This commit fixes a problem with a race between cancellation of task A and
completion of task B, when A waits on B. If task B completes just before
task A is cancelled then the cancellation of A does not work. Instead,
the CancelledError meant to cancel A gets passed through to B (that's
expected behaviour) but B handles it as a "Task exception wasn't retrieved"
scenario, printing out such a message (this is because finished tasks point
their "coro" attribute to themselves to indicate they are done, and
implement the throw() method, but that method inadvertently catches the
CancelledError). The correct behaviour is for B to bounce that
CancelledError back out.
This bug is mainly seen when wait_for() is used, and in that context the
symptoms are:
- occurs when using wait_for(T, S), if the task T being waited on finishes
at exactly the same time as the wait-for timeout S expires
- task T will have run to completion
- the "Task exception wasn't retrieved message" is printed with
"<class 'CancelledError'>" as the error (ie no traceback)
- the wait_for(T, S) call never returns (it's never put back on the
uasyncio run queue) and all tasks waiting on this are blocked forever
from running
- uasyncio otherwise continues to function and other tasks continue to be
scheduled as normal
The fix here reworks the "waiting" attribute of Task to be called "state"
and uses it to indicate whether a task is: running and not awaited on,
running and awaited on, finished and not awaited on, or finished and
awaited on. This means the task does not need to point "coro" to itself to
indicate finished, and also allows removal of the throw() method.
A benefit of this is that "Task exception wasn't retrieved" messages can go
back to being able to print the name of the coroutine function.
Fixes issue #7386.
Signed-off-by: Damien George <damien@micropython.org>
If digest is called then the hash object is put in a "final" state and
calling update() or digest() again will raise a ValueError (instead of
silently producing the wrong result).
See issue #4119.
Signed-off-by: Damien George <damien@micropython.org>
uctypes.FLOAT32 has a special value representation and
uctypes_struct_scalar_size() should be used instead of GET_SCALAR_SIZE().
Signed-off-by: Damien George <damien@micropython.org>
The generated regex code is limited in the range of jumps and counts, and
this commit checks all cases which can overflow given the right kind of
input regex, and returns an error in such a case.
This change assumes that the results that overflow an int8_t do not
overflow a platform int.
Closes: #7078
Signed-off-by: Jeff Epler <jepler@gmail.com>
Some devices have lower precision than 1ms for time_ns() (eg PYBv1.x has
3.9ms resolution of the RTC) so make the test more lenient for them.
Signed-off-by: Damien George <damien@micropython.org>
The superblock for littlefs is in block 0 and 1, but block 0 may be erased
or partially written, so block 1 must be checked if block 0 does not have a
valid littlefs superblock in it.
Prior to this commit, the mount of a block device which auto-detected the
filysystem type would fail for littlefs if block 0 did not contain a valid
superblock. That is now fixed.
Signed-off-by: Damien George <damien@micropython.org>
According to documentation time() has a precision of at least 1 second.
This test runs for 2.5 seconds and calls all utime functions every 100ms.
Then it checks if they returned enough different results. All functions
with sub-second precision will return ~25 results. This test passes with
15 results or more. Functions that do not exist are skipped silently.
Mounting a bdev directly tries to auto-detect the filesystem and if none is
found an OSError(19,) should be raised.
The fourth parameter of readblocks() and writeblocks() must be optional to
support ports with MICROPY_VFS_FAT=1. Otherwise mounting a bdev may fail
because looking for a FATFS will call readblocks() with only 3 parameters.
This commit switches the roles of the helper task from a cancellation task
to a runner task, to get the correct semantics for cancellation of
wait_for.
Some uasyncio tests are now disabled for the native emitter due to issues
with native code generation of generators and yield-from.
Fixes#5797.
Signed-off-by: Damien George <damien@micropython.org>
This is added because task.coro==None is no longer the way to detect if a
task is finished. Providing a (CPython compatible) function for this
allows the implementation to be abstracted away.
