tests/extmod: Add coverage tests for select module.

Signed-off-by: Damien George <damien@micropython.org>

tests/extmod/select_ipoll.py

@@ -0,0 +1,55 @@
+# Test select.ipoll().
+
+try:
+    import socket, select
+except ImportError:
+    print("SKIP")
+    raise SystemExit
+
+
+def print_poll_output(lst):
+    print([(type(obj), flags) for obj, flags in lst])
+
+
+poller = select.poll()
+
+# Use a new UDP socket for tests, which should be writable but not readable.
+try:
+    s = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
+    s.bind(socket.getaddrinfo("127.0.0.1", 8000)[0][-1])
+except OSError:
+    print("SKIP")
+    raise SystemExit
+
+poller.register(s)
+
+# Basic polling.
+print_poll_output(poller.ipoll(0))
+
+# Pass in flags=1 for one-shot behaviour.
+print_poll_output(poller.ipoll(0, 1))
+
+# Socket should be deregistered and poll should return nothing.
+print_poll_output(poller.ipoll(0))
+
+# Create a second socket.
+s2 = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
+s2.bind(socket.getaddrinfo("127.0.0.1", 8001)[0][-1])
+
+# Register both sockets (to reset the first one).
+poller.register(s)
+poller.register(s2)
+
+# Basic polling with two sockets.
+print_poll_output(poller.ipoll(0))
+
+# Unregister the first socket, to test polling the remaining one.
+poller.unregister(s)
+print_poll_output(poller.ipoll(0))
+
+# Unregister the second socket, to test polling none.
+poller.unregister(s2)
+print_poll_output(poller.ipoll(0))
+
+s2.close()
+s.close()

tests/extmod/select_ipoll.py.exp

@@ -0,0 +1,6 @@
+[(<class 'socket'>, 4)]
+[(<class 'socket'>, 4)]
+[]
+[(<class 'socket'>, 4), (<class 'socket'>, 4)]
+[(<class 'socket'>, 4)]
+[]

tests/extmod/select_poll_basic.py

@@ -16,6 +16,7 @@ poller.register(s)
 # "Registering a file descriptor that’s already registered is not an error,
 # and has the same effect as registering the descriptor exactly once."
 poller.register(s)
+poller.register(s, select.POLLIN | select.POLLOUT)
 
 # 2 args are mandatory unlike register()
 try:

tests/extmod/select_poll_custom.py

@@ -0,0 +1,83 @@
+# Test custom pollable objects implemented in Python.
+
+from micropython import const
+
+try:
+    import socket, select, io
+except ImportError:
+    print("SKIP")
+    raise SystemExit
+
+_MP_STREAM_POLL = const(3)
+_MP_STREAM_GET_FILENO = const(10)
+
+_MP_STREAM_POLL_RD = const(0x0001)
+_MP_STREAM_POLL_WR = const(0x0004)
+
+
+def print_poll_output(lst):
+    print([(type(obj), flags) for obj, flags in lst])
+
+
+class CustomPollable(io.IOBase):
+    def __init__(self):
+        self.poll_state = 0
+
+    def ioctl(self, cmd, arg):
+        if cmd == _MP_STREAM_GET_FILENO:
+            # Bare-metal ports don't call this ioctl, so don't print it.
+            return -1
+
+        print("CustomPollable.ioctl", cmd, arg)
+        if cmd == _MP_STREAM_POLL:
+            if self.poll_state == "delay_rd":
+                self.poll_state = _MP_STREAM_POLL_RD
+                return 0
+            elif self.poll_state < 0:
+                return self.poll_state
+            else:
+                return self.poll_state & arg
+
+
+poller = select.poll()
+
+# Use a new UDP socket for tests, which should be writable but not readable.
+try:
+    s = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
+    s.bind(socket.getaddrinfo("127.0.0.1", 8000)[0][-1])
+except OSError:
+    print("SKIP")
+    raise SystemExit
+
+x = CustomPollable()
+
+# Register both a file-descriptor-based object and a custom pure-Python object.
+poller.register(s)
+poller.register(x)
+
+# Modify the flags for the custom object.
+poller.modify(x, select.POLLIN)
+
+# Test polling.
+print_poll_output(poller.poll(0))
+x.poll_state = _MP_STREAM_POLL_WR
+print_poll_output(poller.poll(0))
+x.poll_state = _MP_STREAM_POLL_RD
+print_poll_output(poller.poll(0))
+
+# The custom object becomes readable only after being polled.
+poller.modify(s, select.POLLIN)
+x.poll_state = "delay_rd"
+print_poll_output(poller.poll())
+
+# The custom object returns an error.
+x.poll_state = -1000
+try:
+    poller.poll(0)
+except OSError as er:
+    print("OSError", er.errno)
+
+poller.unregister(x)
+poller.unregister(s)
+
+s.close()

