From f075f0bb5f9a57cacf4c398d3f01de61016f631d Mon Sep 17 00:00:00 2001
From: TheLazieR Yip <thelazier@gmail.com>
Date: Tue, 22 Nov 2016 20:02:20 -0500
Subject: [PATCH 1/5] Add coin's IRC parameters

---
 lib/coins.py  |  8 ++++++++
 server/irc.py | 23 ++++++++++++++---------
 2 files changed, 22 insertions(+), 9 deletions(-)

diff --git a/lib/coins.py b/lib/coins.py
index 4e56894..71129b6 100644
--- a/lib/coins.py
+++ b/lib/coins.py
@@ -39,6 +39,11 @@ class Coin(object):
     VALUE_PER_COIN = 100000000
     CHUNK_SIZE=2016
     STRANGE_VERBYTE = 0xff
+    # IRC Defaults
+    IRC_PREFIX = "E_"
+    IRC_CHANNEL = "#electrum"
+    IRC_SERVER = "irc.freenode.net"
+    IRC_PORT = 6667
 
     @classmethod
     def lookup_coin_class(cls, name, net):
@@ -359,6 +364,8 @@ class Dash(Coin):
     TX_COUNT = 2157510
     TX_PER_BLOCK = 4
     DEFAULT_RPC_PORT = 9998
+    IRC_PREFIX = "D_"
+    IRC_CHANNEL = "#electrum-dash"
 
     @classmethod
     def header_hashes(cls, header):
@@ -381,3 +388,4 @@ class DashTestnet(Dash):
     TX_COUNT = 132681
     TX_PER_BLOCK = 1
     DEFAULT_RPC_PORT = 19998
+    IRC_PREFIX = "d_"
diff --git a/server/irc.py b/server/irc.py
index 3a938cd..5ee50ea 100644
--- a/server/irc.py
+++ b/server/irc.py
@@ -30,7 +30,6 @@ def port_text(letter, port, default):
 
 class IRC(LoggedClass):
 
-    PEER_REGEXP = re.compile('(E_[^!]*)!')
     Peer = namedtuple('Peer', 'ip_addr host ports')
 
     class DisconnectedError(Exception):
@@ -45,9 +44,15 @@ class IRC(LoggedClass):
         version = '1.0'
         self.real_name = '{} v{} {} {}'.format(env.report_host, version,
                                                tcp_text, ssl_text)
-        self.nick = 'E_{}'.format(env.irc_nick if env.irc_nick else
+        self.prefix = env.coin.IRC_PREFIX
+        self.nick = '{}{}'.format(self.prefix,
+                                  env.irc_nick if env.irc_nick else
                                   double_sha256(env.report_host.encode())
                                   [:5].hex())
+        self.channel = env.coin.IRC_CHANNEL
+        self.irc_server = env.coin.IRC_SERVER
+        self.irc_port = env.coin.IRC_PORT
+        self.peer_regexp = re.compile('({}[^!]*)!'.format(self.prefix))
         self.peers = {}
 
     async def start(self):
@@ -72,7 +77,7 @@ class IRC(LoggedClass):
         while True:
             try:
                 connection = reactor.server()
-                connection.connect('irc.freenode.net', 6667,
+                connection.connect(self.irc_server, self.irc_port,
                                    self.nick, ircname=self.real_name)
                 connection.set_keepalive(60)
                 while True:
@@ -89,8 +94,8 @@ class IRC(LoggedClass):
                          .format(event.type, event.source, event.arguments))
 
     def on_welcome(self, connection, event):
-        '''Called when we connect to freenode.'''
-        connection.join('#electrum')
+        '''Called when we connect to irc server.'''
+        connection.join(self.channel)
 
     def on_disconnect(self, connection, event):
         '''Called if we are disconnected.'''
@@ -99,20 +104,20 @@ class IRC(LoggedClass):
 
     def on_join(self, connection, event):
         '''Called when someone new connects to our channel, including us.'''
-        match = self.PEER_REGEXP.match(event.source)
+        match = self.peer_regexp.match(event.source)
         if match:
             connection.who(match.group(1))
 
