| Age | Commit message (Collapse) | Author |
|---|
|
When a thread stops, messages may be left in its message queue. Document
this in details, with a way to force processing of pending messages when
the thread is stopped.
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Niklas Söderlund <niklas.soderlund@ragnatech.se>
Reviewed-by: Umang Jain <umang.jain@ideasonboard.com>
Reviewed-by: Hirokazu Honda <hiroh@chromium.org>
Reviewed-by: Jacopo Mondi <jacopo@jmondi.org>
|
|
The asynchronous signal delivery mechanism can't be used by application,
as it requires libcamera to be aware of the application event loop,
which has been dropped a long time ago. Drop the corresponding
documentation paragraph.
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Niklas Söderlund <niklas.soderlund@ragnatech.se>
Reviewed-by: Umang Jain <umang.jain@ideasonboard.com>
Reviewed-by: Hirokazu Honda <hiroh@chromium.org>
|
|
The Thread::dispatchMessages() function is meant to be called from
within the thread only. Catch incorrect usage with an ASSERT().
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Niklas Söderlund <niklas.soderlund@ragnatech.se>
Reviewed-by: Umang Jain <umang.jain@ideasonboard.com>
Reviewed-by: Hirokazu Honda <hiroh@chromium.org>
|
|
The Thread class is incorrectly documented as thread-safe, as the
dispatchMessages() function isn't thread-safe. Fix the documentation by
tagging individual functions as thread-safe as appropriate.
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Niklas Söderlund <niklas.soderlund@ragnatech.se>
Reviewed-by: Umang Jain <umang.jain@ideasonboard.com>
Reviewed-by: Hirokazu Honda <hiroh@chromium.org>
Reviewed-by: Jacopo Mondi <jacopo@jmondi.org>
|
|
s/This method enter/This method enters/
Signed-off-by: Sebastian Fricke <sebastian.fricke@posteo.net>
Reviewed-by: Jacopo Mondi <jacopo@jmondi.org>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
|
|
Custom event dispatchers for threads was an API meant to provide a way
to integrate libcamera in the application's event loop. This isn't used
anymore, as libcamera now creates internal threads. Drop the unused
Thread::setEventDispatcher() function, and update the documentation
accordingly.
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
|
|
There's no user of the EventDispatcher (and the related EventNotifier
and Timer classes) outside of libcamera. Move those classes to the
internal API.
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
Reviewed-by: Niklas Söderlund <niklas.soderlund@ragnatech.se>
|
|
The Thread::wait() function creates a boolean flag 'finished' which
shadows the internal member signal of the same name.
Rename the boolean flag to prevent confusion and shadowing of the signal.
Signed-off-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Niklas Söderlund <niklas.soderlund@ragnatech.se>
|
|
Extend the current dispatchMessages() to support dispatching of
selective messsages according to the Message::Type passed in
the function argument. dispatchMessages() can now be called
explicitly to force deliver selected type's message to the
thread for processing (typically when event loop is not
running).
Signed-off-by: Umang Jain <email@uajain.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
|
|
The libcamera internal headers are located in src/libcamera/include/.
The directory is added to the compiler headers search path with a meson
include_directories() directive, and internal headers are included with
(e.g. for the internal semaphore.h header)
#include "semaphore.h"
All was well, until libcxx decided to implement the C++20
synchronization library. The __threading_support header gained a
#include <semaphore.h>
to include the pthread's semaphore support. As include_directories()
adds src/libcamera/include/ to the compiler search path with -I, the
internal semaphore.h is included instead of the pthread version.
Needless to say, the compiler isn't happy.
Three options have been considered to fix this issue:
- Use -iquote instead of -I. The -iquote option instructs gcc to only
consider the header search path for headers included with the ""
version. Meson unfortunately doesn't support this option.
- Rename the internal semaphore.h header. This was deemed to be the
beginning of a long whack-a-mole game, where namespace clashes with
system libraries would appear over time (possibly dependent on
particular system configurations) and would need to be constantly
fixed.
- Move the internal headers to another directory to create a unique
namespace through path components. This causes lots of churn in all
the existing source files through the all project.
The first option would be best, but isn't available to us due to missing
support in meson. Even if -iquote support was added, we would need to
fix the problem before a new version of meson containing the required
support would be released.
The third option is thus the only practical solution available. Bite the
bullet, and do it, moving headers to include/libcamera/internal/.
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Acked-by: Jacopo Mondi <jacopo@jmondi.org>
|
|
No code change.
