Class StableAttachmentPart

src/jrd/Attachment.h:206–393

RefCounted part of Attachment object, placed into permanent pool

// RefCounted part of Attachment object, placed into permanent pool
//
class StableAttachmentPart : public Firebird::RefCounted, public Firebird::GlobalStorage
{
public:
	class Sync
	{
	public:
		Sync()
			: waiters(0), threadId(0), totalLocksCounter(0), currentLocksCounter(0)
		{ }

		void enter(const char* aReason)
		{
			ThreadId curTid = getThreadId();

			if (threadId == curTid)
			{
				currentLocksCounter++;
				return;
			}

			if (threadId || !syncMutex.tryEnter(aReason))
			{
				// we have contention with another thread
				waiters.fetch_add(1, std::memory_order_relaxed);
				syncMutex.enter(aReason);
				waiters.fetch_sub(1, std::memory_order_relaxed);
			}

			threadId = curTid;
			totalLocksCounter++;
			fb_assert(currentLocksCounter == 0);
			currentLocksCounter++;
		}

		bool tryEnter(const char* aReason)
		{
			ThreadId curTid = getThreadId();

			if (threadId == curTid)
			{
				currentLocksCounter++;
				return true;
			}

			if (threadId || !syncMutex.tryEnter(aReason))
				return false;

			threadId = curTid;
			totalLocksCounter++;
			fb_assert(currentLocksCounter == 0);
			currentLocksCounter++;
			return true;
		}

		void leave()
		{
			fb_assert(currentLocksCounter > 0);