     def on_quit(self, connection, event):
         '''Called when someone leaves our channel.'''
-        match = self.PEER_REGEXP.match(event.source)
+        match = self.peer_regexp.match(event.source)
         if match:
             self.peers.pop(match.group(1), None)
 
     def on_kick(self, connection, event):
         '''Called when someone is kicked from our channel.'''
         self.log_event(event)
-        match = self.PEER_REGEXP.match(event.arguments[0])
+        match = self.peer_regexp.match(event.arguments[0])
         if match:
             self.peers.pop(match.group(1), None)
 
@@ -123,7 +128,7 @@ class IRC(LoggedClass):
         The users are space-separated in the 2nd argument.
         '''
         for peer in event.arguments[2].split():
-            if peer.startswith("E_"):
+            if peer.startswith(self.prefix):
                 connection.who(peer)
 
     def on_whoreply(self, connection, event):

From cebf93cdc3cbd7fad5257f9dad49c71db09912ab Mon Sep 17 00:00:00 2001
From: Neil Booth <kyuupichan@gmail.com>
Date: Wed, 23 Nov 2016 11:52:17 +0900
Subject: [PATCH 2/5] Handle abuse better

- close connections on any encoding error
- if the connection is closing do not process buffered requests
---
 lib/jsonrpc.py | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/lib/jsonrpc.py b/lib/jsonrpc.py
index eff942d..e2ddda2 100644
--- a/lib/jsonrpc.py
+++ b/lib/jsonrpc.py
@@ -97,6 +97,9 @@ class JSONRPC(asyncio.Protocol, LoggedClass):
         decode_message for handling.
         '''
         self.recv_size += len(data)
+        if self.transport.is_closing():
+            return
+
         while True:
             npos = data.find(ord('\n'))
             if npos == -1:
@@ -118,6 +121,7 @@ class JSONRPC(asyncio.Protocol, LoggedClass):
         except UnicodeDecodeError as e:
             msg = 'cannot decode binary bytes: {}'.format(e)
             self.send_json_error(msg, self.PARSE_ERROR)
+            self.transport.close()
             return
 
         try:
@@ -125,6 +129,7 @@ class JSONRPC(asyncio.Protocol, LoggedClass):
         except json.JSONDecodeError as e:
             msg = 'cannot decode JSON: {}'.format(e)
             self.send_json_error(msg, self.PARSE_ERROR)
+            self.transport.close()
             return
 
         self.on_json_request(message)

From bab0d162dee7ab156a48d5d5c54649da8f0c00cc Mon Sep 17 00:00:00 2001
From: Neil Booth <kyuupichan@gmail.com>
Date: Wed, 23 Nov 2016 15:07:16 +0900
Subject: [PATCH 3/5] Merge ServerManager and BlockServer

---
 electrumx_server.py       |   4 +-
 server/block_processor.py |  33 +++------
 server/protocol.py        | 140 ++++++++++++++++----------------------
 3 files changed, 72 insertions(+), 105 deletions(-)

diff --git a/electrumx_server.py b/electrumx_server.py
index d1ef476..940828e 100755
--- a/electrumx_server.py
+++ b/electrumx_server.py
@@ -17,7 +17,7 @@ import traceback
 from functools import partial
 
 from server.env import Env
-from server.protocol import BlockServer
+from server.protocol import ServerManager
 
 SUPPRESS_MESSAGES = [
     'Fatal read error on socket transport',
@@ -45,7 +45,7 @@ def main_loop():
                     'accept_connection2()' in repr(context.get('task'))):
                 loop.default_exception_handler(context)
 
-    server = BlockServer(Env())
+    server = ServerManager(Env())
     future = asyncio.ensure_future(server.main_loop())
 
     # Install signal handlers
diff --git a/server/block_processor.py b/server/block_processor.py
index f911e51..d529659 100644
--- a/server/block_processor.py
+++ b/server/block_processor.py
@@ -133,9 +133,11 @@ class BlockProcessor(server.db.DB):
     Coordinate backing up in case of chain reorganisations.
     '''
 
