Method allocateInternal

src/common/classes/alloc.cpp:2270–2328

}

MemBlock* MemPool::allocateInternal(size_t from, size_t& length, bool flagRedirect)
{
	MutexEnsureUnlock guard(mutex, "MemPool::allocateInternal");
	guard.enter();

	++blocksAllocated;
	++blocksActive;

	// If this is a small block, look for it there

	MemBlock* block = smallObjects.allocateBlock(this, from, length);
	if (block)
		return block;

	// Parent redirection of medium blocks

	if (parent_redirect && flagRedirect && length < PARENT_REDIRECT_THRESHOLD)
	{
		guard.leave();
		block = parent->allocateInternal(from, length, false);
		guard.enter();

		if (block)
		{
			if (parent_redirect)	// someone else redirected block in this pool?
			{
				block->setRedirect();

				parentRedirected.push(block);
				if (parentRedirected.getCount() == parentRedirected.getCapacity())
					parent_redirect = false;

				return block;
			}
			else					// worst case - very low possibility
			{
				guard.leave();
				parent->releaseBlock(block, false);
				guard.enter();
			}
		}
	}

	block = mediumObjects.allocateBlock(this, from, length);
	if (block)
		return block;

	/*
	 *  OK, we've got a "big block" on hands.  To maximize confusing, the indicated
	 *  "length" of a free big block is the length of MemHeader plus body*/

	fb_assert(from == 0);
	size_t hunkLength = MemBigHunk::hdrSize() + offsetof(MemBlock, body) + length;

	// Allocate the new hunk

	MemBigHunk* hunk = new(allocRaw(hunkLength)) MemBigHunk(&bigHunks, hunkLength);
	return hunk->block;