This moves all the public POSIX semaphore functions into libc and with
this most of the user-space logic is also moved; namely cancel point and
errno handling.
This also removes the need for the _SEM_XX macros used to differentiate
which API is used per user-/kernel mode. Such macros are henceforth
unnecessary.
nxsem_timedwait_uninterruptible() must return -ECANCELED if the thread is canceled:
include/nuttx/semaphore.h: Return if nxsem_wait() returns ECANCELED meaning that the thread waiting for the semaphore has been canceled.
sched/semaphore/sem_timedwait.c: Same change (the inline version is in semaphore.h, the non-inlined version is in sem_tickwait.c).
drivers/sensors/lps25h.c and drivers/wireless/bluetooth/bt_uart_bcm4343x.c: Make sure that the caller deals correctly with the -ECANCELED return value.
Refer to issue 619.
I finally figured out why the ez80 code has gotten so big. It is because people have been put putting big inline functions in header files. That is a violation of the coding standard, since only c89 compatibility is required in all common code. But we have been tolerating inline function it because include/nuttx/compiler.h defines 'inline' to be nothing for C89 compilers.
As a result, static inline functions declared within a C file not so bad; the inline qualifier is ignored, if not supported, but otherwise all is well.
But it is catastrophic in header files. Those static inline functions are included as static functions and implemented in EVERY file that includes those header files, even if the functions are never called. That makes the code base huge!So there is another PR coming to fix some of the worst offenders.
This commit fixes two of the worst offenders I have encountered so far: include/nuttx/sempahore.h and cache.h. But there may be a few other changes needed. Under include/nuttx there are still inline functions thread.h, inclue/nuttx/list.h, mutex.h, tree.h, and include/nuttx/crypto/blake2s.h with no protection for compilers that do not handler the inline qualifier. Otherwise we are clean.
With the changes to these two header files, the size of the z20x build is reduced by about 40%. And incredible size savings.
* Simplify EINTR/ECANCEL error handling
1. Add semaphore uninterruptible wait function
2 .Replace semaphore wait loop with a single uninterruptible wait
3. Replace all sem_xxx to nxsem_xxx
* Unify the void cast usage
1. Remove void cast for function because many place ignore the returned value witout cast
2. Replace void cast for variable with UNUSED macro
Squashed commit of the following:
sched: Rename all use of system_t to clock_t.
syscall: Rename all use of system_t to clock_t.
net: Rename all use of system_t to clock_t.
libs: Rename all use of system_t to clock_t.
fs: Rename all use of system_t to clock_t.
drivers: Rename all use of system_t to clock_t.
arch: Rename all use of system_t to clock_t.
include: Remove definition of systime_t; rename all use of system_t to clock_t.
This commit backs out most of commit b4747286b1. That change was added because sem_wait() would sometimes cause cancellation points inappropriated. But with these recent changes, nxsem_wait() is used instead and it is not a cancellation point.
In the OS, all calls to sem_wait() changed to nxsem_wait(). nxsem_wait() does not return errors via errno so each place where nxsem_wait() is now called must not examine the errno variable.
In all OS functions (not libraries), change sem_wait() to nxsem_wait(). This will prevent the OS from creating bogus cancellation points and from modifying the per-task errno variable.
sched/semaphore: Add the function nxsem_wait(). This is a new internal OS interface. It is functionally equivalent to sem_wait() except that (1) it is not a cancellation point, and (2) it does not set the per-thread errno value on return.
libc/semaphore: Add nxsem_getvalue() which is identical to sem_getvalue() except that it never modifies the errno variable. Changed all references to sem_getvalue in the OS to nxsem_getvalue().
sched/semaphore: Rename all internal private functions from sem_xyz to nxsem_xyz. The sem_ prefix is (will be) reserved only for the application semaphore interfaces.
libc/semaphore: Add nxsem_init() which is identical to sem_init() except that it never modifies the errno variable. Changed all references to sem_init in the OS to nxsem_init().
sched/semaphore: Rename sem_tickwait() to nxsem_tickwait() so that it is clear this is an internal OS function.
sched/semaphoate: Rename sem_reset() to nxsem_reset() so that it is clear this is an internal OS function.
