TODO
====

A collection of ideas and notes about stuff to implement in future versions.
"#NNN" occurrences refer to bug tracker issues at:
https://github.com/giampaolo/psutil/issues

FEATURES
========

- (UNIX) process root (different from cwd)

- (Linux) locked files via /proc/locks:
  https://www.centos.org/docs/5/html/5.2/Deployment_Guide/s2-proc-locks.html

- #269: NIC rx/tx queue. This should probably go into net_if_stats().
  Figure out on what platforms this is supported:
  Linux: yes
  Others: ?

- Asynchronous psutil.Popen (see http://bugs.python.org/issue1191964)

- (Windows) fall back on using WMIC for Process methods returning AccessDenied

- #613: thread names; patch for macOS available at:
  https://code.google.com/p/plcrashreporter/issues/detail?id=65
  Sample code:
  https://github.com/janmojzis/pstree/blob/master/proc_kvm.c

- scripts/taskmgr-gui.py (using tk).

- system-wide number of open file descriptors:
  - https://jira.hyperic.com/browse/SIGAR-30

- Number of system threads.
  - Windows: http://msdn.microsoft.com/en-us/library/windows/desktop/ms684824(v=vs.85).aspx

- Doc / wiki which compares similarities between UNIX cli tools and psutil.
  Example:
  ```
  df -a  ->  psutil.disk_partitions
  lsof  ->  psutil.Process.open_files() and psutil.Process.net_connections()
  killall->  (actual script)
  tty  ->  psutil.Process.terminal()
  who  ->  psutil.users()
  ```

- psutil.proc_tree() something which obtains a {pid:ppid, ...} dict for
  all running processes in one shot. This can be factored out from
  Process.children() and exposed as a first class function.
  PROS: on Windows we can take advantage of _psutil_windows.ppid_map()
  which is faster than iterating over all pids and calling ppid().
  CONS: scripts/pstree.py shows this can be easily done in the user code
  so maybe it's not worth the addition.

- advanced cmdline interface exposing the whole API and providing different
  kind of outputs (e.g. pprinted, colorized, json).

- [Linux]: process cgroups (http://en.wikipedia.org/wiki/Cgroups). They look
  similar to prlimit() in terms of functionality but uglier (they should allow
  limiting per-process network IO resources though, which is great). Needs
  further reading.

- Python 3.3. exposed different sched.h functions:
  http://docs.python.org/dev/whatsnew/3.3.html#os
  http://bugs.python.org/issue12655
  http://docs.python.org/dev/library/os.html#interface-to-the-scheduler
  It might be worth to take a look and figure out whether we can include some
  of those in psutil.
  Also, we can probably reimplement wait_pid() on POSIX which is currently
  implemented as a busy-loop.

- os.times() provides 'elapsed' times (cpu_times() might).

- ...also guest_time and cguest_time on Linux.

- Enrich exception classes hierarchy on Python >= 3.3 / post PEP-3151 so that:
   - NoSuchProcess inherits from ProcessLookupError
   - AccessDenied inherits from PermissionError
   - TimeoutExpired inherits from TimeoutError (debatable)
   See: http://docs.python.org/3/library/exceptions.html#os-exceptions

- Process.threads() might grow an extra "id" parameter so that it can be
   used as such:
  ```
  >>> p = psutil.Process(os.getpid())
  >>> p.threads(id=psutil.current_thread_id())
  thread(id=2539, user_time=0.03, system_time=0.02)
  >>>
  ```
  Note: this leads to questions such as "should we have a custom NoSuchThread
  exception? Also see issue #418.
  Note #2: this would work with os.getpid() only.
  psutil.current_thread_id() might be desirable as per issue #418 though.

- should psutil.TimeoutExpired exception have a 'msg' kwarg similar to
  NoSuchProcess and AccessDenied? Not that we need it, but currently we
  cannot raise a TimeoutExpired exception with a specific error string.

- round Process.memory_percent() result?

BUGFIXES
========

- #600: windows / open_files(): support network file handles.

REJECTED IDEAS
==============

- #550: threads per core
- #1667: process_iter(new_only=True)

INCONSISTENCIES
===============

- PROCFS_PATH should have been set_procfs_path().
- `virtual_memory()` should have been `memory_virtual()`.
- `swap_memory()` should have been `memory_swap()`.

RESOURCES
=========

- conky: https://github.com/brndnmtthws/conky/
- sigar: https://github.com/hyperic/sigar (Java)
- zabbix: https://zabbix.org/wiki/Get_Zabbix
- libstatgrab: http://www.i-scream.org/libstatgrab/
- top: http://www.unixtop.org/
- oshi: https://github.com/oshi/oshi
- netdata: https://github.com/netdata/netdata
