"""Provides a pre-kill method to run on Linux.
This timeout pre-kill method relies on the Linux perf-tools
distribution. The appropriate way to obtain this set of tools
will depend on the Linux distribution.
For Ubuntu 16.04, the invoke the following command:
sudo apt-get install perf-tools-unstable
"""
from __future__ import print_function
# system imports
import os
import subprocess
import sys
import tempfile
def do_pre_kill(process_id, runner_context, output_stream, sample_time=3):
"""Samples the given process id, and puts the output to output_stream.
@param process_id the local process to sample.
@param runner_context a dictionary of details about the architectures
and platform on which the given process is running. Expected keys are
archs (array of architectures), platform_name, platform_url, and
platform_working_dir.
@param output_stream file-like object that should be used to write the
results of sampling.
@param sample_time specifies the time in seconds that should be captured.
"""
# Validate args.
if runner_context is None:
raise Exception("runner_context argument is required")
if not isinstance(runner_context, dict):
raise Exception("runner_context argument must be a dictionary")
# We will try to run sample on the local host only if there is no URL
# to a remote.
if "platform_url" in runner_context and (
runner_context["platform_url"] is not None):
import pprint
sys.stderr.write(
"warning: skipping timeout pre-kill sample invocation because we "
"don't know how to run on a remote yet. runner_context={}\n"
.format(pprint.pformat(runner_context)))
# We're going to create a temp file, and immediately overwrite it with the
# following command. This just ensures we don't have any races in
# creation of the temporary sample file.
fileno, filename = tempfile.mkstemp(suffix='perfdata')
os.close(fileno)
fileno = None
try:
with open(os.devnull, 'w') as devnull:
returncode = subprocess.call(['timeout', str(sample_time), 'perf',
'record', '-g', '-o', filename, '-p', str(process_id)],
stdout=devnull, stderr=devnull)
if returncode == 0 or returncode == 124:
# This is okay - this is the timeout return code, which is totally
# expected.
pass
else:
raise Exception("failed to call 'perf record .., error: {}".format(
returncode))
with open(os.devnull, 'w') as devnull:
output = subprocess.check_output(['perf', 'report', '--call-graph',
'--stdio', '-i', filename], stderr=devnull)
output_stream.write(output)
finally:
os.remove(filename)
