Copy construction between Span of compatible type is allowed to fulfil the use
case Span<T> -> Span<const T>. This is achieved by a templated copy constructor
like constructor.
In p0122, the overload is discarded from the constructor set if the ElementType
of the Span in input is not convertible into the ElementType of the Span being
constructed.
To discard function overload, SFINAE has to be used which polutes the documentation
and make the code harder to read and maintain.
Unlike p0122, our Span class doesn't exposes (yet) functions with default argument
or functions that convert container in input into span the only overload with the
a single parameter that we exposes are:
- template<size_t N> Span(ElementType (&element)[N])
- Span(const Span& other): <- generated by the compiler.
For both of this functions we expect exact match and their resolution should not
interfere with the constructor that converts from another type of Span.
As a result it is possible to rely solely on C++ default resolution rules as we
won't hit cases were constructors convert from another type (std::array, std
container, span) and raise an error with a static assert if the element type
can't be converted.
If another copy - conversion - constructor is added then SFINAE has to be
reintroduced.
This commit aims to make Span implementation more in line with what is present in N4762:
- use appropiate index types where applicable.
- use typedefed type inside the class (index_type, reference, pointer, element_type)
- assertion where applicable
- restrict default construction to Span with extent == 0 or extent == dynamic.
- construct span from a range of pointer
- remove non const overload of the subscript operator
- remove non const overload of the data function
- implement subspan function
- implement missing first and last function of dynamic span
The Span class allows the creation of views over contiguous memory. The view
do not own memory, is typed and has a length. It can be used as a replacement of
the traditional pair of pointer and size in parameters or class fields.
Main operations:
- size(): return the lenght of the memory viewed
- empty(): return if the memory viewed is empty
- [index]: access elements viewed
- data(): return a pointer to the memory viewed.
- first(count): Create a subview from the first count elements.
- last(count): Create a subview from the last count elements.
- == and !=: compare two views or a view to array and return if they are equal or
not.
The Span class came in two flavors:
- Static size: The size is encoded in the Span type and it is as lightweitgh as
a single pointer,
- Dynamic size: The object can store arbitrary views and it costs one pointer
and the size of the view.
When the define LPTICKER_DELAY_TICKS is set deep sleep can be randomly
disallowed when using the low power ticker. This is because a Timer
object, which locks deep sleep, is used to protect from back-to-back
writes to lp tickers which can't support that. This causes tests which
assert that deep sleep is allowed to intermittently fail.
To fix this intermittent failure this patch adds the function
sleep_manager_can_deep_sleep_test_check() which checks if deep sleep
is allowed over a duration. It updates all the tests to use
sleep_manager_can_deep_sleep_test_check() rather
than sleep_manager_can_deep_sleep() so the tests work even if deep
sleep is spuriously blocked.
Volatile specifier in this case it not required as we currently have all accesses
to the buffer protected by critical section. This shall optimize accesses in
some cases to the buffer.
Fixes#7702
`handle_error` calls `MBED_CALLER_ADDR()`, but this is always a location from within platform/mbed_error.c. This is because `handle_error` is declared static. This does not cause the function to be inlined however. Instead, it is called by each function within mbed_error.c. For example, mbed_error yields this code:
```
000625c8 <mbed_error>:
625c8: b510 push {r4, lr}
625ca: 460c mov r4, r1
625cc: 4611 mov r1, r2
625ce: 461a mov r2, r3
625d0: 9b02 ldr r3, [sp, #8]
625d2: f7ff feff bl 623d4 <handle_error>
625d6: b968 cbnz r0, 625f4 <mbed_error+0x2c>
625d8: 4620 mov r0, r4
625da: f7ff ff67 bl 624ac <print_error_report.constprop.0>
625de: f7ff fea8 bl 62332 <core_util_is_isr_active>
625e2: b910 cbnz r0, 625ea <mbed_error+0x22>
625e4: f7ff fe9f bl 62326 <core_util_are_interrupts_enabled>
625e8: b908 cbnz r0, 625ee <mbed_error+0x26>
625ea: bf30 wfi
625ec: e7fd b.n 625ea <mbed_error+0x22>
625ee: 2001 movs r0, #1
625f0: f000 f948 bl 62884 <__wrap_exit>
625f4: 4800 ldr r0, [pc, #0] ; (625f8 <mbed_error+0x30>)
625f6: bd10 pop {r4, pc}
625f8: 80ff010f .word 0x80ff010f
```
Note that at `625d2` there is a bl to handle error. That replaces the LR, which means that ALL calls to mbed_error will report a location of 0x625d6 or 0x625d7 (user vs. supervisor). I do not expect that this was the intention of the code. The simplest fix is to change line 99:
```C
static inline mbed_error_status_t handle_error(mbed_error_status_t error_status, unsigned int error_value, const char *filename, int line_number)
```
Since `handle_error()` will be inlined, the link register will be kept the same, so `MBED_CALLER_ADDR()` will yield the expected result. However, there is no guarantee that the compiler will respect the `inline` keyword in all circumstances.
The result is that each function that wishes to report its caller must extract its caller. This code cannot be centralised.
