Squashed commit of the following:
Fix up some final compile isses.
net/netdev: Convert the network down notification logic to use the new wqueue-based notification factility.
net/udp: Convert the UDP readahead notification logic to use the new wqueue-based notification factility.
net/tcp: Convert the TCP readahead notification logic to use the new wqueue-based notification factility.
mm/iob: Convert the IOB notification logic to use the new wqueue-based notification factility.
sched/wqueue: Signals are not good IPCs to support the target poll functionality for several reasons including the amount of data that can be passed with a signal and in the fact that in protected and kernel modes, user threads executing signal handlers in protected, kernel memory is problematic. Instead, convert the same logic to perform the notifications via function callback on the high priority work queue.
Squashed commit of the following:
mm/iob: The IOB available notifier is now just a wrapper around the common signal notifier.
sched/signal: Add a generic signal notification facility.
sched/signal/sig_evthread.c: More trivial naming changes.
sched/signal: Rename nxsig_notification() to nxsig_evthread() to make forthcoming naming additions more consistent.
Squashed commit of the following:
Add procfs support to show stopped tasks. Add nxsig_action() to solve a chicken and egg problem: We needed to use sigaction to set default actions, but sigaction() would refuse to set actions if the default actions could not be caught or ignored.
sched/signal: Add configuration option to selectively enabled/disable default signal actions for SIGSTOP/SIGSTP/SIGCONT and SIGKILL/SIGINT. Fix some compilation issues.
sched/sched: Okay.. I figured out a way to handle state changes that may occur while they were stopped. If a task/thread was already blocked when SIGSTOP/SIGSTP was received, it will restart in the running state. I will appear that to the task/thread that the blocked condition was interrupt by a signal and returns the EINTR error.
sched/group and sched/sched: Finish framework for continue/resume logic.
sched/signal: Roughing out basic structure to support task suspend/resume
drivers/serial/Kconfig: It is no longer necessary to restrict Ctrl-C handling to the FLAT build
sched/signal: Add a new configuration option to select signal default actions, separate handling of signal default actions from both task startup logic and from the serial TTY Ctrl-C logic. Add a signal set in the group structure to keep track of what signals have been set to the default action. In dispatching signals in PROTECTED or KERNEL mode, use this signal set to determine if the default signal handler is attached and dispatch the signal in kernel mode for the default actions.
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.
Fix signal handing for smp
* sched/signal: Remove SMP related logic in sig_dispatch.c
This change prevents from a deadlock in up_schedulesigaction.c
where inter-CPU signal handling is actually implemented.
Signed-off-by: Masayuki Ishikawa <Masayuki.Ishikawa@jp.sony.com>
* arch/arm/src/armv7-m: Fix signal handling for SMP
In previous implementation, signal handling for SMP was incorrect.
Thus, for example, if an inter-CPU signal happened an incorret tcb
was signaled and caused ASSERT().
This change fixes the issues and works for both inter-CPU signal
handling and signal handling on the same CPU.
Signed-off-by: Masayuki Ishikawa <Masayuki.Ishikawa@jp.sony.com>
Approved-by: Gregory Nutt <gnutt@nuttx.org>
sched/mqueue: Rename all private static functions for use the nxmq_ vs. mq_ naming.
sched/mqueue: Rename all OS internal functions declared in sched/mqueue/mqueue.h to begin with nxmq_ vs. mq_. The mq_ prefix is reserved for standard application interfaces.
Replace all calls to sigprocmask() in the OS proper with calls to nxsig_procmask().
sched/signal: Add internal OS interface nxsig_procmask(). This internal interface is equivalent to the standard sigprocmask() used by applications except that it does not modify the errno value. Also fixes a problem in that the original sigprocmask() was not setting the errno.
Replace all calls to sigqueue() in the OS proper with calls to nxsig_queue() to avoid accessing the errno variable.
sched/signal: Add nxsig_queue() which is functionally equivalent to sigqueue() except that it does not modify the errno variable.
Replace all usage kill() in the OS proper with nxsig_kill().
sched/signal: Add nxsig_kill() which is functionally equivalent to kill() except that it does not modify the errno variable.
Squashed commit of the following:
Change all calls to usleep() in the OS proper to calls to nxsig_usleep()
sched/signal: Add a new OS internal function nxsig_usleep() that is functionally equivalent to usleep() but does not cause a cancellaption point and does not modify the errno variable.
sched/signal: Add a new OS internal function nxsig_sleep() that is functionally equivalent to sleep() but does not cause a cancellaption point.
sigtimedwait() -> nxsig_timedwait()
sigwaitinfo() -> nxsig_waitinfo()
nanosleep() -> nxsig_nanosleep()
The internal OS versions differ from the standard application interfaces in that:
- They do not create cancellation points, and
- they do not modify the application's errno variable
Squashed commit of the following:
sched/signal: Replace all usage of sigwaitinfo(), sigtimedwait(), and nanosleep() with the OS internal counterparts nxsig_waitinfo(), nxsig_timedwait(), and nxsig_nanosleep().
sched/signal: Add nxsig_nanosleep(). This is an internal OS version of nanosleep(). It differs in that it does not set the errno varaiable and does not create a cancellation point.
sched/signal: Add nxsig_timedwait() and nxsig_waitinfo(). These are internal OS versions of sigtimedwait() and sigwaitinfo(). They differ in that they do not set the errno varaiable and they do not create cancellation points.
This is analogous to similar renaming that was done previously for semaphores.
Squashed commit of the following:
sched/signal: Fix a few compile warnings introduced by naming changes.
sched/signal: Rename all private, internal signl functions to use the nxsig_ prefix.
sched/signal: Rename sig_removependingsignal, sig_unmaskpendingsignal, and sig_mqnotempty to nxsig_remove_pendingsignal, nxsig_unmask_pendingsignal, and nxsig_mqnotempty to make it clear that these are OS internal interfaces.
sched/signal: Rename sig_findaction and sig_lowest to nxsig_find_action and nxsig_lowest to make it clear that these are OS internal interfaces.
sched/signal: Rename sig_allocatepingsigaction and sig_deliver to nxsig_alloc_pendingsigaction and nxsig_deliver to make it clear that these are OS internal interfaces.
sched/signal: Rename sig_cleanup, sig_release, sig_releasependingaction, and sig_releasependingsignal to nxsig_cleanup, nxsig_release, nxsig_release_pendingaction, and nxsig_release_pendingsignal to make it clear that these are OS internal interfaces.
sched/signal: Rename sig_tcbdispatch and sig_dispatch to nxsig_tcbdispatch and nxsig_dispatch to make it clear that these are OS internal interfaces.
sched/signal: Rename sig_releaseaction and sig_pendingset to nxsig_release_action and nxsig_pendingset to make it clear that these are OS internal interfaces.
sched/signal: Rename sig_initialize and sig_allocateactionblock to nxsig_initialize and nxsig_alloc_actionblock to make it clear that these are OS internal interfaces.
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.
The three fixes are to handle cases in the SMP configuration where one CPU does need to make modifications to TCB and data structures on a task that could be running running on another CPU. Those three cases are task_delete(), task_restart(), and execution of signal handles. In all three cases the solutions is basically the same: (1) Call sched_cpu_pause(tcb) to pause the CPU on which the task is running, (2) perform the necessary operations, then (3) call up_cpu_resume() to restart the paused CPU.
2. Move list of signal actions from the task TCB to the task group. Signal handlers are a property of the entire task group and not of individual threads in the group. I know, I preferred it the other way too but this is more compliant with POSIX.