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
|
|
Add a parameter to the Thread::wait() function to wait with a timeout.
The delay value utils::duration::max() waits forever.
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
Reviewed-by: Niklas Söderlund <niklas.soderlund@ragnatech.se>
|
|
Define the thread-safety attributes of the classes and methods that are
either thread-safe or thread-bound. The CameraManager, Camera and
PipelineHandler will be addressed separately.
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Niklas Söderlund <niklas.soderlund@ragnatech.se>
|
|
Document the design of libcamera's threading support, and prepare to
document thread-safety of classes and functions with a doxygen alias
command.
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Jacopo Mondi <jacopo@jmondi.org>
Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
Reviewed-by: Niklas Söderlund <niklas.soderlund@ragnatech.se>
|
|
The current thread ID is useful when logging message to debug
concurrency issues. Add a method to retrieve it.
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Niklas Söderlund <niklas.soderlund@ragnatech.se>
Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
Reviewed-by: Jacopo Mondi <jacopo@jmondi.org>
|
|
The Object class stores the number of pending messages that have been
posted for it, while the actual messages are stored in a per-thread list
in the ThreadData class. When dispatching messages, the message is
removed from the list, passed to the receiver, and the number of pending
messages is updated.
In order to avoid too much contention on the list lock, the lock is
dropped to pass the message to the receiver and then taken again. This
creates a race condition window with Thread::removeMessages(), as the
number of pending messages for a receiver is briefly out of sync with
the pending messages list. The assertion at the end of removeMessages()
thus sometimes fails.
Fix this by decrementing the pending messages counter before releasing
the lock in Thread::dispatchMessages(). This fixes the slow message
receiver test in MessageTest.
Fixes: 01b930964acd ("libcamera: thread: Add a messaging passing API")
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Jacopo Mondi <jacopo@jmondi.org>
Reviewed-by: Niklas Söderlund <niklas.soderlund@ragnatech.se>
|
|
When moving an Object to a Thread, messages posted for the object are
move to the target thread's message queue. This requires locking the
message queues of the current and target threads, as the target thread
may (and is usually) running. The implementation is faulty as it locks
the thread data instead of the message queue. This creates a race
condition with a tiny but exploitable time window.
The issue was noticed by the event-thread test rarely but reproducibly
failing with the following assertion error:
[1:39:33.850878042]FATAL default thread.cpp:440 assertion "data_ == receiver->thread()->data_" failed
The issue only occurred when libcamera was compiled in release mode,
further hinting of a race condition.
Fixes: 01b930964acd ("libcamera: thread: Add a messaging passing API")
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Niklas Söderlund <niklas.soderlund@ragnatech.se>
|
|
Comply with the coding style by removing lots of unneeded semicolons.
Fix a few other coding style violations on the lines touched by those
fixes.
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
|
|
Add a parent Object to Object instances, and track the parent-children
relationships. Children are bound to the same thread as their parent,
and moving an Object to a thread automatically moves all its children.
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Jacopo Mondi <jacopo@jmondi.org>
Reviewed-by: Niklas Söderlund <niklas.soderlund@ragnatech.se>
|
|
Threads contain message queues and dispatch queued messages in their
event loop, in Thread::exec(). This mechanism prevents the main thread
from dispatching messages as it doesn't run Thread::exec().
Fix this by moving message dispatching from Thread::exec() to
EventDispatcher::processEvents().
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Jacopo Mondi <jacopo@jmondi.org>
Reviewed-by: Niklas Söderlund <niklas.soderlund@ragnatech.se>
|
|
When moving an object to a different thread, messages posted for the
object are moved to the message queue of the new thread. Wake up the new
thread to ensure it processes the moved messages.
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Jacopo Mondi <jacopo@jmondi.org>
Reviewed-by: Niklas Söderlund <niklas.soderlund@ragnatech.se>
|
|
Create a new Message class to model a message that can be passed to an
object living in another thread. Only an invalid message type is
currently defined, more messages will be added in the future.
The Thread class is extended with a messages queue, and the Object class
with thread affinity.
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Niklas Söderlund <niklas.soderlund@ragnatech.se>
|
|
The new Thread class wraps std::thread in order to integrate it with the
Object, Signal and EventDispatcher classes. By default new threads run
an internal event loop, and their run() method can be overloaded to
provide a custom thread loop.
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Niklas Söderlund <niklas.soderlund@ragnatech.se>
|