-    def __init__(self, env):
+    def __init__(self, client, env):
         super().__init__(env)
 
+        self.client = client
+
         # These are our state as we move ahead of DB state
         self.fs_height = self.db_height
         self.fs_tx_count = self.db_tx_count
@@ -146,7 +148,6 @@ class BlockProcessor(server.db.DB):
         self.daemon = Daemon(self.coin.daemon_urls(env.daemon_url))
         self.caught_up = False
         self.touched = set()
-        self.futures = []
 
         # Meta
         self.utxo_MB = env.utxo_MB
@@ -185,7 +186,7 @@ class BlockProcessor(server.db.DB):
 
         Safely flushes the DB on clean shutdown.
         '''
-        self.futures.append(asyncio.ensure_future(self.prefetcher.main_loop()))
+        prefetcher_loop = asyncio.ensure_future(self.prefetcher.main_loop())
 
         # Simulate a reorg if requested
         if self.env.force_reorg > 0:
@@ -197,20 +198,11 @@ class BlockProcessor(server.db.DB):
             while True:
                 await self._wait_for_update()
         except asyncio.CancelledError:
-            self.on_cancel()
-            await self.wait_shutdown()
-
-    def on_cancel(self):
-        '''Called when the main loop is cancelled.
+            pass
 
-        Intended to be overridden in derived classes.'''
-        for future in self.futures:
-            future.cancel()
+        prefetcher_loop.cancel()
         self.flush(True)
-
-    async def wait_shutdown(self):
-        '''Wait for shutdown to complete cleanly, and return.'''
-        await asyncio.sleep(0)
+        await self.client.shutdown()
 
     async def _wait_for_update(self):
         '''Wait for the prefetcher to deliver blocks.
@@ -237,26 +229,21 @@ class BlockProcessor(server.db.DB):
             # Flush everything as queries are performed on the DB and
             # not in-memory.
             self.flush(True)
-            self.notify(self.touched)
+            self.client.notify(self.touched)
         elif time.time() > self.next_cache_check:
             self.check_cache_size()
             self.next_cache_check = time.time() + 60
         self.touched = set()
 
     async def first_caught_up(self):
-        '''Called after each deamon poll if caught up.'''
+        '''Called when first caught up after start, or after a reorg.'''
         self.caught_up = True
         if self.first_sync:
             self.first_sync = False
             self.logger.info('{} synced to height {:,d}.  DB version:'
                              .format(VERSION, self.height, self.db_version))
         self.flush(True)
-
-    def notify(self, touched):
-        '''Called with list of touched addresses by new blocks.
-
-        Only called for blocks found after first_caught_up is called.
-        Intended to be overridden in derived classes.'''
+        await self.client.first_caught_up()
 
     async def handle_chain_reorg(self, count):
         '''Handle a chain reorganisation.
diff --git a/server/protocol.py b/server/protocol.py
index 94261df..dc452e9 100644
--- a/server/protocol.py
+++ b/server/protocol.py
@@ -20,63 +20,14 @@ from functools import partial
 from lib.hash import sha256, double_sha256, hash_to_str, hex_str_to_hash
 from lib.jsonrpc import JSONRPC, json_notification_payload
 from lib.tx import Deserializer
-from lib.util import LoggedClass
+import lib.util as util
 from server.block_processor import BlockProcessor
 from server.daemon import DaemonError
 from server.irc import IRC
 from server.version import VERSION
 
