The 'Timer::Session::trigger_periodic' RPC function used to accept 0 as
a way to de-schedule the periodic processing. Several components such as
nitpicker relied on this special case. In "timeout: rework timeout
framework", the value of zero was silently clamped to 1, which has the
opposite effect: triggering signals at the maximum rate. This results in
a visible effect in Sculpt where the leitzentrale-nitpicker instance
produces a constant load of 2% CPU time.
This patch restores the original timer semantics by
- Documenting it in timer_session.h,
- Handling the case explicitly in the timer implementation, and
- Replacing the silent clamping of the unexpected value 0 passed
to the timeout framework by a diagnostic error message.
Issue #3884
This enforces the use of unsigned 64-bit values for time in the duration type,
the timeout framework, the timer session, the userland timer-drivers, and the
alarm framework on all platforms. The commit also adapts the code that uses
these tools accross all basic repositories (base, base-*, os. gems, libports,
ports, dde_*) to use unsigned 64-bit values for time as well as far as this
does not imply profound modifications.
Fixes#3208
Since the timer and timeout handling is part of the base library (the
dynamic linker), it belongs to the base repository.
Besides moving the timer and its related infrastructure (alarm, timeout
libs, tests) to the base repository, this patch also moves the timer
from the 'drivers' subdirectory directly to 'src' and disamibuates the
timer's build locations for the various kernels. Otherwise the different
timer implementations could interfere with each other when using one
build directory with multiple kernels.
Note that this patch changes the include paths for the former os/timer,
os/alarm.h, os/duration.h, and os/timed_semaphore.h to base/.
Issue #3101
