[bug] properly trap db errors and close resources

SQLCipher database access errors can raise Soledad exceptions. Database access
and multithreading resources are allocated in different places, so we have to
be careful to close all multithreading mechanismis in case of database access
errors. If we don't, zombie threads may haunt the reactor.

This commit adds SQLCipher exception trapping and Soledad exception raising
for database access errors, while properly shutting down multithreading
resources.

1 files changed, 16 insertions, 3 deletions

diff --git a/client/src/leap/soledad/client/api.py b/client/src/leap/soledad/client/api.py
index 8c25243b..1bfbed8a 100644
--- a/client/src/leap/soledad/client/api.py
+++ b/client/src/leap/soledad/client/api.py
@@ -51,6 +51,7 @@ from leap.soledad.common import soledad_assert
 from leap.soledad.common import soledad_assert_type
 from leap.soledad.common.l2db.remote import http_client
 from leap.soledad.common.l2db.remote.ssl_match_hostname import match_hostname
+from leap.soledad.common.errors import DatabaseAccessError
 
 from leap.soledad.client import adbapi
 from leap.soledad.client import events as soledad_events
@@ -213,10 +214,22 @@ class Soledad(object):
         self._init_secrets()
 
         self._crypto = SoledadCrypto(self._secrets.remote_storage_secret)
-        self._init_u1db_sqlcipher_backend()
 
-        if syncable:
-            self._init_u1db_syncer()
+        try:
+            # initialize database access, trap any problems so we can shutdown
+            # smoothly.
+            self._init_u1db_sqlcipher_backend()
+            if syncable:
+                self._init_u1db_syncer()
+        except DatabaseAccessError:
+            # oops! something went wrong with backend initialization. We
+            # have to close any thread-related stuff we have already opened
+            # here, otherwise there might be zombie threads that may clog the
+            # reactor.
+            self._sync_db.close()
+            if hasattr(self, '_dbpool'):
+                self._dbpool.close()
+            raise
 
     #
     # initialization/destruction methods