 
-class BlockServer(BlockProcessor):
-    '''Like BlockProcessor but also has a mempool and a server manager.
-
-    Servers are started immediately the block processor first catches
-    up with the daemon.
-    '''
-
-    def __init__(self, env):
-        super().__init__(env)
-        self.server_mgr = ServerManager(self, env)
-        self.mempool = MemPool(self)
-
-    async def first_caught_up(self):
-        # Call the base class to flush and log first
-        await super().first_caught_up()
-        await self.server_mgr.start_servers()
-        self.futures.append(self.mempool.start())
-
-    def notify(self, touched):
-        '''Called when addresses are touched by new blocks or mempool
-        updates.'''
-        self.server_mgr.notify(self.height, touched)
-
-    def on_cancel(self):
-        '''Called when the main loop is cancelled.'''
-        self.server_mgr.stop()
-        super().on_cancel()
-
-    async def wait_shutdown(self):
-        '''Wait for shutdown to complete cleanly, and return.'''
-        await self.server_mgr.wait_shutdown()
-        await super().wait_shutdown()
-
-    def mempool_transactions(self, hash168):
-        '''Generate (hex_hash, tx_fee, unconfirmed) tuples for mempool
-        entries for the hash168.
-
-        unconfirmed is True if any txin is unconfirmed.
-        '''
-        return self.mempool.transactions(hash168)
-
-    def mempool_value(self, hash168):
-        '''Return the unconfirmed amount in the mempool for hash168.
-
-        Can be positive or negative.
-        '''
-        return self.mempool.value(hash168)
-
-
-class MemPool(LoggedClass):
+class MemPool(util.LoggedClass):
     '''Representation of the daemon's mempool.
 
     Updated regularly in caught-up state.  Goal is to enable efficient
@@ -91,11 +42,14 @@ class MemPool(LoggedClass):
     tx's txins are unconfirmed.  tx hashes are hex strings.
     '''
 
-    def __init__(self, bp):
+    def __init__(self, daemon, coin, db, manager):
         super().__init__()
+        self.daemon = daemon
+        self.coin = coin
+        self.db = db
+        self.manager = manager
         self.txs = {}
         self.hash168s = defaultdict(set)  # None can be a key
-        self.bp = bp
         self.count = -1
 
     def start(self):
@@ -120,7 +74,7 @@ class MemPool(LoggedClass):
         Remove transactions that are no longer in our mempool.
         Request new transactions we don't have then add to our mempool.
         '''
-        hex_hashes = set(await self.bp.daemon.mempool_hashes())
+        hex_hashes = set(await self.daemon.mempool_hashes())
         touched = set()
         missing_utxos = []
 
@@ -145,7 +99,7 @@ class MemPool(LoggedClass):
         # ones the daemon no longer has (it will return None).  Put
         # them into a dictionary of hex hash to deserialized tx.
         hex_hashes.difference_update(self.txs)
-        raw_txs = await self.bp.daemon.getrawtransactions(hex_hashes)
+        raw_txs = await self.daemon.getrawtransactions(hex_hashes)
         if initial:
             self.logger.info('analysing {:,d} mempool txs'
                              .format(len(raw_txs)))
@@ -155,8 +109,8 @@ class MemPool(LoggedClass):
 
         # The mempool is unordered, so process all outputs first so
         # that looking for inputs has full info.
-        script_hash168 = self.bp.coin.hash168_from_script()
-        db_utxo_lookup = self.bp.db_utxo_lookup
+        script_hash168 = self.coin.hash168_from_script()
+        db_utxo_lookup = self.db.db_utxo_lookup
 
         def txout_pair(txout):
             return (script_hash168(txout.pk_script), txout.value)
@@ -195,7 +149,7 @@ class MemPool(LoggedClass):
             try:
                 infos = (txin_info(txin) for txin in tx.inputs)
                 txin_pairs, unconfs = zip(*infos)
-            except self.bp.MissingUTXOError:
+            except self.db.MissingUTXOError:
                 # Drop this TX.  If other mempool txs depend on it
                 # it's harmless - next time the mempool is refreshed
                 # they'll either be cleaned up or the UTXOs will no
@@ -227,7 +181,7 @@ class MemPool(LoggedClass):
             self.logger.info('{:,d} txs touching {:,d} addresses'
                              .format(len(self.txs), len(self.hash168s)))
 
-        self.bp.notify(touched)
+        self.maanger.notify(touched)
 
     def transactions(self, hash168):
         '''Generate (hex_hash, tx_fee, unconfirmed) tuples for mempool
@@ -254,14 +208,19 @@ class MemPool(LoggedClass):
         return value
 
