trace/perf: Introduce a new, generic collector

Introduce a perf collector that is more generic than the previous one
and which is expected to be able to handle all potential calls to perf
(irrespective of the subcommand, flags, options or arguments being
used).

devlib/__init__.py

@@ -47,6 +47,7 @@
 
 from devlib.trace.ftrace import FtraceCollector
 from devlib.trace.perf_stat import PerfStatCollector
+from devlib.trace.perf import PerfCollector
 from devlib.trace.serial_trace import SerialTraceCollector
 
 from devlib.host import LocalConnection

devlib/trace/perf.py

@@ -0,0 +1,76 @@
+#    Copyright 2018-2019 ARM Limited
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+
+import os
+import shlex
+from typing import Any, Dict, Optional
+
+from devlib.host import PACKAGE_BIN_DIRECTORY
+from devlib.trace import TraceCollector
+
+class PerfCollector(TraceCollector):
+    """
+    """
+    def __init__(self,
+                 target,
+                 force_install : bool = False,
+                 pre_commands : Optional[Dict[str, Any]] = None,
+                 commands : Optional[Dict[str, Any]] = None,
+                 post_commands : Optional[Dict[str, Any]] = None):
+        super().__init__(target)
+        self.pre_commands = pre_commands or {}
+        self.commands = commands or {}
+        self.post_commands = post_commands or {}
+
+        self.binary = self.target.get_installed('perf')
+        if force_install or not self.binary:
+            host_binary = os.path.join(PACKAGE_BIN_DIRECTORY,
+                                       self.target.abi, 'perf')
+            self.binary = self.target.install(host_binary)
+
+        self.kill_sleep = False
+
+    # TODO: folder tree for files on device  to avoid clashes
+    # TODO: user has to figure out file classhes (e.g. between perf.data)
+
+    def reset(self):
+        super().reset()
+        self.target.killall('perf', as_root=self.target.is_rooted)
+
+    def start(self):
+        super().start()
+        self.cwd = f'cd {shlex.quote(self.target.working_directory)}'
+        # TODO: why isn't target.execute running in working_directory?
+        for label, command in self.pre_commands.items():
+            self.target.execute(f'{self.cwd} && {self.binary} {command}',
+                                as_root=self.target.is_rooted)
+        for label, command in self.commands.items():
+            self.target.kick_off(f'{self.binary} {command}',
+                                 as_root=self.target.is_rooted)
+            if 'sleep' in command:
+                self.kill_sleep = True
+
+    def stop(self):
+        super().stop()
+        self.target.killall('perf', signal='SIGINT',
+                            as_root=self.target.is_rooted)
+        if self.kill_sleep:
+            self.target.killall('sleep', as_root=self.target.is_rooted)
+        for label, command in self.post_commands.items():
+            self.target.execute(f'{self.cwd} && {self.binary} {command}',
+                                as_root=self.target.is_rooted)
+
+    def get_trace(self, outfile):
+        raise NotImplementedError # TODO

devlib/trace/perf_stat.py

@@ -74,7 +74,7 @@ def __init__(self, target,
         self.events = events if events else DEFAULT_EVENTS
         self.force_install = force_install
         self.labels = labels
-
+# TODO: deprecation log message
         # Validate parameters
         if isinstance(optionstring, list):
             self.optionstrings = optionstring