This patch introduces the MICROPY_ENABLE_PYSTACK option (disabled by
default) which enables a "Python stack" that allows to allocate and free
memory in a scoped, or Last-In-First-Out (LIFO) way, similar to alloca().
A new memory allocation API is introduced along with this Py-stack. It
includes both "local" and "nonlocal" LIFO allocation. Local allocation is
intended to be equivalent to using alloca(), whereby the same function must
free the memory. Nonlocal allocation is where another function may free
the memory, so long as it's still LIFO.
Follow-up patches will convert all uses of alloca() and VLA to the new
scoped allocation API. The old behaviour (using alloca()) will still be
available, but when MICROPY_ENABLE_PYSTACK is enabled then alloca() is no
longer required or used.
The benefits of enabling this option are (or will be once subsequent
patches are made to convert alloca()/VLA):
- Toolchains without alloca() can use this feature to obtain correct and
efficient scoped memory allocation (compared to using the heap instead
of alloca(), which is slower).
- Even if alloca() is available, enabling the Py-stack gives slightly more
efficient use of stack space when calling nested Python functions, due to
the way that compilers implement alloca().
- Enabling the Py-stack with the stackless mode allows for even more
efficient stack usage, as well as retaining high performance (because the
heap is no longer used to build and destroy stackless code states).
- With Py-stack and stackless enabled, Python-calling-Python is no longer
recursive in the C mp_execute_bytecode function.
The micropython.pystack_use() function is included to measure usage of the
Python stack.
This function was implemented as an experiment, and was enabled only in
unix port. To remind, it allows to access arbitrary files frozen as
source modules (vs bytecode).
However, further experimentation showed that the same functionality can
be implemented with frozen bytecode. The process requires more steps, but
with suitable toolset it doesn't matter patch. This process is:
1. Convert binary files into "Python resource module" with
tools/mpy_bin2res.py.
2. Freeze as the bytecode.
3. Use micropython-lib's pkg_resources.resource_stream() to access it.
In other words, the extra step is using tools/mpy_bin2res.py (because
there would be wrapper for uio.resource_stream() anyway).
Going frozen bytecode route allows more flexibility, and same/additional
efficiency:
1. Frozen source support can be disabled altogether for additional code
savings.
2. Resources could be also accessed as a buffer, not just as a stream.
There're few caveats too:
1. It wasn't actually profiled the overhead of storing a resource in
"Python resource module" vs storing it directly, but it's assumed that
overhead is small.
2. The "efficiency" claim above applies to the case when resource
file is frozen as the bytecode. If it's not, it actually will take a
lot of RAM on loading. But in this case, the resource file should not
be used (i.e. generated) in the first place, and micropython-lib's
pkg_resources.resource_stream() implementation has the appropriate
fallback to read the raw files instead. This still poses some distribution
issues, e.g. to deployable to baremetal ports (which almost certainly
would require freezeing as the bytecode), a distribution package should
include the resource module. But for non-freezing deployment, presense
of resource module will lead to memory inefficiency.
All the discussion above reminds why uio.resource_stream() was implemented
in the first place - to address some of the issues above. However, since
then, frozen bytecode approach seems to prevail, so, while there're still
some issues to address with it, this change is being made.
This change saves 488 bytes for the unix x86_64 port.
This patch introduces a new compile-time config option to disable multiple
inheritance at the Python level: MICROPY_MULTIPLE_INHERITANCE. It is
enabled by default.
Disabling multiple inheritance eliminates a lot of recursion in the call
graph (which is important for some embedded systems), and can be used to
reduce code size for ports that are really constrained (by around 200 bytes
for Thumb2 archs).
With multiple inheritance disabled all tests in the test-suite pass except
those that explicitly test for multiple inheritance.
Macros to convert big-endian values to host byte order and vice-versa.
These were defined in adhoc way for some ports (e.g. esp8266), allow
reuse, provide default implementations, while allow ports to override.
Per the comment found here
https://github.com/micropython/micropython-esp32/issues/209#issuecomment-339855157,
this patch adds finaliser code to prevent memory leaks from ussl objects,
which is especially useful when memory for a ussl context is allocated
outside the uPy heap. This patch is in-line with the finaliser code found
in many modsocket implementations for various ports.
This feature is configured via MICROPY_PY_USSL_FINALISER and is disabled by
default because there may be issues using it when the ussl state *is*
allocated on the uPy heap, rather than externally.
