The open coded version has the same problem fixed by Thread abstraction:
the order of the calls matters and it's easy to call in the wrong order.
Here pthread_attr_setschedparam() and pthread_attr_setschedpolicy()
should be swapped, like in 62c2f737d5 (AP_HAL_Linux: fix setting RT priorities.)
If a thread other than the main one calls Scheduler::delay() we could
end up triggering the call of delay callbacks. Those should only ever
happen on the main thread.
This centralized namespace header encourages centralizing things on
umbrella headers that are a pain to maintain. Force each part of
AP_HAL_Linux to include what is used.
While at it, do some whitespace cleanups and minor changes to adhere to
coding style.
Use pthread's barrier so we don't keep waking up threads with possibly
higher priority during initialization phase.
This also synchronizes all of them to a single point. With the previous
approach it was possible (but unlikely) that a thread hadn't reach the
synchronization point when main thread signalize "system initialized".
Implement the new AP_HAL functions and use them in the Scheduler when
possible.
The '_sketch_start_time' was renamed and moved as a detail of
implementation of the functions code. It allows the code to return time
starting from zero.
The 'stopped_clock_usec' was renamed to follow convention in the file
and add a getter so that AP_HAL functions can reach it. It's not a
problem this getter is public because in practice, regular code
shouldn't even access the Linux::Scheduler directly -- only code that
should is from Linux implementation.
prog_char and prog_char_t are now the same as char on supported
platforms. So, just change all places that use them and prefer char
instead.
AVR-specific places were not changed.
This commit changes the way libraries headers are included in source files:
- If the header is in the same directory the source belongs to, so the
notation '#include ""' is used with the path relative to the directory
containing the source.
- If the header is outside the directory containing the source, then we use
the notation '#include <>' with the path relative to libraries folder.
Some of the advantages of such approach:
- Only one search path for libraries headers.
- OSs like Windows may have a better lookup time.
It's undefined behavior to pass the callback to pthread to a class
member like we were doing. Refactor the code so the callbacks are static
members.
This fixes the following warnings:
libraries/AP_HAL_Linux/Scheduler.cpp: In member function 'virtual void Linux::LinuxScheduler::init(void*)':
/home/lucas/p/dronecode/ardupilot/libraries/AP_HAL_Linux/Scheduler.cpp:61:76: warning: converting from 'void* (Linux::LinuxScheduler::*)()' to 'Linux::LinuxScheduler::pthread_startroutine_t {aka void* (*)(void*)}' [-Wpmf-conversions]
(pthread_startroutine_t)&Linux::LinuxScheduler::_timer_thread);
^
libraries/AP_HAL_Linux/Scheduler.cpp:65:76: warning: converting from 'void* (Linux::LinuxScheduler::*)()' to 'Linux::LinuxScheduler::pthread_startroutine_t {aka void* (*)(void*)}' [-Wpmf-conversions]
(pthread_startroutine_t)&Linux::LinuxScheduler::_uart_thread);
^
libraries/AP_HAL_Linux/Scheduler.cpp:69:76: warning: converting from 'void* (Linux::LinuxScheduler::*)()' to 'Linux::LinuxScheduler::pthread_startroutine_t {aka void* (*)(void*)}' [-Wpmf-conversions]
(pthread_startroutine_t)&Linux::LinuxScheduler::_rcin_thread);
^
libraries/AP_HAL_Linux/Scheduler.cpp:73:76: warning: converting from 'void* (Linux::LinuxScheduler::*)()' to 'Linux::LinuxScheduler::pthread_startroutine_t {aka void* (*)(void*)}' [-Wpmf-conversions]
(pthread_startroutine_t)&Linux::LinuxScheduler::_tonealarm_thread);
^
libraries/AP_HAL_Linux/Scheduler.cpp:77:76: warning: converting from 'void* (Linux::LinuxScheduler::*)()' to 'Linux::LinuxScheduler::pthread_startroutine_t {aka void* (*)(void*)}' [-Wpmf-conversions]
(pthread_startroutine_t)&Linux::LinuxScheduler::_io_thread);
LinuxScheduler::init() was not really working as it should. This was the
result of "ps -Leo class,rtprio,wchan,comm | grep ArduCopter":
FF 12 futex_ ArduCopter.elf
FF 12 usleep ArduCopter.elf
FF 12 hrtime ArduCopter.elf
FF 12 poll_s ArduCopter.elf
FF 12 hrtime ArduCopter.elf
FF 12 hrtime ArduCopter.elf
As can be seen all the threads run with the same priority, the one of the main
thread. There were basically 2 mistakes:
1) pthread_attr_setschedpolicy() needs to be called before
pthread_attr_setschedparam(). Otherwise the latter will just return
an error and not set the priority
2) pthread_create() defaults to ignore the priority and inherit the
it from the parent thread. pthread_attr_setinheritsched() needs to
be called to change the behavior to PTHREAD_EXPLICIT_SCHED. See
pthread_attr_setinheritsched(3) for an example program to test the
behaviors.
Also, it's undefined behavior to call pthread_attr_init() several times on the
same pthread_attr_t. Although we could reutilize the same attribute without
calling pthread_attr_init() again, lets refactor the code a little bit, so all
the pthread calls are in a single place. Then also call pthread_attr_destroy()
when we are done.
Peter Barker
Jonathan Challinger
Lucas De Marchi
Andrew Tridgell
Michael du Breuil
Lucas De Marchi
Julien BERAUD
Caio Marcelo de Oliveira Filho
Gustavo Jose de Sousa
Staroselskii Georgii
bugobliterator
Andrew Tridgell
bugobliterator