Build breaks when enabling CONFIG_NEWLIB_LIBC because it has its own
sched.h file.
This is a bad symptom of a greater issue: the build system passes many
'-I<path>' options to the compiler, and that allows including header
files by simply specifying their names (when located somewhere else than
<zephyr>/include/) and can cause clashes when several files in different
locations have the same name, like in this case.
Fixes ZEP-1062.
Change-Id: I81d1d69ee6669a609cd0c420b1b8f870d17dcb67
Signed-off-by: Benjamin Walsh <benjamin.walsh@windriver.com>
Timers are based off timeouts now, which can only be enabled when the
system clock is enabled. So the three are really just one setting now.
Keep the NANO_TIMERS and NANO_TIMEOUTS around for now until all
middleware that rely on them is updated. They are always enabled when
SYS_CLOCK_EXISTS is enabled.
Change-Id: Iaef1302ef9ad8fc5640542ab6d7304d67aafcfdc
Signed-off-by: Benjamin Walsh <benjamin.walsh@windriver.com>
- ensure dummy thread's stack is aligned
- rename nano_init() to prepare_multithreading
- move _Swap() to main thread into its own function
Change-Id: I6c8dbe2a4e034f3db90b55d1a5e30bc73bac3d50
Signed-off-by: Benjamin Walsh <benjamin.walsh@windriver.com>
There is no reason to check if the idle thread is a cooperative thread
before invoking k_yield(); it is safe to unconditionally invoke it every
iteration.
Rationale: If the idle thread is cooperative, k_yield() must be invoked
to allow a new thread to get scheduled to run. If the idle thread is
preemptive, then k_yield() effectively becomes a no-op.
Change-Id: Ide3204c92381640b5d12b39ca0f258d56d8cc3d0
Signed-off-by: Peter Mitsis <peter.mitsis@windriver.com>
Summary of what this includes:
initialization:
Copy from nano_init.c, with the following changes:
- the main thread is the continuation of the init thread, but an idle
thread is created as well
- _main() initializes threads in groups and starts the EXE group
- the ready queues are initialized
- the main thread is marked as non-essential once the system init is
done
- a weak main() symbol is provided if the application does not provide a
main() function
scheduler:
Not an exhaustive list, but basically provide primitives for:
- adding/removing a thread to/from a wait queue
- adding/removing a thread to/from the ready queue
- marking thread as ready
- locking/unlocking the scheduler
- instead of locking interrupts
- getting/setting thread priority
- checking what state (coop/preempt) a thread is currenlty running in
- rescheduling threads
- finding what thread is the next to run
- yielding/sleeping/aborting sleep
- finding the current thread
threads:
- Add operationns on threads, such as creating and starting them.
standardized handling of kernel object return codes:
- Kernel objects now cause _Swap() to return the following values:
0 => operation successful
-EAGAIN => operation timed out
-Exxxxx => operation failed for another reason
- The thread's swap_data field can be used to return any additional
information required to complete the operation, such as the actual
result of a successful operation.
timeouts:
- same as nano timeouts, renamed to simply 'timeouts'
- the kernel is still tick-based, but objects take timeout values in
ms for forward compatibility with a tickless kernel.
semaphores:
- Port of the nanokernel semaphores, which have the same basic behaviour
as the microkernel ones. Semaphore groups are not yet implemented.
- These semaphores are enhanced in that they accept an initial count and a
count limit. This allows configuring them as binary semaphores, and also
provisioning them without having to "give" the semaphore multiple times
before using them.
mutexes:
- Straight port of the microkernel mutexes. An init function is added to
allow defining them at runtime.
pipes:
- straight port
timers:
- amalgamation of nano and micro timers, with all functionalities
intact.
events:
- re-implementation, using semaphores and workqueues.
mailboxes:
- straight port
message queues:
- straight port of microkernel FIFOs
memory maps:
- straight port
workqueues:
- Basically, have all APIs follow the k_ naming rule, and use the _timeout
subsystem from the unified kernel directory, and not the _nano_timeout
one.
stacks:
- Port of the nanokernel stacks. They can now have multiple threads
pending on them and threads can wait with a timeout.
LIFOs:
- Straight port of the nanokernel LIFOs.
FIFOs:
- Straight port of the nanokernel FIFOs.
Work by: Dmitriy Korovkin <dmitriy.korovkin@windriver.com>
Peter Mitsis <peter.mitsis@windriver.com>
Allan Stephens <allan.stephens@windriver.com>
Benjamin Walsh <benjamin.walsh@windriver.com>
Change-Id: Id3cadb3694484ab2ca467889cfb029be3cd3a7d6
Signed-off-by: Benjamin Walsh <benjamin.walsh@windriver.com>
