Weird situation with 'exception ignored'

src/sage/doctest/util.py

@@ -27,6 +27,7 @@
 from os import sysconf, times
 from contextlib import contextmanager
 from cysignals.alarm import alarm, cancel_alarm, AlarmInterrupt
+from cysignals.signals import python_check_interrupt
 
 
 def count_noun(number, noun, plural=None, pad_number=False, pad_noun=False):
@@ -808,6 +809,102 @@ def ensure_interruptible_after(seconds: float, max_wait_after_interrupt: float =
 
     TESTS::
 
+    ::
+
+        sage: cython(r'''
+        ....: from posix.unistd cimport usleep, useconds_t
+        ....: from posix.time cimport clock_gettime, CLOCK_REALTIME, timespec
+        ....: from cysignals.signals cimport sig_check
+        ....: from time import time as walltime
+        ....: from time import sleep
+        ....:
+        ....: cpdef sleep_(double t): usleep(<useconds_t>(t * 1e6))  # cython makes this interruptible
+        ....:
+        ....: cpdef void interruptible_sleep(double seconds):
+        ....:     cdef timespec start_time, target_time
+        ....:     start_walltime = walltime()
+        ....:     clock_gettime(CLOCK_REALTIME, &start_time)
+        ....:
+        ....:     cdef int floor_seconds = <int>seconds
+        ....:     target_time.tv_sec = start_time.tv_sec + floor_seconds
+        ....:     target_time.tv_nsec = start_time.tv_nsec + <int>((seconds - floor_seconds) * 1e9)
+        ....:     if target_time.tv_nsec >= 1000000000:
+        ....:         target_time.tv_nsec -= 1000000000
+        ....:         target_time.tv_sec += 1
+        ....:
+        ....:     while True:
+        ....:         sig_check()
+        ....:         clock_gettime(CLOCK_REALTIME, &start_time)
+        ....:         if start_time.tv_sec > target_time.tv_sec or (start_time.tv_sec == target_time.tv_sec and start_time.tv_nsec >= target_time.tv_nsec):
+        ....:             break
+        ....:
+        ....: cpdef test1(object ensure_interruptible_after):
+        ....:     with ensure_interruptible_after(2) as data: sleep(1)
+        ....:
+        ....: cpdef test2(object ensure_interruptible_after):
+        ....:     with ensure_interruptible_after(2) as data: sleep_(1)
+        ....:
+        ....: cpdef test3(object ensure_interruptible_after):
+        ....:     with ensure_interruptible_after(2) as data: interruptible_sleep(1)
+        ....:
+        ....: cpdef test4(object ensure_interruptible_after):
+        ....:     with ensure_interruptible_after(1) as data: sleep(3)
+        ....:
+        ....: cpdef test5(object ensure_interruptible_after):
+        ....:     with ensure_interruptible_after(1) as data: sleep_(3)
+        ....:
+        ....: cpdef test6(object ensure_interruptible_after):
+        ....:     with ensure_interruptible_after(1) as data: interruptible_sleep(3)
+        ....: ''')
+        sage: with ensure_interruptible_after(2) as data: sleep(1r)
+        Traceback (most recent call last):
+        ...
+        RuntimeError: Function terminates early after 1.00... < 2.0000 seconds
+        sage: with ensure_interruptible_after(2) as data: sleep_(1r)
+        Traceback (most recent call last):
+        ...
+        RuntimeError: Function terminates early after 1.00... < 2.0000 seconds
+        sage: with ensure_interruptible_after(2) as data: uninterruptible_sleep(1r)
+        Traceback (most recent call last):
+        ...
+        RuntimeError: Function terminates early after 1.00... < 2.0000 seconds
+        sage: with ensure_interruptible_after(2) as data: interruptible_sleep(1r)
+        Traceback (most recent call last):
+        ...
+        RuntimeError: Function terminates early after 1.00... < 2.0000 seconds
+        sage: with ensure_interruptible_after(1) as data: sleep(3r)
+        sage: with ensure_interruptible_after(1) as data: sleep_(3r)
+        sage: with ensure_interruptible_after(1) as data: uninterruptible_sleep(3r)
+        Traceback (most recent call last):
+        ...
+        RuntimeError: Function is not interruptible within 1.0000 seconds, only after 3.00... seconds
+        sage: with ensure_interruptible_after(1) as data: interruptible_sleep(3r)
+        sage: test1(ensure_interruptible_after)
+        Traceback (most recent call last):
+        ...
+        RuntimeError: Function terminates early after 1.00... < 2.0000 seconds
+        sage: test2(ensure_interruptible_after)
+        Traceback (most recent call last):
+        ...
+        RuntimeError: Function terminates early after 1.00... < 2.0000 seconds
+        sage: test3(ensure_interruptible_after)
+        Traceback (most recent call last):
+        ...
+        RuntimeError: Function terminates early after 1.00... < 2.0000 seconds
+        sage: test4(ensure_interruptible_after)
+        sage: test5(ensure_interruptible_after)
+        Traceback (most recent call last):
+        ...
+        cysignals.signals.AlarmInterrupt
+        sage: test6(ensure_interruptible_after)
+        Traceback (most recent call last):
+        ...
+        cysignals.signals.AlarmInterrupt: 
+
+    ::
+
+    ::
+
         sage: # we use 1r instead of 1 to avoid unexplained slowdown
         sage: with ensure_interruptible_after(2) as data: sleep(1r)
         Traceback (most recent call last):
@@ -849,6 +946,7 @@ def ensure_interruptible_after(seconds: float, max_wait_after_interrupt: float =
 
     try:
         yield data
+        python_check_interrupt(None, None)  # equivalent to sig_check() (this is implementation detail!)
     except AlarmInterrupt:
         alarm_raised = True
     finally: