tcacheAllocateSmall() — netty Function Reference

Source Code

buffer/src/main/java/io/netty/buffer/PoolArena.java lines 150–189

    private void tcacheAllocateSmall(PoolThreadCache cache, PooledByteBuf<T> buf, final int reqCapacity,
                                     final int sizeIdx) {

        if (cache.allocateSmall(this, buf, reqCapacity, sizeIdx)) {
            // was able to allocate out of the cache so move on
            return;
        }

        /*
         * Synchronize on the head. This is needed as {@link PoolChunk#allocateSubpage(int)} and
         * {@link PoolChunk#free(long)} may modify the doubly linked list as well.
         */
        final PoolSubpage<T> head = smallSubpagePools[sizeIdx];
        final boolean needsNormalAllocation;
        head.lock();
        try {
            final PoolSubpage<T> s = head.next;
            needsNormalAllocation = s == head;
            if (!needsNormalAllocation) {
                assert s.doNotDestroy && s.elemSize == sizeClass.sizeIdx2size(sizeIdx) : "doNotDestroy=" +
                        s.doNotDestroy + ", elemSize=" + s.elemSize + ", sizeIdx=" + sizeIdx;
                long handle = s.allocate();
                assert handle >= 0;
                s.chunk.initBufWithSubpage(buf, null, handle, reqCapacity, cache, false);
            }
        } finally {
            head.unlock();
        }

        if (needsNormalAllocation) {
            lock();
            try {
                allocateNormal(buf, reqCapacity, sizeIdx, cache);
            } finally {
                unlock();
            }
        }

        incSmallAllocation();
    }