ext: Remove sandbox module from testlib

The sandbox module is providing a sandbox environment for
a specific TestCase via the multiprocessing package.

This isolation/complexity is not strictly needed as testlib is already
forking a new process via subprocess. As it is now, a TestRunner will
generate:

TestRunner -> multiprocessing.Process -> subprocess.Popen
(2 generated procs)

With this patch we are removing the intermediate layer

TestRunner -> subprocess.Popen
(1 generated proc)

JIRA: https://gem5.atlassian.net/projects/GEM5/issues/GEM5-533

Change-Id: Icd5cadbe316653a9269ab098ec4c07f21b864ad3
Signed-off-by: Giacomo Travaglini <giacomo.travaglini@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/30215
Maintainer: Bobby R. Bruce <bbruce@ucdavis.edu>
Tested-by: kokoro <noreply+kokoro@google.com>
Reviewed-by: Hoa Nguyen <hoanguyen@ucdavis.edu>

ext/testlib/runner.py

@@ -1,3 +1,15 @@
+# Copyright (c) 2020 ARM Limited
+# All rights reserved.
+#
+# The license below extends only to copyright in the software and shall
+# not be construed as granting a license to any other intellectual
+# property including but not limited to intellectual property relating
+# to a hardware implementation of the functionality of the software
+# licensed hereunder.  You may use the software subject to the license
+# terms below provided that you ensure that this notice is replicated
+# unmodified and in its entirety in all distributions of the software,
+# modified or unmodified, in source code or in binary form.
+#
 # Copyright (c) 2017 Mark D. Hill and David A. Wood
 # All rights reserved.
 #
@@ -33,7 +45,6 @@ import traceback
 import testlib.helper as helper
 import testlib.state as state
 import testlib.log as log
-import testlib.sandbox as sandbox
 
 from testlib.state import Status, Result
 from testlib.fixture import SkipException
@@ -128,14 +139,14 @@ class RunnerPattern:
 
 class TestRunner(RunnerPattern):
     def test(self):
-        self.sandbox_test()
+        test_params = TestParameters(
+            self.testable,
+            self.testable.parent_suite)
 
-    def sandbox_test(self):
         try:
-            sandbox.Sandbox(TestParameters(
+            # Running the test
-                    self.testable,
+            test_params.test.test(test_params)
-                    self.testable.parent_suite))
+        except Exception:
-        except sandbox.SubprocessException:
             self.testable.result = Result(Result.Failed,
                     traceback.format_exc())
         else:

