Commit 5d9025a7 authored by Paul Sokolovsky's avatar Paul Sokolovsky
Browse files

tests/extmod: Add test for utimeq module.

parent d02f6a99
# Test for utimeq module which implements task queue with support for
# wraparound time (utime.ticks_ms() style).
try:
from utime import ticks_add, ticks_diff
from utimeq import utimeq
except ImportError:
print("SKIP")
import sys
sys.exit()
DEBUG = 0
MAX = ticks_add(0, -1)
MODULO_HALF = MAX // 2 + 1
if DEBUG:
def dprint(*v):
print(*v)
else:
def dprint(*v):
pass
# Try not to crash on invalid data
h = utimeq(10)
try:
h.push(1)
assert False
except TypeError:
pass
try:
h.pop(1)
assert False
except IndexError:
pass
def pop_all(h):
l = []
while h:
item = [0, 0, 0]
h.pop(item)
#print("!", item)
l.append(tuple(item))
dprint(l)
return l
def add(h, v):
h.push(v, 0, 0)
dprint("-----")
#h.dump()
dprint("-----")
h = utimeq(10)
add(h, 0)
add(h, MAX)
add(h, MAX - 1)
add(h, 101)
add(h, 100)
add(h, MAX - 2)
dprint(h)
l = pop_all(h)
for i in range(len(l) - 1):
diff = ticks_diff(l[i + 1][0], l[i][0])
assert diff > 0
def edge_case(edge, offset):
h = utimeq(10)
add(h, ticks_add(0, offset))
add(h, ticks_add(edge, offset))
dprint(h)
l = pop_all(h)
diff = ticks_diff(l[1][0], l[0][0])
dprint(diff, diff > 0)
return diff
dprint("===")
diff = edge_case(MODULO_HALF - 1, 0)
assert diff == MODULO_HALF - 1
assert edge_case(MODULO_HALF - 1, 100) == diff
assert edge_case(MODULO_HALF - 1, -100) == diff
# We expect diff to be always positive, per the definition of heappop() which should return
# the smallest value.
# This is the edge case where this invariant breaks, due to assymetry of two's-complement
# range - there's one more negative integer than positive, so heappushing values like below
# will then make ticks_diff() return the minimum negative value. We could make heappop
# return them in a different order, but ticks_diff() result would be the same. Conclusion:
# never add to a heap values where (a - b) == MODULO_HALF (and which are >= MODULO_HALF
# ticks apart in real time of course).
dprint("===")
diff = edge_case(MODULO_HALF, 0)
assert diff == -MODULO_HALF
assert edge_case(MODULO_HALF, 100) == diff
assert edge_case(MODULO_HALF, -100) == diff
dprint("===")
diff = edge_case(MODULO_HALF + 1, 0)
assert diff == MODULO_HALF - 1
assert edge_case(MODULO_HALF + 1, 100) == diff
assert edge_case(MODULO_HALF + 1, -100) == diff
print("OK")
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