Signed-off-by: Damien George <damien@micropython.org>
When a tasks raises an exception which is uncaught, and no other task
await's on that task, then an error message is printed (or a user function
called) via a call to Loop.call_exception_handler. In CPython this call is
made when the Task object is freed (eg via reference counting) because it's
at that point that it is known that the exception that was raised will
never be handled.
MicroPython does not have reference counting and the current behaviour is
to deal with uncaught exceptions as early as possible, ie as soon as they
terminate the task. But this can be undesirable because in certain cases
a task can start and raise an exception immediately (before any await is
executed in that task's coro) and before any other task gets a chance to
await on it to catch the exception.
This commit changes the behaviour so that tasks which end due to an
uncaught exception are scheduled one more time for execution, and if they
are not await'ed on by the next scheduling loop, then the exception handler
is called (eg the exception is printed out).
Signed-off-by: Damien George <damien@micropython.org>
Prior to this change machine.mem32['foo'] (or using any other non-integer
subscript) could result in a fault due to 'foo' being interpreted as an
integer. And when writing code it's hard to tell if the fault is due to a
bad subscript type, or an integer subscript that specifies an invalid
memory address.
The type of the object used in the subscript is now tested to be an
integer by using mp_obj_get_int_truncated instead of
mp_obj_int_get_truncated. The performance hit of this change is minimal,
and machine.memX objects are more for convenience than performance (there
are many other ways to read/write memory in a faster way),
Fixes issue #6588.
If a port provides MICROPY_PY_URANDOM_SEED_INIT_FUNC as a source of
randomness then this will be used when urandom.seed() is called without
an argument (or with None as the argument) to seed the pRNG.
Other related changes in this commit:
- mod_urandom___init__ is changed to call seed() without arguments, instead
of explicitly passing in the result of MICROPY_PY_URANDOM_SEED_INIT_FUNC.
- mod_urandom___init__ will only ever seed the pRNG once (before it could
seed it again if imported by, eg, random and then urandom).
- The Yasmarang state is moved to the BSS for builds where the state is
guaranteed to be initialised on import of the (u)random module.
Signed-off-by: Damien George <damien@micropython.org>
It requires mp_hal_time_ns() to be provided by a port. This function
allows very accurate absolute timestamps.
Enabled on unix, windows, stm32, esp8266 and esp32.
Signed-off-by: Damien George <damien@micropython.org>
Prior to this commit, uos.chdir('/') followed by uos.stat('noexist') would
succeed that stat even though the entry did not exist (some other functions
like listdir would have similar issues). This is because, if the current
directory was the root and the path was relative, mp_vfs_lookup_path would
return success for bad paths.
Signed-off-by: Damien George <damien@micropython.org>
This is consistent with the other 'micro' modules and allows implementing
additional features in Python via e.g. micropython-lib's sys.
Note this is a breaking change (not backwards compatible) for ports which
do not enable weak links, as "import sys" must now be replaced with
"import usys".
Verifies mtime timestamps on files match the value returned by time.time().
Also update vfs_fat_ramdisk.py so it doesn't check FAT timestamp of the
root, because that may change across runs/ports.
Signed-off-by: Damien George <damien@micropython.org>
This commit fixes the cases when a TCP socket is in STATE_NEW,
STATE_LISTENING or STATE_CONNECTING and recv() is called on it. It now
raises ENOTCONN instead of a random error code due to it previously
indexing beyond the start of error_lookup_table[].
Signed-off-by: Damien George <damien@micropython.org>
Updating to Black v20.8b1 there are two changes that affect the code in
this repository:
- If there is a trailing comma in a list (eg [], () or function call) then
that list is now written out with one line per element. So remove such
trailing commas where the list should stay on one line.
- Spaces at the start of """ doc strings are removed.