This allows to configure support for inplace special methods separately,
similar to "normal" and reverse special methods. This is useful, because
inplace methods are "the most optional" ones, for example, if inplace
methods aren't defined, the operation will be executed using normal
methods instead.
As a caveat, __iadd__ and __isub__ are implemented even if
MICROPY_PY_ALL_INPLACE_SPECIAL_METHODS isn't defined. This is similar
to the state of affairs before binary operations refactor, and allows
to run existing tests even if MICROPY_PY_ALL_INPLACE_SPECIAL_METHODS
isn't defined.
This adds a new configuration option to print runtime warnings and errors to
stderr. On Unix, CPython prints warnings and unhandled exceptions to stderr,
so the unix port here is configured to use this option.
The unix port already printed unhandled exceptions on the main thread to
stderr. This patch fixes unhandled exceptions on other threads and warnings
(issue #2838) not printing on stderr.
Additionally, a couple tests needed to be fixed to handle this new behavior.
This is done by also capturing stderr when running tests.
If, for class X, X.__add__(Y) doesn't exist (or returns NotImplemented),
try Y.__radd__(X) instead.
This patch could be simpler, but requires undoing operand swap and
operation switch to get non-confusing error message in case __radd__
doesn't exist.
This patch adds a function utf8_check() to check for a valid UTF-8 encoded
string, and calls it when constructing a str from raw bytes. The feature
is selectable at compile time via MICROPY_PY_BUILTINS_STR_UNICODE_CHECK and
is enabled if unicode is enabled. It costs about 110 bytes on Thumb-2, 150
bytes on Xtensa and 170 bytes on x86-64.
The code conventions suggest using header guards, but do not define how
those should look like and instead point to existing files. However, not
all existing files follow the same scheme, sometimes omitting header guards
altogether, sometimes using non-standard names, making it easy to
accidentally pick a "wrong" example.
This commit ensures that all header files of the MicroPython project (that
were not simply copied from somewhere else) follow the same pattern, that
was already present in the majority of files, especially in the py folder.
The rules are as follows.
Naming convention:
* start with the words MICROPY_INCLUDED
* contain the full path to the file
* replace special characters with _
In addition, there are no empty lines before #ifndef, between #ifndef and
one empty line before #endif. #endif is followed by a comment containing
the name of the guard macro.
py/grammar.h cannot use header guards by design, since it has to be
included multiple times in a single C file. Several other files also do not
need header guards as they are only used internally and guaranteed to be
included only once:
* MICROPY_MPHALPORT_H
* mpconfigboard.h
* mpconfigport.h
* mpthreadport.h
* pin_defs_*.h
* qstrdefs*.h
The implementation is taken from stmhal/input.c, with code added to handle
ctrl-C. This built-in is controlled by MICROPY_PY_BUILTINS_INPUT and is
disabled by default. It uses readline() to capture input but this can be
overridden by defining the mp_hal_readline macro.
The with semantics of this function is close to
pkg_resources.resource_stream() function from setuptools, which
is the canonical way to access non-source files belonging to a package
(resources), regardless of what medium the package uses (e.g. individual
source files vs zip archive). In the case of MicroPython, this function
allows to access resources which are frozen into the executable, besides
accessing resources in the file system.
This is initial stage of the implementation, which actually doesn't
implement "package" part of the semantics, just accesses frozen resources
from "root", or filesystem resource - from current dir.
With this optimisation enabled the compiler optimises the if-else
expression within a return statement. The optimisation reduces bytecode
size by 2 bytes for each use of such a return-if-else statement. Since
such a statement is not often used, and costs bytes for the code, the
feature is disabled by default.
For example the following code:
def f(x):
return 1 if x else 2
compiles to this bytecode with the optimisation disabled (left column is
bytecode offset in bytes):
00 LOAD_FAST 0
01 POP_JUMP_IF_FALSE 8
04 LOAD_CONST_SMALL_INT 1
05 JUMP 9
08 LOAD_CONST_SMALL_INT 2
09 RETURN_VALUE
and to this bytecode with the optimisation enabled:
00 LOAD_FAST 0
01 POP_JUMP_IF_FALSE 6
04 LOAD_CONST_SMALL_INT 1
05 RETURN_VALUE
06 LOAD_CONST_SMALL_INT 2
07 RETURN_VALUE
So the JUMP to RETURN_VALUE is optimised and replaced by RETURN_VALUE,
saving 2 bytes and making the code a bit faster.
