This patch largely reverts the commit "base: lay groundwork for
base-linux caps change" because the use of 'epoll' instead of 'select'
alleviated the need to allocate large FD sets, which motivated the
introduction of the 'Native_context' hook.
Related to issue #3581
The topics are either covered by the Genode Founations book for by our
tools, in particular the integration of the prepare_port mechanism with
the run tool.
The mutex class is more restrictive in usage compared to
Genode::Lock.
- At initialiation time it is ever unlocked.
- No thread is permitted to lock twice. Warn about it
in case it happens.
- Only the lock onwer is permitted to unlock the mutex.
Warn about it and don't unlock the mutex in case it happens.
Issue #3612
This patch adjusts the implementation of the base library and core such
that the code no longer relies on deprecated APIs except for very few
cases, mainly to keep those deprecated APIs in tact for now.
The most prominent changes are:
- Removing the use of base/printf.h
- Removing of the log backend for printf. The 'Console' with the
format-string parser is still there along with 'snprintf.h' because
the latter is still used at a few places, most prominently the
'Connection' classes.
- Removing the notion of a RAM session, which does not exist in
Genode anymore. Still the types were preserved (by typedefs to
PD session) to keep up compatibility. But this transition should
come to an end now.
- Slight rennovation of core's tracing service, e.g., the use of an
Attached_dataspace as the Argument_buffer.
- Reducing the reliance on global accessors like deprecated_env() or
core_env(). Still there is a longish way to go to eliminate all such
calls. A useful pattern (or at least a stop-gap solution) is to
pass the 'Env' to the individual compilation units via init functions.
- Avoiding the use of the old 'Child_policy::resolve_session_request'
interface that returned a 'Service' instead of a 'Route'.
Issue #1987
This patch replaces the former prominent use of pointers by references
wherever feasible. This has the following benefits:
* The contract between caller and callee becomes more obvious. When
passing a reference, the contract says that the argument cannot be
a null pointer. The caller is responsible to ensure that. Therefore,
the use of reference eliminates the need to add defensive null-pointer
checks at the callee site, which sometimes merely exist to be on the
safe side. The bottom line is that the code becomes easier to follow.
* Reference members must be initialized via an object initializer,
which promotes a programming style that avoids intermediate object-
construction states. Within core, there are still a few pointers
as member variables left though. E.g., caused by the late association
of 'Platform_thread' objects with their 'Platform_pd' objects.
* If no pointers are present as member variables, we don't need to
manually provide declarations of a private copy constructor and
an assignment operator to avoid -Weffc++ errors "class ... has
pointer data members [-Werror=effc++]".
This patch also changes a few system bindings on NOVA and Fiasco.OC,
e.g., the return value of the global 'cap_map' accessor has become a
reference. Hence, the patch touches a few places outside of core.
Fixes#3135
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
