fire_interrupt function should be used for events in the past. As we have now
64bit timestamp, we can figure out what is in the past, and ask a target to invoke
an interrupt immediately. The previous attemps in the target HAL tickers were not ideal, as it can wrap around easily (16 or 32 bit counters). This new
functionality should solve this problem.
set_interrupt for tickers in HAL code should not handle anything but the next match interrupt. If it was in the past is handled by the upper layer.
It is possible that we are setting next event to the close future, so once it is set it is already in the past. Therefore we add a check after set interrupt to verify it is in future.
If it is not, we fire interrupt immediately. This results in
two events - first one immediate, correct one. The second one might be scheduled in far future (almost entire ticker range),
that should be discarded.
The specification for the fire_interrupts are:
- should set pending bit for the ticker interrupt (as soon as possible),
the event we are scheduling is already in the past, and we do not want to skip
any events
- no arguments are provided, neither return value, not needed
- ticker should be initialized prior calling this function (no need to check if it is already initialized)
All our targets provide this new functionality, removing old misleading if (timestamp is in the past) checks.
On some platforms, the in-application memory is not memory mapped
and therefore cannot be accessed using memcpy.
The flash_read function added to flash_api.h (with a weak
implementation using memcpy in mbed_flash_api.c) can be used for
reading data from areas that are not memory mapped.
- A new 64 timestamp type has been added: us_timestamp_t.
- Changed type of timestamp in ticker_events iinto us_timestamp_t.
- Event queue now have a to store a current, absolute timestamp.
- Add alternative versions of ticker_insert_event and ticker_read which accept
in input us_timestamp_t.
- Add documentation explaining the limitation and behavior of ticker_read and
ticker_insert_event.
ticker_insert_event() can crash on KLXX (and probably other platforms) if an event is inserted with a timestamp before the current real time.
The problem is easy to trigger: you just need to set up a Ticker object, and then disable interrupts for slightly longer than the Ticker object's interval. It's generally bad practice to disable interrupts for too long, but there are some cases where it's unavoidable, and anyway it would be better for the core library function not to crash. The case where I had an unavoidably long interrupts-off interval was writing flash with the FTFA. The FTFA hardware prohibits flash reads while an FTFA command is in progress, so interrupts must be disabled for the whole duration of each command to ensure that there are no instruction fetches from flash-resident ISRs in the course of the execution. An FTFA "erase sector" command takes a fairly long time (milliseconds), and I have a fairly high frequency Ticker (1ms).
The problem and the fix are pretty straightforward. ticker_insert_event() searches the linked list to figure out where to insert the new event, looking for a spot earlier than any event currently queued. If the event is in the past, it'll usually end up at the head of the list. When the routine sees that the new event belongs at the head of the list, it calls data->interface->set_interrupt() to schedule the interrupt for the event, since it's the new soonest event. The KLXX version of us_ticker_set_interrupt() then looks to see if the event is in the past, which we've stipulated that it is, so rather than actually setting the interrupt, it simply calls the handler directly. The first thing the Ticker interrupt handler does is re-schedule itself, so we re-enter ticker_insert_event() at this point. This is where the problem comes in: we didn't finish updating the linked list before we called set_interrupt() and thus before we recursed back into ticker_insert_event(). We set the head of the list to the new event but we didn't set the new event's 'next' pointer.
The fix is simply to finish updating the list before we call set_interrupt(), which we can do by moving the obj->next initialization ahead of the head pointer update.
If target supports flash algo, it can get common HAL implementation, providing
feature "HAL_FLASH_CMSIS_ALGO". This simplifies target code, and having
one implementation that can be shared by many targets.
Be careful with flash cmsis algo, in some cases they execute code that
can affect the system. For instance, it can disable cache, or affect
some system clocks. Therefore this feature should be well tested.
Add sleep/deepsleep functions to platform layer which are replacing HAL
functions with the same name, rename existing symbols in HAL layer
to hal_sleep/hal_deepsleep. This way sleep functions
are always available, even if target doesn't implement them, which makes
the code using sleep clearer. It also enables us to make decision on in
which builds (debug/release) the sleep will be enabled.
