Previously, __restore_context was meddling with the to-be-restored
context SR on the stack, not correctly restoring GIE.
Now, we let the CPU restore the correct status register as saved in
__save_context.
Contains some simplification of the context save/restore logic.
Fixes warnings of the kind:
/data/riotbuild/riotbase/sys/bloom/bloom.c: In function 'bloom_new':
/data/riotbuild/riotbase/sys/bloom/bloom.c:39:5: error: implicit declaration of function 'calloc' [-Werror=implicit-function-declaration]
/data/riotbuild/riotbase/sys/bloom/bloom.c:39:22: error: incompatible implicit declaration of built-in function 'calloc' [-Werror]
As discussed in #2725, this commit renames a number of stacksize constants to
better convey their intended usage. In addition, constants for thread priority
are given a `THREAD_` prefix. Changes are:
* KERNEL_CONF_STACKSIZE_PRINTF renamed to THREAD_EXTRA_STACKSIZE_PRINTF
* KERNEL_CONF_STACKSIZE_DEFAULT renamed to THREAD_STACKSIZE_DEFAULT
* KERNEL_CONF_STACKSIZE_IDLE renamed to THREAD_STACKSIZE_IDLE
* KERNEL_CONF_STACKSIZE_MAIN renamed to THREAD_STACKSIZE_MAIN
* Move thread stacksizes from kernel.h to thread.h, since the prefix changed
* PRIORITY_MIN renamed to THREAD_PRIORITY_MIN
* PRIORITY_IDLE renamed to THREAD_PRIORITY_IDLE
* PRIORITY_MAIN renamed to THREAD_PRIORITY_MAIN
* Move thread priorities from kernel.h to thread.h since the prefix has changed
* MINIMUM_STACK_SIZE renamed to THREAD_STACKSIZE_MINIMUM for consistency
- Move generic implementation of atomic_set_return to core/atomic.c
- Generic implementation of atomic compare and swap in core/atomic.c
- atomic_cas is used to implement atomic counters in core/include/atomic.h
- atomic_int_t is an atomic integer type
- ATOMIC_INIT can be used as an initializer for atomic_int_t
- ATOMIC_VALUE gets a reference to the value of an atomic integer
Fixes#1708.
Currently involuntary preemption causes the current thread not only to
yield for a higher prioritized thread, but all other threads of its own
priority class, too.
This PR adds the function `thread_yield_higher()`, which will yield the
current thread in favor of higher prioritized functions, but not for
threads of its own priority class.
Boards now need to implement `thread_yield_higher()` instead of
`thread_yield()`, but `COREIF_NG` boards are not affected in any way.
`thread_yield()` retains its old meaning: yield for every thread that
has the same or a higher priority.
This PR does not touch the occurrences of `thread_yield()` in the periph
drivers, because the author of this PR did not look into the logic of
the various driver implementations.
