twister: run tests on device with twister on windows

Currently, support for Twister on Windows is only build.
The only thing that needs to be ported is that select()
cannot wait on file descriptors on Windows. Therefore
the serial monitor function needs to be reworked to
support both OSes.

Signed-off-by: Cong Nguyen Huu <cong.nguyenhuu@nxp.com>

scripts/pylib/twister/twisterlib/handlers.py

@@ -2,6 +2,7 @@
 # vim: set syntax=python ts=4 :
 #
 # Copyright (c) 20180-2022 Intel Corporation
+# Copyright 2022 NXP
 # SPDX-License-Identifier: Apache-2.0
 
 import math
@@ -317,16 +318,13 @@ class DeviceHandler(Handler):
         """
         super().__init__(instance, type_str)
 
-    def monitor_serial(self, ser, halt_fileno, harness):
+    def monitor_serial(self, ser, halt_event, harness):
         if harness.is_pytest:
             harness.handle(None)
             return
 
         log_out_fp = open(self.log, "wt")
 
-        ser_fileno = ser.fileno()
-        readlist = [halt_fileno, ser_fileno]
-
         if self.options.coverage:
             # Set capture_coverage to True to indicate that right after
             # test results we should get coverage data, otherwise we exit
@@ -349,14 +347,16 @@ class DeviceHandler(Handler):
         ser.timeout = old_timeout
 
         while ser.isOpen():
-            readable, _, _ = select.select(readlist, [], [], self.timeout)
-
-            if halt_fileno in readable:
+            if halt_event.is_set():
                 logger.debug('halted')
                 ser.close()
                 break
-            if ser_fileno not in readable:
-                continue  # Timeout.
+
+            if not ser.in_waiting:
+                # no incoming bytes are waiting to be read from the serial
+                # input buffer, let other threads run
+                time.sleep(0.001)
+                continue
 
             serial_line = None
             try:
@@ -542,12 +542,12 @@ class DeviceHandler(Handler):
         harness_import = HarnessImporter(harness_name)
         harness = harness_import.instance
         harness.configure(self.instance)
-        read_pipe, write_pipe = os.pipe()
-        start_time = time.time()
+        halt_monitor_evt = threading.Event()
 
         t = threading.Thread(target=self.monitor_serial, daemon=True,
-                             args=(ser, read_pipe, harness))
+                             args=(ser, halt_monitor_evt, harness))
         t.start()
+        start_time = time.time()
 
         d_log = "{}/device.log".format(self.instance.build_dir)
         logger.debug('Flash command: %s', command)
@@ -566,10 +566,10 @@ class DeviceHandler(Handler):
                         flash_error = True
                         with open(d_log, "w") as dlog_fp:
                             dlog_fp.write(stderr.decode())
-                        os.write(write_pipe, b'x')  # halt the thread
+                        halt_monitor_evt.set()
                 except subprocess.TimeoutExpired:
                     logger.warning("Flash operation timed out.")
-                    proc.kill()
+                    self.terminate(proc)
                     (stdout, stderr) = proc.communicate()
                     self.instance.status = "error"
                     self.instance.reason = "Device issue (Timeout)"
@@ -579,7 +579,7 @@ class DeviceHandler(Handler):
                 dlog_fp.write(stderr.decode())
 
         except subprocess.CalledProcessError:
-            os.write(write_pipe, b'x')  # halt the thread
+            halt_monitor_evt.set()
             self.instance.status = "error"
             self.instance.reason = "Device issue (Flash error)"
             flash_error = True
@@ -608,9 +608,6 @@ class DeviceHandler(Handler):
             outs, errs = ser_pty_process.communicate()
             logger.debug("Process {} terminated outs: {} errs {}".format(serial_pty, outs, errs))
 
-        os.close(write_pipe)
-        os.close(read_pipe)
-
         handler_time = time.time() - start_time
 
         if harness.is_pytest:

scripts/pylib/twister/twisterlib/testinstance.py

@@ -1,6 +1,7 @@
 # vim: set syntax=python ts=4 :
 #
 # Copyright (c) 2018-2022 Intel Corporation
+# Copyright 2022 NXP
 # SPDX-License-Identifier: Apache-2.0
 
 import os
@@ -183,9 +184,8 @@ class TestInstance:
     # Global testsuite parameters
     def check_runnable(self, enable_slow=False, filter='buildable', fixtures=[]):
 
-        # right now we only support building on windows. running is still work
-        # in progress.
-        if os.name == 'nt':
+        # running on simulators is currently not supported on Windows
+        if os.name == 'nt' and self.platform.simulation != 'na':
             return False
 
         # we asked for build-only on the command line