Create periodic and one-shot timeouts with the maximum duration
to see if triggers any corner-case bugs. They must not trigger during
the test.
Ref #2490
If we add an absolute timeout to the back-end alarm-scheduler we must first
call 'handle' at the scheduler to update its internal time value.
Otherwise, it might happen that we add a timeout who's deadline is so big that
it normally belongs to the next time-counter period but the scheduler thinks
that it belongs to the current period as its time is older than the one used
to calculate the deadline.
Ref #2490
When we have two time values of an unsigned integer type and we create
the difference and want to know wether it is positive or negative within
the same value we loose at least one half of the value range for casting
to signed integers. This was the case in the alarm scheduler when
checking wether an alarm already triggered. Even worse, we casted from
'unsigned long' to 'signed int' which caused further loss on at least
x86_64. Thus, big timeouts like ~0UL falsely triggered directly.
Now, we use an extra boolean value to remember in which period of the
time counter we are and to which period of the time counter the deadline
of an alarm belongs. This boolean switches its value each time the time
counter wraps. This way, we can avoid any casting by checking wether the
current time is of the same period as the deadline of the alarm that we
inspect. If so, the alarm is pending if "current time >= alarm
deadline", otherwise it is pending if "current time < alarm deadline".
Ref #2490
If the PIT timer driver gets activated too slow (e.g. because of a bad priority
configuration), it might miss counter wraps and would than produce sudden time
jumps. The driver now detects this problem dynamically, warns about it and
adapts the affected values to avoid time jumps.
Ref #2400
The NIC router always reports the link state "Up" (true) because
the effective link state depends on the targeted remote interface
and thus on the individual routing for each packet. Consequently,
also the signal handler for state changes gets ignored.
Ref #2490
IP stacks may treat a network interface as "down" when it states a MAC
address with the I/G bit (bit 40) set to "Group" (value 0) instead of
"Individual" (value 1). This was observed with a TinyCore 8 inside a
Virtualbox VM. Thus, the previously choosen 03:03:03:03:03:00 as base
for the MAC address allocator is bad. Now we use the 02:02:02:02:02:00
instead. This also ensures that the MAC addresses are not marked as
"Universal" but as "Local" (bit 41, value 1) which is correct in general
as the router allocates MAC addresses only for virtual networks.
Ref #2490
The timer driver should always be of the highest priority to avoid
problem with timers that have low max-counter values like the PIT
with only 53 ms.
Ref #2400
The NIC dump component didn't support forwarding of link states and link-state
signals until now. Furthermore, it now prints MAC address and link state
on session creation and on every link state change.
Ref #2490
Previously, the uplink session was created on component startup while the
creation of the downlink session is timed by the client component. This
created a time span in which packets from the uplink were dropped at the
nic_dump. Now the uplink session-request is done by the session component
of the downlink.
Ref #2490
Add a "writeable" policy option to the ahci_drv and part_blk Block
servers and default from writeable to ready-only. Should a policy
permit write acesss the session request argument "writeable" may still
downgrade a session to ready-only.
Fix#2469
There are hardware timers whose frequency can't be expressed as
ticks-per-microsecond integer-value because only a ticks-per-millisecond
integer-value is precise enough. We don't want to use expensive
floating-point values here but nonetheless want to translate from ticks
to time with microseconds precision. Thus, we split the input in two and
translate both parts separately. This way, we can raise precision by
shifting the values to their optimal bit position. Afterwards, the results
are shifted back and merged together again.
As this algorithm is not so trivial anymore and used by at least three
timer drivers (base-hw/x86_64, base-hw/cortex_a9, timer/pit), move it to a
generic header to avoid redundancy.
Ref #2400
Due to the simplicity of the algorithm that translated from timer ticks
to time, we lost microseconds precision although the timer allows for it.
Ref #2400
When synchronizing with the remote time source, we have to take care that the
measured time difference cannot become null because its real value is smaller
than the measurement granularity. Since the granularity is one microsecond, we
simply go on polling timestamp and time until the microsecond has passed.
This busy waiting should be no problem for the system for two reasons. First,
it is limited to a relatively small amount of time and second, a busy lock
does not happen because the time source that is responsible for the limiting
factor is explicitely called on each poll.
Ref #2400
The VFS library can be used in single-threaded or multi-threaded
environments and depending on that, signals are handled by the same thread
which uses the VFS library or possibly by a different thread. If a VFS
plugin needs to block to wait for a signal, there is currently no way
which works reliably in both environments.
