The api doc indicates the possibility to pass -1, and calling
osmo_tdef_get() actually casts the arg to a signed long. To end the
confusion, change default_timeout from unsigned long to long.
Change-Id: I51b9172603984839448346c9836e43c8c802fcf8
Some applications may need submillisecond timers, such as those
interacting with modbus serial lines (RS-485, RTU), which require
timers of values around 1.5 char-time (T1.5), where a data char is
composed of 11 bits sent on the line: 1 start bit, 8 data bits,
1 stop bit, and and parity bit (or 2nd stop bits if no parity).
For instance, for a baudrate of 9600:
1.5 * 11 / 9600 = 1.718 ms = 1718 us
So having a granularity of MS is not enough here.
Change-Id: I71848d7c1ee0649929ce07680ee7320bb2a42f0e
This is useful for timers expected to have a range of valid or expected
values.
Validation is done at runtime when timer values are set by the app or by
the user through the VTY.
Related: OS#4190
Change-Id: I4661ac41c29a009a1d5fc57d87aaee6041c7d1b2
I missed code review, so here are my comments in form of a follow-up patch
for Id56a1226d724a374f04231df85fe5b49ffd2c43c.
- Fix 'as_unit' arg name to 'val_unit' as in the C file and API doc.
- Explain rounding-up behavior of value conversion in API doc.
- Use osmo_tdef_get_entry() instead of a loop.
Related: OS#4190
Change-Id: Ia91c2f17e40fb9e79ffa5a7f28ce9c3605664402
This API is already useful for users willing to set a given timer to a
given value. It will also contain code later that checks for value being
inside valid range for that timer.
Related: OS#4190
Change-Id: Id56a1226d724a374f04231df85fe5b49ffd2c43c
The intention of osmo_tdef_get()'s val_if_not_present argument was to return a
default timeout, or to optionally abort the program for missing timer
definitions if the default timeout is < 0. This was the case in the original
implementation of this API in osmo-bsc, but in the migration to libosmocore,
the argument was by accident changed to an unsigned type. In consequence, the
assertion in the implementation that was intended to abort the program seemed
bogus to coverity, and was fixed by removal in
I7a544d2d43b83135def296674f777e48fe5fd80a -- the wrong direction, as is obvious
from the API doc for osmo_tdef_get().
Note that osmo-bsc master passes -1 in various places and expects the
program-abort behavior that was missing from the libosmocore implementation.
Change the val_if_not_present argument to a signed type, and revert removal of
the assertion, so that passing -1 has the effect described in the API doc:
program abort on missing timer definition.
This bug was not detected because it is hard to write tests that expect a
program abort to happen, hence no tests for this API feature exist.
Related: OS#4152
Change-Id: Ie61c3c85069916336e6dbd91a2c16f7634816417
fi->T values are int, i.e. can be negative. Do not log them as unsigned, but
define a distinct timer class "Xnnnn" for negative T values: i.e. for T == -1,
print "Timeout of X1" instead of "Timeout of T4294967295".
The negative T timer number space is useful to distinguish freely invented
timers from proper 3GPP defined T numbers. So far I was using numbers like
T993210 or T9999 for invented T, but X1, X2 etc. is a better solution. This way
we can make sure to not accidentally define an invented timer number that
actually collides with a proper 3GPP specified timer number that the author was
not aware of at the time of writing.
Add OSMO_T_FMT and OSMO_T_FMT_ARGS() macros as standardized timer number print
format. Use that in fsm.c, tdef_vty.c, and adjust vty tests accordingly.
Mention the two timer classes in various API docs and VTY online-docs.
Change-Id: I3a59457623da9309fbbda235fe18fadd1636bff6
Move T_def from osmo-bsc to libosmocore as osmo_tdef. Adjust naming to be more
consistent. Upgrade to first class API:
- add timer grouping
- add generic vty support
- add mising API doc
- add C test
- add VTY transcript tests, also as examples for using the API
From osmo_fsm_inst_state_chg() API doc, cross reference to osmo_tdef API.
The root reason for moving to libosmocore is that I want to use the
mgw_endpoint_fsm in osmo-msc for inter-MSC handover, and hence want to move the
FSM to libosmo-mgcp-client. This FSM uses the T_def from osmo-bsc. Though the
mgw_endpoint_fsm's use of T_def is minimal, I intend to use the osmo_tdef API
in osmo-msc (and probably elsewhere) as well. libosmocore is the most sensible
place for this.
osmo_tdef provides:
- a list of Tnnnn (GSM) timers with description, unit and default value.
- vty UI to allow users to configure non-default timeouts.
- API to tie T timers to osmo_fsm states and set them on state transitions.
- a few standard units (minute, second, millisecond) as well as a custom unit
(which relies on the timer's human readable description to indicate the
meaning of the value).
- conversion for standard units: for example, some GSM timers are defined in
minutes, while our FSM definitions need timeouts in seconds. Conversion is
for convenience only and can be easily avoided via the custom unit.
By keeping separate osmo_tdef arrays, several groups of timers can be kept
separately. The VTY tests in tests/tdef/ showcase different schemes:
- tests/vty/tdef_vty_test_config_root.c:
Keep several timer definitions in separately named groups: showcase the
osmo_tdef_vty_groups*() API. Each timer group exists exactly once.
- tests/vty/tdef_vty_test_config_subnode.c:
Keep a single list of timers without separate grouping.
Put this list on a specific subnode below the CONFIG_NODE.
There could be several separate subnodes with timers like this, i.e.
continuing from this example, sets timers could be separated by placing
timers in specific config subnodes instead of using the global group name.
- tests/vty/tdef_vty_test_dynamic.c:
Dynamically allocate timer definitions per each new created object.
Thus there can be an arbitrary number of independent timer definitions, one
per allocated object.
T_def was introduced during the recent osmo-bsc refactoring for inter-BSC
handover, and has proven useful:
- without osmo_tdef, each invocation of osmo_fsm_inst_state_chg() needs to be
programmed with the right timeout value, for all code paths that invoke this
state change. It is a likely source of errors to get one of them wrong. By
defining a T timer exactly for an FSM state, the caller can merely invoke the
state change and trust on the original state definition to apply the correct
timeout.
- it is helpful to have a standardized config file UI to provide user
configurable timeouts, instead of inventing new VTY commands for each
separate application of T timer numbers.
Change-Id: Ibd6b1ed7f1bd6e1f2e0fde53352055a4468f23e5
Neels Hofmeyr
Pau Espin