:462–490

}

Dictionary::Word* Dictionary::Segment::getSpace(FB_SIZE_T len DIC_STAT_SEGMENT_PAR)
{
	len = getWordLength(len);

	// get old position value
	unsigned oldPos = position.load(std::memory_order_acquire);

	// restart loop
	for(;;)
	{
		// calculate and check new position
		unsigned newPos = oldPos + len;
		if (newPos >= SEG_BUFFER_SIZE)
			break;

		// try to store it safely in segment header
		if (position.compare_exchange_weak(oldPos, newPos, std::memory_order_release, std::memory_order_acquire))
		{
			return reinterpret_cast<Word*>(&buffer[oldPos]);
		}

#if DIC_STATS > 0
		++retries;
#endif
	}

	// Segment out of space
	return nullptr;
}

} // namespace Jrd