For this reason, this commit makes the interface of the VFS library
nonblocking, similar to the File_system session interface.
The most important changes are:
- Directories are created and opened with the 'opendir()' function and the
directory entries are read with the recently introduced 'queue_read()'
and 'complete_read()' functions.
- Symbolic links are created and opened with the 'openlink()' function and
the link target is read with the 'queue_read()' and 'complete_read()'
functions and written with the 'write()' function.
- The 'write()' function does not wait for signals anymore. This can have
the effect that data written by a VFS library user has not been
processed by a file system server yet when the library user asks for the
size of the file or closes it (both done with RPC functions at the file
system server). For this reason, a user of the VFS library should
request synchronization before calling 'stat()' or 'close()'. To make
sure that a file system server has processed all write request packets
which a client submitted before the synchronization request,
synchronization is now requested at the file system server with a
synchronization packet instead of an RPC function. Because of this
change, the synchronization interface of the VFS library is now split
into 'queue_sync()' and 'complete_sync()' functions.
Fixes#2399
This patch changes init's service forwarding such that pending requests
are kept unanswered as long as the requested service is not present
(yet). In dynamic-init scenarios, this is needed in situtions where the
dynamic init is known to eventually provide the service but the internal
subsystem is not ready yet. Previously, a client that attempted to
request a session in this early phase would get a 'Service_denied'
exception. By deferring the forwarding in this situation, the behaviour
becomes deterministic.
If a matching '<service>' exists but there is no matching policy sub
node, the request is answered with 'Service_denied' - as expected.
Currently, init does not test wether a service is abandoned on a new
configuration if the service was routed via an any-child route. Trigger
this behaviour in the init test.
Ref #2483
The calibration of the interpolation parameters was previously only done
periodically every 500 ms. Together with the fact that the parameters
had to be stable for at least 3 calibration steps to enable
interpolation, it took at least 1.5 seconds after establishing a
connection to get microseconds-precise time values.
This is a problem for some drivers that directly start to poll time.
Thus, the timer connection now does a calibration burst as soon as it
switches to the modern mode (the mode with microseconds precision).
During this phase it does several (currently 9) calibration steps
without a delay inbetween. It is assumed that this is fast enough to not
get interrupted by scheduling. Thus, despite being small, the measured
values should be very stable which is why the burst should in most cases
be sufficient to get the interpolation initialized.
Ref #2400
When in modern mode (with local time interpolation), the timer
connection used to maximize the left shifting of its
timestamp-to-microseconds factor. The higher the shift the more precise
is the translation from timestamps to microseconds. If the timestamp
values used for determining the best shift were small - i.e. the delay
between the calibration steps were small - we may got a pretty big
shift. If we then used the shift with bigger timestamp values - i.e.
called curr_time seldom or raised calibration delays - the big shift
value became a problem. The framework had to scale down all measured
timestamps and time values temporarily to stay operative until the next
calibration step.
Thus, we now raise the shift only that much that the resulting factor
fullfills a given minimum. This keeps it as low as possible according
to the precision requirement. Currently, this requirement is set to 8
meaning that the shifted factor shall be at least 2^8 = 256.
Ref #2400
As the timer session now provides a method 'elapsed_us', there is no more need
for doing any internal calculations with values of milliseconds.
Ref #2400
As timer sessions are not expected to be microseconds precise (because
of RPC latency and scheduling), the session interface provided only a
method 'elapsed_ms' although the back end of this method in the timer
driver works with microseconds.
However, in some cases it makes sense to have a method 'elapsed_us'. The
values it returns might be milliseconds away from the "real" time but it
allows you to work with delays smaller than a millisecond without
getting a zero delta value.
This commit is motivated by the need for fast bursts of calibration
steps for the time interpolation in the new timer connection.
Ref #2400
The run script did not consider the routing for the environment ROM
sessions for the test-iso component. It routed all ROM sessions -
including the ones for the executable and the dynamic linker - to
fs_rom. The patch also adds the cap quota definitions required since
version 17.05 and fixes a whitespace inconsistency between the test
program and the run script.
Thanks to Steven Harp for reporting!
This is expected by hardware terminals, ie., terminal programs connected
to null-modem serial connections. Otherwise, the next line starts at the
column right after the last line.
The new version of the test exercises the combination of fs_report with
ram_fs and fs_rom as a more flexible alternative to report_rom.
