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.
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: Add Ctrl-C/Ctrl-X support. This is an initial working implementation that still requires that several details be resolved.
sched/task/task_start.c: Add default signal action to SIGKILL.
A few bugfixes in initial testing on the i.MX6. Behavior seems a little more stable, but there are still memory corruption issues. Also print CPU number on assertion.
Add a file missed in the last big commit.
arch/arm/src/armv7a and imx6: Add support for per-CPU IRQ and FIQ interrupt stacks (bugfix). Add support so that up_assert will print the correct interrupt stack on an assertion (FIQ stack is still not printed).
arch/arm/src/lc823450: Combine the content of smp_macros.h into chip.h. Add support so that up_assert will print the correct interrupt stack on an assertion.
sched/: Convert legitimate uses of task_create() to nxtask_create(). Review handling of returned values from all uses of kthread_create() (as well as nxtask_create()).
graphics/: Review return values for all calls to kthread_start() because it no longer returns an errno.
drivers/: threads started by drivers should be kernel threads, not user tasks. Review return values for all calls to kthread_start() because it no longer returns an errno.
configs/: threads started by board bringup logic should be kernel threads, not user tasksi (part 2 of 2).
sched/task: Add nxtask_create(). Kthread_create() and nxtask_create() are internal OS functions and should not modify the errno variable. configs/: threads started by board bringup logic should be kernel threads, not user tasks.
sched/sched: Correct some build issues introduced by last set of changes.
sched/sched: Add new internal OS function nxsched_setaffinity() that is identical to sched_isetaffinity() except that it does not modify the errno value. All usage of sched_setaffinity() within the OS is replaced with nxsched_setaffinity().
sched/sched: Internal functions sched_reprioritize() and sched_setpriority() no longer movidify the errno value. Also renamed to nxsched_reprioritize() and sched_setpriority().
sched/sched: Add new internal OS function nxsched_getscheduler() that is identical to sched_getscheduler() except that it does not modify the errno value. All usage of sched_getscheduler() within the OS is replaced with nxsched_getscheduler().
sched/sched: Add new internal OS function nxsched_setparam() that is identical to sched_setparam() except that it does not modify the errno value. All usage of sched_setparam() within the OS is replaced with nxsched_setparam().
sched/sched: Add new internal OS function nxsched_getparam() that is identical to sched_getparam() except that it does not modify the errno value (actually, the previous value erroneously neglected to set the errno value to begin with, but this fixes both issues). All usage of sched_getparam() within the OS is replaced with nxsched_getparam().
fs: Add truncate() support for userfs
fs/unionfs: Add truncate() support to the unionfs
fs/tmpfs: Add ftruncate() support to tmpfs
syscall/: Add system call support for ftruncate()
net/route: Adding ftruncate() support eliminates an issue in file-based routing table management.
fs: Add basic framework to support truncate() and ftruncate(). The infrastructure is complete. Now, however, the actual implementation of ftruncate() will have to be done for each file system.
This conversion is unfortunate in the sense that Unix local domain sockets are relatively lightweight. LocalHost UDP sockets are much heavier weight since they rely on the full UDP stack. If anyone is up for a complete redesign, then using some shared memory and a POSIX message queue would be lightweight again.
This commit also fixes several bugs that were not testable before the inode tree deadlock. I cannot say that the logic is 100% stable but it does not have basic functionality.
Squashed commit of the following:
fs/userfs: Order locking so that access to the shared I/O buffer is also locked.
fs/userfs: Converts to use LocalHost UDP loopback for IPC.
fs/mount: Implements procfs /proc/fs/blocks and /proc/fs/usage files, replacing the NSH df command.
fs/mount: Implements procfs /proc/fs/mount file, replacing the NSH mount command when there are not arguments.
fs/: Move prototype of foreach_mountpoint out of include/nuttx/fs/fs.h to fs/mount/mount.h. Add framework for the mount procfs (initial commit is just a close of the net/route table procfs.