tests/extmod/select_poll_custom.py.exp

@@ -0,0 +1,11 @@
+CustomPollable.ioctl 3 1
+[(<class 'socket'>, 4)]
+CustomPollable.ioctl 3 1
+[(<class 'socket'>, 4)]
+CustomPollable.ioctl 3 1
+[(<class 'socket'>, 4), (<class 'CustomPollable'>, 1)]
+CustomPollable.ioctl 3 1
+CustomPollable.ioctl 3 1
+[(<class 'CustomPollable'>, 1)]
+CustomPollable.ioctl 3 1
+OSError 1000

tests/extmod/select_poll_eintr.py

@@ -0,0 +1,47 @@
+# Test interruption of select.poll by EINTR signal, when
+# MICROPY_PY_SELECT_POSIX_OPTIMISATIONS is enabled.
+
+try:
+    import time, gc, select, socket, _thread
+
+    time.time_ns  # Check for time_ns on MicroPython
+    select.poll  # Raises AttributeError for CPython implementations without poll()
+except (ImportError, AttributeError):
+    print("SKIP")
+    raise SystemExit
+
+
+def thread_main():
+    lock.acquire()
+    time.sleep(0.2)
+    print("thread gc start")
+    # The unix gc.collect() implementation will raise EINTR on other threads.
+    # Could possibly use _thread._interrupt_main() instead if MicroPython had it.
+    gc.collect()
+    print("thread gc end")
+
+
+# Start a thread to interrupt the main thread during its call to poll.
+lock = _thread.allocate_lock()
+lock.acquire()
+_thread.start_new_thread(thread_main, ())
+
+# Use a new UDP socket for tests, which should be writable but not readable.
+s = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
+s.bind(socket.getaddrinfo("127.0.0.1", 8000)[0][-1])
+
+# Create the poller object.
+poller = select.poll()
+poller.register(s, select.POLLIN)
+
+# Poll on the UDP socket for a set timeout, which should be reached.
+print("poll")
+lock.release()
+t0 = time.time_ns()
+result = poller.poll(400)
+dt_ms = (time.time_ns() - t0) / 1e6
+print("result:", result)
+print("dt in range:", 380 <= dt_ms <= 500)
+
+# Clean up.
+s.close()

tests/extmod/select_poll_fd.py

@@ -0,0 +1,44 @@
+# Test select.poll in combination with file descriptors.
+
+try:
+    import select, errno
+
+    select.poll  # Raises AttributeError for CPython implementations without poll()
+except (ImportError, AttributeError):
+    print("SKIP")
+    raise SystemExit
+
+# Check that poll supports registering file descriptors (integers).
+try:
+    select.poll().register(0)
+except OSError:
+    print("SKIP")
+    raise SystemExit
+
+# Register invalid file descriptor.
+try:
+    select.poll().register(-1)
+except ValueError:
+    print("ValueError")
+
+# Test polling stdout, it should be writable.
+poller = select.poll()
+poller.register(1)
+poller.modify(1, select.POLLOUT)
+print(poller.poll())
+
+# Unregister then re-register.
+poller.unregister(1)
+poller.register(1, select.POLLIN)
+
+# Poll for input, should return an empty list.
+print(poller.poll(0))
+
+# Test registering a very large number of file descriptors.
+poller = select.poll()
+for fd in range(6000):
+    poller.register(fd)
+try:
+    poller.poll()
+except OSError as er:
+    print(er.errno == errno.EINVAL)