nuttx/Documentation/reference/user
Marco Casaroli ca8287e690 Documentation: describe the fork()/vfork()/task_fork() split
Documentation/guides/fork_vfork_migration.rst is new.  It says what changed
and why, gives the three primitives as a table, states plainly what breaks,
and answers "which replacement do I want?" from the reader's own reason for
having called fork() -- posix_spawn() or vfork() to run a program,
pthread_create() or task_fork() for a second flow of control that shares
memory, fork() itself for an independent copy, FORK_IS_TASK_FORK for code
that cannot be changed today.  It also documents the seven configuration
symbols, what an architecture has to implement to gain real fork(), and the
one visible consequence of moving the vfork() suspension into the kernel:
a waitpid() after a child that _exit()s can only report status where
CONFIG_SCHED_CHILD_STATUS is enabled.

reference/user/01_task_control.rst gains entries for fork() and task_fork()
and rewrites the one for vfork(), which described NuttX's limitations rather
than the interface's contract.  standards/posix.rst moves fork() from "No" to
"Cond." and vfork() from "Yes" to "Cond.", both being conditional on the
configuration now.  implementation/memory_configurations.rst no longer lists
fork() as unimplementable in the presence of address environments, which was
the whole point of that section's wish list.  Three long-standing typos in
that file are corrected while touching it, since codespell checks the whole
of any file a patch modifies.

Signed-off-by: Marco Casaroli <marco.casaroli@gmail.com>

Assisted-by: Claude Opus 5 (1M context) <noreply@anthropic.com>
2026-07-30 11:45:24 +02:00
..
01_task_control.rst Documentation: describe the fork()/vfork()/task_fork() split 2026-07-30 11:45:24 +02:00
02_task_scheduling.rst Documentation: Fix a typo in scheduler docs 2025-06-02 23:09:02 +08:00
03_task_control.rst sched: Dynamically extend the pid hash table 2021-07-11 19:42:30 -07:00
04_message_queue.rst Documentation:fix error describe on message queue 2022-04-26 16:09:37 +08:00
05_counting_semaphore.rst sched/semaphore: add support to customize semaphore max allowed value 2025-09-04 09:48:34 +08:00
06_clocks_timers.rst Documentation: various cosmetic changes 2023-10-30 20:29:54 +08:00
07_signals.rst docs: Update Signal Interfaces documentation 2026-01-31 10:07:36 -03:00
08_pthread.rst pthread: add pthread_{get|set}concurrency support 2025-08-22 20:50:13 +08:00
09_env_vars.rst documentation: spelling and grammar fixes 2025-07-24 14:44:02 +08:00
10_filesystem.rst documentation: spelling and grammar fixes 2025-07-24 14:44:02 +08:00
11_network.rst 11_network.rst: Add a "Network Interfaces Overview" section and 2025-11-13 11:29:38 -03:00
12_shared_memory.rst Documentation: various cosmetic changes 2023-10-30 20:29:54 +08:00
13_boardctl.rst doc: Migrating the rest of documentation from cwiki. 2026-05-28 09:34:04 +08:00
14_logging.rst docs/guides/lwl: move lwl's README.txt to lwl.rst 2025-12-23 15:20:06 +01:00
index.rst Docs: Fix broken links and references in docs 2020-10-22 10:22:11 -03:00
structures.rst Documentation: various cosmetic changes 2023-10-30 20:29:54 +08:00