From 7126864052c57cc92dffa33b252eec216672c3ff Mon Sep 17 00:00:00 2001
From: Neil Booth <kyuupichan@gmail.com>
Date: Fri, 12 Jan 2018 15:19:36 +0800
Subject: [PATCH] Wait for mempool to sync before starting external servers

Closes #335
---
 server/controller.py | 10 +++++-----
 server/mempool.py    | 18 +++++-------------
 2 files changed, 10 insertions(+), 18 deletions(-)

diff --git a/server/controller.py b/server/controller.py
index fecb4b9..e7e45b9 100644
--- a/server/controller.py
+++ b/server/controller.py
@@ -125,9 +125,8 @@ class Controller(ServerBase):
         return self.mempool.value(hashX)
 
     def sent_tx(self, tx_hash):
-        '''Call when a TX is sent.  Tells mempool to prioritize it.'''
+        '''Call when a TX is sent.'''
         self.txs_sent += 1
-        self.mempool.prioritize(tx_hash)
 
     def setup_bands(self):
         bands = []
@@ -206,14 +205,15 @@ class Controller(ServerBase):
                 self.next_log_sessions = time.time() + self.env.log_sessions
 
     async def wait_for_bp_catchup(self):
-        '''Wait for the block processor to catch up, then kick off server
-        background processes.'''
+        '''Wait for the block processor to catch up, and for the mempool to
+        synchronize, then kick off server background processes.'''
         await self.bp.caught_up_event.wait()
         self.logger.info('block processor has caught up')
+        self.ensure_future(self.mempool.main_loop())
+        await self.mempool.synchronized_event.wait()
         self.ensure_future(self.peer_mgr.main_loop())
         self.ensure_future(self.log_start_external_servers())
         self.ensure_future(self.housekeeping())
-        self.ensure_future(self.mempool.main_loop())
 
     def close_servers(self, kinds):
         '''Close the servers of the given kinds (TCP etc.).'''
diff --git a/server/mempool.py b/server/mempool.py
index 219a38c..4193c83 100644
--- a/server/mempool.py
+++ b/server/mempool.py
@@ -38,15 +38,10 @@ class MemPool(util.LoggedClass):
         self.coin = bp.coin
         self.db = bp
         self.touched = set()
-        self.prioritized = set()
         self.stop = False
         self.txs = {}
         self.hashXs = defaultdict(set)  # None can be a key
-
-    def prioritize(self, tx_hash):
-        '''Prioritize processing the given hash.  This is important during
-        initial mempool sync.'''
-        self.prioritized.add(tx_hash)
+        self.synchronized_event = asyncio.Event()
 
     def _resync_daemon_hashes(self, unprocessed, unfetched):
         '''Re-sync self.txs with the list of hashes in the daemon's mempool.
@@ -91,9 +86,9 @@ class MemPool(util.LoggedClass):
         fetch_size = 800
         process_some = self._async_process_some(fetch_size // 2)
 
-        await self.daemon.mempool_refresh_event.wait()
         self.logger.info('beginning processing of daemon mempool.  '
                          'This can take some time...')
+        await self.daemon.mempool_refresh_event.wait()
         next_log = 0
         loops = -1  # Zero during initial catchup
 
@@ -111,6 +106,8 @@ class MemPool(util.LoggedClass):
                                  '({:,d} txs left)'.format(pct, todo))
             if not todo:
                 loops += 1
+                if loops > 0:
+                    self.synchronized_event.set()
                 now = time.time()
                 if now >= next_log and loops:
                     self.logger.info('{:,d} txs touching {:,d} addresses'
@@ -119,7 +116,6 @@ class MemPool(util.LoggedClass):
 
             try:
                 if not todo:
-                    self.prioritized.clear()
                     await self.daemon.mempool_refresh_event.wait()
 
                 self._resync_daemon_hashes(unprocessed, unfetched)
@@ -148,10 +144,6 @@ class MemPool(util.LoggedClass):
 
             raw_txs = {}
 
-            for hex_hash in self.prioritized:
-                if hex_hash in unprocessed:
-                    raw_txs[hex_hash] = unprocessed.pop(hex_hash)
-
             while unprocessed and len(raw_txs) < limit:
                 hex_hash, raw_tx = unprocessed.popitem()
                 raw_txs[hex_hash] = raw_tx
@@ -213,7 +205,7 @@ class MemPool(util.LoggedClass):
         db_utxo_lookup = self.db.db_utxo_lookup
         txs = self.txs
 
-        # Deserialize each tx and put it in our priority queue
+        # Deserialize each tx and put it in a pending list
         for tx_hash, raw_tx in raw_tx_map.items():
             if tx_hash not in txs:
                 continue