Kernel Release Notes

Kernel 2.1.1

Fixed errors and malfunctions

• ets:file2tab which uses disk_log now uses the read_only option to disk_log:open when it opens the file.
  Own Id: OTP-1716
  Aux Id: OTP-1765
• All applications are now informed of all changed, new and removed configuration parameters at installation of a new release. The new call-back functions is defined as Mod:config_changed(Changed, New, Removed). Where Mod is the module defined in the .app file. Refer to the reference manual application(3).
  Own Id: OTP-2012
• When killing a shell in the ^G command level using the sequence "^G k", some processes associated with the shell were left running. Now, there are no extra processes left anymore.
  Own Id: OTP-2317
• The function gen_tcp:controlling_process(S, NewOwner) did hang the calling process if it was not the current owner of S. This is now corrected. If called by any other process than the current owner {error, eperm} will be returned.
  Own Id: OTP-2321
  Aux Id: seq 779
• When application environment variables are given on the command line, no error message was given if the variable's value was malformed; application:get_env/2 simply returned 'undefined'. Now, application:start/1 returns an error in those cases.
  (*** POTENTIAL INCOMPATIBILITY ***)
  Own Id: OTP-2350
  Aux Id: OTP-2347, OTP-2348
• If a process attempts to call erl_ddll:unload_driver/1 on a driver for which it didn't previously call erl_ddll:load_driver/2, the unloading fails. In previous release, either the result 'ok' was returned, or in certain cases the erl_ddll server crashed. Now the correct error tuple is returned.
  (*** POTENTIAL INCOMPATIBILITY ***)
  Own Id: OTP-2568
• Sometimes when a R3 node and a R4 node were connected, global could crash due to not checked '{badrpc,nodedown}' messages. This is now corrected.
  Own Id: OTP-2648
  Aux Id: Seq 987
• The processes which controls a port corresponding to a socket is now set to priority high instead of normal to assure that e.g node-ticks between distributed nodes are sent fast enough.
  Own Id: OTP-2709

Improvements and new features

• The documentation has been augmented with a description of the error return values from erl_ddll:load_driver/2 and erl_ddll:unload_driver/1, and the error formatting function format_error/1.
  Own Id: OTP-2569
• The 'backlog' option to gen_tcp:listen/2 is now documented.
  Own Id: OTP-2674

Kernel 2.1

Fixed errors and malfunctions

• For the arguments to the command-line option -s, the documentation was incorrect. It has been changed to reflect the actual behaviour, namely that all arguments to the function called by -s are passed as atoms.
  Own Id: OTP-2087
• When using the -boot and -config command-line options on Windows, filenames in the native Windows syntax using only backslashes didn't work -- forward slashes had to be used. Now backslashes work as well as forward slashes.
  Own Id: OTP-2373
• An unnecessary report to the error logger caused by a timeout from inet:gethostbyname and inet:gethostbyaddr is removed.
  Own Id: OTP-2478

Improvements and new features

• New start type, {failover, node()}, added. Note, for compability reasons this is only valid if the new key start_phases is defined in the .app-file for the application, refer to application (3). It is also possible to check the current start type by application:start_type(), refer to application (3)
  Own Id: OTP-1504
  Aux Id: OTP-1979, OTP-2498
• A first increment to allow several global name spaces to exist in the same system. The Global Groups are defined in the .config file by the key '{node_groups, [{GroupName, [Node]}]}. If the node_groups-key is not defined the system behaves as before; if the Global Group service is used then it is required that all nodes in a system are defined in one. and only one, Global Group. It is not possible to mix nodes belonging to a global group and nodes not belonging to a global group in the same system, if global group functionality is used.
  Missing functionality: Reconfiguration, at the moment it is not possible to change the configuration without restarting all nodes.
  Own Id: OTP-1559
  Aux Id: OTP-2497
• Better error messages for erroneous .config file.
  Own Id: OTP-1983
• The functions write_file_info/2, change_owner/2,3, and change_time/2,3 in the file module are now documented.
  Own Id: OTP-2252
  Aux Id: seq 710
• It is now possible to synchronize the start of an application by defining a new key in the .app file, {start-phases, [{Phase, Args}]}. This will result that the new call back function Mod:start_phase(Phase, Args) is called, Mod is the module defined in the mod key of the application. There is also a generic help module to syncronize the start of included applications, application_starter. If this module is defined in the mod key for the top application, the included applications will be started in each start phase in the order of appearance in the included_applications key.
  Own Id: OTP-2498
  Aux Id: OTP-1504
• It is added to the documentation of file:list_dir/1 that the returned filenames are not sorted.
  Own Id: OTP-2508
  Aux Id: seq 891
• A new key, id, in the application resource file (.app, ). It can be used to define the product identification of the application.
  Own Id: OTP-2518
• The description of error_handler:undefined_global_name/2 has been removed, since it's no longer called from Erlang 4.6 and later.
  Own Id: OTP-2525
• Sequential tracing is available in alfa status and only for JAM systems. Since it is an alpha release the programmatic interface could be slightly changed based on experience from users. The module seq_trace contains the interface. Sequential tracing makes it possible to trace all messages that are a direct result from one initiating message e.g. all messages in a call-setup for one connection.
  Own Id: OTP-2527
• It is now possible to read an application's resource file (.app) keys. New functions: application:get_all_key() application:get_all_key(Application) application:get_key() application:get_key(Application, Key)
  Own Id: OTP-2535