Just like they handled in other read*(). Note that behavior of readline()
in case there's no data when it's called is underspecified in Python lib
spec, implemented to behave as read() - return None.
With this patch a port can enable module weak link support and provide
a dict of qstr->module mapping. This mapping is looked up only if an
import fails to find the requested module in the filesystem.
This allows to have the builtin module named, eg, usocket, and provide
a weak link of "socket" to the same module, but this weak link can be
overridden if a file by the name "socket.py" is found in the import
path.
This has benefits all round: code factoring for parse/compile/execute,
proper context save/restore for exec, allow to sepcify globals/locals
for eval, and reduced ROM usage by >100 bytes on stmhal and unix.
Also, the call to mp_parse_compile_execute is tail call optimised for
the import code, so it doesn't increase stack memory usage.
In CPython IOError (and EnvironmentError) is deprecated and aliased to
OSError. All modules that used to raise IOError now raise OSError (or a
derived exception).
In Micro Python we never used IOError (except 1 place, incorrectly) and
so don't need to keep it.
See http://legacy.python.org/dev/peps/pep-3151/ for background.
Viper can now do the following:
def store(p:ptr8, c:int):
p[0] = c
This does a store of c to the memory pointed to by p using a machine
instructions inline in the code.
It seems most sensible to use size_t for measuring "number of bytes" in
malloc and vstr functions (since that's what size_t is for). We don't
use mp_uint_t because malloc and vstr are not Micro Python specific.
mp_parse_node_free now frees the memory associated with non-interned
strings. And the parser calls mp_parse_node_free when discarding a
non-used node (such as a doc string).
Also, the compiler now frees the parse tree explicitly just before it
exits (as opposed to relying on the caller to do this).
Addresses issue #708 as best we can.
Stack is full descending and must be 8-byte aligned. It must start off
pointing to just above the last byte of RAM.
Previously, stack started pointed to last byte of RAM (eg 0x2001ffff)
and so was not 8-byte aligned. This caused a bug in combination with
alloca.
This patch also updates some debug printing code.
Addresses issue #872 (among many other undiscovered issues).
Heap RAM was being allocated to print dicts and do some other types of
iterating. Now these iterations use 1 word of state on the stack.
Deleting elements from a dict was not allowing the value to be reclaimed
by the GC. This is now fixed.
sys.exit always raises SystemExit so doesn't need a special
implementation for each port. If C exit() is really needed, use the
standard os._exit function.
Also initialise mp_sys_path and mp_sys_argv in teensy port.
Eventually, viper wants to be able to use raw pointers to strings and
arrays for efficient access. But for now, let's just load strings as a
Python object so they can be used as normal. This will anyway be
compatible with eventual intended viper behaviour.
Addresses issue #857.
Type representing signed size doesn't have to be int, so use special value
which defaults to SSIZE_MAX, but as it's not defined by C standard (but rather
by POSIX), allow ports to set it.
Previously, mpz was restricted to using at most 15 bits in each digit,
where a digit was a uint16_t.
With this patch, mpz can use all 16 bits in the uint16_t (improvement
to mpn_div was required). This gives small inprovements in speed and
RAM usage. It also yields savings in ROM code size because all of the
digit masking operations become no-ops.
Also, mpz can now use a uint32_t as the digit type, and hence use 32
bits per digit. This will give decent improvements in mpz speed on
64-bit machines.
Test for big integer division added.
Code-info size, block name, source name, n_state and n_exc_stack now use
variable length encoded uints. This saves 7-9 bytes per bytecode
function for most functions.
This way, the native glue code is only compiled if native code is
enabled (which makes complete sense; thanks to Paul Sokolovsky for
the idea).
Should fix issue #834.
The heap allocation is now exactly as it was before the "faster gc
alloc" patch, but it's still nearly as fast. It is fixed by being
careful to always update the "last free block" pointer whenever the heap
changes (eg free or realloc).
Tested on all tests by enabling EXTENSIVE_HEAP_PROFILING in py/gc.c:
old and new allocator have exactly the same behaviour, just the new one
is much faster.