 
-class ServerManager(LoggedClass):
-    '''Manages the servers.'''
+class ServerManager(util.LoggedClass):
+    '''Manages the client servers, a mempool, and a block processor.
+
+    Servers are started immediately the block processor first catches
+    up with the daemon.
+    '''
 
     MgrTask = namedtuple('MgrTask', 'session task')
 
-    def __init__(self, bp, env):
+    def __init__(self, env):
         super().__init__()
-        self.bp = bp
+        self.bp = BlockProcessor(self, env)
+        self.mempool = MemPool(self.db.daemon, env.coin, self.bp, self)
         self.env = env
         self.servers = []
         self.irc = IRC(env)
@@ -269,11 +228,27 @@ class ServerManager(LoggedClass):
         self.max_subs = env.max_subs
         self.subscription_count = 0
         self.irc_future = None
+        self.mempool_future = None
         self.logger.info('max subscriptions across all sessions: {:,d}'
                          .format(self.max_subs))
         self.logger.info('max subscriptions per session: {:,d}'
                          .format(env.max_session_subs))
 
+    def mempool_transactions(self, hash168):
+        '''Generate (hex_hash, tx_fee, unconfirmed) tuples for mempool
+        entries for the hash168.
+
+        unconfirmed is True if any txin is unconfirmed.
+        '''
+        return self.mempool.transactions(hash168)
+
+    def mempool_value(self, hash168):
+        '''Return the unconfirmed amount in the mempool for hash168.
+
+        Can be positive or negative.
+        '''
+        return self.mempool.value(hash168)
+
     async def start_server(self, kind, *args, **kw_args):
         loop = asyncio.get_event_loop()
         protocol_class = LocalRPC if kind == 'RPC' else ElectrumX
@@ -315,35 +290,40 @@ class ServerManager(LoggedClass):
         else:
             self.logger.info('IRC disabled')
 
-    def notify(self, height, touched):
+    async def first_caught_up(self):
+        if not self.mempool_future:
+            self.mempool_future = self.mempool.start()
+            await self.server_mgr.start_servers()
+
+    def notify(self, touched):
         '''Notify sessions about height changes and touched addresses.'''
         cache = {}
         for session in self.sessions:
             if isinstance(session, ElectrumX):
                 # Use a tuple to distinguish from JSON
-                session.jobs.put_nowait((height, touched, cache))
+                session.jobs.put_nowait((self.bp.height, touched, cache))
 
-    def stop(self):
-        '''Close listening servers.'''
+    async def shutdown(self):
+        '''Call to shutdown the servers.  Returns when done.'''
         for server in self.servers:
             server.close()
+        for server in self.servers:
+            await server.wait_closed()
+        self.servers = []
+
         if self.irc_future:
             self.irc_future.cancel()
+        if self.mempool_future:
+            self.mempool_future.cancel()
         if self.sessions:
-            self.logger.info('cleanly closing client sessions, please wait...')
+            await self.close_sessions()
+
+    async def close_sessions(self, secs=60):
+        self.logger.info('cleanly closing client sessions, please wait...')
         for session in self.sessions:
             self.close_session(session)
-
-    async def wait_shutdown(self):
-        # Wait for servers to close
-        for server in self.servers:
-            await server.wait_closed()
-        self.servers = []
-
-        secs = 60
         self.logger.info('server listening sockets closed, waiting '
                          '{:d} seconds for socket cleanup'.format(secs))
-
         limit = time.time() + secs
         while self.sessions and time.time() < limit:
             await asyncio.sleep(4)
@@ -628,7 +608,7 @@ class ElectrumX(Session):
         # Note history is ordered and mempool unordered in electrum-server
         # For mempool, height is -1 if unconfirmed txins, otherwise 0
         history = await self.async_get_history(hash168)
-        mempool = self.bp.mempool_transactions(hash168)
+        mempool = self.manager.mempool_transactions(hash168)
 
