Use a bit allocator for the allocation management of thread contexts,
instead of holding allocation information within the Thread_base objects,
which lead to race conditions in the past.
Moreover, extend the Thread_base class interface with the ability to
to add additional stacks to a thread, and associate the context they're
located in with the corresponding Thread_base object. Additional stacks
can be used to do user-level scheduling with stack switching, without breaking
Genode's API.
Fixes#1024Fixes#1036
If an RM client gets dissolved the RM server tries to first
dissolve and then destruct the according pager object. As pager objects
previously cancelled unresolved faults only in destructor the dissolve
operation blocked forever when an unresolved fault existed.
As every pager object should get dissolved before it gets destructed
(signal-context complains otherwise) no more unresolved-fault cancelling
is needed in the destructor.
ref #989
Kernel::signal_context_kill can be used by any program to halt the processing
of a signal context synchronously to prevent broken refs when core destructs
the according kernel object. In turn, Kernel::bin_signal_context doesn't block
anymore and destructs a signal context no matter if there are unacknowledged
signals. This way, cores entrypoint doesn't depend on signal acks of a
untrustworthy client anymore.
ref #989
In the future bin_* means the direct destruction of a kernel object
without any blocking. kill_* in contrast is used for bringing a
kernel object such as signal contexts synchronized into a sleeping
state from where they can be destructed without the risk of getting
broken refs in userland.
ref #989
To remap its UTCB to its context area later, a main thread needs
to know the according dataspace capability. This is done through
the start-info it receives from its creator at startup.
ref #989
When using the initial SP of a main thread for the UTCB
startup-argument, fork_trampoline in libc_noux gets broken.
The function expects the SP to be initialized already in contrast
to the _start function in crt0.s that is called for processes that
are not forked. As the main-thread UTCB is located at the same virtual
address for every PD anyways, we can circumvent this problem by
defining it statically.
ref #964
Struct Msg was introduced due to the handling of pagefaults
and interrupts via synchronous IPC. Its only purpose was to provide
the message type in front of the typed message. Now pagefaults and
interrupts are handled via signals and struct Msg is not necessary
anymore.
ref #958
Every thread receives a startup message from its creator through the initial
state of its userland thread-context. The thread-startup code remembers the
kernel name of the new thread by reading this message before the userland
thread-context gets polluted. This way, Kernel::current_thread_id becomes
unnecessary.
fix#953
Don't set priority and label in platform thread and then communicate this
core object via Kernel::new_thread but communicate priority and label directly.
This way kernel doesn't need to know anymore what a platform thread is.
ref #953
Instead of writing initial thread context to the platform-thread members
and then communicating this core object to kernel, core calls
Kernel::access_thread_regs first to initialize thread context and then
Kernel::start_thread without a platform-thread pointer. This way
the frontend as well as the backend of Kernel::start_thread loose
complexity and it is a first step to remove platform thread from the
vocabulary of the kernel.
ref #953
Enable routing of thread events to signal contexts via
Kernel::route_thread_event.
Replace Kernel::set_pager by Kernel::route_thread_event.
In base-hw a pager object is a signal context and a pager activation
is a signal receiver. If a thread wants to start communicating its page
faults via a pager object, the thread calls Kernel::route_thread_event with
its thread ID, event ID "FAULT", and the signal context ID of the pager object.
If a pager activation wants to start handling page faults of a pager object,
the pager activation assigns the corresponding signal context to its signal
receiver. If a pager activation wants to stop handling page faults of a pager
object, the pager activation dissolves the corresponding signal context from
its signal receiver. If a thread wants to start communicating its page faults
via a pager object, the thread calls Kernel::route_thread_event with its
thread ID, event ID "FAULT", and the invalid signal context ID.
Remove Kernel::resume_faulter.
Move all page fault related code from generic kernel sources to CPU
specific cpu_support.h and cpu_support.cc.
fix#935
