From de4fe9db693b0bdf2f97ce558552d0068fb977d9 Mon Sep 17 00:00:00 2001 From: SomberNight Date: Thu, 5 Apr 2018 08:32:02 +0200 Subject: [PATCH] fix a race condition in synchronizer wallet.synchronizer gets assigned a newly constructed Synchronizer instance. Synchronizer in tx_response refers to the value of wallet.synchronizer. If the wallet has a missing txn, there could be a race condition that synchronizer asks for a txn and we get the callback from the network WHILE the constructor is still running, in which case wallet.synchronizer would still be None and we would consider the callback "orphan", and the wallet would get "stuck" synchronizing. --- lib/synchronizer.py | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) diff --git a/lib/synchronizer.py b/lib/synchronizer.py index 4b81810db..f3f4cbb5f 100644 --- a/lib/synchronizer.py +++ b/lib/synchronizer.py @@ -50,6 +50,8 @@ class Synchronizer(ThreadJob): self.requested_histories = {} self.requested_addrs = set() self.lock = Lock() + + self.initialized = False self.initialize() def parse_response(self, response): @@ -84,7 +86,7 @@ class Synchronizer(ThreadJob): return bh2u(hashlib.sha256(status.encode('ascii')).digest()) def on_address_status(self, response): - if self.wallet.synchronizer is None: + if self.wallet.synchronizer is None and self.initialized: return # we have been killed, this was just an orphan callback params, result = self.parse_response(response) if not params: @@ -100,7 +102,7 @@ class Synchronizer(ThreadJob): self.requested_addrs.remove(addr) def on_address_history(self, response): - if self.wallet.synchronizer is None: + if self.wallet.synchronizer is None and self.initialized: return # we have been killed, this was just an orphan callback params, result = self.parse_response(response) if not params: @@ -131,7 +133,7 @@ class Synchronizer(ThreadJob): self.requested_histories.pop(addr) def tx_response(self, response): - if self.wallet.synchronizer is None: + if self.wallet.synchronizer is None and self.initialized: return # we have been killed, this was just an orphan callback params, result = self.parse_response(response) if not params: @@ -183,6 +185,7 @@ class Synchronizer(ThreadJob): if self.requested_tx: self.print_error("missing tx", self.requested_tx) self.subscribe_to_addresses(set(self.wallet.get_addresses())) + self.initialized = True def run(self): '''Called from the network proxy thread main loop.'''