Merge with bsddb3 2002.11.23.10.42.36
diff --git a/Lib/bsddb/dbutils.py b/Lib/bsddb/dbutils.py
index fe08407..d21069f 100644
--- a/Lib/bsddb/dbutils.py
+++ b/Lib/bsddb/dbutils.py
@@ -1,11 +1,5 @@
#------------------------------------------------------------------------
#
-# In my performance tests, using this (as in dbtest.py test4) is
-# slightly slower than simply compiling _db.c with MYDB_THREAD
-# undefined to prevent multithreading support in the C module.
-# Using NoDeadlockDb also prevent deadlocks from mutliple processes
-# accessing the same database.
-#
# Copyright (C) 2000 Autonomous Zone Industries
#
# License: This is free software. You may use this software for any
@@ -18,7 +12,7 @@
# Author: Gregory P. Smith <greg@electricrain.com>
#
# Note: I don't know how useful this is in reality since when a
-# DBDeadlockError happens the current transaction is supposed to be
+# DBLockDeadlockError happens the current transaction is supposed to be
# aborted. If it doesn't then when the operation is attempted again
# the deadlock is still happening...
# --Robin
@@ -34,35 +28,47 @@
_sleep = sleep
del sleep
-import _db
+import _bsddb
-_deadlock_MinSleepTime = 1.0/64 # always sleep at least N seconds between retrys
-_deadlock_MaxSleepTime = 1.0 # never sleep more than N seconds between retrys
+_deadlock_MinSleepTime = 1.0/64 # always sleep at least N seconds between retrys
+_deadlock_MaxSleepTime = 3.14159 # never sleep more than N seconds between retrys
+_deadlock_VerboseFile = None # Assign a file object to this for a "sleeping"
+ # message to be written to it each retry
def DeadlockWrap(function, *_args, **_kwargs):
"""DeadlockWrap(function, *_args, **_kwargs) - automatically retries
function in case of a database deadlock.
- This is a DeadlockWrapper method which DB calls can be made using to
- preform infinite retrys with sleeps in between when a DBLockDeadlockError
- exception is raised in a database call:
+ This is a function intended to be used to wrap database calls such
+ that they perform retrys with exponentially backing off sleeps in
+ between when a DBLockDeadlockError exception is raised.
+
+ A 'max_retries' parameter may optionally be passed to prevent it
+ from retrying forever (in which case the exception will be reraised).
d = DB(...)
d.open(...)
DeadlockWrap(d.put, "foo", data="bar") # set key "foo" to "bar"
"""
sleeptime = _deadlock_MinSleepTime
- while (1) :
+ max_retries = _kwargs.get('max_retries', -1)
+ if _kwargs.has_key('max_retries'):
+ del _kwargs['max_retries']
+ while 1:
try:
return apply(function, _args, _kwargs)
except _db.DBLockDeadlockError:
- print 'DeadlockWrap sleeping ', sleeptime
+ if _deadlock_VerboseFile:
+ _deadlock_VerboseFile.write('dbutils.DeadlockWrap: sleeping %1.3f\n' % sleeptime)
_sleep(sleeptime)
# exponential backoff in the sleep time
sleeptime = sleeptime * 2
if sleeptime > _deadlock_MaxSleepTime :
sleeptime = _deadlock_MaxSleepTime
+ max_retries = max_retries - 1
+ if max_retries == -1:
+ raise
#------------------------------------------------------------------------