This patch is the first step of re-organizing the internal structure of
the libc. The original version involved many direct calls of global
functions (often with side effects) across compilation units, which
made the control flow (e.g., the initialization sequence) hard to
follow.
The new version replaces those ad-hoc interactions with dedicated
interfaces (like suspend.h, resume.h, select.h, current_time.h). The
underlying facilities are provided by the central Libc::Kernel and
selectively propagated to the various compilation units. The latter is
done by a sequence of 'init_*' calls, which eventually will be replaced
by constructor calls.
The addition of new headers increases the chance for name clashes with
existing (public) headers. To disambiguate libc-internal header files
from public headers, this patch moves the former into a new 'internal/'
subdirectory. This makes the include directives easier to follow and the
libc's source-tree structure more tidy.
There are still a few legacies left, which cannot easily be removed
right now (e.g., because noux relies on them). However, the patch moves
those bad apples to legacy.h and legacy.cc, which highlights the
deprecation of those functions.
Issue #3497
The former 'Genode::Timed_semaphore' mechanism is moved to the private
part of the two remaining users, namely dde_rump and the libc. Note
there are now two private copies of 'timed_semaphore.h'. This should be
regarded as an interim step until the use of this mechanism is removed
from both users.
This patch also cleans up the mechanism from legacy Genode API calls and
global side effects (alarm-thread singleton). The test/timed_semaphore
is now located at the libports repository as it now tests a mechanism of
the libc. The former timed_semaphore library is no more.
Fixes#3121
Norman Feske