diff --git a/src/bdberl.erl b/src/bdberl.erl
index a4d0896..b92ee11 100644
--- a/src/bdberl.erl
+++ b/src/bdberl.erl
@@ -29,14 +29,14 @@
          txn_stat/0, txn_stat/1,
          txn_stat_print/0, txn_stat_print/1,
          env_stat_print/0, env_stat_print/1, 
-         transaction/1, transaction/2, transaction/3,
+         transaction/1, transaction/2, transaction/3, transaction/4,
          put/3, put/4,
          put_r/3, put_r/4,
          put_commit/3, put_commit/4,
          put_commit_r/3, put_commit_r/4,
          get/2, get/3,
          get_r/2, get_r/3,
-         update/3, update/4, update/5,
+         update/3, update/4, update/5, update/6, update/7,
          truncate/0, truncate/1,
          delete_database/1,
          cursor_open/1, cursor_next/0, cursor_prev/0, cursor_current/0, cursor_close/0,
@@ -62,6 +62,7 @@
 
 -type db_txn_fun() :: fun(() -> term()).
 -type db_txn_retries() :: infinity | non_neg_integer().
+-type db_txn_timeleft() :: infinity | non_neg_integer().
 -type db_txn_error() :: {error, db_error_reason() | {transaction_failed, _}}.
 
 -type db_update_fun() :: fun((db_key(), db_value(), any()) -> db_value()).
@@ -447,8 +448,8 @@ txn_abort() ->
 %% where
 %%    Fun = function()
 %%
-%% @equiv transaction(Fun, infinity, [])
-%% @see transaction/3
+%% @equiv transaction(Fun, infinity, infinity, [])
+%% @see transaction/4
 %% @end
 %%--------------------------------------------------------------------
 -spec transaction(Fun :: db_txn_fun()) -> {ok, db_value()} | db_txn_error().
@@ -466,8 +467,8 @@ transaction(Fun) ->
 %%    Fun = function()
 %%    Retries = infinity | integer()
 %%
-%% @equiv transaction(Fun, Retries, [])
-%% @see transaction/3
+%% @equiv transaction(Fun, Retries, infinity, [])
+%% @see transaction/4
 %% @end
 %%--------------------------------------------------------------------
 -spec transaction(Fun :: db_txn_fun(), Retries :: db_txn_retries()) ->
@@ -477,6 +478,27 @@ transaction(Fun, Retries) ->
     transaction(Fun, Retries, []).
 
 
+%%--------------------------------------------------------------------
+%% @doc
+%% Execute a fun inside of a transaction.
+%%
+%% @spec transaction(Fun, Retries, Opts) -> {ok, Value} | {error, Error}
+%% where
+%%    Fun = function()
+%%    Retries = infinity | integer()
+%%    Opts = [atom()]
+%% @equiv transaction(Fun, Retries, infinity, Opts)
+%% @see transaction/4
+%% @end
+%%--------------------------------------------------------------------
+-spec transaction(Fun :: db_txn_fun(), Retries :: db_txn_retries(), Opts :: db_flags()) ->
+    {ok, db_value()} | db_txn_error().
+
+transaction(Fun, Retries, Opts) ->
+    transaction(Fun, Retries, infinity, Opts).
+
+
+
 %%--------------------------------------------------------------------
 %% @doc
 %% Execute a fun inside of a transaction.
@@ -489,25 +511,31 @@ transaction(Fun, Retries) ->
 %%
 %% If the transaction deadlocks on commit, the function will be executed
 %% again until the commit succeeds or the number of retries exceeds the
-%% value of the `Retries' parameter.
+%% value of the `Retries' parameter or `TimeLeft' microseconds have elapsed
+%% (the accounting isn't perfect - it just measures time in the txn).
 %%
 %% The 'Opts' parameter is used to set flags for the call to txn_begin/1.
 %%
-%% @spec transaction(Fun, Retries, Opts) -> {ok, Value} | {error, Error}
+%% @spec transaction(Fun, Retries, TimeLeft, Opts) -> {ok, Value} | {error, Error}
 %% where
 %%    Fun = function()
 %%    Retries = infinity | integer()
+%%    TimeLeft = infinity | integer()
 %%    Opts = [atom()]
 %%
 %% @end
 %%--------------------------------------------------------------------
--spec transaction(Fun :: db_txn_fun(), Retries :: db_txn_retries(), Opts :: db_flags()) ->
+-spec transaction(Fun :: db_txn_fun(), Retries :: db_txn_retries(), 
+                  TimeLeft :: db_txn_timeleft(), Opts :: db_flags()) ->
     {ok, db_value()} | db_txn_error().
+transaction(_Fun, _Retries, TimeLeft, _Opts) when TimeLeft =/= infinity, TimeLeft < 0 ->
+    {error, {transaction_failed, time_limit_reached}};
 
-transaction(_Fun, 0, _Opts) ->
+transaction(_Fun, 0, _TimeLeft, _Opts) ->
     {error, {transaction_failed, retry_limit_reached}};
 
-transaction(Fun, Retries, Opts) ->
+transaction(Fun, Retries, TimeLeft, Opts) ->
+    Start = now(),
     case txn_begin(Opts) of
         ok ->
             try Fun() of
@@ -529,7 +557,11 @@ transaction(Fun, Retries, Opts) ->
                             infinity -> infinity;
                             Retries -> Retries - 1
                         end,
-                    transaction(Fun, R);
+                    T = case TimeLeft of
+                            infinity -> infinity;
+                            TimeLeft -> TimeLeft - timer:now_diff(now(), Start)
+                        end,
+                    transaction(Fun, R, T, Opts);
 
