The reasons are discussed in #71.
Namely:
- transfers are self-paced, TCP clients are divided among threads
- due to the nature of DNS, most of the connections should be active
- if not, it is probably an attack, long idling connections are disconnected
- even then the performance degradation is not so severe

fixes #71

refs #54

- Works, but there are leaks
- Missing doxygens
- The estimate is not accurate - it reports about a half of the actual consumption on a 32bit system

Refs #37

Two reasons:
- There's some rare race condition in the queue implementation
- Doesn't scale and current performance is almost the same (-~2%)
- Created branch with the queue still retained for future inspection

refs #2463

Change-Id: I7a686f92bf9879e248f7878974f1840d179d84d0

Mempool is a type of memory allocator that allows to
free all allocated elements at once.
Removed unnecessary string and state operations.
Licensed under LGPL, same as lists and heap.

Change-Id: I8b8f84f41dcc321f37e51894b5c121f463c4f111

General idea is regular search with keeping node stack.
If node is found, then return current node.
If node is htable, search for suffixes in htable.
If anything fails, walk up the visited nodes and check if
any visited node has value. If yes, then it is a prefix.

f.e. searching for 'abcd'
visited nodes: root -a-> {1:trie} -b-> {2:htable}
1. search htable for 'cd', 'c'
2. retrace to node {1}, does it have value?
3. yes, node1 is prefix 'ab' for 'abcd'

Change-Id: I622adbe9a127d8317b933af4bf56e1411e2d915f

Fallback for x86/amd64 architectures using full barrier.

Change-Id: I80e3beaa721653f760f2d0a6d26a80dd422ab618

- Simplified and decoupled I/O from processing code.
- Single reader with multiple workers.
- Reader is bound to specific CPU for lowest possible latency.
- Reverted to select() instead of fdset wrapper as epoll/kqueue could
  be quite slower for a single or handful of sockets.
- Reader I/O calls are non-blocking.

General idea is:
- Reader takes free request from a rx_queue
- Receives data and pushes it to the tx_queue
- Worker processes the packets, sends answers and returns the request
  to the rx_queue

Semi lock-free queue is used for communication.
This is measured to be slightly better than singlethreading, as socket
contention could be better predicted - the reader cannot check sockets
for new events when tx_queue is full.

Change-Id: Ifc40889b355404a9e78e10d77c26cb3fc4c58386

refs #2413

Change-Id: I5d029c5a9eb655a42f6eaaf23be062e0a8ef96d3

refs #2137

Change-Id: Ic8adef04228925e5c8131431c2a126d31310a488

refs #2381

norefs

The unittests-libknot content is in unittests now.

- Changed paths in Knot.file, Makefile.am and in the test files.

- Fixed Knot.files

refs #2353

refs #2353

refs #2353

refs #2353

refs #2137

- Move text zone dump to knot.
- Separate rrset dump and leave it in libknot.
- Add auxiliary function for text dump.

refs @2138

refs @2138

Based on memo and implementation notes from
Vixie and Schryver.
http://ss.vix.su/~vixie/isc-tn-2012-1.txt

Basically a token bucket algorithm, no interpolation
yet. Classification of responses based on:
<address prefix, resp.class, name, seed>

address prefix = /24 for IPv4, /56 for IPv6
resp.class = based on rcode,question and ancount
name = either qname or answer
seed = secret to harden collision prediction

No SLIP yet.

- Add missing descriptors.
- Extend descriptor structure with type name.
- Add conversion functions num<->str for types and classes.

refs @2138

Conflicts:

	src/common/descriptor_new.c
	src/common/descriptor_new.h

- Add missing descriptors.
- Extend descriptor structure with type name.
- Add conversion functions num<->str for types and classes.

refs @2138