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>
- the purpose is to ensure that every WorkItem (and WorkItems scheduled
by WorkItems) is allowed to run to completion every step
- per workqueue register a lockstep component whenever a work item is
added (if not already registered)
- once the work queue is empty unregister component
- only record start time on first run rather than init
- increase name length
- round average interval to nearest microsecond
- basic formatting consistency (google style guide)
The existing behavior is unexpected: if the work item is already on the
runnable queue, it will still be triggered after a call to ScheduleClear().
This can lead to race conditions.
and remove the px4_ prefix, except for px4_config.h.
command to update includes:
for k in app.h atomic.h cli.h console_buffer.h defines.h getopt.h i2c.h init.h log.h micro_hal.h module.h module_params.h param.h param_macros.h posix.h sem.h sem.hpp shmem.h shutdown.h tasks.h time.h workqueue.h; do for i in $(grep -rl 'include <px4_'$k src platforms boards); do sed -i 's/#include <px4_'$k'/#include <px4_platform_common\/'$k/ $i; done; done
for in $(grep -rl 'include <px4_config.h' src platforms boards); do sed -i 's/#include <px4_config.h/#include <px4_platform_common\/px4_config.h'/ $i; done
Transitional headers for submodules are added (px4_{defines,log,time}.h)
This could happen in the following cases:
- IRQ/publisher rate is faster than the processing rate, and therefore
WorkQueue::Add is called at a higher rate
- a long-running or stuck task that blocks the work queue a long time
Both cases are not expected to happen under 'normal' circumstances (if the
system runs as expected).
* adds a work_queue systemcmd that will bring a tree view of all active work queues and work items
* WorkQueues now track attached WorkItems and will shutdown when the last WorkItem is detached
Script to update include paths:
for i in $(grep -rl 'include <px4_work_queue' src platforms); do sed -i 's/#include <px4_work_queue/#include <px4_platform_common\/px4_work_queue/' $i; done