ext/testlib/sandbox.py

@@ -1,191 +0,0 @@
-# Copyright (c) 2017 Mark D. Hill and David A. Wood
-# All rights reserved.
-#
-# Redistribution and use in source and binary forms, with or without
-# modification, are permitted provided that the following conditions are
-# met: redistributions of source code must retain the above copyright
-# notice, this list of conditions and the following disclaimer;
-# redistributions in binary form must reproduce the above copyright
-# notice, this list of conditions and the following disclaimer in the
-# documentation and/or other materials provided with the distribution;
-# neither the name of the copyright holders nor the names of its
-# contributors may be used to endorse or promote products derived from
-# this software without specific prior written permission.
-#
-# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
-# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
-# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
-# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
-# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
-# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
-# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
-# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
-# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
-# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
-# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
-#
-# Authors: Sean Wilson
-
-import multiprocessing
-import pdb
-import os
-import sys
-import threading
-import traceback
-
-import testlib.log as log
-
-pdb._Pdb = pdb.Pdb
-class ForkedPdb(pdb._Pdb):
-    '''
-    A Pdb subclass that may be used from a forked multiprocessing child
-    '''
-    io_manager = None
-    def interaction(self, *args, **kwargs):
-        _stdin = sys.stdin
-        self.io_manager.restore_pipes()
-        try:
-            sys.stdin = open('/dev/stdin')
-            pdb._Pdb.interaction(self, *args, **kwargs)
-        finally:
-            sys.stdin = _stdin
-            self.io_manager.replace_pipes()
-
-
-#TODO Refactor duplicate stdout, stderr logic
-class IoManager(object):
-    def __init__(self, test, suite):
-        self.test = test
-        self.suite = suite
-        self.log = log.test_log
-        self._init_pipes()
-
-    def _init_pipes(self):
-        self.stdout_rp, self.stdout_wp = os.pipe()
-        self.stderr_rp, self.stderr_wp = os.pipe()
-
-    def close_parent_pipes(self):
-        os.close(self.stdout_wp)
-        os.close(self.stderr_wp)
-
-    def setup(self):
-        self.replace_pipes()
-        self.fixup_pdb()
-
-    def fixup_pdb(self):
-        ForkedPdb.io_manager = self
-        pdb.Pdb = ForkedPdb
-
-    def replace_pipes(self):
-        self.old_stderr = os.dup(sys.stderr.fileno())
-        self.old_stdout = os.dup(sys.stdout.fileno())
-
-        os.dup2(self.stderr_wp, sys.stderr.fileno())
-        sys.stderr = os.fdopen(self.stderr_wp, 'w')
-        os.dup2(self.stdout_wp, sys.stdout.fileno())
-        sys.stdout = os.fdopen(self.stdout_wp, 'w')
-
-    def restore_pipes(self):
-        self.stderr_wp = os.dup(sys.stderr.fileno())
-        self.stdout_wp = os.dup(sys.stdout.fileno())
-
-        os.dup2(self.old_stderr, sys.stderr.fileno())
-        sys.stderr = open(self.old_stderr, 'w')
-        os.dup2(self.old_stdout, sys.stdout.fileno())
-        sys.stdout = open(self.old_stdout, 'w')
-
-    def start_loggers(self):
-        self.log_ouput()
-
-    def log_ouput(self):
-        def _log_output(pipe, log_callback):
-            with os.fdopen(pipe, 'r') as pipe:
-                # Read iteractively, don't allow input to fill the pipe.
-                for line in iter(pipe.readline, ''):
-                    log_callback(line)
-
-        # Don't keep a backpointer to self in the thread.
-        log = self.log
-        test = self.test
-        suite = self.suite
-
-        self.stdout_thread = threading.Thread(
-                target=_log_output,
-                args=(self.stdout_rp,
-                      lambda buf: log.test_stdout(test, suite, buf))
-        )
-        self.stderr_thread = threading.Thread(
-                target=_log_output,
-                args=(self.stderr_rp,
-                      lambda buf: log.test_stderr(test, suite, buf))
-        )
-
-        # Daemon + Join to not lock up main thread if something breaks
-        # but provide consistent execution if nothing goes wrong.
-        self.stdout_thread.daemon = True
-        self.stderr_thread.daemon = True
-        self.stdout_thread.start()
-        self.stderr_thread.start()
-
-    def join_loggers(self):
-        self.stdout_thread.join()
-        self.stderr_thread.join()
-
-
-class SubprocessException(Exception):
-    def __init__(self, trace):
-        super(SubprocessException, self).__init__(trace)
-
-class ExceptionProcess(multiprocessing.Process):
-    class Status(object):
-        def __init__(self, exitcode, exception_tuple):
-            self.exitcode = exitcode
-            if exception_tuple is not None:
-                self.trace = exception_tuple[0]
-            else:
-                self.trace = None
-
-    def __init__(self, *args, **kwargs):
-        multiprocessing.Process.__init__(self, *args, **kwargs)
-        self._pconn, self._cconn = multiprocessing.Pipe()
-        self._exception = None
-
-    def run(self):
-        try:
-            super(ExceptionProcess, self).run()
-            self._cconn.send(None)
-        except Exception:
-            tb = traceback.format_exc()
-            self._cconn.send((tb, ))
-            raise
-
-    @property
-    def status(self):
-        if self._pconn.poll():
-            self._exception = self._pconn.recv()
-
-        return self.Status(self.exitcode, self._exception)
-
-
-class Sandbox(object):
-    def __init__(self, test_parameters):
-
-        self.params = test_parameters
-        self.io_manager = IoManager(self.params.test, self.params.suite)
-
-        self.p = ExceptionProcess(target=self.entrypoint)
-        # Daemon + Join to not lock up main thread if something breaks
-        self.p.daemon = True
-        self.io_manager.start_loggers()
-        self.p.start()
-        self.io_manager.close_parent_pipes()
-        self.p.join()
-        self.io_manager.join_loggers()
-
-        status = self.p.status
-        if status.exitcode:
-            raise SubprocessException(status.trace)
-
-    def entrypoint(self):
-        self.io_manager.setup()
-        self.params.test.test(self.params)