It controls the character that's used to (asynchronously) raise a
KeyboardInterrupt exception. Passing "-1" allows to disable the
interception of the interrupt character (as long as a port allows such a
behaviour).
Split this setting from MICROPY_CPYTHON_COMPAT. The idea is to be able to
keep MICROPY_CPYTHON_COMPAT disabled, but still pass more of regression
testsuite. In particular, this fixes last failing test in basics/ for
Zephyr port.
It's configured by MICROPY_PY_UERRNO_ERRORCODE and enabled by default
(since that's the behaviour before this patch).
Without this dict the lookup of errno codes to strings must use the
uerrno module itself.
This improves efficiency of GIL release within the VM, by only doing the
release after a fixed number of jump-opcodes have executed in the current
thread.
This patch implements support for class methods __delattr__ and __setattr__
for customising attribute access. It is controlled by the config option
MICROPY_PY_DELATTR_SETATTR and is disabled by default.
Updated modbuiltin.c to add conditional support for 3-arg calls to
pow() using MICROPY_PY_BUILTINS_POW3 config parameter. Added support in
objint_mpz.c for for optimised implementation.
This provides mp_vfs_XXX functions (eg mount, open, listdir) which are
agnostic to the underlying filesystem type, and just require an object with
the relevant filesystem-like methods (eg .mount, .open, .listidr) which can
then be mounted.
These mp_vfs_XXX functions would typically be used by a port to implement
the "uos" module, and mp_vfs_open would be the builtin open function.
This feature is controlled by MICROPY_VFS, disabled by default.
This is how CPython does it, and it's very useful to help users discover
the available modules for a given port, especially built-in and frozen
modules. The function does not list modules that are in the filesystem
because this would require a fair bit of work to do correctly, and is very
port specific (depending on the filesystem).
import utimeq, utime
# Max queue size, the queue allocated statically on creation
q = utimeq.utimeq(10)
q.push(utime.ticks_ms(), data1, data2)
res = [0, 0, 0]
# Items in res are filled up with results
q.pop(res)
Defining and initialising mp_kbd_exception is boiler-plate code and so the
core runtime can provide it, instead of each port needing to do it
themselves.
The exception object is placed in the VM state rather than on the heap.
sys.exit() is an important function to terminate a program. In particular,
the testsuite relies on it to skip tests (i.e. any other functionality may
be disabled, but sys.exit() is required to at least report that properly).
This patch adds the MICROPY_EMIT_INLINE_XTENSA option, which, when
enabled, allows the @micropython.asm_xtensa decorator to be used.
The following opcodes are currently supported (ax is a register, a0-a15):
ret_n()
callx0(ax)
j(label)
jx(ax)
beqz(ax, label)
bnez(ax, label)
mov(ax, ay)
movi(ax, imm) # imm can be full 32-bit, uses l32r if needed
and_(ax, ay, az)
or_(ax, ay, az)
xor(ax, ay, az)
add(ax, ay, az)
sub(ax, ay, az)
mull(ax, ay, az)
l8ui(ax, ay, imm)
l16ui(ax, ay, imm)
l32i(ax, ay, imm)
s8i(ax, ay, imm)
s16i(ax, ay, imm)
s32i(ax, ay, imm)
l16si(ax, ay, imm)
addi(ax, ay, imm)
ball(ax, ay, label)
bany(ax, ay, label)
bbc(ax, ay, label)
bbs(ax, ay, label)
beq(ax, ay, label)
bge(ax, ay, label)
bgeu(ax, ay, label)
blt(ax, ay, label)
bnall(ax, ay, label)
bne(ax, ay, label)
bnone(ax, ay, label)
Upon entry to the assembly function the registers a0, a12, a13, a14 are
pushed to the stack and the stack pointer (a1) decreased by 16. Upon
exit, these registers and the stack pointer are restored, and ret.n is
executed to return to the caller (caller address is in a0).
Note that the ABI for the Xtensa emitters is non-windowing.
Implementations of persistent-code reader are provided for POSIX systems
and systems using FatFS. Macros to use these are MICROPY_READER_POSIX and
MICROPY_READER_FATFS respectively. If an alternative implementation is
needed then a port can define the function mp_reader_new_file.
As long as a port implement mp_hal_sleep_ms(), mp_hal_ticks_ms(), etc.
functions, it can just use standard implementations of utime.sleel_ms(),
utime.ticks_ms(), etc. Python-level functions.
This new config option allows to control whether MicroPython uses its own
internal printf or not (if not, an external one should be linked in).