I have modified `mbed_error.c` to report the caller of each error reporting function, rather than the error reporting function itself.
I added the powerdown func by GIC in mbed_application because Cortex-A9 use GIC instead of NVIC.
This process prevent unexpected interrupt when updating software by using bootloader.
I added the process for Cortex-A in mbed_application.c because this process was for only Cortex-M.
Also I enabled the macro of MBED_APPLICATION_SUPPORT for Cortex-A.
The new configuration make Error history tracking switched off by default and enabled by using the config flag MBED_CONF_PLATFORM_ERROR_HIST_ENABLED.
Config flag MBED_CONF_PLATFORM_ERROR_ALL_THREADS_INFO enables printing info of all threads. This will be turned off by default.
With "mov r2, #0", compile OK with GCC_ARM, but failed with ARMC6.
With "ldr r2, =0", compile OK with ARMC6, but failed with GCC_ARM.
Finally, with "movw r2, #0"/"movt r2, #0", compile OK with both ARMC6 and GCC_ARM.
The errno.h header file defines the type error_t, unfortunately this
is a common type name that may be defined in user code. For at least GCC
we can work around this by telling errno that the error_t is already
defined.
Unfortunately, some toolchains don't define the same errno codes that
are used fairly consistently on Linux based platforms, which means they
also don't match the errno codes used in the retarget layer.
If a user includes errno.h after mbed.h, the errno codes can be
redefined incorrectly.
Adding an include of errno.h in mbed.h forces the order to be fixed.
CPUID base register is available for Cortex-M processors only.
Cortex-A devices have Main ID Register, which can be used in future to
get processor info.
Add the POSIX fcntl call, but only implementing F_SETFL and F_GETFL
for O_NONBLOCK, so users can control the blocking flag of streams
with only the integer file descriptor.
Necessary to portably control the blockingness of the console:
int flags = fcntl(STDOUT_FILENO, F_GETFL);
fcntl(STDOUT_FILENO, F_SETFL, flags | O_NONBLOCK);
There was no way to check current blocking state, so no way to modify
and restore status.
Also have default FileHandle::set_blocking() used by real files return a
correct error code when asked for non-blocking, and success when asked
for blocking.
These were minor omissions that are required to implement POSIX fcntl
properly.
fixup! Add `is_blocking()` method to FileHandle
Some platforms have interface chips with hardware flow control
enabled by default. This commit adds configurable flow control to
STDOUT.
Usage:
* Define pin names STDIO_UART_RTS for Rx-flow-control and
STDIO_UART_CTS for Tx-flow-control.
* Set target.console-uart-flow-control. Valid options are:
null, RTS, CTS, and RTSCTS.
- Move macro definition to mbed_toolchain.h
- Remove double underscores from macro which are reserved.
- Fix macro for IAR until compiler flags to disable path are added again.
Sleep manager tracing strips the path from filenames and uses the result as an
identifier to track drivers that unlock/lock sleep tracing. Replace the function
that strips the path from the string, replace this function with a new macro,
__FILENAME__ which performs the same action in a compiler specific manner.
- GCC_ARM, use __builtin_strrchr which is optimized out at compile time.
- ARM, use __MODULE__ which returns the filename without path.
- IAR, specifiy the --no_path_in_file_macros compiler flag.
The atomic functions preserve volatile semantics - they only perform the
accesses specified. Add the volatile qualifier to the value pointer to
reflect this. This does not change existing caller code - it's
equivalent to adding a const qualifier to indicate we don't write to
a pointer - it means people can pass us qualified pointers without
casts, letting the compile check const- or volatile-correctness.
This is consistent with C11 <stdatomic.h>, which volatile-qualifies its
equivalent functions.
Note that this useage of volatile has nothing to do with the atomicity -
objects accessed via the atomic functions do not need to be volatile.
But it does permit these calls to be used on objects which have been
declared volatile.
The volatile qualifier on the __LDREX/__STREX prototypes only means that
it's safe to use them on volatile objects. Doesn't mean you actually
have to pass them volatile pointers.
Adding the volatile is a bit like doing strlen((const char *) ptr)
because you've got a non-const pointer.
Add tracing output to console to track when drivers lock and unlock deep
sleep. Tracing output is enabled by configuring the
'SLEEP_PROFILING_ENABLED' at compile time.
- Wrapped sleep_manager_lock/sleep_manager_unlock in a macro to
conditionally call tracing functions when 'SLEEP_PROFILING_ENABLED' is
set.
- Define a global structure to track driver names and how many locks
they hold in the sleep manager.
Deepika
Russ Butler
Cruz Monrreal
Vincent Coubard
Amanda Butler
Martin Kojtal
Oren Cohen
Donatien Garnier
Senthil Ramakrishnan
David Saada
kegilbert
Brendan Moran
ccli8
TomoYamanaka
Bartek Szatkowski
Christopher Haster
Kevin Bracey
James Wang
Marcus Chang
Yossi Levy
amq
Cruz Monrreal
Steven Cartmell
Wolfgang Betz
Anna Bridge