There is a good case on sim platform:
When we input some cmd and click enter key to start application in terminal,
this context will change to application from IDLE loop. Althrough entey key '\r'
has been received to recv buffer and complete post semaphore of reader, but
pollnotify may not be called because context change. So when application run
poll function, because no events happend and poll enter wait, context will
again change to IDLE loop, this pollnotify of IDLE loop will run to send poll
events, poll function of applicaton will wake up. It's wrong!
Change-Id: I812a889f2e90781a9c3cb4b0251cccc4d32bebd1
Signed-off-by: dongjiuzhu <dongjiuzhu1@xiaomi.com>
Resolution of Issue 619 will require multiple steps, this part of the first step in that resolution: Every call to nxsem_wait_uninterruptible() must handle the return value from nxsem_wait_uninterruptible properly. This commit is only for those files under drivers/pipes and drivers/wireless.
This commit does two things:
1. First, it reorganizes the driver Kconfig files so that each is self contained. Before, a part of the driver configuration was in drivers/Kconfig and the rest was in in drivers/xyz/Konfig. Now, all of the driver configuration is consolitated in the latter.
2. Second, this commit correct numerous serious errors introduced in a previous reorganization of the driver Kconfig files. This was first noted by Nicholas Chin in PR270 for the case of the drivers/i2c/Kconfig but some examination indicates that the error was introduced into several other Kconfig files as well.
The nature of the introduced error was basically this:
- Nothing must intervene between the menuconfig selection and the following conditional configuration otpions.
- A previous PR erroneously introduced unconditional options between the menuconfig and the following confditional logic, thus corrupting the driver menus.
This error was easy to make because the driver Kconfig files were not well modularized. Making them fully self-contained should eliminate this kind of error in the future.
* 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
arch/: Removed all references to CONFIG_DISABLE_POLL. The standard POSIX poll() can not longer be disabled.
sched/ audio/ crypto/: Removed all references to CONFIG_DISABLE_POLL. The standard POSIX poll() can not longer be disabled.
Documentation/: Removed all references to CONFIG_DISABLE_POLL. The standard POSIX poll() can not longer be disabled.
fs/: Removed all references to CONFIG_DISABLE_POLL. The standard POSIX poll() can not longer be disabled.
graphics/: Removed all references to CONFIG_DISABLE_POLL. The standard POSIX poll() can not longer be disabled.
net/: Removed all references to CONFIG_DISABLE_POLL. The standard POSIX poll() can not longer be disabled.
drivers/: Removed all references to CONFIG_DISABLE_POLL. The standard POSIX poll() can not longer be disabled.
include/, syscall/, wireless/: Removed all references to CONFIG_DISABLE_POLL. The standard POSIX poll() can not longer be disabled.
configs/: Remove all references to CONFIG_DISABLE_POLL. Standard POSIX poll can no longer be disabled.
Squashed commit of the following:
configs/: The few configurations that formerly set CONFIG_NFILE_DESCRIPTORS=0 should not default, rather they should set the number of descriptors to 3.
fs/: Remove all conditional logic based on CONFIG_NFILE_DESCRIPTORS == 0
tools/: Tools updates for changes to usage of CONFIG_NFILE_DESCRIPTORS.
syscall/: Remove all conditional logic based on CONFIG_NFILE_DESCRIPTORS == 0
libs/: Remove all conditional logic based on CONFIG_NFILE_DESCRIPTORS == 0
include/: Remove all conditional logic based on CONFIG_NFILE_DESCRIPTORS == 0
drivers/: Remove all conditional logic based on CONFIG_NFILE_DESCRIPTORS == 0
Documentation/: Remove all references to CONFIG_NFILE_DESCRIPTORS == 0
binfmt/: Remove all conditional logic based on CONFIG_NFILE_DESCRIPTORS == 0
arch/: Remove all conditional logic based on CONFIG_NFILE_DESCRIPTORS == 0
net/: Remove all conditional logic based on CONFIG_NFILE_DESCRIPTORS == 0
sched/: Remove all conditional logic based on CONFIG_NFILE_DESCRIPTORS == 0
sched/Kconfig: CONFIG_NFILE_DESCRIPTORS may no longer to set to a value less than 3
configs/: Remove all settings for CONFIG_NFILE_DESCRIPTORS < 3
many locations: Change occurences of open() followed by file_detach() to file_open(). Change most non-controversion calls to open() to nx_open().
fs/inode/fs_fileopen.c: Flesh out file_open() with some interim, placeholder logic.
fs/inode/fs_fileopen.c: Add a framework for a file_open() implementation (no real logic in place yet).
fs/vfs/fs_open.c: Add nx_open() which is the same as open() except that it does not create a cancellation point nor does it modify the errno variable.
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.
sched/semaphore: Add nxsem_post() which is identical to sem_post() except that it never modifies the errno variable. Changed all references to sem_post in the OS to nxsem_post().
sched/semaphore: Add nxsem_destroy() which is identical to sem_destroy() except that it never modifies the errno variable. Changed all references to sem_destroy() in the OS to nxsem_destroy().
libc/semaphore and sched/semaphore: Add nxsem_getprotocol() and nxsem_setprotocola which are identical to sem_getprotocol() and set_setprotocol() except that they never modifies the errno variable. Changed all references to sem_setprotocol in the OS to nxsem_setprotocol(). sem_getprotocol() was not used in the OS
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.