         status = ''.join('{}:{:d}:'.format(hash_to_str(tx_hash), height)
                          for tx_hash, height in history)
@@ -666,7 +646,7 @@ class ElectrumX(Session):
     def unconfirmed_history(self, hash168):
         # Note unconfirmed history is unordered in electrum-server
         # Height is -1 if unconfirmed txins, otherwise 0
-        mempool = self.bp.mempool_transactions(hash168)
+        mempool = self.manager.mempool_transactions(hash168)
         return [{'tx_hash': tx_hash, 'height': -unconfirmed, 'fee': fee}
                 for tx_hash, fee, unconfirmed in mempool]
 
@@ -707,7 +687,7 @@ class ElectrumX(Session):
     async def get_balance(self, hash168):
         utxos = await self.get_utxos(hash168)
         confirmed = sum(utxo.value for utxo in utxos)
-        unconfirmed = self.bp.mempool_value(hash168)
+        unconfirmed = self.manager.mempool_value(hash168)
         return {'confirmed': confirmed, 'unconfirmed': unconfirmed}
 
     async def list_unspent(self, hash168):

From 9e220820aaa59bc93767a35dc4ab064b7b0a64a8 Mon Sep 17 00:00:00 2001
From: Neil Booth <kyuupichan@gmail.com>
Date: Wed, 23 Nov 2016 16:55:23 +0900
Subject: [PATCH 4/5] Rework futures and event handling

---
 server/block_processor.py | 31 +++++++++----------
 server/irc.py             | 10 ++++--
 server/protocol.py        | 65 ++++++++++++++++++++++-----------------
 3 files changed, 58 insertions(+), 48 deletions(-)

diff --git a/server/block_processor.py b/server/block_processor.py
index d529659..2456956 100644
--- a/server/block_processor.py
+++ b/server/block_processor.py
@@ -147,6 +147,7 @@ class BlockProcessor(server.db.DB):
 
         self.daemon = Daemon(self.coin.daemon_urls(env.daemon_url))
         self.caught_up = False
+        self.event = asyncio.Event()
         self.touched = set()
 
         # Meta
@@ -182,27 +183,23 @@ class BlockProcessor(server.db.DB):
         self.clean_db()
 
     async def main_loop(self):
-        '''Main loop for block processing.
-
-        Safely flushes the DB on clean shutdown.
-        '''
-        prefetcher_loop = asyncio.ensure_future(self.prefetcher.main_loop())
-
-        # Simulate a reorg if requested
-        if self.env.force_reorg > 0:
-            self.logger.info('DEBUG: simulating chain reorg of {:,d} blocks'
-                             .format(self.env.force_reorg))
-            await self.handle_chain_reorg(self.env.force_reorg)
-
+        '''Main loop for block processing.'''
         try:
+            # Simulate a reorg if requested
+            if self.env.force_reorg > 0:
+                self.logger.info('DEBUG: simulating reorg of {:,d} blocks'
+                                 .format(self.env.force_reorg))
+                await self.handle_chain_reorg(self.env.force_reorg)
+
             while True:
                 await self._wait_for_update()
         except asyncio.CancelledError:
             pass
 
-        prefetcher_loop.cancel()
+    async def shutdown(self):
+        '''Shut down the DB cleanly.'''
+        self.logger.info('flushing state to DB for clean shutdown...')
         self.flush(True)
-        await self.client.shutdown()
 
     async def _wait_for_update(self):
         '''Wait for the prefetcher to deliver blocks.
@@ -211,7 +208,7 @@ class BlockProcessor(server.db.DB):
         '''
         blocks = await self.prefetcher.get_blocks()
         if not blocks:
-            await self.first_caught_up()
+            self.first_caught_up()
             return
 
         '''Strip the unspendable genesis coinbase.'''
@@ -235,7 +232,7 @@ class BlockProcessor(server.db.DB):
             self.next_cache_check = time.time() + 60
         self.touched = set()
 
