When the last WorkItem is deleted, it is removed from a work queue and the
queue is being stopped. But, the queue itself might get deleted in the middle,
in a higher priority thread than where the WorkItem deletion was performed from
If the WorkQueue::Detach accesses the member variables after this, there is memory
corruption
This happens in particular when launching i2c or spi devices in
I2CSPIDriverBase::module_start:
- The "initializer" is deleted when the instance is not found and the iterator
while loop continues.
- The workqueue is deleted in the middle of "initializer" deletion when the
WorkQueueRunner returns.
This prevents deletion of the WorkQueue before the Detach has been finished,
in the specific case that the ::Detach triggers the deletion
Signed-off-by: Jukka Laitinen <jukkax@ssrc.tii.ae>
With Makefile build, generate_component_general.py was called twice during
build, which did not happen with the ninja build.
This created a race condition with the following error in rare cases:
Traceback (most recent call last):
File "/__w/PX4-Autopilot/PX4-Autopilot/src/lib/component_information/generate_component_general.py", line 79, in <module>
save_compressed(filename)
File "/__w/PX4-Autopilot/PX4-Autopilot/src/lib/component_information/generate_component_general.py", line 33, in save_compressed
with open(filename, 'r') as content_file:
FileNotFoundError: [Errno 2] No such file or directory: '/__w/PX4-Autopilot/PX4-Autopilot/build/px4_sitl_default/component_general.json'
make[3]: *** [src/lib/component_information/CMakeFiles/component_information_header.dir/build.make:68: component_general.json] Error 1
Merging the targets avoids the duplicate execution.
This is to avoid blocking in any case.
If we don't do that, ioctl() may signal data available while the other
protocol does a read(), and when the first protocol tries to do a read(),
it would not have data anymore and would block (so this avoids a race
condition).
Julian Oes
Daniel Agar
Hylke Faas
Jukka Laitinen
Jacob Crabill
Beat Küng
Kjersti Brynestad
Andrew Brahim
Thomas Stauber
Thomas
David Sidrane
Christian Llanes