Calling it from lwIP accept callback will lead incorrect functioning
and/or packet leaks if Python callback has any networking calls, due
to lwIP non-reentrancy. So, instead schedule "poll" callback to do
that, which will be called by lwIP when it does not perform networking
activities. "Poll" callback is called infrequently though (docs say
every 0.5s by default), so for better performance, lwIP needs to be
patched to call poll callback soon after accept callback, but when
current packet is already processed.
For example, the following code now works with a file on the SD card:
f = open('test', 'rb') # test must be 1024 bytes or more in size
f.seek(511)
f.read(513)
Also works for writing.
Fixes issue #1863.
Address printed was truncated anyway and in general confusing to outsider.
A line which dumps it is still left in the source, commented, for peculiar
cases when it may be needed (e.g. when running under debugger).
In some compliation enviroments (e.g. mbed online compiler) with
strict standards compliance, <math.h> does not define constants such
as M_PI. Provide fallback definitions of M_E and M_PI where needed.
If an OSError is raised with an integer argument, and that integer
corresponds to an errno, then the string for the errno is used as the
argument to the exception, instead of the integer. Only works if
the uerrno module is enabled.
These are typical consumers of large chunks of memory, so it's useful to
see at least their number (how much memory isn't clearly shown, as the data
for these objects is allocated elsewhere).
These symbols are still defined in terms of the system Exxx symbols, and
can be switched to internal numeric definitions at a later stage.
Note that extmod/modlwip still uses many system Exxx symbols.
Effect measured on esp8266 port:
Before:
>>> pystone_lowmem.main(10000)
Pystone(1.2) time for 10000 passes = 44214 ms
This machine benchmarks at 226 pystones/second
>>> pystone_lowmem.main(10000)
Pystone(1.2) time for 10000 passes = 44246 ms
This machine benchmarks at 226 pystones/second
After:
>>> pystone_lowmem.main(10000)
Pystone(1.2) time for 10000 passes = 44343ms
This machine benchmarks at 225 pystones/second
>>> pystone_lowmem.main(10000)
Pystone(1.2) time for 10000 passes = 44376ms
This machine benchmarks at 225 pystones/second
vstr_null_terminated_str is almost certainly a vstr finalization operation,
so it should add the requested NUL byte, and not try to pre-allocate more.
The previous implementation could actually allocate double of the buffer
size.
Previous to this patch bignum division and modulo would temporarily
modify the RHS argument to the operation (eg x/y would modify y), but on
return the RHS would be restored to its original value. This is not
allowed because arguments to binary operations are const, and in
particular might live in ROM. The modification was to normalise the arg
(and then unnormalise before returning), and this patch makes it so the
normalisation is done on the fly and the arg is now accessed as read-only.
This change doesn't increase the order complexity of the operation, and
actually reduces code size.
This is kind of compensation for 4K FatFs buffer size which is eaten away
from it on FS mount. This should still leave enough of networking ("OS")
heap.