Unfortunately, it is very difficult to infer the parameters of
function-objects generically in C++03 without any additional type
information. The current implementation fails to do so, and the compiler
simply bails with "unable to deduce template parameter".
Rather than leaving the user with a small novel of error messages, this
patch removes the problematic callback overloads, leaving only callback
overloads for the original pointer types.
The callback class can now accept generalized function-objects:
class Thing {
public:
int value;
void operator()() {
printf("hi! %d\n", value);
}
};
Callback<void()> cb(Thing(2));
However, with the intention of avoiding implicit dynamic-memory
allocations, the Callback class is limited to a single word of storage.
Exceeding this size will eliminate the function-object type from the
overload set and fail to compile.
Effort was invested to make this situation very clear to the user. Here
is an example error message with noise removed:
[ERROR] ./main.cpp: In function 'int main()':
./mbed-os/hal/api/Ticker.h:101:10: note:
no known conversion for argument 1 from 'BigFunc' to 'mbed::Callback<void()>'
The real benefit of this change is the ability for users to hook into
the attributes of the Callback class. This mostly allows lifetime
management of the function-objects from third-party libraries (such as
the Event class from mbed-events).
Note: The convenient `callback` function may become ambiguous if
provided with a type that defines multiple incompatible `operator()`
member functions.
This allows additional attributes to be attached to the internally
generated type such as move and destructor operations with no increase
in RAM footprint.
The current overloads can't take advantage of this, but it does open
the possibility for more powerful overloads that can provide these
additional attributes.
Changes to mbed-os memory consumption:
.text .data .bss
before 57887 2292 7692
after 57842 2292 7691
Enable the low power timer for the following targets:
- NUCLEO_F411RE
- NUCLEO_F401RE
- DISCO_F429ZI
- NUCLEO_F446RE
- NUCLEO_F410RB
- DISCO_F469NI
- NUCLEO_F446ZE
- B86B_F446VE
This change allows a port to provide its own implementation of:
* core_util_critical_section_enter
* core_util_critical_section_exit
Some system like the NRF series require specific behavior for the critical
section and now can override it properly.
* 'master' of https://github.com/ARMmbed/mbed-os: (63 commits)
[XDOT_L151] add IAR support
Modify mbedtls scripts to add config-no-entropy.h
Remove extra spaces
[XDOT_L151] include xDot in mbed 5 releases
[STM32F429ZI] INITIAL_SP correction
[STM32F091RC] patch for tests-mbedmicro-rtos-mbed-threads
mbedtls trng - remove MBEDTLS_ENTROPY_HARDWARE_ALT
targets - add TRNG device_has to STM32F7 targets
mbedtls - move TRNG mbed impl into platform folder
TRNG HAL - fix length doc wording for get_bytes
HAL TRNG - add dummy variable to empty structs
TRNG - protect HAL implementation if DEVICE_TRNG is not defined
TRNG - remove set seed function
HAL - RNG rename to TRNG
HAL - rng nuvoton cleanup code style
RNG - fix warnings due to obj not used for some targets
RNG - rename rng_get_numbers to rng_get_bytes
mbedtls - mbed wrapper rename to mbed_rng
HAL: Add rng set seed value function
NUMAKER_PFM_NUC472: Add RGN HAL API implementation
...
# Conflicts:
# hal/targets/hal/TARGET_NORDIC/TARGET_NRF5/serial_api.c
Martin Kojtal
Deepika
Marcus Chang
Sam Grove
Kevin Gilbert
Russ Butler
Christopher Haster
Vincent Coubard
adustm
mjrgh
0xc0170
Bartek Szatkowski
Jimmy Brisson
Bogdan Marinescu
andreas.larsson
svastm
Mike Fiore
Mika Leppänen
Głąbek, Andrzej
Andres AG
jeromecoutant