Signed-off-by: Damien George <damien@micropython.org>
With sleep(0.2) a multiple of sleep(0.1), the order of task 2 and 3
execution is not well defined, and depends on the precision of the system
clock and how fast the rest of the code runs. So change 0.2 to 0.18 to
make the test more reliable.
Also fix a typo of t3/t4, and cancel t4 at the end.
Signed-off-by: Damien George <damien@micropython.org>
This commit adds support for modification time of files on littlefs v2
filesystems, using file attributes. For some background see issue #6114.
Features/properties of this implementation:
- Only supported on littlefs2 (not littlefs1).
- Uses littlefs2's general file attributes to store the timestamp.
- The timestamp is 64-bits and stores nanoseconds since 1970/1/1 (if the
range to the year 2554 is not enough then additional bits can be added to
this timestamp by adding another file attribute).
- mtime is enabled by default but can be disabled in the constructor, eg:
uos.mount(uos.VfsLfs2(bdev, mtime=False), '/flash')
- It's fully backwards compatible, existing littlefs2 filesystems will work
without reformatting and timestamps will be added transparently to
existing files (once they are opened for writing).
- Files without timestamps will open correctly, and stat will just return 0
for their timestamp.
- mtime can be disabled or enabled each mount time and timestamps will only
be updated if mtime is enabled (otherwise they will be untouched).
Signed-off-by: Damien George <damien@micropython.org>
Otherwise a task that continuously awaits on a large negative sleep can
monopolise the scheduler (because its wake time is always less than
everything else in the pairing heap).
Signed-off-by: Damien George <damien@micropython.org>
mp_reader_new_file() is used to read in files for importing, either .py or
.mpy files, for the lexer and persistent code loader respectively. In both
cases the file should be opened in raw bytes mode: the lexer handles
unicode characters itself, and .mpy files contain 8-bit bytes by nature.
Before this commit importing was working correctly because, although the
file was opened in text mode, all native filesystem implementations (POSIX,
FAT, LFS) would access the file in raw bytes mode via mp_stream_rw()
calling mp_stream_p_t.read(). So it was only an issue for non-native
filesystems, such as those implemented in Python. For Python-based
filesystem implementations, a call to mp_stream_rw() would go via IOBase
and then to readinto() at the Python level, and readinto() is only defined
on files opened in raw bytes mode.
Signed-off-by: Damien George <damien@micropython.org>
This commit adds human readable error messages when mbedtls or axtls raise
an exception. Currently often just an EIO error is raised so the user is
lost and can't tell whether it's a cert error, buffer overrun, connecting
to a non-ssl port, etc. The axtls and mbedtls error raising in the ussl
module is modified to raise:
OSError(-err_num, "error string")
For axtls a small error table of strings is added and used for the second
argument of the OSErrer. For mbedtls the code uses mbedtls' built-in
strerror function, and if there is an out of memory condition it just
produces OSError(-err_num). Producing the error string for mbedtls is
conditional on them being included in the mbedtls build, via
MBEDTLS_ERROR_C.
If the new name start with '/', cur_dir is not prepened any more, so that
the current working directory is respected. And extend the test cases for
rename to cover this functionality.
This change scans for '.', '..' and multiple '/' and normalizes the new
path name. If the resulting path does not exist, an error is raised.
Non-existing interim path elements are ignored if they are removed during
normalization.
This fixes the bug, that stat(filename) would not consider the current
working directory. So if e.g. the cwd is "lib", then stat("main.py") would
return the info for "/main.py" instead of "/lib/main.py".
For ports that have a system malloc which is not garbage collected (eg
unix, esp32), the stream object for the DB must be retained separately to
prevent it from being reclaimed by the MicroPython GC (because the
berkeley-db library uses malloc to allocate the DB structure which stores
the only reference to the stream).
Although in some cases the user code will explicitly retain a reference to
the underlying stream because it needs to call close() on it, this is not
always the case, eg in cases where the DB is intended to live forever.
Fixes issue #5940.
