diff options
Diffstat (limited to 'lib/snmp/src/agent/snmpa_vacm.erl')
| -rw-r--r-- | lib/snmp/src/agent/snmpa_vacm.erl | 34 |
1 files changed, 32 insertions, 2 deletions
diff --git a/lib/snmp/src/agent/snmpa_vacm.erl b/lib/snmp/src/agent/snmpa_vacm.erl index 892dc265f1..2cbc11d280 100644 --- a/lib/snmp/src/agent/snmpa_vacm.erl +++ b/lib/snmp/src/agent/snmpa_vacm.erl @@ -1,7 +1,7 @@ %% %% %CopyrightBegin% %% -%% Copyright Ericsson AB 1999-2010. All Rights Reserved. +%% Copyright Ericsson AB 1999-2012. All Rights Reserved. %% %% The contents of this file are subject to the Erlang Public License, %% Version 1.1, (the "License"); you may not use this file except in @@ -266,9 +266,10 @@ dump_table(true) -> dump_table(_) -> ok. + dump_table() -> [{_, FName}] = ets:lookup(snmp_agent_table, snmpa_vacm_file), - TmpName = FName ++ ".tmp", + TmpName = unique_table_name(FName), case ets:tab2file(snmpa_vacm, TmpName) of ok -> case file:rename(TmpName, FName) of @@ -283,6 +284,35 @@ dump_table() -> [FName, Reason]) end. +%% This little thing is an attempt to create a "unique" filename +%% in order to minimize the risk of two processes at the same +%% time dumping the table. +unique_table_name(Pre) -> + %% We want something that is guaranteed to be unique, + %% therefor we use erlang:now() instead of os:timestamp() + unique_table_name(Pre, erlang:now()). + +unique_table_name(Pre, {_A, _B, C} = Now) -> + {Date, Time} = calendar:now_to_datetime(Now), + {YYYY, MM, DD} = Date, + {Hour, Min, Sec} = Time, + FormatDate = + io_lib:format("~.4w~.2.0w~.2.0w_~.2.0w~.2.0w~.2.0w_~w", + [YYYY, MM, DD, Hour, Min, Sec, round(C/1000)]), + unique_table_name2(Pre, FormatDate). + +unique_table_name2(Pre, FormatedDate) -> + PidPart = unique_table_name_pid(), + lists:flatten(io_lib:format("~s.~s~s.tmp", [Pre, PidPart, FormatedDate])). + +unique_table_name_pid() -> + case string:tokens(pid_to_list(self()), [$<,$.,$>]) of + [A, B, C] -> + A ++ B ++ C ++ "."; + _ -> + "" + end. + %%----------------------------------------------------------------- %% Alg. |