It covers two corner cases that remained unaddressed by fs_rom and
ram_fs so far: First, the late installation of a ROM-update signal
handler at fs_rom right before the content of the file is modified.
Second, the case where the requested file is not present on the file
system at the creation time of the ROM session. Here, the ram_fs missed
to inform listeners for the compound directory about the later created
file.
This patch ensures that fs_rom delivers a ROM-update notification in the
case where the underlying file was changed in-between requesting the
initial ROM content and registering the signal handler.
With the introduction of the CONTENT_CHANGED notifications delivered via
the packet stream, the assumption that no more than one READ packet is
in flight at all times does no longer hold. If the fs server responds
to a CONTENT_CHANGED packet while the fs_rom expects the completion of a
read request, the '_update_dataspace' method would prematurely return,
leaving the dataspace unpopulated. This patch solves the problem by
specifically waiting for the completion of the read request.
Session_requester inherits from Dynamic_rom_session::Content_producer
which specifies the Buffer_capacity_exceeded exception which is thrown
on insufficient buffer space.
On platforms that use the PIT timer driver, 'elapsed_ms' is pretty
inprecise/unsteady (up to 3 ms deviation) for a reason that is not
clearly determined yet. On Fiasco and Fiasco.OC, that use kernel timing,
it is the same. So, on these platforms, our locally interpolated time
seems to be fine but the reference time is bad. Until this is fixed, we
raise the error tolerance for these platforms in the run script.
Ref #2400
Appending a suffix to report filenames was behavior inherited from
fs_log, it prevents creating files where directories need to be created
later. But unlike logs, only a subset of the hierarchy will report and
those that do append a component-local label, so the risk of collision
is low.
By removing the suffix fs_rom can serve reports back as ROM just as
report_rom does.
Ref #2422
In the timeout framework, we maintain a translation factor value to
translate between time and timestamps. To raise precision we scale-up
the factor when we calculate it and scale-down the result of its
appliance later again. This up and down scaling is achieved through
left and right shifting. Until now, the shift width was statically
choosen. However, some platforms need a big shift width and others a
smaller one. The one static shift width couldn't cover all platforms
which caused overflows or precision problems.
Now, the shift width is choosen optimally for the actual translation
factor each time it gets re-calculated. This way, we can take care that
the shift always renders the best precision level without the risk for
overflows.
Ref #2400
The result-buffer related members of the fast polling test are
the same for each buffered result type. Thus, we can make the
code easier by providing them through a struct.
Ref #2400
This patch increases init's preserved RAM and capability quota to
account for a current limitation of init with respect to the creation of
sessions to parent services:
In contrast to regular routed services, sessions to parent services are
created via 'Env::session'. The implementation of 'Env::session'
automatically upgrades session quotas on demand, which is the desired
behavior for regular 'Connection' objects. However, for sessions
established on the behalf of init's children, we would need to reflect
the error condition to the child instead of resolving it locally within
init (by subsidizing the session with init's quota). This patch leaves
this issue unresolved but fixes the symptom for the bomb test. It is
meant as an interim solution until the handling of parent sessions is
revised.
On QEMU, NOVA uses the pretty unstable TSC emulation as primary time
source. Thus, timeouts do not trigger with the common precision (< 50
ms). Use an error tolerance of 200 ms for this platform constellation.
Ref #2400
Apparently this construct leads to a compiler errors like
error: second operand to the conditional operator is of type ‘void’, but
the third operand is neither a throw-expression nor of type ‘void’
The fast polling test uses one timer session for raw 'elapsed_ms' calls
and another one for potentially interpolated 'curr_time' calls. It then
compares the two results against each other. However, until now, the
test did not consider that the duration of the session construction may
create a remarkable shift between the local times of the two sessions.
This shift is now determined and compensated before doing any
comparison.
Ref #2400
The multiple-handlers test was checking if handlers at one signal were
activated in a fair manner. But on Qemu, the error tolerance of one was
too small in rare cases (2 of 100 runs). However, having multiple
handlers for the same signal context can be considered deprecated
anyway. With the recommended Signal_handler wrapper for signal sessions,
you can't use this feature. Thus, we removed the multiple-handlers test.
Fixes#2450
We incorrectly used 'unsigned long' (which is 32 or 64 bit depending on
the CPU architecture) for a timestamp (which is always 64 bit) in the
timer-connection implementation.
Ref #2435
On platforms were we do not have local time interpolation we can simply
skip the first test stage in the timeout test. This way, we can at least
test the rest.
Fixes#2435