-    async def first_caught_up(self):
+    def first_caught_up(self):
         '''Called when first caught up after start, or after a reorg.'''
         self.caught_up = True
         if self.first_sync:
@@ -243,7 +240,7 @@ class BlockProcessor(server.db.DB):
             self.logger.info('{} synced to height {:,d}.  DB version:'
                              .format(VERSION, self.height, self.db_version))
         self.flush(True)
-        await self.client.first_caught_up()
+        self.event.set()
 
     async def handle_chain_reorg(self, count):
         '''Handle a chain reorganisation.
diff --git a/server/irc.py b/server/irc.py
index 5ee50ea..14ba8da 100644
--- a/server/irc.py
+++ b/server/irc.py
@@ -54,10 +54,16 @@ class IRC(LoggedClass):
         self.irc_port = env.coin.IRC_PORT
         self.peer_regexp = re.compile('({}[^!]*)!'.format(self.prefix))
         self.peers = {}
+        self.disabled = env.irc is None
 
-    async def start(self):
+    async def start(self, caught_up):
+        '''Start IRC connections once caught up if enabled in environment.'''
+        await caught_up.wait()
         try:
-            await self.join()
+            if self.disabled:
+                self.logger.info('IRC is disabled')
+            else:
+                await self.join()
         except asyncio.CancelledError:
             pass
         except Exception as e:
diff --git a/server/protocol.py b/server/protocol.py
index dc452e9..c14e745 100644
--- a/server/protocol.py
+++ b/server/protocol.py
@@ -52,12 +52,11 @@ class MemPool(util.LoggedClass):
         self.hash168s = defaultdict(set)  # None can be a key
         self.count = -1
 
-    def start(self):
-        '''Starts the mempool synchronization mainloop.  Return a future.'''
-        return asyncio.ensure_future(self.main_loop())
+    async def main_loop(self, caught_up):
+        '''Asynchronously maintain mempool status with daemon.
 
-    async def main_loop(self):
-        '''Asynchronously maintain mempool status with daemon.'''
+        Waits until the caught up event is signalled.'''
+        await caught_up.wait()
         self.logger.info('maintaining state with daemon...')
         while True:
             try:
@@ -181,7 +180,7 @@ class MemPool(util.LoggedClass):
             self.logger.info('{:,d} txs touching {:,d} addresses'
                              .format(len(self.txs), len(self.hash168s)))
 
-        self.maanger.notify(touched)
+        self.manager.notify(touched)
 
     def transactions(self, hash168):
         '''Generate (hex_hash, tx_fee, unconfirmed) tuples for mempool
@@ -220,15 +219,14 @@ class ServerManager(util.LoggedClass):
     def __init__(self, env):
         super().__init__()
         self.bp = BlockProcessor(self, env)
-        self.mempool = MemPool(self.db.daemon, env.coin, self.bp, self)
+        self.mempool = MemPool(self.bp.daemon, env.coin, self.bp, self)
+        self.irc = IRC(env)
         self.env = env
         self.servers = []
-        self.irc = IRC(env)
         self.sessions = {}
         self.max_subs = env.max_subs
         self.subscription_count = 0
-        self.irc_future = None
-        self.mempool_future = None
+        self.futures = []
         self.logger.info('max subscriptions across all sessions: {:,d}'
                          .format(self.max_subs))
         self.logger.info('max subscriptions per session: {:,d}'
@@ -249,6 +247,24 @@ class ServerManager(util.LoggedClass):
         '''
         return self.mempool.value(hash168)
 
+    async def main_loop(self):
+        '''Server manager main loop.'''
+        def add_future(coro):
+            self.futures.append(asyncio.ensure_future(coro))
+
+        add_future(self.bp.main_loop())
+        add_future(self.bp.prefetcher.main_loop())
+        add_future(self.mempool.main_loop(self.bp.event))
+        add_future(self.irc.start(self.bp.event))
+        add_future(self.start_servers(self.bp.event))
+
+        for future in asyncio.as_completed(self.futures):
+            try:
+                await future  # Note: future is not one of self.futures
+            except asyncio.CancelledError:
+                break
+        await self.shutdown()
+
     async def start_server(self, kind, *args, **kw_args):
         loop = asyncio.get_event_loop()
         protocol_class = LocalRPC if kind == 'RPC' else ElectrumX
@@ -265,12 +281,14 @@ class ServerManager(util.LoggedClass):
             self.logger.info('{} server listening on {}:{:d}'
                              .format(kind, host, port))
 
-    async def start_servers(self):
+    async def start_servers(self, caught_up):
         '''Connect to IRC and start listening for incoming connections.
 
