Xiang Xiao 6a3c2aded6 Fix wait loop and void cast (#24)
* 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
2020-01-02 10:54:43 -06:00
..

fs/procfs README
================

  This is a tiny procfs file system that allows read-only access to a few
  attributes of a task or thread.  This tiny procfs fs file system can be
  built into the system by enabling:

    CONFIG_FS_PROCFS=y

  It can then be mounted from the NSH command like like:

    nsh> mount -t procfs /proc

Example
=======

  NuttShell (NSH) NuttX-6.31
  nsh> mount -t procfs /proc

  nsh> ls /proc
  /proc:
   0/
   1/

  nsh> ls /proc/1
  /proc/1:
   status
   cmdline

  nsh> cat /proc/1/status
  Name:       init
  Type:       Task
  State:      Running
  Priority:   100
  Scheduler:  SCHED_FIFO
  SigMask:    00000000

  nsh> cat /proc/1/cmdline
  init

  nsh> sleep 100 &
  sleep [2:100]
  nsh> ls /proc
  ls /proc
  /proc:
   0/
   1/
   2/

  nsh> cat /proc/2/cmdline
  <pthread> 0x527420