Accompanying this new option is the inclusion of lib/utils/printf.c in the
core list of source files, so that ports no longer need to include it
themselves.
The idea is that all ports can use these helper methods and only need to
provide initialisation of the SPI bus, as well as a single transfer
function. The coding pattern follows the stream protocol and helper
methods.
There can be stray pointers in memory blocks that are not properly zero'd
after allocation. This patch adds a new config option to always zero all
allocated memory (via gc_alloc and gc_realloc) and hence help to eliminate
stray pointers.
See issue #2195.
To filter out even prototypes of mp_stream_posix_*() functions, which
require POSIX types like ssize_t & off_t, which may be not available in
some ports.
Something like:
if foo == "bar":
will be always false if foo is b"bar". In CPython, warning is issued if
interpreter is started as "python3 -b". In MicroPython,
MICROPY_PY_STR_BYTES_CMP_WARN setting controls it.
Currently, MicroPython runs GC when it could not allocate a block of memory,
which happens when heap is exhausted. However, that policy can't work well
with "inifinity" heaps, e.g. backed by a virtual memory - there will be a
lot of swap thrashing long before VM will be exhausted. Instead, in such
cases "allocation threshold" policy is used: a GC is run after some number of
allocations have been made. Details vary, for example, number or total amount
of allocations can be used, threshold may be self-adjusting based on GC
outcome, etc.
This change implements a simple variant of such policy for MicroPython. Amount
of allocated memory so far is used for threshold, to make it useful to typical
finite-size, and small, heaps as used with MicroPython ports. And such GC policy
is indeed useful for such types of heaps too, as it allows to better control
fragmentation. For example, if a threshold is set to half size of heap, then
for an application which usually makes big number of small allocations, that
will (try to) keep half of heap memory in a nice defragmented state for an
occasional large allocation.
For an application which doesn't exhibit such behavior, there won't be any
visible effects, except for GC running more frequently, which however may
affect performance. To address this, the GC threshold is configurable, and
by default is off so far. It's configured with gc.threshold(amount_in_bytes)
call (can be queries without an argument).
Disabled by default, enabled in unix port. Need for this method easily
pops up when working with text UI/reporting, and coding workalike
manually again and again counter-productive.
The config variable MICROPY_MODULE_FROZEN is now made of two separate
parts: MICROPY_MODULE_FROZEN_STR and MICROPY_MODULE_FROZEN_MPY. This
allows to have none, either or both of frozen strings and frozen mpy
files (aka frozen bytecode).
They are sugar for marking function as generator, "yield from"
and pep492 python "semantically equivalents" respectively.
@dpgeorge was the original author of this patch, but @pohmelie made
changes to implement `async for` and `async with`.
This new compile-time option allows to make the bytecode compiler
configurable at runtime by setting the fields in the mp_dynamic_compiler
structure. By using this feature, the compiler can generate bytecode
that targets any MicroPython runtime/VM, regardless of the host and
target compile-time settings.
Options so far that fall under this dynamic setting are:
- maximum number of bits that a small int can hold;
- whether caching of lookups is used in the bytecode;
- whether to use unicode strings or not (lexer behaviour differs, and
therefore generated string constants differ).
These can be used to insert arbitrary checks, polling, etc into the VM.
They are left general because the VM is a highly tuned loop and it should
be up to a given port how that port wants to modify the VM internals.
One common use would be to insert a polling check, but only done after
a certain number of opcodes were executed, so as not to slow down the VM
too much. For example:
#define MICROPY_VM_HOOK_COUNT (30)
#define MICROPY_VM_HOOK_INIT static uint vm_hook_divisor = MICROPY_VM_HOOK_COUNT
#define MICROPY_VM_HOOK_POLL if (--vm_hook_divisor == 0) { \
vm_hook_divisor = MICROPY_VM_HOOK_COUNT;
extern void vm_hook_function(void);
vm_hook_function();
}
#define MICROPY_VM_HOOK_LOOP MICROPY_VM_HOOK_POLL
#define MICROPY_VM_HOOK_RETURN MICROPY_VM_HOOK_POLL
For these 3 bitwise operations there are now fast functions for
positive-only arguments, and general functions for arbitrary sign
arguments (the fast functions are the existing implementation).
By default the fast functions are not used (to save space) and instead
the general functions are used for all operations.
Enable MICROPY_OPT_MPZ_BITWISE to use the fast functions for positive
arguments.
