vendor/lldb/lldb-trunk-r290819

1 files changed, 76 insertions, 0 deletions

diff --git a/packages/Python/lldbsuite/pre_kill_hook/linux.py b/packages/Python/lldbsuite/pre_kill_hook/linux.py
new file mode 100644
index 0000000000000..d4cd9be27c829
--- /dev/null
+++ b/packages/Python/lldbsuite/pre_kill_hook/linux.py
@@ -0,0 +1,76 @@
+"""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)