This patch changes the threading implementation from simple round-robin
with busy waits on mutexs, to proper scheduling whereby threads that are
waiting on a mutex are only scheduled when the mutex becomes available.
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.
It's more efficient using the system mutexs instead of synthetic ones with
a busy-wait loop. The system can do proper scheduling and blocking of the
threads waiting on the mutex.
Depending on the thread scheduler, a busy-wait loop can hog the CPU and
make the tests very slow. So convert such loops to loops that have an
explicit sleep, allowing the worker threads to do their job.
This allows using the test runner for other scenarios than just
testing uPy itself.
The principle of comparing either to CPython or else to a .exp
file is really handy but to be able to test custom modules not
built into micropython.exe one needs to be able to specify the
module search path a.k.a MICROPYPATH.
MicroPython guarantees '/' to be a path separator, so extra constant taking
precious ROM space are not needed. MicroPython never had such constant, only
one vendor port had it (now unmaintained).
Just one sample is updated with on()/off() for now, there should be
remaining sample(s) showing .value() use (but more can be converted later,
as long as 1 or so good samples of .value() remains).
ipoll() allows to poll streams without allocating any memory: this method
returns an iterator (a poll object itself), and the iterator yields
preallocated "callee-owned tuple" with polling results for each active
stream. The only operation a caller is allowed to do with this tuple is
extracting values from it (storing the tuple as a whole somewhere is
not allowed).
Previous to this patch, for large chunks of bytecode that originated from
a single source-code line, the bytecode-line mapping would generate
something like (for 42 bytecode bytes and 1 line):
BC_SKIP=31 LINE_SKIP=1
BC_SKIP=11 LINE_SKIP=0
This would mean that any errors in the last 11 bytecode bytes would be
reported on the following line. This patch fixes it to generate instead:
BC_SKIP=31 LINE_SKIP=0
BC_SKIP=11 LINE_SKIP=1
Damien George
Paul Sokolovsky
stijn
Dave Hylands
Johannes Wågen