Recent speed up of GC allocation made the GC have a fragmented heap.
This patch restores "original fragmentation behaviour" whilst still
retaining relatively fast allocation. This patch works because there is
always going to be a single block allocated now and then, which advances
the gc_last_free_atb_index pointer often enough so that the whole heap
doesn't need scanning.
Should address issue #836.
With a file with 1 line (and an error on that line), used to show the
line as number 0. Now shows it correctly as line number 1.
But, when line numbers are disabled, it now prints line number 1 for any
line that has an error (instead of 0 as previously). This might end up
being confusing, but requires extra RAM and/or hack logic to make it
print something special in the case of no line numbers.
These functions are generally 1 machine instruction, and are used in
critical code, so makes sense to have them inline.
Also leave these functions uninverted (ie 0 means enable, 1 means
disable) and provide macro constants if you really need to distinguish
the states. This makes for smaller code as well (combined with
inlining).
Applied to teensy port as well.
Because (for Thumb) a function pointer has the LSB set, pointers to
dynamic functions in RAM (eg native, viper or asm functions) were not
being traced by the GC. This patch is a comprehensive fix for this.
Addresses issue #820.
This simple patch gives a very significant speed up for memory allocation
with the GC.
Eg, on PYBv1.0:
tests/basics/dict_del.py: 3.55 seconds -> 1.19 seconds
tests/misc/rge_sm.py: 15.3 seconds -> 2.48 seconds
Multiplication of a tuple, list, str or bytes now yields an empty
sequence (instead of crashing). Addresses issue #799
Also added ability to mult bytes on LHS by integer.
Can now index ranges with integers and slices, and reverse ranges
(although reversing is not very efficient).
Not sure how useful this stuff is, but gets us closer to having all of
Python's builtins.
reversed function now implemented, and works for tuple, list, str, bytes
and user objects with __len__ and __getitem__.
Renamed mp_builtin_len to mp_obj_len to make it publically available (eg
for reversed).
This happens for example for zero-size arrays. As .get_buffer() method now
has explicit return value, it's enough to distinguish success vs failure
of getting buffer.
This was a nasty bug to track down. It only had consequences when the
heap size was just the right size to expose the rounding error in the
calculation of the finaliser table size. And, a script had to allocate
a small (1 or 2 cell) object at the very end of the heap. And, this
object must not have a finaliser. And, the initial state of the heap
must have been all bits set to 1. All these conspire on the pyboard,
but only if your run the script fresh (so unused memory is all 1's),
and if your script allocates a lot of small objects (eg 2-char strings
that are not interned).
qstr_init is always called exactly before mp_init, so makes sense to
just have mp_init call it. Similarly with
mp_init_emergency_exception_buf. Doing this makes the ports simpler and
less error prone (ie they can no longer forget to call these).
Reduces by about a factor of 10 on average the amount of RAM needed to
store the line-number to bytecode map in the bytecode prelude.
Using CPython3.4's stdlib for statistics: previously, an average of
13 bytes were used per (bytecode offset, line-number offset) pair, and
now with this improvement, that's down to 1.3 bytes on average.
Large RAM usage before was due to some very large steps in line numbers,
both from the start of the first line in a function way down in the
file, and also functions that have big comments and/or big strings in
them (both cases were significant).
Although the savings are large on average for the CPython stdlib, it
won't have such a big effect for small scripts used in embedded
programming.
Addresses issue #648.
This removes mpz_as_int, since that was a terrible function (it
implemented saturating conversion).
Use mpz_as_int_checked and mpz_as_uint_checked. These now work
correctly (they previously had wrong overflow checking, eg
print(chr(10000000000000)) on 32-bit machine would incorrectly convert
this large number to a small int).
Many OSes/CPUs have affinity to put "user" data into lower half of address
space. Take advantage of that and remap such addresses into full small int
range (including negative part).
If address is from upper half, long int will be used. Previously, small
int was returned for lower quarter of address space, and upper quarter. For
2 middle quarters, long int was used, which is clearly worse schedule than
the above.
Damien George
Paul Sokolovsky
Dave Hylands
Fabian Vogt
bvernoux