         Only connect to IRC if enabled.  Start listening on RCP, TCP
-        and SSL ports only if the port wasn pecified.
+        and SSL ports only if the port wasn't pecified.  Waits for the
+        caught_up event to be signalled.
         '''
+        await caught_up.wait()
         env = self.env
 
         if env.rpc_port is not None:
@@ -285,16 +303,6 @@ class ServerManager(util.LoggedClass):
             sslc.load_cert_chain(env.ssl_certfile, keyfile=env.ssl_keyfile)
             await self.start_server('SSL', env.host, env.ssl_port, ssl=sslc)
 
-        if env.irc:
-            self.irc_future = asyncio.ensure_future(self.irc.start())
-        else:
-            self.logger.info('IRC disabled')
-
-    async def first_caught_up(self):
-        if not self.mempool_future:
-            self.mempool_future = self.mempool.start()
-            await self.server_mgr.start_servers()
-
     def notify(self, touched):
         '''Notify sessions about height changes and touched addresses.'''
         cache = {}
@@ -305,18 +313,17 @@ class ServerManager(util.LoggedClass):
 
     async def shutdown(self):
         '''Call to shutdown the servers.  Returns when done.'''
+        for future in self.futures:
+            future.cancel()
         for server in self.servers:
             server.close()
-        for server in self.servers:
             await server.wait_closed()
-        self.servers = []
-
-        if self.irc_future:
-            self.irc_future.cancel()
-        if self.mempool_future:
-            self.mempool_future.cancel()
+        self.servers = [] # So add_session closes new sessions
+        while not all(future.done() for future in self.futures):
+            await asyncio.sleep(0)
         if self.sessions:
             await self.close_sessions()
+        await self.bp.shutdown()
 
     async def close_sessions(self, secs=60):
         self.logger.info('cleanly closing client sessions, please wait...')

From 86086cac633849bf787183ca4b12ddf55cb9f2b0 Mon Sep 17 00:00:00 2001
From: Neil Booth <kyuupichan@gmail.com>
Date: Wed, 23 Nov 2016 17:59:18 +0900
Subject: [PATCH 5/5] Prepare 0.7.5

---
 docs/RELEASE-NOTES | 14 ++++++++++++++
 server/version.py  |  2 +-
 2 files changed, 15 insertions(+), 1 deletion(-)

diff --git a/docs/RELEASE-NOTES b/docs/RELEASE-NOTES
index 7d67cbe..f62be6a 100644
--- a/docs/RELEASE-NOTES
+++ b/docs/RELEASE-NOTES
@@ -1,3 +1,17 @@
+version 0.7.5
+-------------
+
+- refactoring of server manager and event handling.  One side effect
+  is to fix a bug in 0.7.4 where after a reorg ElectrumX might create
+  a second mempool and/or kick off more servers.  Your testing would
+  be appreciated.  This is part of the refactoring necessary to
+  process incoming blocks asynchronously so client connections are not
+  left waiting for several seconds
+- close connections on first bad JSON encoding.  Do not process buffered
+  requests of a closing connection
+- make IRC params a function of the coin (TheLazier) and supply them for
+  Dash
+
 version 0.7.4
 -------------
 
diff --git a/server/version.py b/server/version.py
index aa6eb22..c7103aa 100644
--- a/server/version.py
+++ b/server/version.py
@@ -1 +1 @@
-VERSION = "ElectrumX 0.7.4"
+VERSION = "ElectrumX 0.7.5"