proxmox-mirrors/mirror_frr
1
0
Fork 0
mirror of https://git.proxmox.com/git/mirror_frr synced 2025-08-09 12:39:21 +00:00
Code Issues Actions Packages Projects Releases Wiki Activity

doc: Adjust pthread description

Browse Source 
Refer to the latest code, modified the description of pthread.

Signed-off-by: anlan_cs <vic.lan@pica8.com>
This commit is contained in:
anlan_cs 2023-06-12 12:56:24 +08:00
parent e631541b68
commit eb678efed8
1 changed files with 6 additions and 5 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

11
doc/developer/process-architecture.rst
View File

@ -210,7 +210,8 @@ Kernel Thread Wrapper
The basis for the integration of pthreads and the event system is a lightweight The basis for the integration of pthreads and the event system is a lightweight
wrapper for both systems implemented in :file:`lib/frr_pthread.[ch]`. The wrapper for both systems implemented in :file:`lib/frr_pthread.[ch]`. The
header provides a core datastructure, ``struct frr_pthread``, that encapsulates header provides a core datastructure, ``struct frr_pthread``, that encapsulates
structures from both POSIX threads and :file:`thread.[ch]`. In particular, this structures from both POSIX threads and :file:`event.c`, :file:`frrevent.h`.
In particular, this
datastructure has a pointer to a ``threadmaster`` that runs within the pthread. datastructure has a pointer to a ``threadmaster`` that runs within the pthread.
It also has fields for a name as well as start and stop functions that have It also has fields for a name as well as start and stop functions that have
signatures similar to the POSIX arguments for ``pthread_create()``. signatures similar to the POSIX arguments for ``pthread_create()``.
@ -218,18 +219,18 @@ signatures similar to the POSIX arguments for ``pthread_create()``.
Calling ``frr_pthread_new()`` creates and registers a new ``frr_pthread``. The Calling ``frr_pthread_new()`` creates and registers a new ``frr_pthread``. The
returned structure has a pre-initialized ``threadmaster``, and its ``start`` returned structure has a pre-initialized ``threadmaster``, and its ``start``
and ``stop`` functions are initialized to defaults that will run a basic event and ``stop`` functions are initialized to defaults that will run a basic event
loop with the given threadmaster. Calling ``frr_pthread_run`` starts the thread loop with the given threadmaster. Calling ``frr_pthread_run()`` starts the thread
with the ``start`` function. From there, the model is the same as the regular with the ``start`` function. From there, the model is the same as the regular
event model. To schedule tasks on a particular pthread, simply use the regular event model. To schedule tasks on a particular pthread, simply use the regular
:file:`thread.c` functions as usual and provide the ``threadmaster`` pointed to :file:`event.c` functions as usual and provide the ``threadmaster`` pointed to
from the ``frr_pthread``. As part of implementing the wrapper, the from the ``frr_pthread``. As part of implementing the wrapper, the
:file:`thread.c` functions were made thread-safe. Consequently, it is safe to :file:`event.c` functions were made thread-safe. Consequently, it is safe to
schedule events on a ``threadmaster`` belonging both to the calling thread as schedule events on a ``threadmaster`` belonging both to the calling thread as
well as *any other pthread*. This serves as the basis for inter-thread well as *any other pthread*. This serves as the basis for inter-thread
communication and boils down to a slightly more complicated method of message communication and boils down to a slightly more complicated method of message
passing, where the messages are the regular task events as used in the passing, where the messages are the regular task events as used in the
event-driven model. The only difference is thread cancellation, which requires event-driven model. The only difference is thread cancellation, which requires
calling ``event_cancel_async()`` instead of ``event_cancel`` to cancel a task calling ``event_cancel_async()`` instead of ``event_cancel()`` to cancel a task
currently scheduled on a ``threadmaster`` belonging to a different pthread. currently scheduled on a ``threadmaster`` belonging to a different pthread.
This is necessary to avoid race conditions in the specific case where one This is necessary to avoid race conditions in the specific case where one
pthread wants to guarantee that a task on another pthread is cancelled before pthread wants to guarantee that a task on another pthread is cancelled before