Functions added are:
- randint
- randrange
- choice
- random
- uniform
They are enabled with configuration variable
MICROPY_PY_URANDOM_EXTRA_FUNCS, which is disabled by default. It is
enabled for unix coverage build and stmhal.
Seedable and reproducible pseudo-random number generator. Implemented
functions are getrandbits(n) (n <= 32) and seed().
The algorithm used is Yasmarang by Ilya Levin:
http://www.literatecode.com/yasmarang
POSIX doesn't guarantee something like that to work, but it works on any
system with careful signal implementation. Roughly, the requirement is
that signal handler is executed in the context of the process, its main
thread, etc. This is true for Linux. Also tested to work without issues
on MacOSX.
This makes all tests pass again for 64bit windows builds which would
previously fail for anything printing ranges (builtin_range/unpack1)
because they were printed as range( ld, ld ).
This is done by reusing the mp_vprintf implementation for MICROPY_OBJ_REPR_D
for 64bit windows builds (both msvc and mingw-w64) since the format specifier
used for 64bit integers is also %lld, or %llu for the unsigned version.
Note these specifiers used to be fetched from inttypes.h, which is the
C99 way of working with printf/scanf in a portable way, but mingw-w64
wants to be backwards compatible with older MS C runtimes and uses
the non-portable %I64i instead of %lld in inttypes.h, so remove the use
of said header again in mpconfig.h and define the specifiers manually.
MICROPY_ENABLE_COMPILER can be used to enable/disable the entire compiler,
which is useful when only loading of pre-compiled bytecode is supported.
It is enabled by default.
MICROPY_PY_BUILTINS_EVAL_EXEC controls support of eval and exec builtin
functions. By default they are only included if MICROPY_ENABLE_COMPILER
is enabled.
Disabling both options saves about 40k of code size on 32-bit x86.
To use, put the following in mpconfigport.h:
#define MICROPY_OBJ_REPR (MICROPY_OBJ_REPR_D)
#define MICROPY_FLOAT_IMPL (MICROPY_FLOAT_IMPL_DOUBLE)
typedef int64_t mp_int_t;
typedef uint64_t mp_uint_t;
#define UINT_FMT "%llu"
#define INT_FMT "%lld"
Currently does not work with native emitter enabled.
- add mp_int_t/mp_uint_t typedefs in mpconfigport.h
- fix integer suffixes/formatting in mpconfig.h and mpz.h
- use MICROPY_NLR_SETJMP=1 in Makefile since the current nlrx64.S
implementation causes segfaults in gc_free()
- update README
MICROPY_PERSISTENT_CODE must be enabled, and then enabling
MICROPY_PERSISTENT_CODE_LOAD/SAVE (either or both) will allow loading
and/or saving of code (at the moment just bytecode) from/to a .mpy file.
Main changes when MICROPY_PERSISTENT_CODE is enabled are:
- qstrs are encoded as 2-byte fixed width in the bytecode
- all pointers are removed from bytecode and put in const_table (this
includes const objects and raw code pointers)
Ultimately this option will enable persistence for not just bytecode but
also native code.
This patch adds/subtracts a constant from the 30-bit float representation
so that str/qstr representations are favoured: they now have all the high
bits set to zero. This makes encoding/decoding qstr strings more
efficient (and they are used more often than floats, which are now
slightly less efficient to encode/decode).
Saves about 300 bytes of code space on Thumb 2 arch.
This new object representation puts floats into the object word instead
of on the heap, at the expense of reducing their precision to 30 bits.
It only makes sense when the word size is 32-bits.
Cortex-M0, M0+ and M1 only have ARMv6-M Thumb/Thumb2 instructions. M3,
M4 and M7 have a superset of these, named ARMv7-M. This patch adds a
config option to enable support of the superset of instructions.
It makes much more sense to do constant folding in the parser while the
parse tree is being built. This eliminates the need to create parse
nodes that will just be folded away. The code is slightly simpler and a
bit smaller as well.
Constant folding now has a configuration option,
MICROPY_COMP_CONST_FOLDING, which is enabled by default.
With this patch parse nodes are allocated sequentially in chunks. This
reduces fragmentation of the heap and prevents waste at the end of
individually allocated parse nodes.
Saves roughly 20% of RAM during parse stage.
Damien George
Paul Sokolovsky
stijn
Eric Poulsen
David Lechner
tll
Stefan Naumann
Alexander Steffen
Ville Skyttä
dmazzella
Nicko van Someren
Colin Hogben
Delio Brignoli
pohmelie
Doug Currie
stijn
Tom Soulanille