                 _ : Reason ->
                     error_logger:info_msg("function threw non-lock error - ~p", [Reason]),
@@ -911,7 +943,7 @@ get_r(Db, Key, Opts) ->
 %%    Fun = function()
 %%
 %% @equiv update(Db, Key, Fun, undefined, [])
-%% @see update/5
+%% @see update/7
 %% @end
 %%--------------------------------------------------------------------
 -spec update(Db :: db(), Key :: db_key(), Fun :: db_update_fun()) ->
@@ -932,8 +964,8 @@ update(Db, Key, Fun) ->
 %%    Fun = function()
 %%    Args = any()
 %%
-%% @equiv update(Db, Key, Fun, undefined, [])
-%% @see update/5
+%% @equiv update(Db, Key, Fun, Args, [])
+%% @see update/7
 %% @end
 %%--------------------------------------------------------------------
 -spec update(Db :: db(), Key :: db_key(), Fun :: db_update_fun(), Args :: db_update_fun_args()) ->
@@ -947,14 +979,6 @@ update(Db, Key, Fun, Args) ->
 %% @doc
 %% Updates the value of a key by executing a fun.
 %%
-%% This function updates a key/value pair by calling the provided
-%% function and passing in the key and value as they are
-%% currently. Additional arguments can be provided to the function by
-%% passing them in the `Args' parameter. The entire operation is
-%% executed within the scope of a new transaction.
-%%
-%% The 'Opts' parameter is used to pass flags to transaction/3.
-%%
 %% @spec update(Db, Key, Fun, Args, Opts) -> {ok, Value} | {error, Error}
 %% where
 %%    Db = integer()
@@ -963,12 +987,69 @@ update(Db, Key, Fun, Args) ->
 %%    Args = any()
 %%    Opts = [atom()]
 %%
+%% @equiv update(Db, Key, Fun, Args, infinity, [])
+%% @see update/7
 %% @end
 %%--------------------------------------------------------------------
 -spec update(Db :: db(), Key :: db_key(), Fun :: db_update_fun(), Args :: db_update_fun_args(), Opts :: db_flags()) ->
     {ok, db_value()} | db_txn_error().
 
 update(Db, Key, Fun, Args, Opts) ->
+    update(Db, Key, Fun, Args, infinity, Opts).
+
+%%--------------------------------------------------------------------
+%% @doc
+%% Updates the value of a key by executing a fun.
+%%
+%% @spec update(Db, Key, Fun, Args, Retries, Opts) -> {ok, Value} | {error, Error}
+%% where
+%%    Db = integer()
+%%    Key = term()
+%%    Fun = function()
+%%    Args = any()
+%%    Retries = integer()
+%%    Opts = [atom()]
+%%
+%% @equiv update(Db, Key, Fun, Args, Retries, infinity, [])
+%% @see update/7
+%% @end
+%%--------------------------------------------------------------------
+-spec update(Db :: db(), Key :: db_key(), Fun :: db_update_fun(), Args :: db_update_fun_args(), 
+             Retries :: db_txn_retries(), Opts :: db_flags()) ->
+    {ok, db_value()} | db_txn_error().
+
+update(Db, Key, Fun, Args, Retries, Opts) ->
+    update(Db, Key, Fun, Args, Retries, infinity, Opts).
+
+%%--------------------------------------------------------------------
+%% @doc
+%% Updates the value of a key by executing a fun.
+%%
+%% This function updates a key/value pair by calling the provided
+%% function and passing in the key and value as they are
+%% currently. Additional arguments can be provided to the function by
+%% passing them in the `Args' parameter. The entire operation is
+%% executed within the scope of a new transaction.
+%%
+%% The 'Opts' parameter is used to pass flags to transaction/3.
+%%
+%% @spec update(Db, Key, Fun, Args, Retries, TimeLeft, Opts) -> {ok, Value} | {error, Error}
+%% where
+%%    Db = integer()
+%%    Key = term()
+%%    Fun = function()
+%%    Args = any()
+%%    Retries = integer()
+%%    TimeLeft = integer()
+%%    Opts = [atom()]
+%%
+%% @end
+%%--------------------------------------------------------------------
+-spec update(Db :: db(), Key :: db_key(), Fun :: db_update_fun(), Args :: db_update_fun_args(), 
+             Retries :: db_txn_retries(), TimeLeft :: db_txn_timeleft(),  Opts :: db_flags()) ->
+    {ok, db_value()} | db_txn_error().
+
+update(Db, Key, Fun, Args, Retries, TimeLeft, Opts) ->
     F = fun() ->
             Value = case get_r(Db, Key, [rmw]) of
                         not_found -> not_found;
@@ -981,7 +1062,7 @@ update(Db, Key, Fun, Args, Opts) ->
             put_r(Db, Key, NewValue),
             NewValue
         end,
-    transaction(F, infinity, Opts).
+    transaction(F, Retries, TimeLeft, Opts).
 
 
 %%--------------------------------------------------------------------
@@ -1210,13 +1291,14 @@ get_data_dirs() ->
 %%--------------------------------------------------------------------
 %% @doc
 %% Returns the list of directories that bdberl searches to find databases
-%% with the number of megabytes available for each dir
+%% with the number of megabytes available for each dir.
 %%
-%% @spec get_data_dirs_info() -> {ok, [DirName, Fsid, MbytesAvail]} | {error, Error}
+%% @spec get_data_dirs_info() -> {ok, [{DirName,Fsid,MbytesAvail}]} | {error, Reason}
 %% where
 %%    DirName = string()
 %%    Fsid = binary()
 %%    MbytesAvail = integer()
+%%    Reason = any()
 %%
 %% @end
 %%--------------------------------------------------------------------